#include "config.h"
-#include "glib.h"
+#include "gthread.h"
#include "gthreadprivate.h"
+#include <string.h>
+
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <windows.h>
#endif /* G_OS_WIN32 */
-#include <string.h>
-
-#include "galias.h"
+#include "gslice.h"
+#include "gstrfuncs.h"
+#include "gtestutils.h"
/**
- * SECTION: threads
+ * SECTION:threads
* @title: Threads
- * @short_description: thread abstraction; including threads, different
- * mutexes, conditions and thread private data
+ * @short_description: portable support for threads, mutexes, locks,
+ * conditions and thread private data
* @see_also: #GThreadPool, #GAsyncQueue
*
* Threads act almost like processes, but unlike processes all threads
* threads can be made, unless order is explicitly forced by the
* programmer through synchronization primitives.
*
- * The aim of the thread related functions in GLib is to provide a
+ * The aim of the thread-related functions in GLib is to provide a
* portable means for writing multi-threaded software. There are
* primitives for mutexes to protect the access to portions of memory
- * (#GMutex, #GStaticMutex, #G_LOCK_DEFINE, #GStaticRecMutex and
- * #GStaticRWLock). There are primitives for condition variables to
- * allow synchronization of threads (#GCond). There are primitives for
- * thread-private data - data that every thread has a private instance
- * of (#GPrivate, #GStaticPrivate). Last but definitely not least there
- * are primitives to portably create and manage threads (#GThread).
- *
- * The threading system is initialized with g_thread_init(), which
- * takes an optional custom thread implementation or %NULL for the
- * default implementation. If you want to call g_thread_init() with a
- * non-%NULL argument this must be done before executing any other GLib
- * functions (except g_mem_set_vtable()). This is a requirement even if
- * no threads are in fact ever created by the process.
- *
- * Calling g_thread_init() with a %NULL argument is somewhat more
- * relaxed. You may call any other glib functions in the main thread
- * before g_thread_init() as long as g_thread_init() is not called from
- * a glib callback, or with any locks held. However, many libraries
- * above glib does not support late initialization of threads, so doing
- * this should be avoided if possible.
- *
- * Please note that since version 2.24 the GObject initialization
- * function g_type_init() initializes threads (with a %NULL argument),
- * so most applications, including those using Gtk+ will run with
- * threads enabled. If you want a special thread implementation, make
- * sure you call g_thread_init() before g_type_init() is called.
- *
- * After calling g_thread_init(), GLib is completely thread safe (all
- * global data is automatically locked), but individual data structure
- * instances are not automatically locked for performance reasons. So,
- * for example you must coordinate accesses to the same #GHashTable
- * from multiple threads. The two notable exceptions from this rule
- * are #GMainLoop and #GAsyncQueue, which <emphasis>are</emphasis>
- * threadsafe and need no further application-level locking to be
- * accessed from multiple threads.
- *
- * To help debugging problems in multithreaded applications, GLib
- * supports error-checking mutexes that will give you helpful error
- * messages on common problems. To use error-checking mutexes, define
- * the symbol #G_ERRORCHECK_MUTEXES when compiling the application.
- **/
-
-/**
- * G_THREADS_IMPL_POSIX:
- *
- * This macro is defined if POSIX style threads are used.
- **/
-
-/**
- * G_THREADS_ENABLED:
- *
- * This macro is defined if GLib was compiled with thread support. This
- * does not necessarily mean that there is a thread implementation
- * available, but it does mean that the infrastructure is in place and
- * that once you provide a thread implementation to g_thread_init(),
- * GLib will be multi-thread safe. If #G_THREADS_ENABLED is not
- * defined, then Glib is not, and cannot be, multi-thread safe.
- **/
-
-/**
- * G_THREADS_IMPL_NONE:
- *
- * This macro is defined if no thread implementation is used. You can,
- * however, provide one to g_thread_init() to make GLib multi-thread
- * safe.
- **/
+ * (#GMutex, #GRecMutex and #GRWLock). There is a facility to use
+ * individual bits for locks (g_bit_lock()). There are primitives
+ * for condition variables to allow synchronization of threads (#GCond).
+ * There are primitives for thread-private data - data that every
+ * thread has a private instance of (#GPrivate). There are facilities
+ * for one-time initialization (#GOnce, g_once_init_enter()). Finally,
+ * there are primitives to create and manage threads (#GThread).
+ *
+ * The GLib threading system used to be initialized with g_thread_init().
+ * This is no longer necessary. Since version 2.32, the GLib threading
+ * system is automatically initialized at the start of your program,
+ * and all thread-creation functions and synchronization primitives
+ * are available right away.
+ *
+ * Note that it is not safe to assume that your program has no threads
+ * even if you don't call g_thread_new() yourself. GLib and GIO can
+ * and will create threads for their own purposes in some cases, such
+ * as when using g_unix_signal_source_new() or when using GDBus.
+ *
+ * Originally, UNIX did not have threads, and therefore some traditional
+ * UNIX APIs are problematic in threaded programs. Some notable examples
+ * are
+ * <itemizedlist>
+ * <listitem>
+ * C library functions that return data in statically allocated
+ * buffers, such as strtok() or strerror(). For many of these,
+ * there are thread-safe variants with a _r suffix, or you can
+ * look at corresponding GLib APIs (like g_strsplit() or g_strerror()).
+ * </listitem>
+ * <listitem>
+ * setenv() and unsetenv() manipulate the process environment in
+ * a not thread-safe way, and may interfere with getenv() calls
+ * in other threads. Note that getenv() calls may be
+ * <quote>hidden</quote> behind other APIs. For example, GNU gettext()
+ * calls getenv() under the covers. In general, it is best to treat
+ * the environment as readonly. If you absolutely have to modify the
+ * environment, do it early in main(), when no other threads are around yet.
+ * </listitem>
+ * <listitem>
+ * setlocale() changes the locale for the entire process, affecting
+ * all threads. Temporary changes to the locale are often made to
+ * change the behavior of string scanning or formatting functions
+ * like scanf() or printf(). GLib offers a number of string APIs
+ * (like g_ascii_formatd() or g_ascii_strtod()) that can often be
+ * used as an alternative. Or you can use the uselocale() function
+ * to change the locale only for the current thread.
+ * </listitem>
+ * <listitem>
+ * fork() only takes the calling thread into the child's copy of the
+ * process image. If other threads were executing in critical
+ * sections they could have left mutexes locked which could easily
+ * cause deadlocks in the new child. For this reason, you should
+ * call exit() or exec() as soon as possible in the child and only
+ * make signal-safe library calls before that.
+ * </listitem>
+ * <listitem>
+ * daemon() uses fork() in a way contrary to what is described
+ * above. It should not be used with GLib programs.
+ * </listitem>
+ * </itemizedlist>
+ *
+ * GLib itself is internally completely thread-safe (all global data is
+ * automatically locked), but individual data structure instances are
+ * not automatically locked for performance reasons. For example,
+ * you must coordinate accesses to the same #GHashTable from multiple
+ * threads. The two notable exceptions from this rule are #GMainLoop
+ * and #GAsyncQueue, which <emphasis>are</emphasis> thread-safe and
+ * need no further application-level locking to be accessed from
+ * multiple threads. Most refcounting functions such as g_object_ref()
+ * are also thread-safe.
+ */
/* G_LOCK Documentation {{{1 ---------------------------------------------- */
-/* IMPLEMENTATION NOTE:
- *
- * G_LOCK_DEFINE and friends are convenience macros defined in
- * gthread.h. Their documentation lives here.
- */
-
/**
* G_LOCK_DEFINE:
- * @name: the name of the lock.
+ * @name: the name of the lock
*
- * The %G_LOCK_* macros provide a convenient interface to #GStaticMutex
- * with the advantage that they will expand to nothing in programs
- * compiled against a thread-disabled GLib, saving code and memory
- * there. #G_LOCK_DEFINE defines a lock. It can appear anywhere
+ * The <literal>G_LOCK_*</literal> macros provide a convenient interface to #GMutex.
+ * #G_LOCK_DEFINE defines a lock. It can appear in any place where
* variable definitions may appear in programs, i.e. in the first block
* of a function or outside of functions. The @name parameter will be
- * mangled to get the name of the #GStaticMutex. This means that you
+ * mangled to get the name of the #GMutex. This means that you
* can use names of existing variables as the parameter - e.g. the name
- * of the variable you intent to protect with the lock. Look at our
+ * of the variable you intend to protect with the lock. Look at our
* <function>give_me_next_number()</function> example using the
- * %G_LOCK_* macros:
+ * <literal>G_LOCK_*</literal> macros:
*
* <example>
- * <title>Using the %G_LOCK_* convenience macros</title>
+ * <title>Using the <literal>G_LOCK_*</literal> convenience macros</title>
* <programlisting>
* G_LOCK_DEFINE (current_number);
*
* }
* </programlisting>
* </example>
- **/
+ */
/**
* G_LOCK_DEFINE_STATIC:
- * @name: the name of the lock.
+ * @name: the name of the lock
*
* This works like #G_LOCK_DEFINE, but it creates a static object.
- **/
+ */
/**
* G_LOCK_EXTERN:
- * @name: the name of the lock.
+ * @name: the name of the lock
*
* This declares a lock, that is defined with #G_LOCK_DEFINE in another
* module.
- **/
+ */
/**
* G_LOCK:
- * @name: the name of the lock.
+ * @name: the name of the lock
*
* Works like g_mutex_lock(), but for a lock defined with
* #G_LOCK_DEFINE.
- **/
+ */
/**
* G_TRYLOCK:
- * @name: the name of the lock.
+ * @name: the name of the lock
* @Returns: %TRUE, if the lock could be locked.
*
* Works like g_mutex_trylock(), but for a lock defined with
* #G_LOCK_DEFINE.
- **/
+ */
/**
* G_UNLOCK:
- * @name: the name of the lock.
+ * @name: the name of the lock
*
* Works like g_mutex_unlock(), but for a lock defined with
* #G_LOCK_DEFINE.
- **/
-
-/* GThreadError {{{1 ------------------------------------------------------- */
-/**
- * GThreadError:
- * @G_THREAD_ERROR_AGAIN: a thread couldn't be created due to resource
- * shortage. Try again later.
- *
- * Possible errors of thread related functions.
- **/
-
-/**
- * G_THREAD_ERROR:
- *
- * The error domain of the GLib thread subsystem.
- **/
-GQuark
-g_thread_error_quark (void)
-{
- return g_quark_from_static_string ("g_thread_error");
-}
-
-/* Miscellaneous Structures {{{1 ------------------------------------------ */
-/* Keep this in sync with GRealThread in gmain.c! */
-typedef struct _GRealThread GRealThread;
-struct _GRealThread
-{
- GThread thread;
- gpointer private_data;
- GRealThread *next;
- gpointer retval;
- GSystemThread system_thread;
-};
-
-typedef struct _GStaticPrivateNode GStaticPrivateNode;
-struct _GStaticPrivateNode
-{
- gpointer data;
- GDestroyNotify destroy;
-};
-
-static void g_thread_cleanup (gpointer data);
-static void g_thread_fail (void);
-static guint64 gettime (void);
-
-guint64 (*g_thread_gettime) (void) = gettime;
-
-/* Global Variables {{{1 -------------------------------------------------- */
-
-static GSystemThread zero_thread; /* This is initialized to all zero */
-gboolean g_thread_use_default_impl = TRUE;
-
-/**
- * g_thread_supported:
- * @Returns: %TRUE, if the thread system is initialized.
- *
- * This function returns %TRUE if the thread system is initialized, and
- * %FALSE if it is not.
- *
- * <note><para>This function is actually a macro. Apart from taking the
- * address of it you can however use it as if it was a
- * function.</para></note>
- **/
-
-/* IMPLEMENTATION NOTE:
- *
- * g_thread_supported() is just returns g_threads_got_initialized
*/
-gboolean g_threads_got_initialized = FALSE;
-
-
-/* Thread Implementation Virtual Function Table {{{1 ---------------------- */
-/* Virtual Function Table Documentation {{{2 ------------------------------ */
-/**
- * GThreadFunctions:
- * @mutex_new: virtual function pointer for g_mutex_new()
- * @mutex_lock: virtual function pointer for g_mutex_lock()
- * @mutex_trylock: virtual function pointer for g_mutex_trylock()
- * @mutex_unlock: virtual function pointer for g_mutex_unlock()
- * @mutex_free: virtual function pointer for g_mutex_free()
- * @cond_new: virtual function pointer for g_cond_new()
- * @cond_signal: virtual function pointer for g_cond_signal()
- * @cond_broadcast: virtual function pointer for g_cond_broadcast()
- * @cond_wait: virtual function pointer for g_cond_wait()
- * @cond_timed_wait: virtual function pointer for g_cond_timed_wait()
- * @cond_free: virtual function pointer for g_cond_free()
- * @private_new: virtual function pointer for g_private_new()
- * @private_get: virtual function pointer for g_private_get()
- * @private_set: virtual function pointer for g_private_set()
- * @thread_create: virtual function pointer for g_thread_create()
- * @thread_yield: virtual function pointer for g_thread_yield()
- * @thread_join: virtual function pointer for g_thread_join()
- * @thread_exit: virtual function pointer for g_thread_exit()
- * @thread_set_priority: virtual function pointer for
- * g_thread_set_priority()
- * @thread_self: virtual function pointer for g_thread_self()
- * @thread_equal: used internally by recursive mutex locks and by some
- * assertion checks
- *
- * This function table is used by g_thread_init() to initialize the
- * thread system. The functions in the table are directly used by their
- * g_* prepended counterparts (described in this document). For
- * example, if you call g_mutex_new() then mutex_new() from the table
- * provided to g_thread_init() will be called.
- *
- * <note><para>Do not use this struct unless you know what you are
- * doing.</para></note>
- **/
-/* IMPLEMENTATION NOTE:
- *
- * g_thread_functions_for_glib_use is a global symbol that gets used by
- * most of the "primative" threading calls. g_mutex_lock(), for
- * example, is just a macro that calls the appropriate virtual function
- * out of this table.
- *
- * For that reason, all of those macros are documented here.
- */
-GThreadFunctions g_thread_functions_for_glib_use = {
-/* GMutex Virtual Functions {{{2 ------------------------------------------ */
+/* GMutex Documentation {{{1 ------------------------------------------ */
/**
* GMutex:
*
* It is easy to see that this won't work in a multi-threaded
* application. There current_number must be protected against shared
- * access. A first naive implementation would be:
+ * access. A #GMutex can be used as a solution to this problem:
*
* <example>
- * <title>The wrong way to write a thread-safe function</title>
+ * <title>Using GMutex to protected a shared variable</title>
* <programlisting>
* int
* give_me_next_number (void)
* {
+ * static GMutex mutex;
* static int current_number = 0;
* int ret_val;
- * static GMutex * mutex = NULL;
- *
- * if (!mutex) mutex = g_mutex_new (<!-- -->);
*
- * g_mutex_lock (mutex);
+ * g_mutex_lock (&mutex);
* ret_val = current_number = calc_next_number (current_number);
- * g_mutex_unlock (mutex);
+ * g_mutex_unlock (&mutex);
*
* return ret_val;
* }
* </programlisting>
* </example>
*
- * This looks like it would work, but there is a race condition while
- * constructing the mutex and this code cannot work reliable. Please do
- * not use such constructs in your own programs! One working solution
- * is:
+ * Notice that the #GMutex is not initialised to any particular value.
+ * Its placement in static storage ensures that it will be initialised
+ * to all-zeros, which is appropriate.
*
- * <example>
- * <title>A correct thread-safe function</title>
- * <programlisting>
- * static GMutex *give_me_next_number_mutex = NULL;
+ * If a #GMutex is placed in other contexts (eg: embedded in a struct)
+ * then it must be explicitly initialised using g_mutex_init().
*
- * /<!-- -->* this function must be called before any call to
- * * give_me_next_number(<!-- -->)
- * *
- * * it must be called exactly once.
- * *<!-- -->/
- * void
- * init_give_me_next_number (void)
- * {
- * g_assert (give_me_next_number_mutex == NULL);
- * give_me_next_number_mutex = g_mutex_new (<!-- -->);
- * }
+ * A #GMutex should only be accessed via <function>g_mutex_</function>
+ * functions.
+ */
+
+/* GRecMutex Documentation {{{1 -------------------------------------- */
+
+/**
+ * GRecMutex:
*
- * int
- * give_me_next_number (void)
- * {
- * static int current_number = 0;
- * int ret_val;
+ * The GRecMutex struct is an opaque data structure to represent a
+ * recursive mutex. It is similar to a #GMutex with the difference
+ * that it is possible to lock a GRecMutex multiple times in the same
+ * thread without deadlock. When doing so, care has to be taken to
+ * unlock the recursive mutex as often as it has been locked.
*
- * g_mutex_lock (give_me_next_number_mutex);
- * ret_val = current_number = calc_next_number (current_number);
- * g_mutex_unlock (give_me_next_number_mutex);
+ * If a #GRecMutex is allocated in static storage then it can be used
+ * without initialisation. Otherwise, you should call
+ * g_rec_mutex_init() on it and g_rec_mutex_clear() when done.
*
- * return ret_val;
- * }
- * </programlisting>
- * </example>
+ * A GRecMutex should only be accessed with the
+ * <function>g_rec_mutex_</function> functions.
*
- * #GStaticMutex provides a simpler and safer way of doing this.
+ * Since: 2.32
+ */
+
+/* GRWLock Documentation {{{1 ---------------------------------------- */
+
+/**
+ * GRWLock:
*
- * If you want to use a mutex, and your code should also work without
- * calling g_thread_init() first, then you can not use a #GMutex, as
- * g_mutex_new() requires that the thread system be initialized. Use a
- * #GStaticMutex instead.
+ * The GRWLock struct is an opaque data structure to represent a
+ * reader-writer lock. It is similar to a #GMutex in that it allows
+ * multiple threads to coordinate access to a shared resource.
*
- * A #GMutex should only be accessed via the following functions.
+ * The difference to a mutex is that a reader-writer lock discriminates
+ * between read-only ('reader') and full ('writer') access. While only
+ * one thread at a time is allowed write access (by holding the 'writer'
+ * lock via g_rw_lock_writer_lock()), multiple threads can gain
+ * simultaneous read-only access (by holding the 'reader' lock via
+ * g_rw_lock_reader_lock()).
*
- * <note><para>All of the <function>g_mutex_*</function> functions are
- * actually macros. Apart from taking their addresses, you can however
- * use them as if they were functions.</para></note>
- **/
-
-/**
- * g_mutex_new:
- * @Returns: a new #GMutex.
+ * <example>
+ * <title>An array with access functions</title>
+ * <programlisting>
+ * GRWLock lock;
+ * GPtrArray *array;
*
- * Creates a new #GMutex.
+ * gpointer
+ * my_array_get (guint index)
+ * {
+ * gpointer retval = NULL;
*
- * <note><para>This function will abort if g_thread_init() has not been
- * called yet.</para></note>
- **/
- (GMutex*(*)())g_thread_fail,
-
-/**
- * g_mutex_lock:
- * @mutex: a #GMutex.
+ * if (!array)
+ * return NULL;
*
- * Locks @mutex. If @mutex is already locked by another thread, the
- * current thread will block until @mutex is unlocked by the other
- * thread.
+ * g_rw_lock_reader_lock (&lock);
+ * if (index < array->len)
+ * retval = g_ptr_array_index (array, index);
+ * g_rw_lock_reader_unlock (&lock);
*
- * This function can be used even if g_thread_init() has not yet been
- * called, and, in that case, will do nothing.
+ * return retval;
+ * }
*
- * <note><para>#GMutex is neither guaranteed to be recursive nor to be
- * non-recursive, i.e. a thread could deadlock while calling
- * g_mutex_lock(), if it already has locked @mutex. Use
- * #GStaticRecMutex, if you need recursive mutexes.</para></note>
- **/
- NULL,
-
-/**
- * g_mutex_trylock:
- * @mutex: a #GMutex.
- * @Returns: %TRUE, if @mutex could be locked.
- *
- * Tries to lock @mutex. If @mutex is already locked by another thread,
- * it immediately returns %FALSE. Otherwise it locks @mutex and returns
- * %TRUE.
- *
- * This function can be used even if g_thread_init() has not yet been
- * called, and, in that case, will immediately return %TRUE.
- *
- * <note><para>#GMutex is neither guaranteed to be recursive nor to be
- * non-recursive, i.e. the return value of g_mutex_trylock() could be
- * both %FALSE or %TRUE, if the current thread already has locked
- * @mutex. Use #GStaticRecMutex, if you need recursive
- * mutexes.</para></note>
- **/
- NULL,
-
-/**
- * g_mutex_unlock:
- * @mutex: a #GMutex.
+ * void
+ * my_array_set (guint index, gpointer data)
+ * {
+ * g_rw_lock_writer_lock (&lock);
*
- * Unlocks @mutex. If another thread is blocked in a g_mutex_lock()
- * call for @mutex, it will be woken and can lock @mutex itself.
+ * if (!array)
+ * array = g_ptr_array_new (<!-- -->);
*
- * This function can be used even if g_thread_init() has not yet been
- * called, and, in that case, will do nothing.
- **/
- NULL,
-
-/**
- * g_mutex_free:
- * @mutex: a #GMutex.
+ * if (index >= array->len)
+ * g_ptr_array_set_size (array, index+1);
+ * g_ptr_array_index (array, index) = data;
+ *
+ * g_rw_lock_writer_unlock (&lock);
+ * }
+ * </programlisting>
+ * <para>
+ * This example shows an array which can be accessed by many readers
+ * (the <function>my_array_get()</function> function) simultaneously,
+ * whereas the writers (the <function>my_array_set()</function>
+ * function) will only be allowed once at a time and only if no readers
+ * currently access the array. This is because of the potentially
+ * dangerous resizing of the array. Using these functions is fully
+ * multi-thread safe now.
+ * </para>
+ * </example>
*
- * Destroys @mutex.
+ * If a #GRWLock is allocated in static storage then it can be used
+ * without initialisation. Otherwise, you should call
+ * g_rw_lock_init() on it and g_rw_lock_clear() when done.
*
- * <note><para>Calling g_mutex_free() on a locked mutex may result in
- * undefined behaviour.</para></note>
- **/
- NULL,
+ * A GRWLock should only be accessed with the
+ * <function>g_rw_lock_</function> functions.
+ *
+ * Since: 2.32
+ */
-/* GCond Virtual Functions {{{2 ------------------------------------------ */
+/* GCond Documentation {{{1 ------------------------------------------ */
/**
* GCond:
* condition they signal the #GCond, and that causes the waiting
* threads to be woken up.
*
+ * Consider the following example of a shared variable. One or more
+ * threads can wait for data to be published to the variable and when
+ * another thread publishes the data, it can signal one of the waiting
+ * threads to wake up to collect the data.
+ *
* <example>
* <title>
* Using GCond to block a thread until a condition is satisfied
* </title>
* <programlisting>
- * GCond* data_cond = NULL; /<!-- -->* Must be initialized somewhere *<!-- -->/
- * GMutex* data_mutex = NULL; /<!-- -->* Must be initialized somewhere *<!-- -->/
* gpointer current_data = NULL;
+ * GMutex data_mutex;
+ * GCond data_cond;
*
* void
* push_data (gpointer data)
* {
- * g_mutex_lock (data_mutex);
+ * g_mutex_lock (&data_mutex);
* current_data = data;
- * g_cond_signal (data_cond);
- * g_mutex_unlock (data_mutex);
+ * g_cond_signal (&data_cond);
+ * g_mutex_unlock (&data_mutex);
* }
*
* gpointer
* {
* gpointer data;
*
- * g_mutex_lock (data_mutex);
+ * g_mutex_lock (&data_mutex);
* while (!current_data)
- * g_cond_wait (data_cond, data_mutex);
+ * g_cond_wait (&data_cond, &data_mutex);
* data = current_data;
* current_data = NULL;
- * g_mutex_unlock (data_mutex);
+ * g_mutex_unlock (&data_mutex);
*
* return data;
* }
* </programlisting>
* </example>
*
- * Whenever a thread calls <function>pop_data()</function> now, it will
- * wait until current_data is non-%NULL, i.e. until some other thread
- * has called <function>push_data()</function>.
- *
- * <note><para>It is important to use the g_cond_wait() and
- * g_cond_timed_wait() functions only inside a loop which checks for the
- * condition to be true. It is not guaranteed that the waiting thread
- * will find the condition fulfilled after it wakes up, even if the
- * signaling thread left the condition in that state: another thread may
- * have altered the condition before the waiting thread got the chance
- * to be woken up, even if the condition itself is protected by a
- * #GMutex, like above.</para></note>
- *
- * A #GCond should only be accessed via the following functions.
- *
- * <note><para>All of the <function>g_cond_*</function> functions are
- * actually macros. Apart from taking their addresses, you can however
- * use them as if they were functions.</para></note>
- **/
-
-/**
- * g_cond_new:
- * @Returns: a new #GCond.
- *
- * Creates a new #GCond. This function will abort, if g_thread_init()
- * has not been called yet.
- **/
- (GCond*(*)())g_thread_fail,
-
-/**
- * g_cond_signal:
- * @cond: a #GCond.
- *
- * If threads are waiting for @cond, exactly one of them is woken up.
- * It is good practice to hold the same lock as the waiting thread
- * while calling this function, though not required.
- *
- * This function can be used even if g_thread_init() has not yet been
- * called, and, in that case, will do nothing.
- **/
- NULL,
-
-/**
- * g_cond_broadcast:
- * @cond: a #GCond.
- *
- * If threads are waiting for @cond, all of them are woken up. It is
- * good practice to lock the same mutex as the waiting threads, while
- * calling this function, though not required.
- *
- * This function can be used even if g_thread_init() has not yet been
- * called, and, in that case, will do nothing.
- **/
- NULL,
-
-/**
- * g_cond_wait:
- * @cond: a #GCond.
- * @mutex: a #GMutex, that is currently locked.
- *
- * Waits until this thread is woken up on @cond. The @mutex is unlocked
- * before falling asleep and locked again before resuming.
- *
- * This function can be used even if g_thread_init() has not yet been
- * called, and, in that case, will immediately return.
- **/
- NULL,
-
-/**
- * g_cond_timed_wait:
- * @cond: a #GCond.
- * @mutex: a #GMutex that is currently locked.
- * @abs_time: a #GTimeVal, determining the final time.
- * @Returns: %TRUE if @cond was signalled, or %FALSE on timeout.
- *
- * Waits until this thread is woken up on @cond, but not longer than
- * until the time specified by @abs_time. The @mutex is unlocked before
- * falling asleep and locked again before resuming.
- *
- * If @abs_time is %NULL, g_cond_timed_wait() acts like g_cond_wait().
- *
- * This function can be used even if g_thread_init() has not yet been
- * called, and, in that case, will immediately return %TRUE.
- *
- * To easily calculate @abs_time a combination of g_get_current_time()
- * and g_time_val_add() can be used.
- **/
- NULL,
-
-/**
- * g_cond_free:
- * @cond: a #GCond.
- *
- * Destroys the #GCond.
- **/
- NULL,
-
-/* GPrivate Virtual Functions {{{2 --------------------------------------- */
-
-/**
- * GPrivate:
- *
- * The #GPrivate struct is an opaque data structure to represent a
- * thread private data key. Threads can thereby obtain and set a
- * pointer which is private to the current thread. Take our
- * <function>give_me_next_number(<!-- -->)</function> example from
- * above. Suppose we don't want <literal>current_number</literal> to be
- * shared between the threads, but instead to be private to each thread.
- * This can be done as follows:
- *
- * <example>
- * <title>Using GPrivate for per-thread data</title>
- * <programlisting>
- * GPrivate* current_number_key = NULL; /<!-- -->* Must be initialized somewhere
- * with g_private_new (g_free); *<!-- -->/
- *
- * int
- * give_me_next_number (void)
- * {
- * int *current_number = g_private_get (current_number_key);
- *
- * if (!current_number)
- * {
- * current_number = g_new (int, 1);
- * *current_number = 0;
- * g_private_set (current_number_key, current_number);
- * }
- *
- * *current_number = calc_next_number (*current_number);
- *
- * return *current_number;
- * }
- * </programlisting>
- * </example>
- *
- * Here the pointer belonging to the key
- * <literal>current_number_key</literal> is read. If it is %NULL, it has
- * not been set yet. Then get memory for an integer value, assign this
- * memory to the pointer and write the pointer back. Now we have an
- * integer value that is private to the current thread.
- *
- * The #GPrivate struct should only be accessed via the following
+ * Whenever a thread calls pop_data() now, it will wait until
+ * current_data is non-%NULL, i.e. until some other thread
+ * has called push_data().
+ *
+ * The example shows that use of a condition variable must always be
+ * paired with a mutex. Without the use of a mutex, there would be a
+ * race between the check of <varname>current_data</varname> by the
+ * while loop in <function>pop_data</function> and waiting.
+ * Specifically, another thread could set <varname>pop_data</varname>
+ * after the check, and signal the cond (with nobody waiting on it)
+ * before the first thread goes to sleep. #GCond is specifically useful
+ * for its ability to release the mutex and go to sleep atomically.
+ *
+ * It is also important to use the g_cond_wait() and g_cond_wait_until()
+ * functions only inside a loop which checks for the condition to be
+ * true. See g_cond_wait() for an explanation of why the condition may
+ * not be true even after it returns.
+ *
+ * If a #GCond is allocated in static storage then it can be used
+ * without initialisation. Otherwise, you should call g_cond_init() on
+ * it and g_cond_clear() when done.
+ *
+ * A #GCond should only be accessed via the <function>g_cond_</function>
* functions.
- *
- * <note><para>All of the <function>g_private_*</function> functions are
- * actually macros. Apart from taking their addresses, you can however
- * use them as if they were functions.</para></note>
- **/
+ */
+
+/* GThread Documentation {{{1 ---------------------------------------- */
/**
- * g_private_new:
- * @destructor: a function to destroy the data keyed to #GPrivate when
- * a thread ends.
- * @Returns: a new #GPrivate.
- *
- * Creates a new #GPrivate. If @destructor is non-%NULL, it is a
- * pointer to a destructor function. Whenever a thread ends and the
- * corresponding pointer keyed to this instance of #GPrivate is
- * non-%NULL, the destructor is called with this pointer as the
- * argument.
+ * GThread:
*
- * <note><para>@destructor is used quite differently from @notify in
- * g_static_private_set().</para></note>
+ * The #GThread struct represents a running thread. This struct
+ * is returned by g_thread_new() or g_thread_try_new(). You can
+ * obtain the #GThread struct representing the current thead by
+ * calling g_thread_self().
*
- * <note><para>A #GPrivate can not be freed. Reuse it instead, if you
- * can, to avoid shortage, or use #GStaticPrivate.</para></note>
+ * GThread is refcounted, see g_thread_ref() and g_thread_unref().
+ * The thread represented by it holds a reference while it is running,
+ * and g_thread_join() consumes the reference that it is given, so
+ * it is normally not necessary to manage GThread references
+ * explicitly.
*
- * <note><para>This function will abort if g_thread_init() has not been
- * called yet.</para></note>
- **/
- (GPrivate*(*)(GDestroyNotify))g_thread_fail,
-
-/**
- * g_private_get:
- * @private_key: a #GPrivate.
- * @Returns: the corresponding pointer.
- *
- * Returns the pointer keyed to @private_key for the current thread. If
- * g_private_set() hasn't been called for the current @private_key and
- * thread yet, this pointer will be %NULL.
- *
- * This function can be used even if g_thread_init() has not yet been
- * called, and, in that case, will return the value of @private_key
- * casted to #gpointer. Note however, that private data set
- * <emphasis>before</emphasis> g_thread_init() will
- * <emphasis>not</emphasis> be retained <emphasis>after</emphasis> the
- * call. Instead, %NULL will be returned in all threads directly after
- * g_thread_init(), regardless of any g_private_set() calls issued
- * before threading system intialization.
- **/
- NULL,
+ * The structure is opaque -- none of its fields may be directly
+ * accessed.
+ */
/**
- * g_private_set:
- * @private_key: a #GPrivate.
- * @data: the new pointer.
+ * GThreadFunc:
+ * @data: data passed to the thread
*
- * Sets the pointer keyed to @private_key for the current thread.
+ * Specifies the type of the @func functions passed to g_thread_new()
+ * or g_thread_try_new().
*
- * This function can be used even if g_thread_init() has not yet been
- * called, and, in that case, will set @private_key to @data casted to
- * #GPrivate*. See g_private_get() for resulting caveats.
- **/
- NULL,
+ * Returns: the return value of the thread
+ */
-/* GThread Virtual Functions {{{2 ---------------------------------------- */
/**
- * GThread:
+ * g_thread_supported:
*
- * The #GThread struct represents a running thread. It has three public
- * read-only members, but the underlying struct is bigger, so you must
- * not copy this struct.
+ * This macro returns %TRUE if the thread system is initialized,
+ * and %FALSE if it is not.
*
- * <note><para>Resources for a joinable thread are not fully released
- * until g_thread_join() is called for that thread.</para></note>
- **/
-
-/**
- * GThreadFunc:
- * @data: data passed to the thread.
- * @Returns: the return value of the thread, which will be returned by
- * g_thread_join().
+ * For language bindings, g_thread_get_initialized() provides
+ * the same functionality as a function.
*
- * Specifies the type of the @func functions passed to
- * g_thread_create() or g_thread_create_full().
- **/
-
-/**
- * GThreadPriority:
- * @G_THREAD_PRIORITY_LOW: a priority lower than normal
- * @G_THREAD_PRIORITY_NORMAL: the default priority
- * @G_THREAD_PRIORITY_HIGH: a priority higher than normal
- * @G_THREAD_PRIORITY_URGENT: the highest priority
- *
- * Specifies the priority of a thread.
- *
- * <note><para>It is not guaranteed that threads with different priorities
- * really behave accordingly. On some systems (e.g. Linux) there are no
- * thread priorities. On other systems (e.g. Solaris) there doesn't
- * seem to be different scheduling for different priorities. All in all
- * try to avoid being dependent on priorities.</para></note>
- **/
+ * Returns: %TRUE, if the thread system is initialized
+ */
+/* GThreadError {{{1 ------------------------------------------------------- */
/**
- * g_thread_create:
- * @func: a function to execute in the new thread.
- * @data: an argument to supply to the new thread.
- * @joinable: should this thread be joinable?
- * @error: return location for error.
- * @Returns: the new #GThread on success.
- *
- * This function creates a new thread with the default priority.
- *
- * If @joinable is %TRUE, you can wait for this threads termination
- * calling g_thread_join(). Otherwise the thread will just disappear
- * when it terminates.
- *
- * The new thread executes the function @func with the argument @data.
- * If the thread was created successfully, it is returned.
+ * GThreadError:
+ * @G_THREAD_ERROR_AGAIN: a thread couldn't be created due to resource
+ * shortage. Try again later.
*
- * @error can be %NULL to ignore errors, or non-%NULL to report errors.
- * The error is set, if and only if the function returns %NULL.
+ * Possible errors of thread related functions.
**/
- (void(*)(GThreadFunc, gpointer, gulong,
- gboolean, gboolean, GThreadPriority,
- gpointer, GError**))g_thread_fail,
/**
- * g_thread_yield:
- *
- * Gives way to other threads waiting to be scheduled.
+ * G_THREAD_ERROR:
*
- * This function is often used as a method to make busy wait less evil.
- * But in most cases you will encounter, there are better methods to do
- * that. So in general you shouldn't use this function.
+ * The error domain of the GLib thread subsystem.
**/
- NULL,
-
- NULL, /* thread_join */
- NULL, /* thread_exit */
- NULL, /* thread_set_priority */
- NULL, /* thread_self */
- NULL /* thread_equal */
-};
+GQuark
+g_thread_error_quark (void)
+{
+ return g_quark_from_static_string ("g_thread_error");
+}
/* Local Data {{{1 -------------------------------------------------------- */
-static GMutex *g_once_mutex = NULL;
-static GCond *g_once_cond = NULL;
-static GPrivate *g_thread_specific_private = NULL;
-static GRealThread *g_thread_all_threads = NULL;
-static GSList *g_thread_free_indeces = NULL;
-static GSList* g_once_init_list = NULL;
+static GMutex g_once_mutex;
+static GCond g_once_cond;
+static GSList *g_once_init_list = NULL;
-G_LOCK_DEFINE_STATIC (g_thread);
+static void g_thread_cleanup (gpointer data);
+static GPrivate g_thread_specific_private = G_PRIVATE_INIT (g_thread_cleanup);
-/* Initialisation {{{1 ---------------------------------------------------- */
-
-#ifdef G_THREADS_ENABLED
-/**
- * g_thread_init:
- * @vtable: a function table of type #GThreadFunctions, that provides
- * the entry points to the thread system to be used.
- *
- * If you use GLib from more than one thread, you must initialize the
- * thread system by calling g_thread_init(). Most of the time you will
- * only have to call <literal>g_thread_init (NULL)</literal>.
- *
- * <note><para>Do not call g_thread_init() with a non-%NULL parameter unless
- * you really know what you are doing.</para></note>
- *
- * <note><para>g_thread_init() must not be called directly or indirectly as a
- * callback from GLib. Also no mutexes may be currently locked while
- * calling g_thread_init().</para></note>
- *
- * <note><para>g_thread_init() changes the way in which #GTimer measures
- * elapsed time. As a consequence, timers that are running while
- * g_thread_init() is called may report unreliable times.</para></note>
- *
- * Calling g_thread_init() multiple times is allowed (since version
- * 2.24), but nothing happens except for the first call. If the
- * argument is non-%NULL on such a call a warning will be printed, but
- * otherwise the argument is ignored.
- *
- * If no thread system is available and @vtable is %NULL or if not all
- * elements of @vtable are non-%NULL, then g_thread_init() will abort.
- *
- * <note><para>To use g_thread_init() in your program, you have to link with
- * the libraries that the command <command>pkg-config --libs
- * gthread-2.0</command> outputs. This is not the case for all the
- * other thread related functions of GLib. Those can be used without
- * having to link with the thread libraries.</para></note>
- **/
-
-/* This must be called only once, before any threads are created.
- * It will only be called from g_thread_init() in -lgthread.
- */
-void
-g_thread_init_glib (void)
-{
- /* We let the main thread (the one that calls g_thread_init) inherit
- * the static_private data set before calling g_thread_init
- */
- GRealThread* main_thread = (GRealThread*) g_thread_self ();
-
- /* mutex and cond creation works without g_threads_got_initialized */
- g_once_mutex = g_mutex_new ();
- g_once_cond = g_cond_new ();
-
- /* we may only create mutex and cond in here */
- _g_mem_thread_init_noprivate_nomessage ();
-
- /* setup the basic threading system */
- g_threads_got_initialized = TRUE;
- g_thread_specific_private = g_private_new (g_thread_cleanup);
- g_private_set (g_thread_specific_private, main_thread);
- G_THREAD_UF (thread_self, (&main_thread->system_thread));
-
- /* complete memory system initialization, g_private_*() works now */
- _g_slice_thread_init_nomessage ();
-
- /* accomplish log system initialization to enable messaging */
- _g_messages_thread_init_nomessage ();
-
- /* we may run full-fledged initializers from here */
- _g_atomic_thread_init ();
- _g_convert_thread_init ();
- _g_rand_thread_init ();
- _g_main_thread_init ();
- _g_utils_thread_init ();
- _g_futex_thread_init ();
-#ifdef G_OS_WIN32
- _g_win32_thread_init ();
-#endif
-}
-#endif /* G_THREADS_ENABLED */
-
-/* The following sections implement: GOnce, GStaticMutex, GStaticRecMutex,
- * GStaticPrivate,
- **/
+G_LOCK_DEFINE_STATIC (g_thread_new);
/* GOnce {{{1 ------------------------------------------------------------- */
* struct.
*
* Since: 2.4
- **/
+ */
/**
* G_ONCE_INIT:
*
* A #GOnce must be initialized with this macro before it can be used.
*
- * <informalexample>
- * <programlisting>
+ * |[
* GOnce my_once = G_ONCE_INIT;
- * </programlisting>
- * </informalexample>
+ * ]|
*
* Since: 2.4
- **/
+ */
/**
* GOnceStatus:
* controlled by a #GOnce struct.
*
* Since: 2.4
- **/
+ */
/**
* g_once:
* exactly once. In a threaded environment, calling g_once() ensures
* that the initialization is serialized across multiple threads.
*
- * <note><para>Calling g_once() recursively on the same #GOnce struct in
- * @func will lead to a deadlock.</para></note>
+ * Calling g_once() recursively on the same #GOnce struct in
+ * @func will lead to a deadlock.
*
- * <informalexample>
- * <programlisting>
+ * |[
* gpointer
* get_debug_flags (void)
* {
*
* return my_once.retval;
* }
- * </programlisting>
- * </informalexample>
+ * ]|
*
* Since: 2.4
- **/
+ */
gpointer
g_once_impl (GOnce *once,
GThreadFunc func,
gpointer arg)
{
- g_mutex_lock (g_once_mutex);
+ g_mutex_lock (&g_once_mutex);
while (once->status == G_ONCE_STATUS_PROGRESS)
- g_cond_wait (g_once_cond, g_once_mutex);
+ g_cond_wait (&g_once_cond, &g_once_mutex);
if (once->status != G_ONCE_STATUS_READY)
{
once->status = G_ONCE_STATUS_PROGRESS;
- g_mutex_unlock (g_once_mutex);
+ g_mutex_unlock (&g_once_mutex);
once->retval = func (arg);
- g_mutex_lock (g_once_mutex);
+ g_mutex_lock (&g_once_mutex);
once->status = G_ONCE_STATUS_READY;
- g_cond_broadcast (g_once_cond);
+ g_cond_broadcast (&g_once_cond);
}
- g_mutex_unlock (g_once_mutex);
+ g_mutex_unlock (&g_once_mutex);
return once->retval;
}
/**
* g_once_init_enter:
- * @value_location: location of a static initializable variable
- * containing 0.
- * @Returns: %TRUE if the initialization section should be entered,
- * %FALSE and blocks otherwise
+ * @location: location of a static initializable variable containing 0
*
* Function to be called when starting a critical initialization
- * section. The argument @value_location must point to a static
+ * section. The argument @location must point to a static
* 0-initialized variable that will be set to a value other than 0 at
* the end of the initialization section. In combination with
* g_once_init_leave() and the unique address @value_location, it can
* blocked until initialization completed. To be used in constructs
* like this:
*
- * <informalexample>
- * <programlisting>
+ * |[
* static gsize initialization_value = 0;
*
* if (g_once_init_enter (&initialization_value))
* {
- * gsize setup_value = 42; /<!-- -->* initialization code here *<!-- -->/
+ * gsize setup_value = 42; /** initialization code here **/
*
* g_once_init_leave (&initialization_value, setup_value);
* }
*
- * /<!-- -->* use initialization_value here *<!-- -->/
- * </programlisting>
- * </informalexample>
+ * /** use initialization_value here **/
+ * ]|
+ *
+ * Returns: %TRUE if the initialization section should be entered,
+ * %FALSE and blocks otherwise
*
* Since: 2.14
- **/
+ */
gboolean
-g_once_init_enter_impl (volatile gsize *value_location)
+(g_once_init_enter) (volatile void *location)
{
+ volatile gsize *value_location = location;
gboolean need_init = FALSE;
- g_mutex_lock (g_once_mutex);
+ g_mutex_lock (&g_once_mutex);
if (g_atomic_pointer_get (value_location) == NULL)
{
if (!g_slist_find (g_once_init_list, (void*) value_location))
}
else
do
- g_cond_wait (g_once_cond, g_once_mutex);
+ g_cond_wait (&g_once_cond, &g_once_mutex);
while (g_slist_find (g_once_init_list, (void*) value_location));
}
- g_mutex_unlock (g_once_mutex);
+ g_mutex_unlock (&g_once_mutex);
return need_init;
}
/**
* g_once_init_leave:
- * @value_location: location of a static initializable variable
- * containing 0.
- * @initialization_value: new non-0 value for *@value_location.
+ * @location: location of a static initializable variable containing 0
+ * @result: new non-0 value for *@value_location
*
* Counterpart to g_once_init_enter(). Expects a location of a static
* 0-initialized initialization variable, and an initialization value
* initialization variable.
*
* Since: 2.14
- **/
+ */
void
-g_once_init_leave (volatile gsize *value_location,
- gsize initialization_value)
+(g_once_init_leave) (volatile void *location,
+ gsize result)
{
+ volatile gsize *value_location = location;
+
g_return_if_fail (g_atomic_pointer_get (value_location) == NULL);
- g_return_if_fail (initialization_value != 0);
+ g_return_if_fail (result != 0);
g_return_if_fail (g_once_init_list != NULL);
- g_atomic_pointer_set ((void**)value_location, (void*) initialization_value);
- g_mutex_lock (g_once_mutex);
+ g_atomic_pointer_set (value_location, result);
+ g_mutex_lock (&g_once_mutex);
g_once_init_list = g_slist_remove (g_once_init_list, (void*) value_location);
- g_cond_broadcast (g_once_cond);
- g_mutex_unlock (g_once_mutex);
+ g_cond_broadcast (&g_once_cond);
+ g_mutex_unlock (&g_once_mutex);
}
-/* GStaticMutex {{{1 ------------------------------------------------------ */
-
-/**
- * GStaticMutex:
- *
- * A #GStaticMutex works like a #GMutex, but it has one significant
- * advantage. It doesn't need to be created at run-time like a #GMutex,
- * but can be defined at compile-time. Here is a shorter, easier and
- * safer version of our <function>give_me_next_number()</function>
- * example:
- *
- * <example>
- * <title>
- * Using <structname>GStaticMutex</structname>
- * to simplify thread-safe programming
- * </title>
- * <programlisting>
- * int
- * give_me_next_number (void)
- * {
- * static int current_number = 0;
- * int ret_val;
- * static GStaticMutex mutex = G_STATIC_MUTEX_INIT;
- *
- * g_static_mutex_lock (&mutex);
- * ret_val = current_number = calc_next_number (current_number);
- * g_static_mutex_unlock (&mutex);
- *
- * return ret_val;
- * }
- * </programlisting>
- * </example>
- *
- * Sometimes you would like to dynamically create a mutex. If you don't
- * want to require prior calling to g_thread_init(), because your code
- * should also be usable in non-threaded programs, you are not able to
- * use g_mutex_new() and thus #GMutex, as that requires a prior call to
- * g_thread_init(). In theses cases you can also use a #GStaticMutex.
- * It must be initialized with g_static_mutex_init() before using it
- * and freed with with g_static_mutex_free() when not needed anymore to
- * free up any allocated resources.
- *
- * Even though #GStaticMutex is not opaque, it should only be used with
- * the following functions, as it is defined differently on different
- * platforms.
- *
- * All of the <function>g_static_mutex_*</function> functions apart
- * from <function>g_static_mutex_get_mutex</function> can also be used
- * even if g_thread_init() has not yet been called. Then they do
- * nothing, apart from <function>g_static_mutex_trylock</function>,
- * which does nothing but returning %TRUE.
- *
- * <note><para>All of the <function>g_static_mutex_*</function>
- * functions are actually macros. Apart from taking their addresses, you
- * can however use them as if they were functions.</para></note>
- **/
-
-/**
- * G_STATIC_MUTEX_INIT:
- *
- * A #GStaticMutex must be initialized with this macro, before it can
- * be used. This macro can used be to initialize a variable, but it
- * cannot be assigned to a variable. In that case you have to use
- * g_static_mutex_init().
- *
- * <informalexample>
- * <programlisting>
- * GStaticMutex my_mutex = G_STATIC_MUTEX_INIT;
- * </programlisting>
- * </informalexample>
- **/
+/* GThread {{{1 -------------------------------------------------------- */
/**
- * g_static_mutex_init:
- * @mutex: a #GStaticMutex to be initialized.
- *
- * Initializes @mutex. Alternatively you can initialize it with
- * #G_STATIC_MUTEX_INIT.
- **/
-void
-g_static_mutex_init (GStaticMutex *mutex)
-{
- static const GStaticMutex init_mutex = G_STATIC_MUTEX_INIT;
-
- g_return_if_fail (mutex);
-
- *mutex = init_mutex;
-}
-
-/* IMPLEMENTATION NOTE:
+ * g_thread_ref:
+ * @thread: a #GThread
*
- * On some platforms a GStaticMutex is actually a normal GMutex stored
- * inside of a structure instead of being allocated dynamically. We can
- * only do this for platforms on which we know, in advance, how to
- * allocate (size) and initialise (value) that memory.
+ * Increase the reference count on @thread.
*
- * On other platforms, a GStaticMutex is nothing more than a pointer to
- * a GMutex. In that case, the first access we make to the static mutex
- * must first allocate the normal GMutex and store it into the pointer.
+ * Returns: a new reference to @thread
*
- * configure.in writes macros into glibconfig.h to determine if
- * g_static_mutex_get_mutex() accesses the sturcture in memory directly
- * (on platforms where we are able to do that) or if it ends up here,
- * where we may have to allocate the GMutex before returning it.
+ * Since: 2.32
*/
-
-/**
- * g_static_mutex_get_mutex:
- * @mutex: a #GStaticMutex.
- * @Returns: the #GMutex corresponding to @mutex.
- *
- * For some operations (like g_cond_wait()) you must have a #GMutex
- * instead of a #GStaticMutex. This function will return the
- * corresponding #GMutex for @mutex.
- **/
-GMutex *
-g_static_mutex_get_mutex_impl (GMutex** mutex)
+GThread *
+g_thread_ref (GThread *thread)
{
- if (!g_thread_supported ())
- return NULL;
-
- g_assert (g_once_mutex);
-
- g_mutex_lock (g_once_mutex);
-
- if (!(*mutex))
- g_atomic_pointer_set (mutex, g_mutex_new());
+ GRealThread *real = (GRealThread *) thread;
- g_mutex_unlock (g_once_mutex);
+ g_atomic_int_inc (&real->ref_count);
- return *mutex;
+ return thread;
}
-/* IMPLEMENTATION NOTE:
- *
- * g_static_mutex_lock(), g_static_mutex_trylock() and
- * g_static_mutex_unlock() are all preprocessor macros that wrap the
- * corresponding g_mutex_*() function around a call to
- * g_static_mutex_get_mutex().
- */
-
-/**
- * g_static_mutex_lock:
- * @mutex: a #GStaticMutex.
- *
- * Works like g_mutex_lock(), but for a #GStaticMutex.
- **/
-
-/**
- * g_static_mutex_trylock:
- * @mutex: a #GStaticMutex.
- * @Returns: %TRUE, if the #GStaticMutex could be locked.
- *
- * Works like g_mutex_trylock(), but for a #GStaticMutex.
- **/
-
/**
- * g_static_mutex_unlock:
- * @mutex: a #GStaticMutex.
+ * g_thread_unref:
+ * @thread: a #GThread
*
- * Works like g_mutex_unlock(), but for a #GStaticMutex.
- **/
-
-/**
- * g_static_mutex_free:
- * @mutex: a #GStaticMutex to be freed.
+ * Decrease the reference count on @thread, possibly freeing all
+ * resources associated with it.
*
- * Releases all resources allocated to @mutex.
+ * Note that each thread holds a reference to its #GThread while
+ * it is running, so it is safe to drop your own reference to it
+ * if you don't need it anymore.
*
- * You don't have to call this functions for a #GStaticMutex with an
- * unbounded lifetime, i.e. objects declared 'static', but if you have
- * a #GStaticMutex as a member of a structure and the structure is
- * freed, you should also free the #GStaticMutex.
- *
- * <note><para>Calling g_static_mutex_free() on a locked mutex may
- * result in undefined behaviour.</para></note>
- **/
-void
-g_static_mutex_free (GStaticMutex* mutex)
-{
- GMutex **runtime_mutex;
-
- g_return_if_fail (mutex);
-
- /* The runtime_mutex is the first (or only) member of GStaticMutex,
- * see both versions (of glibconfig.h) in configure.in. Note, that
- * this variable is NULL, if g_thread_init() hasn't been called or
- * if we're using the default thread implementation and it provides
- * static mutexes. */
- runtime_mutex = ((GMutex**)mutex);
-
- if (*runtime_mutex)
- g_mutex_free (*runtime_mutex);
-
- *runtime_mutex = NULL;
-}
-
-/* ------------------------------------------------------------------------ */
-
-/**
- * GStaticRecMutex:
- *
- * A #GStaticRecMutex works like a #GStaticMutex, but it can be locked
- * multiple times by one thread. If you enter it n times, you have to
- * unlock it n times again to let other threads lock it. An exception
- * is the function g_static_rec_mutex_unlock_full(): that allows you to
- * unlock a #GStaticRecMutex completely returning the depth, (i.e. the
- * number of times this mutex was locked). The depth can later be used
- * to restore the state of the #GStaticRecMutex by calling
- * g_static_rec_mutex_lock_full().
- *
- * Even though #GStaticRecMutex is not opaque, it should only be used
- * with the following functions.
- *
- * All of the <function>g_static_rec_mutex_*</function> functions can
- * be used even if g_thread_init() has not been called. Then they do
- * nothing, apart from <function>g_static_rec_mutex_trylock</function>,
- * which does nothing but returning %TRUE.
- **/
-
-/**
- * G_STATIC_REC_MUTEX_INIT:
- *
- * A #GStaticRecMutex must be initialized with this macro before it can
- * be used. This macro can used be to initialize a variable, but it
- * cannot be assigned to a variable. In that case you have to use
- * g_static_rec_mutex_init().
- *
- * <informalexample>
- * <programlisting>
- * GStaticRecMutex my_mutex = G_STATIC_REC_MUTEX_INIT;
- * </programlisting>
- </informalexample>
- **/
-
-/**
- * g_static_rec_mutex_init:
- * @mutex: a #GStaticRecMutex to be initialized.
- *
- * A #GStaticRecMutex must be initialized with this function before it
- * can be used. Alternatively you can initialize it with
- * #G_STATIC_REC_MUTEX_INIT.
- **/
-void
-g_static_rec_mutex_init (GStaticRecMutex *mutex)
-{
- static const GStaticRecMutex init_mutex = G_STATIC_REC_MUTEX_INIT;
-
- g_return_if_fail (mutex);
-
- *mutex = init_mutex;
-}
-
-/**
- * g_static_rec_mutex_lock:
- * @mutex: a #GStaticRecMutex to lock.
- *
- * Locks @mutex. If @mutex is already locked by another thread, the
- * current thread will block until @mutex is unlocked by the other
- * thread. If @mutex is already locked by the calling thread, this
- * functions increases the depth of @mutex and returns immediately.
- **/
+ * Since: 2.32
+ */
void
-g_static_rec_mutex_lock (GStaticRecMutex* mutex)
-{
- GSystemThread self;
-
- g_return_if_fail (mutex);
-
- if (!g_thread_supported ())
- return;
-
- G_THREAD_UF (thread_self, (&self));
-
- if (g_system_thread_equal (self, mutex->owner))
- {
- mutex->depth++;
- return;
- }
- g_static_mutex_lock (&mutex->mutex);
- g_system_thread_assign (mutex->owner, self);
- mutex->depth = 1;
-}
-
-/**
- * g_static_rec_mutex_trylock:
- * @mutex: a #GStaticRecMutex to lock.
- * @Returns: %TRUE, if @mutex could be locked.
- *
- * Tries to lock @mutex. If @mutex is already locked by another thread,
- * it immediately returns %FALSE. Otherwise it locks @mutex and returns
- * %TRUE. If @mutex is already locked by the calling thread, this
- * functions increases the depth of @mutex and immediately returns
- * %TRUE.
- **/
-gboolean
-g_static_rec_mutex_trylock (GStaticRecMutex* mutex)
+g_thread_unref (GThread *thread)
{
- GSystemThread self;
-
- g_return_val_if_fail (mutex, FALSE);
-
- if (!g_thread_supported ())
- return TRUE;
-
- G_THREAD_UF (thread_self, (&self));
+ GRealThread *real = (GRealThread *) thread;
- if (g_system_thread_equal (self, mutex->owner))
+ if (g_atomic_int_dec_and_test (&real->ref_count))
{
- mutex->depth++;
- return TRUE;
+ if (real->ours)
+ g_system_thread_free (real);
+ else
+ g_slice_free (GRealThread, real);
}
-
- if (!g_static_mutex_trylock (&mutex->mutex))
- return FALSE;
-
- g_system_thread_assign (mutex->owner, self);
- mutex->depth = 1;
- return TRUE;
}
-/**
- * g_static_rec_mutex_unlock:
- * @mutex: a #GStaticRecMutex to unlock.
- *
- * Unlocks @mutex. Another thread will be allowed to lock @mutex only
- * when it has been unlocked as many times as it had been locked
- * before. If @mutex is completely unlocked and another thread is
- * blocked in a g_static_rec_mutex_lock() call for @mutex, it will be
- * woken and can lock @mutex itself.
- **/
-void
-g_static_rec_mutex_unlock (GStaticRecMutex* mutex)
+static void
+g_thread_cleanup (gpointer data)
{
- g_return_if_fail (mutex);
-
- if (!g_thread_supported ())
- return;
-
- if (mutex->depth > 1)
- {
- mutex->depth--;
- return;
- }
- g_system_thread_assign (mutex->owner, zero_thread);
- g_static_mutex_unlock (&mutex->mutex);
+ g_thread_unref (data);
}
-/**
- * g_static_rec_mutex_lock_full:
- * @mutex: a #GStaticRecMutex to lock.
- * @depth: number of times this mutex has to be unlocked to be
- * completely unlocked.
- *
- * Works like calling g_static_rec_mutex_lock() for @mutex @depth times.
- **/
-void
-g_static_rec_mutex_lock_full (GStaticRecMutex *mutex,
- guint depth)
+gpointer
+g_thread_proxy (gpointer data)
{
- GSystemThread self;
- g_return_if_fail (mutex);
+ GRealThread* thread = data;
- if (!g_thread_supported ())
- return;
+ g_assert (data);
- if (depth == 0)
- return;
+ /* This has to happen before G_LOCK, as that might call g_thread_self */
+ g_private_set (&g_thread_specific_private, data);
- G_THREAD_UF (thread_self, (&self));
+ /* The lock makes sure that g_thread_new_internal() has a chance to
+ * setup 'func' and 'data' before we make the call.
+ */
+ G_LOCK (g_thread_new);
+ G_UNLOCK (g_thread_new);
- if (g_system_thread_equal (self, mutex->owner))
+ if (thread->name)
{
- mutex->depth += depth;
- return;
+ g_system_thread_set_name (thread->name);
+ g_free (thread->name);
+ thread->name = NULL;
}
- g_static_mutex_lock (&mutex->mutex);
- g_system_thread_assign (mutex->owner, self);
- mutex->depth = depth;
-}
-
-/**
- * g_static_rec_mutex_unlock_full:
- * @mutex: a #GStaticRecMutex to completely unlock.
- * @Returns: number of times @mutex has been locked by the current
- * thread.
- *
- * Completely unlocks @mutex. If another thread is blocked in a
- * g_static_rec_mutex_lock() call for @mutex, it will be woken and can
- * lock @mutex itself. This function returns the number of times that
- * @mutex has been locked by the current thread. To restore the state
- * before the call to g_static_rec_mutex_unlock_full() you can call
- * g_static_rec_mutex_lock_full() with the depth returned by this
- * function.
- **/
-guint
-g_static_rec_mutex_unlock_full (GStaticRecMutex *mutex)
-{
- guint depth;
-
- g_return_val_if_fail (mutex, 0);
-
- if (!g_thread_supported ())
- return 1;
- depth = mutex->depth;
-
- g_system_thread_assign (mutex->owner, zero_thread);
- mutex->depth = 0;
- g_static_mutex_unlock (&mutex->mutex);
+ thread->retval = thread->thread.func (thread->thread.data);
- return depth;
+ return NULL;
}
/**
- * g_static_rec_mutex_free:
- * @mutex: a #GStaticRecMutex to be freed.
+ * g_thread_new:
+ * @name: a name for the new thread
+ * @func: a function to execute in the new thread
+ * @data: an argument to supply to the new thread
*
- * Releases all resources allocated to a #GStaticRecMutex.
+ * This function creates a new thread. The new thread starts by invoking
+ * @func with the argument data. The thread will run until @func returns
+ * or until g_thread_exit() is called from the new thread. The return value
+ * of @func becomes the return value of the thread, which can be obtained
+ * with g_thread_join().
*
- * You don't have to call this functions for a #GStaticRecMutex with an
- * unbounded lifetime, i.e. objects declared 'static', but if you have
- * a #GStaticRecMutex as a member of a structure and the structure is
- * freed, you should also free the #GStaticRecMutex.
- **/
-void
-g_static_rec_mutex_free (GStaticRecMutex *mutex)
-{
- g_return_if_fail (mutex);
-
- g_static_mutex_free (&mutex->mutex);
-}
-
-/* GStaticPrivate {{{1 ---------------------------------------------------- */
-
-/**
- * GStaticPrivate:
+ * The @name can be useful for discriminating threads in a debugger.
+ * Some systems restrict the length of @name to 16 bytes.
*
- * A #GStaticPrivate works almost like a #GPrivate, but it has one
- * significant advantage. It doesn't need to be created at run-time
- * like a #GPrivate, but can be defined at compile-time. This is
- * similar to the difference between #GMutex and #GStaticMutex. Now
- * look at our <function>give_me_next_number()</function> example with
- * #GStaticPrivate:
+ * If the thread can not be created the program aborts. See
+ * g_thread_try_new() if you want to attempt to deal with failures.
*
- * <example>
- * <title>Using GStaticPrivate for per-thread data</title>
- * <programlisting>
- * int
- * give_me_next_number (<!-- -->)
- * {
- * static GStaticPrivate current_number_key = G_STATIC_PRIVATE_INIT;
- * int *current_number = g_static_private_get (&current_number_key);
- *
- * if (!current_number)
- * {
- * current_number = g_new (int,1);
- * *current_number = 0;
- * g_static_private_set (&current_number_key, current_number, g_free);
- * }
+ * To free the struct returned by this function, use g_thread_unref().
+ * Note that g_thread_join() implicitly unrefs the #GThread as well.
*
- * *current_number = calc_next_number (*current_number);
+ * Returns: the new #GThread
*
- * return *current_number;
- * }
- * </programlisting>
- * </example>
- **/
-
-/**
- * G_STATIC_PRIVATE_INIT:
- *
- * Every #GStaticPrivate must be initialized with this macro, before it
- * can be used.
- *
- * <informalexample>
- * <programlisting>
- * GStaticPrivate my_private = G_STATIC_PRIVATE_INIT;
- * </programlisting>
- * </informalexample>
- **/
-
-/**
- * g_static_private_init:
- * @private_key: a #GStaticPrivate to be initialized.
- *
- * Initializes @private_key. Alternatively you can initialize it with
- * #G_STATIC_PRIVATE_INIT.
- **/
-void
-g_static_private_init (GStaticPrivate *private_key)
-{
- private_key->index = 0;
-}
-
-/**
- * g_static_private_get:
- * @private_key: a #GStaticPrivate.
- * @Returns: the corresponding pointer.
- *
- * Works like g_private_get() only for a #GStaticPrivate.
- *
- * This function works even if g_thread_init() has not yet been called.
- **/
-gpointer
-g_static_private_get (GStaticPrivate *private_key)
-{
- GRealThread *self = (GRealThread*) g_thread_self ();
- GArray *array;
-
- array = self->private_data;
- if (!array)
- return NULL;
-
- if (!private_key->index)
- return NULL;
- else if (private_key->index <= array->len)
- return g_array_index (array, GStaticPrivateNode,
- private_key->index - 1).data;
- else
- return NULL;
-}
-
-/**
- * g_static_private_set:
- * @private_key: a #GStaticPrivate.
- * @data: the new pointer.
- * @notify: a function to be called with the pointer whenever the
- * current thread ends or sets this pointer again.
- *
- * Sets the pointer keyed to @private_key for the current thread and
- * the function @notify to be called with that pointer (%NULL or
- * non-%NULL), whenever the pointer is set again or whenever the
- * current thread ends.
- *
- * This function works even if g_thread_init() has not yet been called.
- * If g_thread_init() is called later, the @data keyed to @private_key
- * will be inherited only by the main thread, i.e. the one that called
- * g_thread_init().
- *
- * <note><para>@notify is used quite differently from @destructor in
- * g_private_new().</para></note>
- **/
-void
-g_static_private_set (GStaticPrivate *private_key,
- gpointer data,
- GDestroyNotify notify)
+ * Since: 2.32
+ */
+GThread *
+g_thread_new (const gchar *name,
+ GThreadFunc func,
+ gpointer data)
{
- GRealThread *self = (GRealThread*) g_thread_self ();
- GArray *array;
- static guint next_index = 0;
- GStaticPrivateNode *node;
-
- array = self->private_data;
- if (!array)
- {
- array = g_array_new (FALSE, TRUE, sizeof (GStaticPrivateNode));
- self->private_data = array;
- }
-
- if (!private_key->index)
- {
- G_LOCK (g_thread);
-
- if (!private_key->index)
- {
- if (g_thread_free_indeces)
- {
- private_key->index =
- GPOINTER_TO_UINT (g_thread_free_indeces->data);
- g_thread_free_indeces =
- g_slist_delete_link (g_thread_free_indeces,
- g_thread_free_indeces);
- }
- else
- private_key->index = ++next_index;
- }
-
- G_UNLOCK (g_thread);
- }
-
- if (private_key->index > array->len)
- g_array_set_size (array, private_key->index);
+ GError *error = NULL;
+ GThread *thread;
- node = &g_array_index (array, GStaticPrivateNode, private_key->index - 1);
- if (node->destroy)
- {
- gpointer ddata = node->data;
- GDestroyNotify ddestroy = node->destroy;
+ thread = g_thread_new_internal (name, g_thread_proxy, func, data, 0, &error);
- node->data = data;
- node->destroy = notify;
+ if G_UNLIKELY (thread == NULL)
+ g_error ("creating thread '%s': %s", name ? name : "", error->message);
- ddestroy (ddata);
- }
- else
- {
- node->data = data;
- node->destroy = notify;
- }
+ return thread;
}
/**
- * g_static_private_free:
- * @private_key: a #GStaticPrivate to be freed.
+ * g_thread_try_new:
+ * @name: a name for the new thread
+ * @func: a function to execute in the new thread
+ * @data: an argument to supply to the new thread
+ * @error: return location for error, or %NULL
*
- * Releases all resources allocated to @private_key.
+ * This function is the same as g_thread_new() except that
+ * it allows for the possibility of failure.
*
- * You don't have to call this functions for a #GStaticPrivate with an
- * unbounded lifetime, i.e. objects declared 'static', but if you have
- * a #GStaticPrivate as a member of a structure and the structure is
- * freed, you should also free the #GStaticPrivate.
- **/
-void
-g_static_private_free (GStaticPrivate *private_key)
-{
- guint idx = private_key->index;
- GRealThread *thread;
-
- if (!idx)
- return;
-
- private_key->index = 0;
-
- G_LOCK (g_thread);
-
- thread = g_thread_all_threads;
- while (thread)
- {
- GArray *array = thread->private_data;
- thread = thread->next;
-
- if (array && idx <= array->len)
- {
- GStaticPrivateNode *node = &g_array_index (array,
- GStaticPrivateNode,
- idx - 1);
- gpointer ddata = node->data;
- GDestroyNotify ddestroy = node->destroy;
-
- node->data = NULL;
- node->destroy = NULL;
-
- if (ddestroy)
- {
- G_UNLOCK (g_thread);
- ddestroy (ddata);
- G_LOCK (g_thread);
- }
- }
- }
- g_thread_free_indeces = g_slist_prepend (g_thread_free_indeces,
- GUINT_TO_POINTER (idx));
- G_UNLOCK (g_thread);
-}
-
-/* GThread Extra Functions {{{1 ------------------------------------------- */
-static void
-g_thread_cleanup (gpointer data)
-{
- if (data)
- {
- GRealThread* thread = data;
- if (thread->private_data)
- {
- GArray* array = thread->private_data;
- guint i;
-
- for (i = 0; i < array->len; i++ )
- {
- GStaticPrivateNode *node =
- &g_array_index (array, GStaticPrivateNode, i);
- if (node->destroy)
- node->destroy (node->data);
- }
- g_array_free (array, TRUE);
- }
-
- /* We only free the thread structure, if it isn't joinable. If
- it is, the structure is freed in g_thread_join */
- if (!thread->thread.joinable)
- {
- GRealThread *t, *p;
-
- G_LOCK (g_thread);
- for (t = g_thread_all_threads, p = NULL; t; p = t, t = t->next)
- {
- if (t == thread)
- {
- if (p)
- p->next = t->next;
- else
- g_thread_all_threads = t->next;
- break;
- }
- }
- G_UNLOCK (g_thread);
-
- /* Just to make sure, this isn't used any more */
- g_system_thread_assign (thread->system_thread, zero_thread);
- g_free (thread);
- }
- }
-}
-
-static void
-g_thread_fail (void)
-{
- g_error ("The thread system is not yet initialized.");
-}
-
-#define G_NSEC_PER_SEC 1000000000
-
-static guint64
-gettime (void)
+ * If a thread can not be created (due to resource limits),
+ * @error is set and %NULL is returned.
+ *
+ * Returns: the new #GThread, or %NULL if an error occurred
+ *
+ * Since: 2.32
+ */
+GThread *
+g_thread_try_new (const gchar *name,
+ GThreadFunc func,
+ gpointer data,
+ GError **error)
{
-#ifdef G_OS_WIN32
- guint64 v;
-
- /* Returns 100s of nanoseconds since start of 1601 */
- GetSystemTimeAsFileTime ((FILETIME *)&v);
-
- /* Offset to Unix epoch */
- v -= G_GINT64_CONSTANT (116444736000000000);
- /* Convert to nanoseconds */
- v *= 100;
-
- return v;
-#else
- struct timeval tv;
-
- gettimeofday (&tv, NULL);
-
- return (guint64) tv.tv_sec * G_NSEC_PER_SEC + tv.tv_usec * (G_NSEC_PER_SEC / G_USEC_PER_SEC);
-#endif
+ return g_thread_new_internal (name, g_thread_proxy, func, data, 0, error);
}
-static gpointer
-g_thread_create_proxy (gpointer data)
+GThread *
+g_thread_new_internal (const gchar *name,
+ GThreadFunc proxy,
+ GThreadFunc func,
+ gpointer data,
+ gsize stack_size,
+ GError **error)
{
- GRealThread* thread = data;
-
- g_assert (data);
-
- /* This has to happen before G_LOCK, as that might call g_thread_self */
- g_private_set (g_thread_specific_private, data);
-
- /* the lock makes sure, that thread->system_thread is written,
- before thread->thread.func is called. See g_thread_create. */
- G_LOCK (g_thread);
- G_UNLOCK (g_thread);
-
- thread->retval = thread->thread.func (thread->thread.data);
-
- return NULL;
-}
+ GRealThread *thread;
-/**
- * g_thread_create_full:
- * @func: a function to execute in the new thread.
- * @data: an argument to supply to the new thread.
- * @stack_size: a stack size for the new thread.
- * @joinable: should this thread be joinable?
- * @bound: should this thread be bound to a system thread?
- * @priority: a priority for the thread.
- * @error: return location for error.
- * @Returns: the new #GThread on success.
- *
- * This function creates a new thread with the priority @priority. If
- * the underlying thread implementation supports it, the thread gets a
- * stack size of @stack_size or the default value for the current
- * platform, if @stack_size is 0.
- *
- * If @joinable is %TRUE, you can wait for this threads termination
- * calling g_thread_join(). Otherwise the thread will just disappear
- * when it terminates. If @bound is %TRUE, this thread will be
- * scheduled in the system scope, otherwise the implementation is free
- * to do scheduling in the process scope. The first variant is more
- * expensive resource-wise, but generally faster. On some systems (e.g.
- * Linux) all threads are bound.
- *
- * The new thread executes the function @func with the argument @data.
- * If the thread was created successfully, it is returned.
- *
- * @error can be %NULL to ignore errors, or non-%NULL to report errors.
- * The error is set, if and only if the function returns %NULL.
- *
- * <note><para>It is not guaranteed that threads with different priorities
- * really behave accordingly. On some systems (e.g. Linux) there are no
- * thread priorities. On other systems (e.g. Solaris) there doesn't
- * seem to be different scheduling for different priorities. All in all
- * try to avoid being dependent on priorities. Use
- * %G_THREAD_PRIORITY_NORMAL here as a default.</para></note>
- *
- * <note><para>Only use g_thread_create_full() if you really can't use
- * g_thread_create() instead. g_thread_create() does not take
- * @stack_size, @bound, and @priority as arguments, as they should only
- * be used in cases in which it is unavoidable.</para></note>
- **/
-GThread*
-g_thread_create_full (GThreadFunc func,
- gpointer data,
- gulong stack_size,
- gboolean joinable,
- gboolean bound,
- GThreadPriority priority,
- GError **error)
-{
- GRealThread* result;
- GError *local_error = NULL;
- g_return_val_if_fail (func, NULL);
- g_return_val_if_fail (priority >= G_THREAD_PRIORITY_LOW, NULL);
- g_return_val_if_fail (priority <= G_THREAD_PRIORITY_URGENT, NULL);
-
- result = g_new0 (GRealThread, 1);
-
- result->thread.joinable = joinable;
- result->thread.priority = priority;
- result->thread.func = func;
- result->thread.data = data;
- result->private_data = NULL;
- G_LOCK (g_thread);
- G_THREAD_UF (thread_create, (g_thread_create_proxy, result,
- stack_size, joinable, bound, priority,
- &result->system_thread, &local_error));
- if (!local_error)
- {
- result->next = g_thread_all_threads;
- g_thread_all_threads = result;
- }
- G_UNLOCK (g_thread);
+ g_return_val_if_fail (func != NULL, NULL);
- if (local_error)
+ G_LOCK (g_thread_new);
+ thread = g_system_thread_new (proxy, stack_size, error);
+ if (thread)
{
- g_propagate_error (error, local_error);
- g_free (result);
- return NULL;
+ thread->ref_count = 2;
+ thread->ours = TRUE;
+ thread->thread.joinable = TRUE;
+ thread->thread.func = func;
+ thread->thread.data = data;
+ thread->name = g_strdup (name);
}
+ G_UNLOCK (g_thread_new);
- return (GThread*) result;
+ return (GThread*) thread;
}
/**
* g_thread_exit:
- * @retval: the return value of this thread.
+ * @retval: the return value of this thread
*
- * Exits the current thread. If another thread is waiting for that
- * thread using g_thread_join() and the current thread is joinable, the
- * waiting thread will be woken up and get @retval as the return value
- * of g_thread_join(). If the current thread is not joinable, @retval
- * is ignored. Calling
+ * Terminates the current thread.
*
- * <informalexample>
- * <programlisting>
- * g_thread_exit (retval);
- * </programlisting>
- * </informalexample>
+ * If another thread is waiting for us using g_thread_join() then the
+ * waiting thread will be woken up and get @retval as the return value
+ * of g_thread_join().
*
- * is equivalent to returning @retval from the function @func, as given
- * to g_thread_create().
+ * Calling <literal>g_thread_exit (retval)</literal> is equivalent to
+ * returning @retval from the function @func, as given to g_thread_new().
*
- * <note><para>Never call g_thread_exit() from within a thread of a
- * #GThreadPool, as that will mess up the bookkeeping and lead to funny
- * and unwanted results.</para></note>
- **/
+ * <note><para>
+ * You must only call g_thread_exit() from a thread that you created
+ * yourself with g_thread_new() or related APIs. You must not call
+ * this function from a thread created with another threading library
+ * or or from within a #GThreadPool.
+ * </para></note>
+ */
void
g_thread_exit (gpointer retval)
{
GRealThread* real = (GRealThread*) g_thread_self ();
+
+ if G_UNLIKELY (!real->ours)
+ g_error ("attempt to g_thread_exit() a thread not created by GLib");
+
real->retval = retval;
- G_THREAD_CF (thread_exit, (void)0, ());
+
+ g_system_thread_exit ();
}
/**
* g_thread_join:
- * @thread: a #GThread to be waited for.
- * @Returns: the return value of the thread.
- *
- * Waits until @thread finishes, i.e. the function @func, as given to
- * g_thread_create(), returns or g_thread_exit() is called by @thread.
- * All resources of @thread including the #GThread struct are released.
- * @thread must have been created with @joinable=%TRUE in
- * g_thread_create(). The value returned by @func or given to
- * g_thread_exit() by @thread is returned by this function.
- **/
+ * @thread: a #GThread
+ *
+ * Waits until @thread finishes, i.e. the function @func, as
+ * given to g_thread_new(), returns or g_thread_exit() is called.
+ * If @thread has already terminated, then g_thread_join()
+ * returns immediately.
+ *
+ * Any thread can wait for any other thread by calling g_thread_join(),
+ * not just its 'creator'. Calling g_thread_join() from multiple threads
+ * for the same @thread leads to undefined behaviour.
+ *
+ * The value returned by @func or given to g_thread_exit() is
+ * returned by this function.
+ *
+ * g_thread_join() consumes the reference to the passed-in @thread.
+ * This will usually cause the #GThread struct and associated resources
+ * to be freed. Use g_thread_ref() to obtain an extra reference if you
+ * want to keep the GThread alive beyond the g_thread_join() call.
+ *
+ * Returns: the return value of the thread
+ */
gpointer
-g_thread_join (GThread* thread)
+g_thread_join (GThread *thread)
{
- GRealThread* real = (GRealThread*) thread;
- GRealThread *p, *t;
+ GRealThread *real = (GRealThread*) thread;
gpointer retval;
g_return_val_if_fail (thread, NULL);
- g_return_val_if_fail (thread->joinable, NULL);
- g_return_val_if_fail (!g_system_thread_equal (real->system_thread,
- zero_thread), NULL);
+ g_return_val_if_fail (real->ours, NULL);
- G_THREAD_UF (thread_join, (&real->system_thread));
+ g_system_thread_wait (real);
retval = real->retval;
- G_LOCK (g_thread);
- for (t = g_thread_all_threads, p = NULL; t; p = t, t = t->next)
- {
- if (t == (GRealThread*) thread)
- {
- if (p)
- p->next = t->next;
- else
- g_thread_all_threads = t->next;
- break;
- }
- }
- G_UNLOCK (g_thread);
-
/* Just to make sure, this isn't used any more */
thread->joinable = 0;
- g_system_thread_assign (real->system_thread, zero_thread);
-
- /* the thread structure for non-joinable threads is freed upon
- thread end. We free the memory here. This will leave a loose end,
- if a joinable thread is not joined. */
- g_free (thread);
+ g_thread_unref (thread);
return retval;
}
/**
- * g_thread_set_priority:
- * @thread: a #GThread.
- * @priority: a new priority for @thread.
+ * g_thread_self:
*
- * Changes the priority of @thread to @priority.
+ * This functions returns the #GThread corresponding to the
+ * current thread. Note that this function does not increase
+ * the reference count of the returned struct.
*
- * <note><para>It is not guaranteed that threads with different
- * priorities really behave accordingly. On some systems (e.g. Linux)
- * there are no thread priorities. On other systems (e.g. Solaris) there
- * doesn't seem to be different scheduling for different priorities. All
- * in all try to avoid being dependent on priorities.</para></note>
- **/
-void
-g_thread_set_priority (GThread* thread,
- GThreadPriority priority)
-{
- GRealThread* real = (GRealThread*) thread;
-
- g_return_if_fail (thread);
- g_return_if_fail (!g_system_thread_equal (real->system_thread, zero_thread));
- g_return_if_fail (priority >= G_THREAD_PRIORITY_LOW);
- g_return_if_fail (priority <= G_THREAD_PRIORITY_URGENT);
-
- thread->priority = priority;
-
- G_THREAD_CF (thread_set_priority, (void)0,
- (&real->system_thread, priority));
-}
-
-/**
- * g_thread_self:
- * @Returns: the current thread.
+ * This function will return a #GThread even for threads that
+ * were not created by GLib (i.e. those created by other threading
+ * APIs). This may be useful for thread identification purposes
+ * (i.e. comparisons) but you must not use GLib functions (such
+ * as g_thread_join()) on these threads.
*
- * This functions returns the #GThread corresponding to the calling
- * thread.
- **/
+ * Returns: the #GThread representing the current thread
+ */
GThread*
g_thread_self (void)
{
- GRealThread* thread = g_private_get (g_thread_specific_private);
+ GRealThread* thread = g_private_get (&g_thread_specific_private);
if (!thread)
{
- /* If no thread data is available, provide and set one. This
- can happen for the main thread and for threads, that are not
- created by GLib. */
- thread = g_new0 (GRealThread, 1);
- thread->thread.joinable = FALSE; /* This is a save guess */
- thread->thread.priority = G_THREAD_PRIORITY_NORMAL; /* This is
- just a guess */
- thread->thread.func = NULL;
- thread->thread.data = NULL;
- thread->private_data = NULL;
-
- if (g_thread_supported ())
- G_THREAD_UF (thread_self, (&thread->system_thread));
-
- g_private_set (g_thread_specific_private, thread);
-
- G_LOCK (g_thread);
- thread->next = g_thread_all_threads;
- g_thread_all_threads = thread;
- G_UNLOCK (g_thread);
+ /* If no thread data is available, provide and set one.
+ * This can happen for the main thread and for threads
+ * that are not created by GLib.
+ */
+ thread = g_slice_new0 (GRealThread);
+ thread->ref_count = 1;
+
+ g_private_set (&g_thread_specific_private, thread);
}
- return (GThread*)thread;
+ return (GThread*) thread;
}
-/* GStaticRWLock {{{1 ----------------------------------------------------- */
-
-/**
- * GStaticRWLock:
- *
- * The #GStaticRWLock struct represents a read-write lock. A read-write
- * lock can be used for protecting data that some portions of code only
- * read from, while others also write. In such situations it is
- * desirable that several readers can read at once, whereas of course
- * only one writer may write at a time. Take a look at the following
- * example:
- *
- * <example>
- * <title>An array with access functions</title>
- * <programlisting>
- * GStaticRWLock rwlock = G_STATIC_RW_LOCK_INIT;
- * GPtrArray *array;
- *
- * gpointer
- * my_array_get (guint index)
- * {
- * gpointer retval = NULL;
- *
- * if (!array)
- * return NULL;
- *
- * g_static_rw_lock_reader_lock (&rwlock);
- * if (index < array->len)
- * retval = g_ptr_array_index (array, index);
- * g_static_rw_lock_reader_unlock (&rwlock);
- *
- * return retval;
- * }
- *
- * void
- * my_array_set (guint index, gpointer data)
- * {
- * g_static_rw_lock_writer_lock (&rwlock);
- *
- * if (!array)
- * array = g_ptr_array_new (<!-- -->);
- *
- * if (index >= array->len)
- * g_ptr_array_set_size (array, index+1);
- * g_ptr_array_index (array, index) = data;
- *
- * g_static_rw_lock_writer_unlock (&rwlock);
- * }
- * </programlisting>
- * </example>
- *
- * This example shows an array which can be accessed by many readers
- * (the <function>my_array_get()</function> function) simultaneously,
- * whereas the writers (the <function>my_array_set()</function>
- * function) will only be allowed once at a time and only if no readers
- * currently access the array. This is because of the potentially
- * dangerous resizing of the array. Using these functions is fully
- * multi-thread safe now.
- *
- * Most of the time, writers should have precedence over readers. That
- * means, for this implementation, that as soon as a writer wants to
- * lock the data, no other reader is allowed to lock the data, whereas,
- * of course, the readers that already have locked the data are allowed
- * to finish their operation. As soon as the last reader unlocks the
- * data, the writer will lock it.
- *
- * Even though #GStaticRWLock is not opaque, it should only be used
- * with the following functions.
- *
- * All of the <function>g_static_rw_lock_*</function> functions can be
- * used even if g_thread_init() has not been called. Then they do
- * nothing, apart from <function>g_static_rw_lock_*_trylock</function>,
- * which does nothing but returning %TRUE.
- *
- * <note><para>A read-write lock has a higher overhead than a mutex. For
- * example, both g_static_rw_lock_reader_lock() and
- * g_static_rw_lock_reader_unlock() have to lock and unlock a
- * #GStaticMutex, so it takes at least twice the time to lock and unlock
- * a #GStaticRWLock that it does to lock and unlock a #GStaticMutex. So
- * only data structures that are accessed by multiple readers, and which
- * keep the lock for a considerable time justify a #GStaticRWLock. The
- * above example most probably would fare better with a
- * #GStaticMutex.</para></note>
- **/
-
-/**
- * G_STATIC_RW_LOCK_INIT:
- *
- * A #GStaticRWLock must be initialized with this macro before it can
- * be used. This macro can used be to initialize a variable, but it
- * cannot be assigned to a variable. In that case you have to use
- * g_static_rw_lock_init().
- *
- * <informalexample>
- * <programlisting>
- * GStaticRWLock my_lock = G_STATIC_RW_LOCK_INIT;
- * </programlisting>
- * </informalexample>
- **/
-
-/**
- * g_static_rw_lock_init:
- * @lock: a #GStaticRWLock to be initialized.
- *
- * A #GStaticRWLock must be initialized with this function before it
- * can be used. Alternatively you can initialize it with
- * #G_STATIC_RW_LOCK_INIT.
- **/
-void
-g_static_rw_lock_init (GStaticRWLock* lock)
-{
- static const GStaticRWLock init_lock = G_STATIC_RW_LOCK_INIT;
-
- g_return_if_fail (lock);
-
- *lock = init_lock;
-}
-
-inline static void
-g_static_rw_lock_wait (GCond** cond, GStaticMutex* mutex)
-{
- if (!*cond)
- *cond = g_cond_new ();
- g_cond_wait (*cond, g_static_mutex_get_mutex (mutex));
-}
-
-inline static void
-g_static_rw_lock_signal (GStaticRWLock* lock)
-{
- if (lock->want_to_write && lock->write_cond)
- g_cond_signal (lock->write_cond);
- else if (lock->want_to_read && lock->read_cond)
- g_cond_broadcast (lock->read_cond);
-}
-
-/**
- * g_static_rw_lock_reader_lock:
- * @lock: a #GStaticRWLock to lock for reading.
- *
- * Locks @lock for reading. There may be unlimited concurrent locks for
- * reading of a #GStaticRWLock at the same time. If @lock is already
- * locked for writing by another thread or if another thread is already
- * waiting to lock @lock for writing, this function will block until
- * @lock is unlocked by the other writing thread and no other writing
- * threads want to lock @lock. This lock has to be unlocked by
- * g_static_rw_lock_reader_unlock().
- *
- * #GStaticRWLock is not recursive. It might seem to be possible to
- * recursively lock for reading, but that can result in a deadlock, due
- * to writer preference.
- **/
-void
-g_static_rw_lock_reader_lock (GStaticRWLock* lock)
-{
- g_return_if_fail (lock);
-
- if (!g_threads_got_initialized)
- return;
-
- g_static_mutex_lock (&lock->mutex);
- lock->want_to_read++;
- while (lock->have_writer || lock->want_to_write)
- g_static_rw_lock_wait (&lock->read_cond, &lock->mutex);
- lock->want_to_read--;
- lock->read_counter++;
- g_static_mutex_unlock (&lock->mutex);
-}
-
-/**
- * g_static_rw_lock_reader_trylock:
- * @lock: a #GStaticRWLock to lock for reading.
- * @Returns: %TRUE, if @lock could be locked for reading.
- *
- * Tries to lock @lock for reading. If @lock is already locked for
- * writing by another thread or if another thread is already waiting to
- * lock @lock for writing, immediately returns %FALSE. Otherwise locks
- * @lock for reading and returns %TRUE. This lock has to be unlocked by
- * g_static_rw_lock_reader_unlock().
- **/
-gboolean
-g_static_rw_lock_reader_trylock (GStaticRWLock* lock)
-{
- gboolean ret_val = FALSE;
-
- g_return_val_if_fail (lock, FALSE);
-
- if (!g_threads_got_initialized)
- return TRUE;
-
- g_static_mutex_lock (&lock->mutex);
- if (!lock->have_writer && !lock->want_to_write)
- {
- lock->read_counter++;
- ret_val = TRUE;
- }
- g_static_mutex_unlock (&lock->mutex);
- return ret_val;
-}
-
-/**
- * g_static_rw_lock_reader_unlock:
- * @lock: a #GStaticRWLock to unlock after reading.
- *
- * Unlocks @lock. If a thread waits to lock @lock for writing and all
- * locks for reading have been unlocked, the waiting thread is woken up
- * and can lock @lock for writing.
- **/
-void
-g_static_rw_lock_reader_unlock (GStaticRWLock* lock)
-{
- g_return_if_fail (lock);
-
- if (!g_threads_got_initialized)
- return;
-
- g_static_mutex_lock (&lock->mutex);
- lock->read_counter--;
- if (lock->read_counter == 0)
- g_static_rw_lock_signal (lock);
- g_static_mutex_unlock (&lock->mutex);
-}
-
-/**
- * g_static_rw_lock_writer_lock:
- * @lock: a #GStaticRWLock to lock for writing.
- *
- * Locks @lock for writing. If @lock is already locked for writing or
- * reading by other threads, this function will block until @lock is
- * completely unlocked and then lock @lock for writing. While this
- * functions waits to lock @lock, no other thread can lock @lock for
- * reading. When @lock is locked for writing, no other thread can lock
- * @lock (neither for reading nor writing). This lock has to be
- * unlocked by g_static_rw_lock_writer_unlock().
- **/
-void
-g_static_rw_lock_writer_lock (GStaticRWLock* lock)
-{
- g_return_if_fail (lock);
-
- if (!g_threads_got_initialized)
- return;
-
- g_static_mutex_lock (&lock->mutex);
- lock->want_to_write++;
- while (lock->have_writer || lock->read_counter)
- g_static_rw_lock_wait (&lock->write_cond, &lock->mutex);
- lock->want_to_write--;
- lock->have_writer = TRUE;
- g_static_mutex_unlock (&lock->mutex);
-}
-
-/**
- * g_static_rw_lock_writer_trylock:
- * @lock: a #GStaticRWLock to lock for writing.
- * @Returns: %TRUE, if @lock could be locked for writing.
- *
- * Tries to lock @lock for writing. If @lock is already locked (for
- * either reading or writing) by another thread, it immediately returns
- * %FALSE. Otherwise it locks @lock for writing and returns %TRUE. This
- * lock has to be unlocked by g_static_rw_lock_writer_unlock().
- **/
-gboolean
-g_static_rw_lock_writer_trylock (GStaticRWLock* lock)
-{
- gboolean ret_val = FALSE;
-
- g_return_val_if_fail (lock, FALSE);
-
- if (!g_threads_got_initialized)
- return TRUE;
-
- g_static_mutex_lock (&lock->mutex);
- if (!lock->have_writer && !lock->read_counter)
- {
- lock->have_writer = TRUE;
- ret_val = TRUE;
- }
- g_static_mutex_unlock (&lock->mutex);
- return ret_val;
-}
-
-/**
- * g_static_rw_lock_writer_unlock:
- * @lock: a #GStaticRWLock to unlock after writing.
- *
- * Unlocks @lock. If a thread is waiting to lock @lock for writing and
- * all locks for reading have been unlocked, the waiting thread is
- * woken up and can lock @lock for writing. If no thread is waiting to
- * lock @lock for writing, and some thread or threads are waiting to
- * lock @lock for reading, the waiting threads are woken up and can
- * lock @lock for reading.
- **/
-void
-g_static_rw_lock_writer_unlock (GStaticRWLock* lock)
-{
- g_return_if_fail (lock);
-
- if (!g_threads_got_initialized)
- return;
-
- g_static_mutex_lock (&lock->mutex);
- lock->have_writer = FALSE;
- g_static_rw_lock_signal (lock);
- g_static_mutex_unlock (&lock->mutex);
-}
-
-/**
- * g_static_rw_lock_free:
- * @lock: a #GStaticRWLock to be freed.
- *
- * Releases all resources allocated to @lock.
- *
- * You don't have to call this functions for a #GStaticRWLock with an
- * unbounded lifetime, i.e. objects declared 'static', but if you have
- * a #GStaticRWLock as a member of a structure, and the structure is
- * freed, you should also free the #GStaticRWLock.
- **/
-void
-g_static_rw_lock_free (GStaticRWLock* lock)
-{
- g_return_if_fail (lock);
-
- if (lock->read_cond)
- {
- g_cond_free (lock->read_cond);
- lock->read_cond = NULL;
- }
- if (lock->write_cond)
- {
- g_cond_free (lock->write_cond);
- lock->write_cond = NULL;
- }
- g_static_mutex_free (&lock->mutex);
-}
-
-/* Unsorted {{{1 ---------------------------------------------------------- */
-
-/**
- * g_thread_foreach
- * @thread_func: function to call for all GThread structures
- * @user_data: second argument to @thread_func
- *
- * Call @thread_func on all existing #GThread structures. Note that
- * threads may decide to exit while @thread_func is running, so
- * without intimate knowledge about the lifetime of foreign threads,
- * @thread_func shouldn't access the GThread* pointer passed in as
- * first argument. However, @thread_func will not be called for threads
- * which are known to have exited already.
- *
- * Due to thread lifetime checks, this function has an execution complexity
- * which is quadratic in the number of existing threads.
- *
- * Since: 2.10
- */
-void
-g_thread_foreach (GFunc thread_func,
- gpointer user_data)
-{
- GSList *slist = NULL;
- GRealThread *thread;
- g_return_if_fail (thread_func != NULL);
- /* snapshot the list of threads for iteration */
- G_LOCK (g_thread);
- for (thread = g_thread_all_threads; thread; thread = thread->next)
- slist = g_slist_prepend (slist, thread);
- G_UNLOCK (g_thread);
- /* walk the list, skipping non-existant threads */
- while (slist)
- {
- GSList *node = slist;
- slist = node->next;
- /* check whether the current thread still exists */
- G_LOCK (g_thread);
- for (thread = g_thread_all_threads; thread; thread = thread->next)
- if (thread == node->data)
- break;
- G_UNLOCK (g_thread);
- if (thread)
- thread_func (thread, user_data);
- g_slist_free_1 (node);
- }
-}
-
-/**
- * g_thread_get_initialized
- *
- * Indicates if g_thread_init() has been called.
- *
- * Returns: %TRUE if threads have been initialized.
- *
- * Since: 2.20
- */
-gboolean
-g_thread_get_initialized ()
-{
- return g_thread_supported ();
-}
-
-#define __G_THREAD_C__
-#include "galiasdef.c"
-
+/* Epilogue {{{1 */
+/* vim: set foldmethod=marker: */
projects / platform / upstream / glib2.0.git / blobdiff