-/* -*- mode: C; c-file-style: "gnu" -*- */
+/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
/* dbus-threads.h D-Bus threads handling
*
* Copyright (C) 2002 Red Hat Inc.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*
*/
#if !defined (DBUS_INSIDE_DBUS_H) && !defined (DBUS_COMPILATION)
/** Deprecated, provide DBusRecursiveMutexUnlockFunction instead. Return value is unlock success, but gets ignored in practice. */
typedef dbus_bool_t (* DBusMutexUnlockFunction) (DBusMutex *mutex);
-/** Creates a new recursively-lockable mutex, or returns #NULL if not enough memory.
- * Found in #DBusThreadFunctions. Do not just use PTHREAD_MUTEX_RECURSIVE for this, because
- * it does not save/restore the recursion count when waiting on a condition. libdbus
- * requires the Java-style behavior where the mutex is fully unlocked to wait on
- * a condition.
+/** Creates a new recursively-lockable mutex, or returns #NULL if not
+ * enough memory. Can only fail due to lack of memory. Found in
+ * #DBusThreadFunctions. Do not just use PTHREAD_MUTEX_RECURSIVE for
+ * this, because it does not save/restore the recursion count when
+ * waiting on a condition. libdbus requires the Java-style behavior
+ * where the mutex is fully unlocked to wait on a condition.
*/
typedef DBusMutex* (* DBusRecursiveMutexNewFunction) (void);
/** Frees a recursively-lockable mutex. Found in #DBusThreadFunctions.
*/
typedef void (* DBusRecursiveMutexFreeFunction) (DBusMutex *mutex);
/** Locks a recursively-lockable mutex. Found in #DBusThreadFunctions.
+ * Can only fail due to lack of memory.
*/
typedef void (* DBusRecursiveMutexLockFunction) (DBusMutex *mutex);
/** Unlocks a recursively-lockable mutex. Found in #DBusThreadFunctions.
+ * Can only fail due to lack of memory.
*/
typedef void (* DBusRecursiveMutexUnlockFunction) (DBusMutex *mutex);
/** Creates a new condition variable. Found in #DBusThreadFunctions.
+ * Can only fail (returning #NULL) due to lack of memory.
*/
typedef DBusCondVar* (* DBusCondVarNewFunction) (void);
/** Frees a condition variable. Found in #DBusThreadFunctions.
* condition variables (does not save/restore the recursion count) so
* don't try using simply pthread_cond_wait() and a
* PTHREAD_MUTEX_RECURSIVE to implement this, it won't work right.
+ *
+ * Has no error conditions. Must succeed if it returns.
*/
typedef void (* DBusCondVarWaitFunction) (DBusCondVar *cond,
DBusMutex *mutex);
/** Waits on a condition variable with a timeout. Found in
* #DBusThreadFunctions. Returns #TRUE if the wait did not
* time out, and #FALSE if it did.
+ *
+ * Has no error conditions. Must succeed if it returns.
*/
typedef dbus_bool_t (* DBusCondVarWaitTimeoutFunction) (DBusCondVar *cond,
DBusMutex *mutex,
int timeout_milliseconds);
/** Wakes one waiting thread on a condition variable. Found in #DBusThreadFunctions.
+ *
+ * Has no error conditions. Must succeed if it returns.
*/
typedef void (* DBusCondVarWakeOneFunction) (DBusCondVar *cond);
+
/** Wakes all waiting threads on a condition variable. Found in #DBusThreadFunctions.
+ *
+ * Has no error conditions. Must succeed if it returns.
*/
typedef void (* DBusCondVarWakeAllFunction) (DBusCondVar *cond);
DBUS_THREAD_FUNCTIONS_RECURSIVE_MUTEX_FREE_MASK = 1 << 11,
DBUS_THREAD_FUNCTIONS_RECURSIVE_MUTEX_LOCK_MASK = 1 << 12,
DBUS_THREAD_FUNCTIONS_RECURSIVE_MUTEX_UNLOCK_MASK = 1 << 13,
- DBUS_THREAD_FUNCTIONS_ALL_MASK = (1 << 13) - 1
+ DBUS_THREAD_FUNCTIONS_ALL_MASK = (1 << 14) - 1
} DBusThreadFunctionsMask;
/**
* Functions that must be implemented to make the D-Bus library
- * thread-aware. The recursive mutex functions should be specified
- * rather than the old, deprecated nonrecursive ones.
- *
- * The condition variable functions have to work with recursive
- * mutexes if you provide those, or with nonrecursive mutexes if you
- * provide those.
+ * thread-aware.
*
- * If implementing threads using pthreads, be aware that
- * PTHREAD_MUTEX_RECURSIVE is broken in combination with condition
- * variables. libdbus relies on the Java-style behavior that when
- * waiting on a condition, the recursion count is saved and restored,
- * and the mutex is completely unlocked, not just decremented one
- * level of recursion.
+ * If you supply both recursive and non-recursive mutexes,
+ * libdbus will use the non-recursive version for condition variables,
+ * and the recursive version in other contexts.
*
- * Thus with pthreads you probably have to roll your own emulated
- * recursive mutexes, you can't use PTHREAD_MUTEX_RECURSIVE. This is
- * what dbus_threads_init_default() does on platforms that use
- * pthreads.
+ * The condition variable functions have to work with nonrecursive
+ * mutexes if you provide those, or with recursive mutexes if you
+ * don't.
*/
typedef struct
{
} DBusThreadFunctions;
+DBUS_EXPORT
dbus_bool_t dbus_threads_init (const DBusThreadFunctions *functions);
+DBUS_EXPORT
dbus_bool_t dbus_threads_init_default (void);
/** @} */
projects / platform / upstream / dbus.git / blobdiff