X-Git-Url: http://review.tizen.org/git/?a=blobdiff_plain;f=glib%2Fgthread-posix.c;h=6f5a60664b15830ddbcb6446ea364f3dc347b2da;hb=9f5afe3966d31ef6f1e880d950206a0325e6c777;hp=c4fd6f2cbf71a719c56e20bbb672007a37d28032;hpb=3d4102776e59e748ee8b6e4d456a06a33593f308;p=platform%2Fupstream%2Fglib.git

diff --git a/glib/gthread-posix.c b/glib/gthread-posix.c
index c4fd6f2..6f5a606 100644
--- a/glib/gthread-posix.c
+++ b/glib/gthread-posix.c
@@ -15,9 +15,7 @@
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public
- * License along with this library; if not, write to the
- * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
- * Boston, MA 02111-1307, USA.
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>.
  */
 
 /*
@@ -42,25 +40,97 @@
 #include "config.h"
 
 #include "gthread.h"
+
 #include "gthreadprivate.h"
+#include "gslice.h"
+#include "gmessages.h"
+#include "gstrfuncs.h"
+#include "gmain.h"
 
-#include <pthread.h>
 #include <stdlib.h>
+#include <stdio.h>
 #include <string.h>
 #include <errno.h>
-#include <stdio.h>
+#include <pthread.h>
+
+#include <sys/time.h>
+#include <unistd.h>
+
+#ifdef HAVE_SCHED_H
+#include <sched.h>
+#endif
+#ifdef HAVE_SYS_PRCTL_H
+#include <sys/prctl.h>
+#endif
+#ifdef G_OS_WIN32
+#include <windows.h>
+#endif
 
 static void
 g_thread_abort (gint         status,
                 const gchar *function)
 {
   fprintf (stderr, "GLib (gthread-posix.c): Unexpected error from C library during '%s': %s.  Aborting.\n",
-           strerror (status), function);
+           function, strerror (status));
   abort ();
 }
 
 /* {{{1 GMutex */
 
+static pthread_mutex_t *
+g_mutex_impl_new (void)
+{
+  pthread_mutexattr_t *pattr = NULL;
+  pthread_mutex_t *mutex;
+  gint status;
+#ifdef PTHREAD_ADAPTIVE_MUTEX_INITIALIZER_NP
+  pthread_mutexattr_t attr;
+#endif
+
+  mutex = malloc (sizeof (pthread_mutex_t));
+  if G_UNLIKELY (mutex == NULL)
+    g_thread_abort (errno, "malloc");
+
+#ifdef PTHREAD_ADAPTIVE_MUTEX_INITIALIZER_NP
+  pthread_mutexattr_init (&attr);
+  pthread_mutexattr_settype (&attr, PTHREAD_MUTEX_ADAPTIVE_NP);
+  pattr = &attr;
+#endif
+
+  if G_UNLIKELY ((status = pthread_mutex_init (mutex, pattr)) != 0)
+    g_thread_abort (status, "pthread_mutex_init");
+
+#ifdef PTHREAD_ADAPTIVE_MUTEX_NP
+  pthread_mutexattr_destroy (&attr);
+#endif
+
+  return mutex;
+}
+
+static void
+g_mutex_impl_free (pthread_mutex_t *mutex)
+{
+  pthread_mutex_destroy (mutex);
+  free (mutex);
+}
+
+static inline pthread_mutex_t *
+g_mutex_get_impl (GMutex *mutex)
+{
+  pthread_mutex_t *impl = g_atomic_pointer_get (&mutex->p);
+
+  if G_UNLIKELY (impl == NULL)
+    {
+      impl = g_mutex_impl_new ();
+      if (!g_atomic_pointer_compare_and_exchange (&mutex->p, NULL, impl))
+        g_mutex_impl_free (impl);
+      impl = mutex->p;
+    }
+
+  return impl;
+}
+
+
 /**
  * g_mutex_init:
  * @mutex: an uninitialized #GMutex
@@ -70,34 +140,32 @@ g_thread_abort (gint         status,
  * This function is useful to initialize a mutex that has been
  * allocated on the stack, or as part of a larger structure.
  * It is not necessary to initialize a mutex that has been
- * created with g_mutex_new(). Also see #G_MUTEX_INITIALIZER
- * for an alternative way to initialize statically allocated mutexes.
+ * statically allocated.
  *
- * |[
+ * |[<!-- language="C" --> 
  *   typedef struct {
  *     GMutex m;
- *     /&ast; ... &ast;/
+ *     ...
  *   } Blob;
  *
  * Blob *b;
  *
  * b = g_new (Blob, 1);
  * g_mutex_init (&b->m);
- * /&ast; ... &ast;/
  * ]|
  *
  * To undo the effect of g_mutex_init() when a mutex is no longer
  * needed, use g_mutex_clear().
  *
+ * Calling g_mutex_init() on an already initialized #GMutex leads
+ * to undefined behaviour.
+ *
  * Since: 2.32
  */
 void
 g_mutex_init (GMutex *mutex)
 {
-  gint status;
-
-  if G_UNLIKELY ((status = pthread_mutex_init (&mutex->impl, NULL)) != 0)
-    g_thread_abort (status, "pthread_mutex_init");
+  mutex->p = g_mutex_impl_new ();
 }
 
 /**
@@ -106,18 +174,18 @@ g_mutex_init (GMutex *mutex)
  *
  * Frees the resources allocated to a mutex with g_mutex_init().
  *
- * #GMutexes that have have been created with g_mutex_new() should
- * be freed with g_mutex_free() instead.
+ * This function should not be used with a #GMutex that has been
+ * statically allocated.
+ *
+ * Calling g_mutex_clear() on a locked mutex leads to undefined
+ * behaviour.
  *
  * Sine: 2.32
  */
 void
 g_mutex_clear (GMutex *mutex)
 {
-  gint status;
-
-  if G_UNLIKELY ((status = pthread_mutex_destroy (&mutex->impl)) != 0)
-    g_thread_abort (status, "pthread_mutex_destroy");
+  g_mutex_impl_free (mutex->p);
 }
 
 /**
@@ -128,20 +196,17 @@ g_mutex_clear (GMutex *mutex)
  * current thread will block until @mutex is unlocked by the other
  * thread.
  *
- * This function can be used even if g_thread_init() has not yet been
- * called, and, in that case, will do nothing.
- *
- * <note>#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.</note>
+ * #GMutex is neither guaranteed to be recursive nor to be
+ * non-recursive.  As such, calling g_mutex_lock() on a #GMutex that has
+ * already been locked by the same thread results in undefined behaviour
+ * (including but not limited to deadlocks).
  */
 void
 g_mutex_lock (GMutex *mutex)
 {
   gint status;
 
-  if G_UNLIKELY ((status = pthread_mutex_lock (&mutex->impl)) != 0)
+  if G_UNLIKELY ((status = pthread_mutex_lock (g_mutex_get_impl (mutex))) != 0)
     g_thread_abort (status, "pthread_mutex_lock");
 }
 
@@ -150,18 +215,18 @@ g_mutex_lock (GMutex *mutex)
  * @mutex: a #GMutex
  *
  * Unlocks @mutex. If another thread is blocked in a g_mutex_lock()
- * call for @mutex, it will be woken and can lock @mutex itself.
+ * call for @mutex, it will become unblocked and can lock @mutex itself.
  *
- * This function can be used even if g_thread_init() has not yet been
- * called, and, in that case, will do nothing.
+ * Calling g_mutex_unlock() on a mutex that is not locked by the
+ * current thread leads to undefined behaviour.
  */
 void
 g_mutex_unlock (GMutex *mutex)
 {
   gint status;
 
-  if G_UNLIKELY ((status = pthread_mutex_unlock (&mutex->impl)) != 0)
-    g_thread_abort (status, "pthread_mutex_lock");
+  if G_UNLIKELY ((status = pthread_mutex_unlock (g_mutex_get_impl (mutex))) != 0)
+    g_thread_abort (status, "pthread_mutex_unlock");
 }
 
 /**
@@ -172,23 +237,19 @@ g_mutex_unlock (GMutex *mutex)
  * 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>#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.</note>
+ * #GMutex is neither guaranteed to be recursive nor to be
+ * non-recursive.  As such, calling g_mutex_lock() on a #GMutex that has
+ * already been locked by the same thread results in undefined behaviour
+ * (including but not limited to deadlocks or arbitrary return values).
 
- * Returns: %TRUE, if @mutex could be locked
+ * Returns: %TRUE if @mutex could be locked
  */
 gboolean
 g_mutex_trylock (GMutex *mutex)
 {
   gint status;
 
-  if G_LIKELY ((status = pthread_mutex_trylock (&mutex->impl)) == 0)
+  if G_LIKELY ((status = pthread_mutex_trylock (g_mutex_get_impl (mutex))) == 0)
     return TRUE;
 
   if G_UNLIKELY (status != EBUSY)
@@ -197,100 +258,473 @@ g_mutex_trylock (GMutex *mutex)
   return FALSE;
 }
 
+/* {{{1 GRecMutex */
+
+static pthread_mutex_t *
+g_rec_mutex_impl_new (void)
+{
+  pthread_mutexattr_t attr;
+  pthread_mutex_t *mutex;
+
+  mutex = malloc (sizeof (pthread_mutex_t));
+  if G_UNLIKELY (mutex == NULL)
+    g_thread_abort (errno, "malloc");
+
+  pthread_mutexattr_init (&attr);
+  pthread_mutexattr_settype (&attr, PTHREAD_MUTEX_RECURSIVE);
+  pthread_mutex_init (mutex, &attr);
+  pthread_mutexattr_destroy (&attr);
+
+  return mutex;
+}
+
+static void
+g_rec_mutex_impl_free (pthread_mutex_t *mutex)
+{
+  pthread_mutex_destroy (mutex);
+  free (mutex);
+}
+
+static inline pthread_mutex_t *
+g_rec_mutex_get_impl (GRecMutex *rec_mutex)
+{
+  pthread_mutex_t *impl = g_atomic_pointer_get (&rec_mutex->p);
+
+  if G_UNLIKELY (impl == NULL)
+    {
+      impl = g_rec_mutex_impl_new ();
+      if (!g_atomic_pointer_compare_and_exchange (&rec_mutex->p, NULL, impl))
+        g_rec_mutex_impl_free (impl);
+      impl = rec_mutex->p;
+    }
+
+  return impl;
+}
+
+/**
+ * g_rec_mutex_init:
+ * @rec_mutex: an uninitialized #GRecMutex
+ *
+ * Initializes a #GRecMutex so that it can be used.
+ *
+ * This function is useful to initialize a recursive mutex
+ * that has been allocated on the stack, or as part of a larger
+ * structure.
+ *
+ * It is not necessary to initialise a recursive mutex that has been
+ * statically allocated.
+ *
+ * |[<!-- language="C" --> 
+ *   typedef struct {
+ *     GRecMutex m;
+ *     ...
+ *   } Blob;
+ *
+ * Blob *b;
+ *
+ * b = g_new (Blob, 1);
+ * g_rec_mutex_init (&b->m);
+ * ]|
+ *
+ * Calling g_rec_mutex_init() on an already initialized #GRecMutex
+ * leads to undefined behaviour.
+ *
+ * To undo the effect of g_rec_mutex_init() when a recursive mutex
+ * is no longer needed, use g_rec_mutex_clear().
+ *
+ * Since: 2.32
+ */
+void
+g_rec_mutex_init (GRecMutex *rec_mutex)
+{
+  rec_mutex->p = g_rec_mutex_impl_new ();
+}
+
+/**
+ * g_rec_mutex_clear:
+ * @rec_mutex: an initialized #GRecMutex
+ *
+ * Frees the resources allocated to a recursive mutex with
+ * g_rec_mutex_init().
+ *
+ * This function should not be used with a #GRecMutex that has been
+ * statically allocated.
+ *
+ * Calling g_rec_mutex_clear() on a locked recursive mutex leads
+ * to undefined behaviour.
+ *
+ * Sine: 2.32
+ */
+void
+g_rec_mutex_clear (GRecMutex *rec_mutex)
+{
+  g_rec_mutex_impl_free (rec_mutex->p);
+}
+
+/**
+ * g_rec_mutex_lock:
+ * @rec_mutex: a #GRecMutex
+ *
+ * Locks @rec_mutex. If @rec_mutex is already locked by another
+ * thread, the current thread will block until @rec_mutex is
+ * unlocked by the other thread. If @rec_mutex is already locked
+ * by the current thread, the 'lock count' of @rec_mutex is increased.
+ * The mutex will only become available again when it is unlocked
+ * as many times as it has been locked.
+ *
+ * Since: 2.32
+ */
+void
+g_rec_mutex_lock (GRecMutex *mutex)
+{
+  pthread_mutex_lock (g_rec_mutex_get_impl (mutex));
+}
+
+/**
+ * g_rec_mutex_unlock:
+ * @rec_mutex: a #GRecMutex
+ *
+ * Unlocks @rec_mutex. If another thread is blocked in a
+ * g_rec_mutex_lock() call for @rec_mutex, it will become unblocked
+ * and can lock @rec_mutex itself.
+ *
+ * Calling g_rec_mutex_unlock() on a recursive mutex that is not
+ * locked by the current thread leads to undefined behaviour.
+ *
+ * Since: 2.32
+ */
+void
+g_rec_mutex_unlock (GRecMutex *rec_mutex)
+{
+  pthread_mutex_unlock (rec_mutex->p);
+}
+
+/**
+ * g_rec_mutex_trylock:
+ * @rec_mutex: a #GRecMutex
+ *
+ * Tries to lock @rec_mutex. If @rec_mutex is already locked
+ * by another thread, it immediately returns %FALSE. Otherwise
+ * it locks @rec_mutex and returns %TRUE.
+ *
+ * Returns: %TRUE if @rec_mutex could be locked
+ *
+ * Since: 2.32
+ */
+gboolean
+g_rec_mutex_trylock (GRecMutex *rec_mutex)
+{
+  if (pthread_mutex_trylock (g_rec_mutex_get_impl (rec_mutex)) != 0)
+    return FALSE;
+
+  return TRUE;
+}
+
 /* {{{1 GRWLock */
 
+static pthread_rwlock_t *
+g_rw_lock_impl_new (void)
+{
+  pthread_rwlock_t *rwlock;
+  gint status;
+
+  rwlock = malloc (sizeof (pthread_rwlock_t));
+  if G_UNLIKELY (rwlock == NULL)
+    g_thread_abort (errno, "malloc");
+
+  if G_UNLIKELY ((status = pthread_rwlock_init (rwlock, NULL)) != 0)
+    g_thread_abort (status, "pthread_rwlock_init");
+
+  return rwlock;
+}
+
+static void
+g_rw_lock_impl_free (pthread_rwlock_t *rwlock)
+{
+  pthread_rwlock_destroy (rwlock);
+  free (rwlock);
+}
+
+static inline pthread_rwlock_t *
+g_rw_lock_get_impl (GRWLock *lock)
+{
+  pthread_rwlock_t *impl = g_atomic_pointer_get (&lock->p);
+
+  if G_UNLIKELY (impl == NULL)
+    {
+      impl = g_rw_lock_impl_new ();
+      if (!g_atomic_pointer_compare_and_exchange (&lock->p, NULL, impl))
+        g_rw_lock_impl_free (impl);
+      impl = lock->p;
+    }
+
+  return impl;
+}
+
+/**
+ * g_rw_lock_init:
+ * @rw_lock: an uninitialized #GRWLock
+ *
+ * Initializes a #GRWLock so that it can be used.
+ *
+ * This function is useful to initialize a lock that has been
+ * allocated on the stack, or as part of a larger structure.  It is not
+ * necessary to initialise a reader-writer lock that has been statically
+ * allocated.
+ *
+ * |[<!-- language="C" --> 
+ *   typedef struct {
+ *     GRWLock l;
+ *     ...
+ *   } Blob;
+ *
+ * Blob *b;
+ *
+ * b = g_new (Blob, 1);
+ * g_rw_lock_init (&b->l);
+ * ]|
+ *
+ * To undo the effect of g_rw_lock_init() when a lock is no longer
+ * needed, use g_rw_lock_clear().
+ *
+ * Calling g_rw_lock_init() on an already initialized #GRWLock leads
+ * to undefined behaviour.
+ *
+ * Since: 2.32
+ */
 void
-g_rw_lock_init (GRWLock *lock)
+g_rw_lock_init (GRWLock *rw_lock)
 {
-  pthread_rwlock_init (&lock->impl, NULL);
+  rw_lock->p = g_rw_lock_impl_new ();
 }
 
+/**
+ * g_rw_lock_clear:
+ * @rw_lock: an initialized #GRWLock
+ *
+ * Frees the resources allocated to a lock with g_rw_lock_init().
+ *
+ * This function should not be used with a #GRWLock that has been
+ * statically allocated.
+ *
+ * Calling g_rw_lock_clear() when any thread holds the lock
+ * leads to undefined behaviour.
+ *
+ * Sine: 2.32
+ */
 void
-g_rw_lock_clear (GRWLock *lock)
+g_rw_lock_clear (GRWLock *rw_lock)
 {
-  pthread_rwlock_destroy (&lock->impl);
+  g_rw_lock_impl_free (rw_lock->p);
 }
 
+/**
+ * g_rw_lock_writer_lock:
+ * @rw_lock: a #GRWLock
+ *
+ * Obtain a write lock on @rw_lock. If any thread already holds
+ * a read or write lock on @rw_lock, the current thread will block
+ * until all other threads have dropped their locks on @rw_lock.
+ *
+ * Since: 2.32
+ */
 void
-g_rw_lock_writer_lock (GRWLock *lock)
+g_rw_lock_writer_lock (GRWLock *rw_lock)
 {
-  pthread_rwlock_wrlock (&lock->impl);
+  pthread_rwlock_wrlock (g_rw_lock_get_impl (rw_lock));
 }
 
+/**
+ * g_rw_lock_writer_trylock:
+ * @rw_lock: a #GRWLock
+ *
+ * Tries to obtain a write lock on @rw_lock. If any other thread holds
+ * a read or write lock on @rw_lock, it immediately returns %FALSE.
+ * Otherwise it locks @rw_lock and returns %TRUE.
+ *
+ * Returns: %TRUE if @rw_lock could be locked
+ *
+ * Since: 2.32
+ */
 gboolean
-g_rw_lock_writer_trylock (GRWLock *lock)
+g_rw_lock_writer_trylock (GRWLock *rw_lock)
 {
-  return pthread_rwlock_trywrlock (&lock->impl);
+  if (pthread_rwlock_trywrlock (g_rw_lock_get_impl (rw_lock)) != 0)
+    return FALSE;
+
+  return TRUE;
 }
 
+/**
+ * g_rw_lock_writer_unlock:
+ * @rw_lock: a #GRWLock
+ *
+ * Release a write lock on @rw_lock.
+ *
+ * Calling g_rw_lock_writer_unlock() on a lock that is not held
+ * by the current thread leads to undefined behaviour.
+ *
+ * Since: 2.32
+ */
 void
-g_rw_lock_writer_unlock (GRWLock *lock)
+g_rw_lock_writer_unlock (GRWLock *rw_lock)
 {
-  pthread_rwlock_unlock (&lock->impl);
+  pthread_rwlock_unlock (g_rw_lock_get_impl (rw_lock));
 }
 
+/**
+ * g_rw_lock_reader_lock:
+ * @rw_lock: a #GRWLock
+ *
+ * Obtain a read lock on @rw_lock. If another thread currently holds
+ * the write lock on @rw_lock or blocks waiting for it, the current
+ * thread will block. Read locks can be taken recursively.
+ *
+ * It is implementation-defined how many threads are allowed to
+ * hold read locks on the same lock simultaneously.
+ *
+ * Since: 2.32
+ */
 void
-g_rw_lock_reader_lock (GRWLock *lock)
+g_rw_lock_reader_lock (GRWLock *rw_lock)
 {
-  pthread_rwlock_rdlock (&lock->impl);
+  pthread_rwlock_rdlock (g_rw_lock_get_impl (rw_lock));
 }
 
+/**
+ * g_rw_lock_reader_trylock:
+ * @rw_lock: a #GRWLock
+ *
+ * Tries to obtain a read lock on @rw_lock and returns %TRUE if
+ * the read lock was successfully obtained. Otherwise it
+ * returns %FALSE.
+ *
+ * Returns: %TRUE if @rw_lock could be locked
+ *
+ * Since: 2.32
+ */
 gboolean
-g_rw_lock_reader_trylock (GRWLock *lock)
+g_rw_lock_reader_trylock (GRWLock *rw_lock)
 {
-  return pthread_rwlock_tryrdlock (&lock->impl);
+  if (pthread_rwlock_tryrdlock (g_rw_lock_get_impl (rw_lock)) != 0)
+    return FALSE;
+
+  return TRUE;
 }
 
+/**
+ * g_rw_lock_reader_unlock:
+ * @rw_lock: a #GRWLock
+ *
+ * Release a read lock on @rw_lock.
+ *
+ * Calling g_rw_lock_reader_unlock() on a lock that is not held
+ * by the current thread leads to undefined behaviour.
+ *
+ * Since: 2.32
+ */
 void
-g_rw_lock_reader_unlock (GRWLock *lock)
+g_rw_lock_reader_unlock (GRWLock *rw_lock)
 {
-  pthread_rwlock_unlock (&lock->impl);
+  pthread_rwlock_unlock (g_rw_lock_get_impl (rw_lock));
 }
 
 /* {{{1 GCond */
 
+static pthread_cond_t *
+g_cond_impl_new (void)
+{
+  pthread_condattr_t attr;
+  pthread_cond_t *cond;
+  gint status;
+
+  pthread_condattr_init (&attr);
+
+#ifdef HAVE_PTHREAD_COND_TIMEDWAIT_RELATIVE_NP
+#elif defined (HAVE_PTHREAD_CONDATTR_SETCLOCK) && defined (CLOCK_MONOTONIC)
+  if G_UNLIKELY ((status = pthread_condattr_setclock (&attr, CLOCK_MONOTONIC)) != 0)
+    g_thread_abort (status, "pthread_condattr_setclock");
+#else
+#error Cannot support GCond on your platform.
+#endif
+
+  cond = malloc (sizeof (pthread_cond_t));
+  if G_UNLIKELY (cond == NULL)
+    g_thread_abort (errno, "malloc");
+
+  if G_UNLIKELY ((status = pthread_cond_init (cond, &attr)) != 0)
+    g_thread_abort (status, "pthread_cond_init");
+
+  pthread_condattr_destroy (&attr);
+
+  return cond;
+}
+
+static void
+g_cond_impl_free (pthread_cond_t *cond)
+{
+  pthread_cond_destroy (cond);
+  free (cond);
+}
+
+static inline pthread_cond_t *
+g_cond_get_impl (GCond *cond)
+{
+  pthread_cond_t *impl = g_atomic_pointer_get (&cond->p);
+
+  if G_UNLIKELY (impl == NULL)
+    {
+      impl = g_cond_impl_new ();
+      if (!g_atomic_pointer_compare_and_exchange (&cond->p, NULL, impl))
+        g_cond_impl_free (impl);
+      impl = cond->p;
+    }
+
+  return impl;
+}
+
 /**
  * g_cond_init:
  * @cond: an uninitialized #GCond
  *
- * Initialized a #GCond so that it can be used.
+ * Initialises a #GCond so that it can be used.
  *
- * This function is useful to initialize a #GCond that has been
- * allocated on the stack, or as part of a larger structure.
- * It is not necessary to initialize a #GCond that has been
- * created with g_cond_new(). Also see #G_COND_INITIALIZER
- * for an alternative way to initialize statically allocated
- * #GConds.
+ * This function is useful to initialise a #GCond that has been
+ * allocated as part of a larger structure.  It is not necessary to
+ * initialise a #GCond that has been statically allocated.
+ *
+ * To undo the effect of g_cond_init() when a #GCond is no longer
+ * needed, use g_cond_clear().
+ *
+ * Calling g_cond_init() on an already-initialised #GCond leads
+ * to undefined behaviour.
  *
  * Since: 2.32
  */
 void
 g_cond_init (GCond *cond)
 {
-  gint status;
-
-  if G_UNLIKELY ((status = pthread_cond_init (&cond->impl, NULL)) != 0)
-    g_thread_abort (status, "pthread_cond_init");
+  cond->p = g_cond_impl_new ();
 }
 
 /**
  * g_cond_clear:
- * @cond: an initialized #GCond
+ * @cond: an initialised #GCond
+ *
+ * Frees the resources allocated to a #GCond with g_cond_init().
  *
- * Frees the resources allocated ot a #GCond with g_cond_init().
+ * This function should not be used with a #GCond that has been
+ * statically allocated.
  *
- * #GConds that have been created with g_cond_new() should
- * be freed with g_cond_free() instead.
+ * Calling g_cond_clear() for a #GCond on which threads are
+ * blocking leads to undefined behaviour.
  *
  * Since: 2.32
  */
 void
 g_cond_clear (GCond *cond)
 {
-  gint status;
-
-  if G_UNLIKELY ((status = pthread_cond_destroy (&cond->impl)) != 0)
-    g_thread_abort (status, "pthread_cond_destroy");
+  g_cond_impl_free (cond->p);
 }
 
 /**
@@ -298,20 +732,28 @@ g_cond_clear (GCond *cond)
  * @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.
+ * Atomically releases @mutex and waits until @cond is signalled.
+ * When this function returns, @mutex is locked again and owned by the
+ * calling thread.
  *
- * This function can be used even if g_thread_init() has not yet been
- * called, and, in that case, will immediately return.
- */
+ * When using condition variables, it is possible that a spurious wakeup
+ * may occur (ie: g_cond_wait() returns even though g_cond_signal() was
+ * not called).  It's also possible that a stolen wakeup may occur.
+ * This is when g_cond_signal() is called, but another thread acquires
+ * @mutex before this thread and modifies the state of the program in
+ * such a way that when g_cond_wait() is able to return, the expected
+ * condition is no longer met.
+ *
+ * For this reason, g_cond_wait() must always be used in a loop.  See
+ * the documentation for #GCond for a complete example.
+ **/
 void
 g_cond_wait (GCond  *cond,
              GMutex *mutex)
 {
   gint status;
 
-  if G_UNLIKELY ((status = pthread_cond_wait (&cond->impl, &mutex->impl)) != 0)
+  if G_UNLIKELY ((status = pthread_cond_wait (g_cond_get_impl (cond), g_mutex_get_impl (mutex))) != 0)
     g_thread_abort (status, "pthread_cond_wait");
 }
 
@@ -319,19 +761,17 @@ g_cond_wait (GCond  *cond,
  * g_cond_signal:
  * @cond: a #GCond
  *
- * If threads are waiting for @cond, exactly one of them is woken up.
+ * If threads are waiting for @cond, at least one of them is unblocked.
+ * If no threads are waiting for @cond, this function has no effect.
  * 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.
  */
 void
 g_cond_signal (GCond *cond)
 {
   gint status;
 
-  if G_UNLIKELY ((status = pthread_cond_signal (&cond->impl)) != 0)
+  if G_UNLIKELY ((status = pthread_cond_signal (g_cond_get_impl (cond))) != 0)
     g_thread_abort (status, "pthread_cond_signal");
 }
 
@@ -339,61 +779,122 @@ g_cond_signal (GCond *cond)
  * g_cond_broadcast:
  * @cond: a #GCond
  *
- * If threads are waiting for @cond, all of them are woken up.
+ * If threads are waiting for @cond, all of them are unblocked.
+ * If no threads are waiting for @cond, this function has no effect.
  * 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.
  */
 void
 g_cond_broadcast (GCond *cond)
 {
   gint status;
 
-  if G_UNLIKELY ((status = pthread_cond_broadcast (&cond->impl)) != 0)
+  if G_UNLIKELY ((status = pthread_cond_broadcast (g_cond_get_impl (cond))) != 0)
     g_thread_abort (status, "pthread_cond_broadcast");
 }
 
 /**
- * g_cond_timed_wait:
+ * g_cond_wait_until:
  * @cond: a #GCond
  * @mutex: a #GMutex that is currently locked
- * @abs_time: a #GTimeVal, determining the final time
+ * @end_time: the monotonic time to wait until
  *
- * 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.
+ * Waits until either @cond is signalled or @end_time has passed.
  *
- * If @abs_time is %NULL, g_cond_timed_wait() acts like g_cond_wait().
+ * As with g_cond_wait() it is possible that a spurious or stolen wakeup
+ * could occur.  For that reason, waiting on a condition variable should
+ * always be in a loop, based on an explicitly-checked predicate.
  *
- * This function can be used even if g_thread_init() has not yet been
- * called, and, in that case, will immediately return %TRUE.
+ * %TRUE is returned if the condition variable was signalled (or in the
+ * case of a spurious wakeup).  %FALSE is returned if @end_time has
+ * passed.
  *
- * To easily calculate @abs_time a combination of g_get_current_time()
- * and g_time_val_add() can be used.
+ * The following code shows how to correctly perform a timed wait on a
+ * condition variable (extending the example presented in the
+ * documentation for #GCond):
  *
- * Returns: %TRUE if @cond was signalled, or %FALSE on timeout
- */
+ * |[<!-- language="C" --> 
+ * gpointer
+ * pop_data_timed (void)
+ * {
+ *   gint64 end_time;
+ *   gpointer data;
+ *
+ *   g_mutex_lock (&data_mutex);
+ *
+ *   end_time = g_get_monotonic_time () + 5 * G_TIME_SPAN_SECOND;
+ *   while (!current_data)
+ *     if (!g_cond_wait_until (&data_cond, &data_mutex, end_time))
+ *       {
+ *         // timeout has passed.
+ *         g_mutex_unlock (&data_mutex);
+ *         return NULL;
+ *       }
+ *
+ *   // there is data for us
+ *   data = current_data;
+ *   current_data = NULL;
+ *
+ *   g_mutex_unlock (&data_mutex);
+ *
+ *   return data;
+ * }
+ * ]|
+ *
+ * Notice that the end time is calculated once, before entering the
+ * loop and reused.  This is the motivation behind the use of absolute
+ * time on this API -- if a relative time of 5 seconds were passed
+ * directly to the call and a spurious wakeup occurred, the program would
+ * have to start over waiting again (which would lead to a total wait
+ * time of more than 5 seconds).
+ *
+ * Returns: %TRUE on a signal, %FALSE on a timeout
+ * Since: 2.32
+ **/
 gboolean
-g_cond_timed_wait (GCond    *cond,
-                   GMutex   *mutex,
-                   GTimeVal *abs_time)
+g_cond_wait_until (GCond  *cond,
+                   GMutex *mutex,
+                   gint64  end_time)
 {
-  struct timespec end_time;
+  struct timespec ts;
   gint status;
 
-  if (abs_time == NULL)
-    {
-      g_cond_wait (cond, mutex);
-      return TRUE;
-    }
+#ifdef HAVE_PTHREAD_COND_TIMEDWAIT_RELATIVE_NP
+  /* end_time is given relative to the monotonic clock as returned by
+   * g_get_monotonic_time().
+   *
+   * Since this pthreads wants the relative time, convert it back again.
+   */
+  {
+    gint64 now = g_get_monotonic_time ();
+    gint64 relative;
 
-  end_time.tv_sec = abs_time->tv_sec;
-  end_time.tv_nsec = abs_time->tv_usec * 1000;
+    if (end_time <= now)
+      return FALSE;
 
-  if ((status = pthread_cond_timedwait (&cond->impl, &mutex->impl, &end_time)) == 0)
-    return TRUE;
+    relative = end_time - now;
+
+    ts.tv_sec = relative / 1000000;
+    ts.tv_nsec = (relative % 1000000) * 1000;
+
+    if ((status = pthread_cond_timedwait_relative_np (g_cond_get_impl (cond), g_mutex_get_impl (mutex), &ts)) == 0)
+      return TRUE;
+  }
+#elif defined (HAVE_PTHREAD_CONDATTR_SETCLOCK) && defined (CLOCK_MONOTONIC)
+  /* This is the exact check we used during init to set the clock to
+   * monotonic, so if we're in this branch, timedwait() will already be
+   * expecting a monotonic clock.
+   */
+  {
+    ts.tv_sec = end_time / 1000000;
+    ts.tv_nsec = (end_time % 1000000) * 1000;
+
+    if ((status = pthread_cond_timedwait (g_cond_get_impl (cond), g_mutex_get_impl (mutex), &ts)) == 0)
+      return TRUE;
+  }
+#else
+#error Cannot support GCond on your platform.
+#endif
 
   if G_UNLIKELY (status != ETIMEDOUT)
     g_thread_abort (status, "pthread_cond_timedwait");
@@ -401,89 +902,158 @@ g_cond_timed_wait (GCond    *cond,
   return FALSE;
 }
 
+/* {{{1 GPrivate */
+
 /**
- * g_cond_timedwait:
- * @cond: a #GCond
- * @mutex: a #GMutex that is currently locked
- * @abs_time: the final time, in microseconds
+ * GPrivate:
  *
- * A variant of g_cond_timed_wait() that takes @abs_time
- * as a #gint64 instead of a #GTimeVal.
- * See g_cond_timed_wait() for details.
+ * The #GPrivate struct is an opaque data structure to represent a
+ * thread-local data key. It is approximately equivalent to the
+ * pthread_setspecific()/pthread_getspecific() APIs on POSIX and to
+ * TlsSetValue()/TlsGetValue() on Windows.
  *
- * Returns: %TRUE if @cond was signalled, or %FALSE on timeout
+ * If you don't already know why you might want this functionality,
+ * then you probably don't need it.
  *
- * Since: 2.32
+ * #GPrivate is a very limited resource (as far as 128 per program,
+ * shared between all libraries). It is also not possible to destroy a
+ * #GPrivate after it has been used. As such, it is only ever acceptable
+ * to use #GPrivate in static scope, and even then sparingly so.
+ *
+ * See G_PRIVATE_INIT() for a couple of examples.
+ *
+ * The #GPrivate structure should be considered opaque.  It should only
+ * be accessed via the g_private_ functions.
  */
-gboolean
-g_cond_timedwait (GCond  *cond,
-                  GMutex *mutex,
-                  gint64  abs_time)
+
+/**
+ * G_PRIVATE_INIT:
+ * @notify: a #GDestroyNotify
+ *
+ * A macro to assist with the static initialisation of a #GPrivate.
+ *
+ * This macro is useful for the case that a #GDestroyNotify function
+ * should be associated the key.  This is needed when the key will be
+ * used to point at memory that should be deallocated when the thread
+ * exits.
+ *
+ * Additionally, the #GDestroyNotify will also be called on the previous
+ * value stored in the key when g_private_replace() is used.
+ *
+ * If no #GDestroyNotify is needed, then use of this macro is not
+ * required -- if the #GPrivate is declared in static scope then it will
+ * be properly initialised by default (ie: to all zeros).  See the
+ * examples below.
+ *
+ * |[<!-- language="C" --> 
+ * static GPrivate name_key = G_PRIVATE_INIT (g_free);
+ *
+ * // return value should not be freed
+ * const gchar *
+ * get_local_name (void)
+ * {
+ *   return g_private_get (&name_key);
+ * }
+ *
+ * void
+ * set_local_name (const gchar *name)
+ * {
+ *   g_private_replace (&name_key, g_strdup (name));
+ * }
+ *
+ *
+ * static GPrivate count_key;   // no free function
+ *
+ * gint
+ * get_local_count (void)
+ * {
+ *   return GPOINTER_TO_INT (g_private_get (&count_key));
+ * }
+ *
+ * void
+ * set_local_count (gint count)
+ * {
+ *   g_private_set (&count_key, GINT_TO_POINTER (count));
+ * }
+ * ]|
+ *
+ * Since: 2.32
+ **/
+
+static pthread_key_t *
+g_private_impl_new (GDestroyNotify notify)
 {
-  struct timespec end_time;
+  pthread_key_t *key;
   gint status;
 
-  end_time.tv_sec = abs_time / 1000000;
-  end_time.tv_nsec = (abs_time % 1000000) * 1000;
+  key = malloc (sizeof (pthread_key_t));
+  if G_UNLIKELY (key == NULL)
+    g_thread_abort (errno, "malloc");
+  status = pthread_key_create (key, notify);
+  if G_UNLIKELY (status != 0)
+    g_thread_abort (status, "pthread_key_create");
 
-  if ((status = pthread_cond_timedwait (&cond->impl, &mutex->impl, &end_time)) == 0)
-    return TRUE;
+  return key;
+}
 
-  if G_UNLIKELY (status != ETIMEDOUT)
-    g_thread_abort (status, "pthread_cond_timedwait");
+static void
+g_private_impl_free (pthread_key_t *key)
+{
+  gint status;
 
-  return FALSE;
+  status = pthread_key_delete (*key);
+  if G_UNLIKELY (status != 0)
+    g_thread_abort (status, "pthread_key_delete");
+  free (key);
 }
 
-/* {{{1 GPrivate */
-
-void
-g_private_init (GPrivate       *key,
-                GDestroyNotify  notify)
+static inline pthread_key_t *
+g_private_get_impl (GPrivate *key)
 {
-  pthread_key_create (&key->key, notify);
-  key->ready = TRUE;
+  pthread_key_t *impl = g_atomic_pointer_get (&key->p);
+
+  if G_UNLIKELY (impl == NULL)
+    {
+      impl = g_private_impl_new (key->notify);
+      if (!g_atomic_pointer_compare_and_exchange (&key->p, NULL, impl))
+        {
+          g_private_impl_free (impl);
+          impl = key->p;
+        }
+    }
+
+  return impl;
 }
 
 /**
  * g_private_get:
- * @private_key: a #GPrivate
- *
- * 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 initialization.
- *
- * Returns: the corresponding pointer
+ * @key: a #GPrivate
+ *
+ * Returns the current value of the thread local variable @key.
+ *
+ * If the value has not yet been set in this thread, %NULL is returned.
+ * Values are never copied between threads (when a new thread is
+ * created, for example).
+ *
+ * Returns: the thread-local value
  */
 gpointer
 g_private_get (GPrivate *key)
 {
-  if (!key->ready)
-    return key->single_value;
-
   /* quote POSIX: No errors are returned from pthread_getspecific(). */
-  return pthread_getspecific (key->key);
+  return pthread_getspecific (*g_private_get_impl (key));
 }
 
 /**
  * g_private_set:
- * @private_key: a #GPrivate
- * @data: the new pointer
+ * @key: a #GPrivate
+ * @value: the new value
  *
- * Sets the pointer keyed to @private_key for the current thread.
+ * Sets the thread local variable @key to have the value @value in the
+ * current thread.
  *
- * 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.
+ * This function differs from g_private_replace() in the following way:
+ * the #GDestroyNotify for @key is not called on the old value.
  */
 void
 g_private_set (GPrivate *key,
@@ -491,34 +1061,41 @@ g_private_set (GPrivate *key,
 {
   gint status;
 
-  if (!key->ready)
-    {
-      key->single_value = value;
-      return;
-    }
-
-  if G_UNLIKELY ((status = pthread_setspecific (key->key, value)) != 0)
+  if G_UNLIKELY ((status = pthread_setspecific (*g_private_get_impl (key), value)) != 0)
     g_thread_abort (status, "pthread_setspecific");
 }
 
-/* {{{1 GThread */
+/**
+ * g_private_replace:
+ * @key: a #GPrivate
+ * @value: the new value
+ *
+ * Sets the thread local variable @key to have the value @value in the
+ * current thread.
+ *
+ * This function differs from g_private_set() in the following way: if
+ * the previous value was non-%NULL then the #GDestroyNotify handler for
+ * @key is run on it.
+ *
+ * Since: 2.32
+ **/
+void
+g_private_replace (GPrivate *key,
+                   gpointer  value)
+{
+  pthread_key_t *impl = g_private_get_impl (key);
+  gpointer old;
+  gint status;
 
-#include "glib.h"
-#include "gthreadprivate.h"
+  old = pthread_getspecific (*impl);
+  if (old && key->notify)
+    key->notify (old);
 
-#include <pthread.h>
-#include <errno.h>
-#include <stdlib.h>
-#ifdef HAVE_SYS_TIME_H
-# include <sys/time.h>
-#endif
-#ifdef HAVE_UNISTD_H
-# include <unistd.h>
-#endif
+  if G_UNLIKELY ((status = pthread_setspecific (*impl, value)) != 0)
+    g_thread_abort (status, "pthread_setspecific");
+}
 
-#ifdef HAVE_SCHED_H
-#include <sched.h>
-#endif
+/* {{{1 GThread */
 
 #define posix_check_err(err, name) G_STMT_START{			\
   int error = (err); 							\
@@ -530,20 +1107,38 @@ g_private_set (GPrivate *key,
 
 #define posix_check_cmd(cmd) posix_check_err (cmd, #cmd)
 
-#define G_MUTEX_SIZE (sizeof (pthread_mutex_t))
+typedef struct
+{
+  GRealThread thread;
+
+  pthread_t system_thread;
+  gboolean  joined;
+  GMutex    lock;
+} GThreadPosix;
 
 void
-g_system_thread_create (GThreadFunc       thread_func,
-                        gpointer          arg,
-                        gulong            stack_size,
-                        gboolean          joinable,
-                        gpointer          thread,
-                        GError          **error)
+g_system_thread_free (GRealThread *thread)
 {
+  GThreadPosix *pt = (GThreadPosix *) thread;
+
+  if (!pt->joined)
+    pthread_detach (pt->system_thread);
+
+  g_mutex_clear (&pt->lock);
+
+  g_slice_free (GThreadPosix, pt);
+}
+
+GRealThread *
+g_system_thread_new (GThreadFunc   thread_func,
+                     gulong        stack_size,
+                     GError      **error)
+{
+  GThreadPosix *thread;
   pthread_attr_t attr;
   gint ret;
 
-  g_return_if_fail (thread_func);
+  thread = g_slice_new0 (GThreadPosix);
 
   posix_check_cmd (pthread_attr_init (&attr));
 
@@ -559,31 +1154,32 @@ g_system_thread_create (GThreadFunc       thread_func,
     }
 #endif /* HAVE_PTHREAD_ATTR_SETSTACKSIZE */
 
-  posix_check_cmd (pthread_attr_setdetachstate (&attr,
-          joinable ? PTHREAD_CREATE_JOINABLE : PTHREAD_CREATE_DETACHED));
-
-  ret = pthread_create (thread, &attr, (void* (*)(void*))thread_func, arg);
+  ret = pthread_create (&thread->system_thread, &attr, (void* (*)(void*))thread_func, thread);
 
   posix_check_cmd (pthread_attr_destroy (&attr));
 
   if (ret == EAGAIN)
     {
       g_set_error (error, G_THREAD_ERROR, G_THREAD_ERROR_AGAIN, 
-		   "Error creating thread: %s", g_strerror (ret));
-      return;
+                   "Error creating thread: %s", g_strerror (ret));
+      g_slice_free (GThreadPosix, thread);
+      return NULL;
     }
 
   posix_check_err (ret, "pthread_create");
+
+  g_mutex_init (&thread->lock);
+
+  return (GRealThread *) thread;
 }
 
 /**
  * g_thread_yield:
  *
- * Gives way to other threads waiting to be scheduled.
+ * Causes the calling thread to voluntarily relinquish the CPU, so
+ * that other threads can run.
  *
  * 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.
  */
 void
 g_thread_yield (void)
@@ -592,10 +1188,19 @@ g_thread_yield (void)
 }
 
 void
-g_system_thread_join (gpointer thread)
+g_system_thread_wait (GRealThread *thread)
 {
-  gpointer ignore;
-  posix_check_cmd (pthread_join (*(pthread_t*)thread, &ignore));
+  GThreadPosix *pt = (GThreadPosix *) thread;
+
+  g_mutex_lock (&pt->lock);
+
+  if (!pt->joined)
+    {
+      posix_check_cmd (pthread_join (pt->system_thread, NULL));
+      pt->joined = TRUE;
+    }
+
+  g_mutex_unlock (&pt->lock);
 }
 
 void
@@ -605,16 +1210,13 @@ g_system_thread_exit (void)
 }
 
 void
-g_system_thread_self (gpointer thread)
-{
-  *(pthread_t*)thread = pthread_self();
-}
-
-gboolean
-g_system_thread_equal (gpointer thread1,
-                       gpointer thread2)
+g_system_thread_set_name (const gchar *name)
 {
-  return (pthread_equal (*(pthread_t*)thread1, *(pthread_t*)thread2) != 0);
+#ifdef HAVE_SYS_PRCTL_H
+#ifdef PR_SET_NAME
+  prctl (PR_SET_NAME, name, 0, 0, 0, 0);
+#endif
+#endif
 }
 
 /* {{{1 Epilogue */