/* GLIB - Library of useful routines for C programming * Copyright (C) 1995-1997 Peter Mattis, Spencer Kimball and Josh MacDonald * * gthread.c: MT safety related functions * Copyright 1998 Sebastian Wilhelmi; University of Karlsruhe * Owen Taylor * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * 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. */ /* * Modified by the GLib Team and others 1997-2000. See the AUTHORS * file for a list of people on the GLib Team. See the ChangeLog * files for a list of changes. These files are distributed with * GLib at ftp://ftp.gtk.org/pub/gtk/. */ /* * MT safe */ /* implement gthread.h's inline functions */ #define G_IMPLEMENT_INLINES 1 #define __G_THREAD_C__ #include "config.h" #include "glib.h" #include "gthreadprivate.h" #ifdef HAVE_UNISTD_H #include #endif #ifndef G_OS_WIN32 #include #include #else #include #endif /* G_OS_WIN32 */ #include #include "galias.h" GQuark g_thread_error_quark (void) { return g_quark_from_static_string ("g_thread_error"); } /* 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 */ static GSystemThread zero_thread; /* This is initialized to all zero */ gboolean g_thread_use_default_impl = TRUE; gboolean g_threads_got_initialized = FALSE; GThreadFunctions g_thread_functions_for_glib_use = { (GMutex*(*)())g_thread_fail, /* mutex_new */ NULL, /* mutex_lock */ NULL, /* mutex_trylock */ NULL, /* mutex_unlock */ NULL, /* mutex_free */ (GCond*(*)())g_thread_fail, /* cond_new */ NULL, /* cond_signal */ NULL, /* cond_broadcast */ NULL, /* cond_wait */ NULL, /* cond_timed_wait */ NULL, /* cond_free */ (GPrivate*(*)(GDestroyNotify))g_thread_fail, /* private_new */ NULL, /* private_get */ NULL, /* private_set */ (void(*)(GThreadFunc, gpointer, gulong, gboolean, gboolean, GThreadPriority, gpointer, GError**))g_thread_fail, /* thread_create */ NULL, /* thread_yield */ NULL, /* thread_join */ NULL, /* thread_exit */ NULL, /* thread_set_priority */ NULL, /* thread_self */ NULL /* thread_equal */ }; /* Local data */ 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; G_LOCK_DEFINE_STATIC (g_thread); #ifdef G_THREADS_ENABLED /* 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 (); #ifdef G_OS_WIN32 _g_win32_thread_init (); #endif } #endif /* G_THREADS_ENABLED */ gpointer g_once_impl (GOnce *once, GThreadFunc func, gpointer arg) { g_mutex_lock (g_once_mutex); while (once->status == G_ONCE_STATUS_PROGRESS) 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); once->retval = func (arg); g_mutex_lock (g_once_mutex); once->status = G_ONCE_STATUS_READY; g_cond_broadcast (g_once_cond); } g_mutex_unlock (g_once_mutex); return once->retval; } gboolean g_once_init_enter_impl (volatile gsize *value_location) { gboolean need_init = FALSE; 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)) { need_init = TRUE; g_once_init_list = g_slist_prepend (g_once_init_list, (void*) value_location); } else do 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); return need_init; } void g_once_init_leave (volatile gsize *value_location, gsize initialization_value) { g_return_if_fail (g_atomic_pointer_get (value_location) == NULL); g_return_if_fail (initialization_value != 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_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); } void g_static_mutex_init (GStaticMutex *mutex) { static const GStaticMutex init_mutex = G_STATIC_MUTEX_INIT; g_return_if_fail (mutex); *mutex = init_mutex; } GMutex * g_static_mutex_get_mutex_impl (GMutex** mutex) { 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()); g_mutex_unlock (g_once_mutex); return *mutex; } 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; } 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; } 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; } gboolean g_static_rec_mutex_trylock (GStaticRecMutex* mutex) { GSystemThread self; g_return_val_if_fail (mutex, FALSE); if (!g_thread_supported ()) return TRUE; G_THREAD_UF (thread_self, (&self)); if (g_system_thread_equal (self, mutex->owner)) { mutex->depth++; return TRUE; } if (!g_static_mutex_trylock (&mutex->mutex)) return FALSE; g_system_thread_assign (mutex->owner, self); mutex->depth = 1; return TRUE; } void g_static_rec_mutex_unlock (GStaticRecMutex* mutex) { 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); } void g_static_rec_mutex_lock_full (GStaticRecMutex *mutex, guint depth) { GSystemThread self; g_return_if_fail (mutex); if (!g_thread_supported ()) return; if (depth == 0) return; G_THREAD_UF (thread_self, (&self)); if (g_system_thread_equal (self, mutex->owner)) { mutex->depth += depth; return; } g_static_mutex_lock (&mutex->mutex); g_system_thread_assign (mutex->owner, self); mutex->depth = depth; } 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); return depth; } void g_static_rec_mutex_free (GStaticRecMutex *mutex) { g_return_if_fail (mutex); g_static_mutex_free (&mutex->mutex); } void g_static_private_init (GStaticPrivate *private_key) { private_key->index = 0; } 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; } void g_static_private_set (GStaticPrivate *private_key, gpointer data, GDestroyNotify notify) { 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); node = &g_array_index (array, GStaticPrivateNode, private_key->index - 1); if (node->destroy) { gpointer ddata = node->data; GDestroyNotify ddestroy = node->destroy; node->data = data; node->destroy = notify; ddestroy (ddata); } else { node->data = data; node->destroy = notify; } } 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); } 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) { #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 } static gpointer g_thread_create_proxy (gpointer data) { 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; } 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); if (local_error) { g_propagate_error (error, local_error); g_free (result); return NULL; } return (GThread*) result; } void g_thread_exit (gpointer retval) { GRealThread* real = (GRealThread*) g_thread_self (); real->retval = retval; G_THREAD_CF (thread_exit, (void)0, ()); } gpointer g_thread_join (GThread* thread) { GRealThread* real = (GRealThread*) thread; GRealThread *p, *t; 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_THREAD_UF (thread_join, (&real->system_thread)); 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); return retval; } 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)); } GThread* g_thread_self (void) { 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); } return (GThread*)thread; } 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); } 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); } 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; } 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); } 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); } 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; } 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); } 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); } /** * 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"