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Diffstat (limited to 'protocols/Sametime/src/glib/gthreadpool.c')
| -rw-r--r-- | protocols/Sametime/src/glib/gthreadpool.c | 996 |
1 files changed, 996 insertions, 0 deletions
diff --git a/protocols/Sametime/src/glib/gthreadpool.c b/protocols/Sametime/src/glib/gthreadpool.c new file mode 100644 index 0000000000..3bab274192 --- /dev/null +++ b/protocols/Sametime/src/glib/gthreadpool.c @@ -0,0 +1,996 @@ +/* GLIB - Library of useful routines for C programming + * Copyright (C) 1995-1997 Peter Mattis, Spencer Kimball and Josh MacDonald + * + * GAsyncQueue: thread pool implementation. + * Copyright (C) 2000 Sebastian Wilhelmi; University of Karlsruhe + * + * 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. + */ + +/* + * MT safe + */ + +#include "config.h" + +#include "gthreadpool.h" + +#include "gasyncqueue.h" +#include "gmain.h" +#include "gtestutils.h" +#include "gtimer.h" + +/** + * SECTION: thread_pools + * @title: Thread Pools + * @short_description: pools of threads to execute work concurrently + * @see_also: <para> <variablelist> <varlistentry> + * <term>#GThread</term> <listitem><para>GLib thread + * system.</para></listitem> </varlistentry> </variablelist> + * </para> + * + * Sometimes you wish to asynchronously fork out the execution of work + * and continue working in your own thread. If that will happen often, + * the overhead of starting and destroying a thread each time might be + * too high. In such cases reusing already started threads seems like a + * good idea. And it indeed is, but implementing this can be tedious + * and error-prone. + * + * Therefore GLib provides thread pools for your convenience. An added + * advantage is, that the threads can be shared between the different + * subsystems of your program, when they are using GLib. + * + * To create a new thread pool, you use g_thread_pool_new(). It is + * destroyed by g_thread_pool_free(). + * + * If you want to execute a certain task within a thread pool, you call + * g_thread_pool_push(). + * + * To get the current number of running threads you call + * g_thread_pool_get_num_threads(). To get the number of still + * unprocessed tasks you call g_thread_pool_unprocessed(). To control + * the maximal number of threads for a thread pool, you use + * g_thread_pool_get_max_threads() and g_thread_pool_set_max_threads(). + * + * Finally you can control the number of unused threads, that are kept + * alive by GLib for future use. The current number can be fetched with + * g_thread_pool_get_num_unused_threads(). The maximal number can be + * controlled by g_thread_pool_get_max_unused_threads() and + * g_thread_pool_set_max_unused_threads(). All currently unused threads + * can be stopped by calling g_thread_pool_stop_unused_threads(). + **/ + +#define DEBUG_MSG(x) +/* #define DEBUG_MSG(args) g_printerr args ; g_printerr ("\n"); */ + +typedef struct _GRealThreadPool GRealThreadPool; + +/** + * GThreadPool: + * @func: the function to execute in the threads of this pool + * @user_data: the user data for the threads of this pool + * @exclusive: are all threads exclusive to this pool + * + * The #GThreadPool struct represents a thread pool. It has three + * public read-only members, but the underlying struct is bigger, so + * you must not copy this struct. + **/ +struct _GRealThreadPool +{ + GThreadPool pool; + GAsyncQueue* queue; + GCond* cond; + gint max_threads; + gint num_threads; + gboolean running; + gboolean immediate; + gboolean waiting; + GCompareDataFunc sort_func; + gpointer sort_user_data; +}; + +/* The following is just an address to mark the wakeup order for a + * thread, it could be any address (as long, as it isn't a valid + * GThreadPool address) */ +static const gpointer wakeup_thread_marker = (gpointer) &g_thread_pool_new; +static gint wakeup_thread_serial = 0; + +/* Here all unused threads are waiting */ +static GAsyncQueue *unused_thread_queue = NULL; +static gint unused_threads = 0; +static gint max_unused_threads = 0; +static gint kill_unused_threads = 0; +static guint max_idle_time = 0; + +static void g_thread_pool_queue_push_unlocked (GRealThreadPool *pool, + gpointer data); +static void g_thread_pool_free_internal (GRealThreadPool *pool); +static gpointer g_thread_pool_thread_proxy (gpointer data); +static void g_thread_pool_start_thread (GRealThreadPool *pool, + GError **error); +static void g_thread_pool_wakeup_and_stop_all (GRealThreadPool *pool); +static GRealThreadPool* g_thread_pool_wait_for_new_pool (void); +static gpointer g_thread_pool_wait_for_new_task (GRealThreadPool *pool); + +static void +g_thread_pool_queue_push_unlocked (GRealThreadPool *pool, + gpointer data) +{ + if (pool->sort_func) + g_async_queue_push_sorted_unlocked (pool->queue, + data, + pool->sort_func, + pool->sort_user_data); + else + g_async_queue_push_unlocked (pool->queue, data); +} + +static GRealThreadPool* +g_thread_pool_wait_for_new_pool (void) +{ + GRealThreadPool *pool; + gint local_wakeup_thread_serial; + guint local_max_unused_threads; + gint local_max_idle_time; + gint last_wakeup_thread_serial; + gboolean have_relayed_thread_marker = FALSE; + + local_max_unused_threads = g_atomic_int_get (&max_unused_threads); + local_max_idle_time = g_atomic_int_get (&max_idle_time); + last_wakeup_thread_serial = g_atomic_int_get (&wakeup_thread_serial); + + g_atomic_int_inc (&unused_threads); + + do + { + if (g_atomic_int_get (&unused_threads) >= local_max_unused_threads) + { + /* If this is a superfluous thread, stop it. */ + pool = NULL; + } + else if (local_max_idle_time > 0) + { + /* If a maximal idle time is given, wait for the given time. */ + GTimeVal end_time; + + g_get_current_time (&end_time); + g_time_val_add (&end_time, local_max_idle_time * 1000); + + DEBUG_MSG (("thread %p waiting in global pool for %f seconds.", + g_thread_self (), local_max_idle_time / 1000.0)); + + pool = g_async_queue_timed_pop (unused_thread_queue, &end_time); + } + else + { + /* If no maximal idle time is given, wait indefinitely. */ + DEBUG_MSG (("thread %p waiting in global pool.", + g_thread_self ())); + pool = g_async_queue_pop (unused_thread_queue); + } + + if (pool == wakeup_thread_marker) + { + local_wakeup_thread_serial = g_atomic_int_get (&wakeup_thread_serial); + if (last_wakeup_thread_serial == local_wakeup_thread_serial) + { + if (!have_relayed_thread_marker) + { + /* If this wakeup marker has been received for + * the second time, relay it. + */ + DEBUG_MSG (("thread %p relaying wakeup message to " + "waiting thread with lower serial.", + g_thread_self ())); + + g_async_queue_push (unused_thread_queue, wakeup_thread_marker); + have_relayed_thread_marker = TRUE; + + /* If a wakeup marker has been relayed, this thread + * will get out of the way for 100 microseconds to + * avoid receiving this marker again. */ + g_usleep (100); + } + } + else + { + if (g_atomic_int_exchange_and_add (&kill_unused_threads, -1) > 0) + { + pool = NULL; + break; + } + + DEBUG_MSG (("thread %p updating to new limits.", + g_thread_self ())); + + local_max_unused_threads = g_atomic_int_get (&max_unused_threads); + local_max_idle_time = g_atomic_int_get (&max_idle_time); + last_wakeup_thread_serial = local_wakeup_thread_serial; + + have_relayed_thread_marker = FALSE; + } + } + } + while (pool == wakeup_thread_marker); + + g_atomic_int_add (&unused_threads, -1); + + return pool; +} + +static gpointer +g_thread_pool_wait_for_new_task (GRealThreadPool *pool) +{ + gpointer task = NULL; + + if (pool->running || (!pool->immediate && + g_async_queue_length_unlocked (pool->queue) > 0)) + { + /* This thread pool is still active. */ + if (pool->num_threads > pool->max_threads && pool->max_threads != -1) + { + /* This is a superfluous thread, so it goes to the global pool. */ + DEBUG_MSG (("superfluous thread %p in pool %p.", + g_thread_self (), pool)); + } + else if (pool->pool.exclusive) + { + /* Exclusive threads stay attached to the pool. */ + task = g_async_queue_pop_unlocked (pool->queue); + + DEBUG_MSG (("thread %p in exclusive pool %p waits for task " + "(%d running, %d unprocessed).", + g_thread_self (), pool, pool->num_threads, + g_async_queue_length_unlocked (pool->queue))); + } + else + { + /* A thread will wait for new tasks for at most 1/2 + * second before going to the global pool. + */ + GTimeVal end_time; + + g_get_current_time (&end_time); + g_time_val_add (&end_time, G_USEC_PER_SEC / 2); /* 1/2 second */ + + DEBUG_MSG (("thread %p in pool %p waits for up to a 1/2 second for task " + "(%d running, %d unprocessed).", + g_thread_self (), pool, pool->num_threads, + g_async_queue_length_unlocked (pool->queue))); + + task = g_async_queue_timed_pop_unlocked (pool->queue, &end_time); + } + } + else + { + /* This thread pool is inactive, it will no longer process tasks. */ + DEBUG_MSG (("pool %p not active, thread %p will go to global pool " + "(running: %s, immediate: %s, len: %d).", + pool, g_thread_self (), + pool->running ? "true" : "false", + pool->immediate ? "true" : "false", + g_async_queue_length_unlocked (pool->queue))); + } + + return task; +} + + +static gpointer +g_thread_pool_thread_proxy (gpointer data) +{ + GRealThreadPool *pool; + + pool = data; + + DEBUG_MSG (("thread %p started for pool %p.", + g_thread_self (), pool)); + + g_async_queue_lock (pool->queue); + + while (TRUE) + { + gpointer task; + + task = g_thread_pool_wait_for_new_task (pool); + if (task) + { + if (pool->running || !pool->immediate) + { + /* A task was received and the thread pool is active, so + * execute the function. + */ + g_async_queue_unlock (pool->queue); + DEBUG_MSG (("thread %p in pool %p calling func.", + g_thread_self (), pool)); + pool->pool.func (task, pool->pool.user_data); + g_async_queue_lock (pool->queue); + } + } + else + { + /* No task was received, so this thread goes to the global + * pool. + */ + gboolean free_pool = FALSE; + + DEBUG_MSG (("thread %p leaving pool %p for global pool.", + g_thread_self (), pool)); + pool->num_threads--; + + if (!pool->running) + { + if (!pool->waiting) + { + if (pool->num_threads == 0) + { + /* If the pool is not running and no other + * thread is waiting for this thread pool to + * finish and this is the last thread of this + * pool, free the pool. + */ + free_pool = TRUE; + } + else + { + /* If the pool is not running and no other + * thread is waiting for this thread pool to + * finish and this is not the last thread of + * this pool and there are no tasks left in the + * queue, wakeup the remaining threads. + */ + if (g_async_queue_length_unlocked (pool->queue) == + - pool->num_threads) + g_thread_pool_wakeup_and_stop_all (pool); + } + } + else if (pool->immediate || + g_async_queue_length_unlocked (pool->queue) <= 0) + { + /* If the pool is not running and another thread is + * waiting for this thread pool to finish and there + * are either no tasks left or the pool shall stop + * immediatly, inform the waiting thread of a change + * of the thread pool state. + */ + g_cond_broadcast (pool->cond); + } + } + + g_async_queue_unlock (pool->queue); + + if (free_pool) + g_thread_pool_free_internal (pool); + + if ((pool = g_thread_pool_wait_for_new_pool ()) == NULL) + break; + + g_async_queue_lock (pool->queue); + + DEBUG_MSG (("thread %p entering pool %p from global pool.", + g_thread_self (), pool)); + + /* pool->num_threads++ is not done here, but in + * g_thread_pool_start_thread to make the new started thread + * known to the pool, before itself can do it. + */ + } + } + + return NULL; +} + +static void +g_thread_pool_start_thread (GRealThreadPool *pool, + GError **error) +{ + gboolean success = FALSE; + + if (pool->num_threads >= pool->max_threads && pool->max_threads != -1) + /* Enough threads are already running */ + return; + + g_async_queue_lock (unused_thread_queue); + + if (g_async_queue_length_unlocked (unused_thread_queue) < 0) + { + g_async_queue_push_unlocked (unused_thread_queue, pool); + success = TRUE; + } + + g_async_queue_unlock (unused_thread_queue); + + if (!success) + { + GError *local_error = NULL; + /* No thread was found, we have to start a new one */ + g_thread_create (g_thread_pool_thread_proxy, pool, FALSE, &local_error); + + if (local_error) + { + g_propagate_error (error, local_error); + return; + } + } + + /* See comment in g_thread_pool_thread_proxy as to why this is done + * here and not there + */ + pool->num_threads++; +} + +/** + * g_thread_pool_new: + * @func: a function to execute in the threads of the new thread pool + * @user_data: user data that is handed over to @func every time it + * is called + * @max_threads: the maximal number of threads to execute concurrently in + * the new thread pool, -1 means no limit + * @exclusive: should this thread pool be exclusive? + * @error: return location for error + * + * This function creates a new thread pool. + * + * Whenever you call g_thread_pool_push(), either a new thread is + * created or an unused one is reused. At most @max_threads threads + * are running concurrently for this thread pool. @max_threads = -1 + * allows unlimited threads to be created for this thread pool. The + * newly created or reused thread now executes the function @func with + * the two arguments. The first one is the parameter to + * g_thread_pool_push() and the second one is @user_data. + * + * The parameter @exclusive determines, whether the thread pool owns + * all threads exclusive or whether the threads are shared + * globally. If @exclusive is %TRUE, @max_threads threads are started + * immediately and they will run exclusively for this thread pool until + * it is destroyed by g_thread_pool_free(). If @exclusive is %FALSE, + * threads are created, when needed and shared between all + * non-exclusive thread pools. This implies that @max_threads may not + * be -1 for exclusive thread pools. + * + * @error can be %NULL to ignore errors, or non-%NULL to report + * errors. An error can only occur when @exclusive is set to %TRUE and + * not all @max_threads threads could be created. + * + * Return value: the new #GThreadPool + **/ +GThreadPool* +g_thread_pool_new (GFunc func, + gpointer user_data, + gint max_threads, + gboolean exclusive, + GError **error) +{ + GRealThreadPool *retval; + G_LOCK_DEFINE_STATIC (init); + + g_return_val_if_fail (func, NULL); + g_return_val_if_fail (!exclusive || max_threads != -1, NULL); + g_return_val_if_fail (max_threads >= -1, NULL); + g_return_val_if_fail (g_thread_supported (), NULL); + + retval = g_new (GRealThreadPool, 1); + + retval->pool.func = func; + retval->pool.user_data = user_data; + retval->pool.exclusive = exclusive; + retval->queue = g_async_queue_new (); + retval->cond = NULL; + retval->max_threads = max_threads; + retval->num_threads = 0; + retval->running = TRUE; + retval->sort_func = NULL; + retval->sort_user_data = NULL; + + G_LOCK (init); + if (!unused_thread_queue) + unused_thread_queue = g_async_queue_new (); + G_UNLOCK (init); + + if (retval->pool.exclusive) + { + g_async_queue_lock (retval->queue); + + while (retval->num_threads < retval->max_threads) + { + GError *local_error = NULL; + g_thread_pool_start_thread (retval, &local_error); + if (local_error) + { + g_propagate_error (error, local_error); + break; + } + } + + g_async_queue_unlock (retval->queue); + } + + return (GThreadPool*) retval; +} + +/** + * g_thread_pool_push: + * @pool: a #GThreadPool + * @data: a new task for @pool + * @error: return location for error + * + * Inserts @data into the list of tasks to be executed by @pool. When + * the number of currently running threads is lower than the maximal + * allowed number of threads, a new thread is started (or reused) with + * the properties given to g_thread_pool_new (). Otherwise @data stays + * in the queue until a thread in this pool finishes its previous task + * and processes @data. + * + * @error can be %NULL to ignore errors, or non-%NULL to report + * errors. An error can only occur when a new thread couldn't be + * created. In that case @data is simply appended to the queue of work + * to do. + **/ +void +g_thread_pool_push (GThreadPool *pool, + gpointer data, + GError **error) +{ + GRealThreadPool *real; + + real = (GRealThreadPool*) pool; + + g_return_if_fail (real); + g_return_if_fail (real->running); + + g_async_queue_lock (real->queue); + + if (g_async_queue_length_unlocked (real->queue) >= 0) + /* No thread is waiting in the queue */ + g_thread_pool_start_thread (real, error); + + g_thread_pool_queue_push_unlocked (real, data); + g_async_queue_unlock (real->queue); +} + +/** + * g_thread_pool_set_max_threads: + * @pool: a #GThreadPool + * @max_threads: a new maximal number of threads for @pool + * @error: return location for error + * + * Sets the maximal allowed number of threads for @pool. A value of -1 + * means, that the maximal number of threads is unlimited. + * + * Setting @max_threads to 0 means stopping all work for @pool. It is + * effectively frozen until @max_threads is set to a non-zero value + * again. + * + * A thread is never terminated while calling @func, as supplied by + * g_thread_pool_new (). Instead the maximal number of threads only + * has effect for the allocation of new threads in g_thread_pool_push(). + * A new thread is allocated, whenever the number of currently + * running threads in @pool is smaller than the maximal number. + * + * @error can be %NULL to ignore errors, or non-%NULL to report + * errors. An error can only occur when a new thread couldn't be + * created. + **/ +void +g_thread_pool_set_max_threads (GThreadPool *pool, + gint max_threads, + GError **error) +{ + GRealThreadPool *real; + gint to_start; + + real = (GRealThreadPool*) pool; + + g_return_if_fail (real); + g_return_if_fail (real->running); + g_return_if_fail (!real->pool.exclusive || max_threads != -1); + g_return_if_fail (max_threads >= -1); + + g_async_queue_lock (real->queue); + + real->max_threads = max_threads; + + if (pool->exclusive) + to_start = real->max_threads - real->num_threads; + else + to_start = g_async_queue_length_unlocked (real->queue); + + for ( ; to_start > 0; to_start--) + { + GError *local_error = NULL; + + g_thread_pool_start_thread (real, &local_error); + if (local_error) + { + g_propagate_error (error, local_error); + break; + } + } + + g_async_queue_unlock (real->queue); +} + +/** + * g_thread_pool_get_max_threads: + * @pool: a #GThreadPool + * + * Returns the maximal number of threads for @pool. + * + * Return value: the maximal number of threads + **/ +gint +g_thread_pool_get_max_threads (GThreadPool *pool) +{ + GRealThreadPool *real; + gint retval; + + real = (GRealThreadPool*) pool; + + g_return_val_if_fail (real, 0); + g_return_val_if_fail (real->running, 0); + + g_async_queue_lock (real->queue); + retval = real->max_threads; + g_async_queue_unlock (real->queue); + + return retval; +} + +/** + * g_thread_pool_get_num_threads: + * @pool: a #GThreadPool + * + * Returns the number of threads currently running in @pool. + * + * Return value: the number of threads currently running + **/ +guint +g_thread_pool_get_num_threads (GThreadPool *pool) +{ + GRealThreadPool *real; + guint retval; + + real = (GRealThreadPool*) pool; + + g_return_val_if_fail (real, 0); + g_return_val_if_fail (real->running, 0); + + g_async_queue_lock (real->queue); + retval = real->num_threads; + g_async_queue_unlock (real->queue); + + return retval; +} + +/** + * g_thread_pool_unprocessed: + * @pool: a #GThreadPool + * + * Returns the number of tasks still unprocessed in @pool. + * + * Return value: the number of unprocessed tasks + **/ +guint +g_thread_pool_unprocessed (GThreadPool *pool) +{ + GRealThreadPool *real; + gint unprocessed; + + real = (GRealThreadPool*) pool; + + g_return_val_if_fail (real, 0); + g_return_val_if_fail (real->running, 0); + + unprocessed = g_async_queue_length (real->queue); + + return MAX (unprocessed, 0); +} + +/** + * g_thread_pool_free: + * @pool: a #GThreadPool + * @immediate: should @pool shut down immediately? + * @wait_: should the function wait for all tasks to be finished? + * + * Frees all resources allocated for @pool. + * + * If @immediate is %TRUE, no new task is processed for + * @pool. Otherwise @pool is not freed before the last task is + * processed. Note however, that no thread of this pool is + * interrupted, while processing a task. Instead at least all still + * running threads can finish their tasks before the @pool is freed. + * + * If @wait_ is %TRUE, the functions does not return before all tasks + * to be processed (dependent on @immediate, whether all or only the + * currently running) are ready. Otherwise the function returns immediately. + * + * After calling this function @pool must not be used anymore. + **/ +void +g_thread_pool_free (GThreadPool *pool, + gboolean immediate, + gboolean wait_) +{ + GRealThreadPool *real; + + real = (GRealThreadPool*) pool; + + g_return_if_fail (real); + g_return_if_fail (real->running); + + /* If there's no thread allowed here, there is not much sense in + * not stopping this pool immediately, when it's not empty + */ + g_return_if_fail (immediate || + real->max_threads != 0 || + g_async_queue_length (real->queue) == 0); + + g_async_queue_lock (real->queue); + + real->running = FALSE; + real->immediate = immediate; + real->waiting = wait_; + + if (wait_) + { + real->cond = g_cond_new (); + + while (g_async_queue_length_unlocked (real->queue) != -real->num_threads && + !(immediate && real->num_threads == 0)) + g_cond_wait (real->cond, _g_async_queue_get_mutex (real->queue)); + } + + if (immediate || g_async_queue_length_unlocked (real->queue) == -real->num_threads) + { + /* No thread is currently doing something (and nothing is left + * to process in the queue) + */ + if (real->num_threads == 0) + { + /* No threads left, we clean up */ + g_async_queue_unlock (real->queue); + g_thread_pool_free_internal (real); + return; + } + + g_thread_pool_wakeup_and_stop_all (real); + } + + /* The last thread should cleanup the pool */ + real->waiting = FALSE; + g_async_queue_unlock (real->queue); +} + +static void +g_thread_pool_free_internal (GRealThreadPool* pool) +{ + g_return_if_fail (pool); + g_return_if_fail (pool->running == FALSE); + g_return_if_fail (pool->num_threads == 0); + + g_async_queue_unref (pool->queue); + + if (pool->cond) + g_cond_free (pool->cond); + + g_free (pool); +} + +static void +g_thread_pool_wakeup_and_stop_all (GRealThreadPool* pool) +{ + guint i; + + g_return_if_fail (pool); + g_return_if_fail (pool->running == FALSE); + g_return_if_fail (pool->num_threads != 0); + + pool->immediate = TRUE; + + for (i = 0; i < pool->num_threads; i++) + g_thread_pool_queue_push_unlocked (pool, GUINT_TO_POINTER (1)); +} + +/** + * g_thread_pool_set_max_unused_threads: + * @max_threads: maximal number of unused threads + * + * Sets the maximal number of unused threads to @max_threads. If + * @max_threads is -1, no limit is imposed on the number of unused + * threads. + **/ +void +g_thread_pool_set_max_unused_threads (gint max_threads) +{ + g_return_if_fail (max_threads >= -1); + + g_atomic_int_set (&max_unused_threads, max_threads); + + if (max_threads != -1) + { + max_threads -= g_atomic_int_get (&unused_threads); + if (max_threads < 0) + { + g_atomic_int_set (&kill_unused_threads, -max_threads); + g_atomic_int_inc (&wakeup_thread_serial); + + g_async_queue_lock (unused_thread_queue); + + do + { + g_async_queue_push_unlocked (unused_thread_queue, + wakeup_thread_marker); + } + while (++max_threads); + + g_async_queue_unlock (unused_thread_queue); + } + } +} + +/** + * g_thread_pool_get_max_unused_threads: + * + * Returns the maximal allowed number of unused threads. + * + * Return value: the maximal number of unused threads + **/ +gint +g_thread_pool_get_max_unused_threads (void) +{ + return g_atomic_int_get (&max_unused_threads); +} + +/** + * g_thread_pool_get_num_unused_threads: + * + * Returns the number of currently unused threads. + * + * Return value: the number of currently unused threads + **/ +guint +g_thread_pool_get_num_unused_threads (void) +{ + return g_atomic_int_get (&unused_threads); +} + +/** + * g_thread_pool_stop_unused_threads: + * + * Stops all currently unused threads. This does not change the + * maximal number of unused threads. This function can be used to + * regularly stop all unused threads e.g. from g_timeout_add(). + **/ +void +g_thread_pool_stop_unused_threads (void) +{ + guint oldval; + + oldval = g_thread_pool_get_max_unused_threads (); + + g_thread_pool_set_max_unused_threads (0); + g_thread_pool_set_max_unused_threads (oldval); +} + +/** + * g_thread_pool_set_sort_function: + * @pool: a #GThreadPool + * @func: the #GCompareDataFunc used to sort the list of tasks. + * This function is passed two tasks. It should return + * 0 if the order in which they are handled does not matter, + * a negative value if the first task should be processed before + * the second or a positive value if the second task should be + * processed first. + * @user_data: user data passed to @func. + * + * Sets the function used to sort the list of tasks. This allows the + * tasks to be processed by a priority determined by @func, and not + * just in the order in which they were added to the pool. + * + * Note, if the maximum number of threads is more than 1, the order + * that threads are executed can not be guranteed 100%. Threads are + * scheduled by the operating system and are executed at random. It + * cannot be assumed that threads are executed in the order they are + * created. + * + * Since: 2.10 + **/ +void +g_thread_pool_set_sort_function (GThreadPool *pool, + GCompareDataFunc func, + gpointer user_data) +{ + GRealThreadPool *real; + + real = (GRealThreadPool*) pool; + + g_return_if_fail (real); + g_return_if_fail (real->running); + + g_async_queue_lock (real->queue); + + real->sort_func = func; + real->sort_user_data = user_data; + + if (func) + g_async_queue_sort_unlocked (real->queue, + real->sort_func, + real->sort_user_data); + + g_async_queue_unlock (real->queue); +} + +/** + * g_thread_pool_set_max_idle_time: + * @interval: the maximum @interval (1/1000ths of a second) a thread + * can be idle. + * + * This function will set the maximum @interval that a thread waiting + * in the pool for new tasks can be idle for before being + * stopped. This function is similar to calling + * g_thread_pool_stop_unused_threads() on a regular timeout, except, + * this is done on a per thread basis. + * + * By setting @interval to 0, idle threads will not be stopped. + * + * This function makes use of g_async_queue_timed_pop () using + * @interval. + * + * Since: 2.10 + **/ +void +g_thread_pool_set_max_idle_time (guint interval) +{ + guint i; + + g_atomic_int_set (&max_idle_time, interval); + + i = g_atomic_int_get (&unused_threads); + if (i > 0) + { + g_atomic_int_inc (&wakeup_thread_serial); + g_async_queue_lock (unused_thread_queue); + + do + { + g_async_queue_push_unlocked (unused_thread_queue, + wakeup_thread_marker); + } + while (--i); + + g_async_queue_unlock (unused_thread_queue); + } +} + +/** + * g_thread_pool_get_max_idle_time: + * + * This function will return the maximum @interval that a thread will + * wait in the thread pool for new tasks before being stopped. + * + * If this function returns 0, threads waiting in the thread pool for + * new work are not stopped. + * + * Return value: the maximum @interval to wait for new tasks in the + * thread pool before stopping the thread (1/1000ths of a second). + * + * Since: 2.10 + **/ +guint +g_thread_pool_get_max_idle_time (void) +{ + return g_atomic_int_get (&max_idle_time); +} |