/* GLIB - Library of useful routines for C programming
* Copyright (C) 1995-1997 Peter Mattis, Spencer Kimball and Josh MacDonald
*
- * GAsyncQueue: thread pool implementation.
+ * GThreadPool: thread pool implementation.
* Copyright (C) 2000 Sebastian Wilhelmi; University of Karlsruhe
*
* This library is free software; you can redistribute it and/or
* 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/>.
*/
/*
#include "gthreadpool.h"
#include "gasyncqueue.h"
+#include "gasyncqueueprivate.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>
+ * @see_also: #GThread
*
* Sometimes you wish to asynchronously fork out the execution of work
* and continue working in your own thread. If that will happen often,
* 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().
+ * 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().
+ * 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
* 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(x)
/* #define DEBUG_MSG(args) g_printerr args ; g_printerr ("\n"); */
typedef struct _GRealThreadPool GRealThreadPool;
* @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.
- **/
+ * 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;
+ GAsyncQueue *queue;
+ GCond cond;
gint max_threads;
gint num_threads;
gboolean running;
/* 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) */
+ * 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 max_unused_threads = 2;
static gint kill_unused_threads = 0;
-static guint max_idle_time = 0;
+static guint max_idle_time = 15 * 1000;
static void g_thread_pool_queue_push_unlocked (GRealThreadPool *pool,
- gpointer data);
+ 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 gboolean 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)
+ gpointer data)
{
- if (pool->sort_func)
- g_async_queue_push_sorted_unlocked (pool->queue,
- data,
- pool->sort_func,
- pool->sort_user_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);
}
do
{
if (g_atomic_int_get (&unused_threads) >= local_max_unused_threads)
- {
- /* If this is a superfluous thread, stop it. */
- pool = NULL;
- }
+ {
+ /* 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);
- }
+ {
+ /* If a maximal idle time is given, wait for the given time. */
+ DEBUG_MSG (("thread %p waiting in global pool for %f seconds.",
+ g_thread_self (), local_max_idle_time / 1000.0));
+
+ pool = g_async_queue_timeout_pop (unused_thread_queue,
+ local_max_idle_time * 1000);
+ }
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 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;
- }
- }
+ {
+ 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_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);
gpointer task = NULL;
if (pool->running || (!pool->immediate &&
- g_async_queue_length_unlocked (pool->queue) > 0))
+ 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));
- }
+ {
+ /* 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)));
- }
+ {
+ /* 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);
- }
+ {
+ /* A thread will wait for new tasks for at most 1/2
+ * second before going to the global pool.
+ */
+ 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_timeout_pop_unlocked (pool->queue,
+ G_USEC_PER_SEC / 2);
+ }
}
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)));
+ "(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
+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));
+ DEBUG_MSG (("thread %p started for pool %p.", g_thread_self (), pool));
g_async_queue_lock (pool->queue);
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);
- }
- }
+ {
+ 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.
- */
- }
+ {
+ /* 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
+ * immediately, 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)
+static gboolean
+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;
+ return TRUE;
g_async_queue_lock (unused_thread_queue);
if (!success)
{
- GError *local_error = NULL;
+ GThread *thread;
+
/* 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;
- }
+ thread = g_thread_try_new ("pool", g_thread_pool_thread_proxy, pool, error);
+
+ if (thread == NULL)
+ return FALSE;
+
+ g_thread_unref (thread);
}
/* See comment in g_thread_pool_thread_proxy as to why this is done
* here and not there
*/
pool->num_threads++;
+
+ return TRUE;
}
/**
- * g_thread_pool_new:
+ * 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
+ * @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
+ * @error: return location for error, or %NULL
*
* This function creates a new thread pool.
*
* 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
+ * 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.
+ * The parameter @exclusive determines whether the thread pool owns
+ * all threads exclusive or shares them with other thread pools.
+ * 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. Besides, exclusive thread
+ * pools are not affected by g_thread_pool_set_max_idle_time()
+ * since their threads are never considered idle and returned to the
+ * global pool.
*
* @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)
+ * errors. An error can only occur when @exclusive is set to %TRUE
+ * and not all @max_threads threads could be created.
+ * See #GThreadError for possible errors that may occur.
+ * Note, even in case of error a valid #GThreadPool is returned.
+ *
+ * Returns: 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.user_data = user_data;
retval->pool.exclusive = exclusive;
retval->queue = g_async_queue_new ();
- retval->cond = NULL;
+ g_cond_init (&retval->cond);
retval->max_threads = max_threads;
retval->num_threads = 0;
retval->running = TRUE;
+ retval->immediate = FALSE;
+ retval->waiting = FALSE;
retval->sort_func = NULL;
retval->sort_user_data = NULL;
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;
- }
- }
+ {
+ GError *local_error = NULL;
+
+ if (!g_thread_pool_start_thread (retval, &local_error))
+ {
+ g_propagate_error (error, local_error);
+ break;
+ }
+ }
g_async_queue_unlock (retval->queue);
}
* 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: return location for error, or %NULL
+ *
+ * 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
+ * created. In that case @data is simply appended to the queue of
+ * work to do.
+ *
+ * Before version 2.32, this function did not return a success status.
+ *
+ * Returns: %TRUE on success, %FALSE if an error occurred
+ */
+gboolean
g_thread_pool_push (GThreadPool *pool,
- gpointer data,
- GError **error)
+ gpointer data,
+ GError **error)
{
GRealThreadPool *real;
+ gboolean result;
real = (GRealThreadPool*) pool;
- g_return_if_fail (real);
- g_return_if_fail (real->running);
+ g_return_val_if_fail (real, FALSE);
+ g_return_val_if_fail (real->running, FALSE);
+
+ result = TRUE;
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);
+ {
+ /* No thread is waiting in the queue */
+ GError *local_error = NULL;
+
+ if (!g_thread_pool_start_thread (real, &local_error))
+ {
+ g_propagate_error (error, local_error);
+ result = FALSE;
+ }
+ }
g_thread_pool_queue_push_unlocked (real, data);
g_async_queue_unlock (real->queue);
+
+ return result;
}
/**
* 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.
- *
+ * @max_threads: a new maximal number of threads for @pool,
+ * or -1 for unlimited
+ * @error: return location for error, or %NULL
+ *
+ * Sets the maximal allowed number of threads for @pool.
+ * A value of -1 means that the maximal number of threads
+ * is unlimited. If @pool is an exclusive thread pool, setting
+ * the maximal number of threads to -1 is not allowed.
+ *
+ * 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().
+ * 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
+ * created.
+ *
+ * Before version 2.32, this function did not return a success status.
+ *
+ * Returns: %TRUE on success, %FALSE if an error occurred
+ */
+gboolean
g_thread_pool_set_max_threads (GThreadPool *pool,
- gint max_threads,
- GError **error)
+ gint max_threads,
+ GError **error)
{
GRealThreadPool *real;
gint to_start;
+ gboolean result;
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_return_val_if_fail (real, FALSE);
+ g_return_val_if_fail (real->running, FALSE);
+ g_return_val_if_fail (!real->pool.exclusive || max_threads != -1, FALSE);
+ g_return_val_if_fail (max_threads >= -1, FALSE);
+
+ result = TRUE;
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;
- }
+ if (!g_thread_pool_start_thread (real, &local_error))
+ {
+ g_propagate_error (error, local_error);
+ result = FALSE;
+ break;
+ }
}
-
+
g_async_queue_unlock (real->queue);
+
+ return result;
}
/**
*
* Returns the maximal number of threads for @pool.
*
- * Return value: the maximal number of threads
- **/
+ * Returns: the maximal number of threads
+ */
gint
g_thread_pool_get_max_threads (GThreadPool *pool)
{
*
* Returns the number of threads currently running in @pool.
*
- * Return value: the number of threads currently running
- **/
+ * Returns: the number of threads currently running
+ */
guint
g_thread_pool_get_num_threads (GThreadPool *pool)
{
*
* Returns the number of tasks still unprocessed in @pool.
*
- * Return value: the number of unprocessed tasks
- **/
+ * Returns: the number of unprocessed tasks
+ */
guint
g_thread_pool_unprocessed (GThreadPool *pool)
{
*
* 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 @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.
+ * 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.
- **/
+ * After calling this function @pool must not be used anymore.
+ */
void
g_thread_pool_free (GThreadPool *pool,
- gboolean immediate,
- gboolean wait_)
+ gboolean immediate,
+ gboolean wait_)
{
GRealThreadPool *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
+ * 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_return_if_fail (immediate ||
+ real->max_threads != 0 ||
+ g_async_queue_length (real->queue) == 0);
g_async_queue_lock (real->queue);
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));
+ !(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)
+ * 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;
- }
+ 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;
+ real->waiting = FALSE;
g_async_queue_unlock (real->queue);
}
g_return_if_fail (pool->num_threads == 0);
g_async_queue_unref (pool->queue);
-
- if (pool->cond)
- g_cond_free (pool->cond);
+ g_cond_clear (&pool->cond);
g_free (pool);
}
static void
-g_thread_pool_wakeup_and_stop_all (GRealThreadPool* pool)
+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;
+ pool->immediate = TRUE;
+ /*
+ * So here we're sending bogus data to the pool threads, which
+ * should cause them each to wake up, and check the above
+ * pool->immediate condition. However we don't want that
+ * data to be sorted (since it'll crash the sorter).
+ */
for (i = 0; i < pool->num_threads; i++)
- g_thread_pool_queue_push_unlocked (pool, GUINT_TO_POINTER (1));
+ g_async_queue_push_unlocked (pool->queue, 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.
- **/
+ * 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.
+ *
+ * The default value is 2.
+ */
void
g_thread_pool_set_max_unused_threads (gint max_threads)
{
- g_return_if_fail (max_threads >= -1);
+ g_return_if_fail (max_threads >= -1);
g_atomic_int_set (&max_unused_threads, max_threads);
{
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_atomic_int_set (&kill_unused_threads, -max_threads);
+ g_atomic_int_inc (&wakeup_thread_serial);
- g_async_queue_lock (unused_thread_queue);
+ g_async_queue_lock (unused_thread_queue);
- do
- {
- g_async_queue_push_unlocked (unused_thread_queue,
- wakeup_thread_marker);
- }
- while (++max_threads);
+ do
+ {
+ g_async_queue_push_unlocked (unused_thread_queue,
+ wakeup_thread_marker);
+ }
+ while (++max_threads);
- g_async_queue_unlock (unused_thread_queue);
- }
+ 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
- **/
+ * Returns: the maximal number of unused threads
+ */
gint
g_thread_pool_get_max_unused_threads (void)
{
/**
* g_thread_pool_get_num_unused_threads:
- *
+ *
* Returns the number of currently unused threads.
*
- * Return value: the number of currently unused threads
- **/
-guint
+ * Returns: 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_sort_function:
* @pool: a #GThreadPool
- * @func: the #GCompareDataFunc used to sort the list of tasks.
+ * @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,
+ * 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
+ * the second or a positive value if the second task should be
* processed first.
- * @user_data: user data passed to @func.
+ * @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 cannot be guranteed 100%. Threads are
+ * that threads are executed cannot be guaranteed 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.
+ * created.
*
* Since: 2.10
- **/
-void
+ */
+void
g_thread_pool_set_sort_function (GThreadPool *pool,
- GCompareDataFunc func,
- gpointer user_data)
-{
+ GCompareDataFunc func,
+ gpointer user_data)
+{
GRealThreadPool *real;
real = (GRealThreadPool*) pool;
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);
+
+ 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.
+ * @interval: the maximum @interval (in milliseconds)
+ * 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.
+ * 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.
+ *
+ * The default value is 15000 (15 seconds).
*
* Since: 2.10
- **/
+ */
void
g_thread_pool_set_max_idle_time (guint interval)
-{
+{
guint i;
g_atomic_int_set (&max_idle_time, interval);
g_async_queue_lock (unused_thread_queue);
do
- {
- g_async_queue_push_unlocked (unused_thread_queue,
- wakeup_thread_marker);
- }
+ {
+ 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.
+ * 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.
+ *
+ * Returns: the maximum @interval (milliseconds) to wait
+ * for new tasks in the thread pool before stopping the
+ * thread
*
- * 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);
}
projects / platform / upstream / glib.git / blobdiff