/* GLIB - Library of useful routines for C programming
* Copyright (C) 1995-1997 Peter Mattis, Spencer Kimball and Josh MacDonald
*
- * GAsyncQueue: asyncronous queue implementation, based on Gqueue.
+ * GAsyncQueue: asynchronous queue implementation, based on GQueue.
* 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 Library General Public
+ * 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
- * Library General Public License for more details.
+ * Lesser General Public License for more details.
*
- * You should have received a copy of the GNU Library 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.
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>.
*/
/*
* MT safe
*/
-#include "glib.h"
+#include "config.h"
+#include "gasyncqueue.h"
+#include "gasyncqueueprivate.h"
+
+#include "gmain.h"
+#include "gmem.h"
+#include "gqueue.h"
+#include "gtestutils.h"
+#include "gtimer.h"
+#include "gthread.h"
+#include "deprecated/gthread.h"
+
+
+/**
+ * SECTION:async_queues
+ * @title: Asynchronous Queues
+ * @short_description: asynchronous communication between threads
+ * @see_also: #GThreadPool
+ *
+ * Often you need to communicate between different threads. In general
+ * it's safer not to do this by shared memory, but by explicit message
+ * passing. These messages only make sense asynchronously for
+ * multi-threaded applications though, as a synchronous operation could
+ * as well be done in the same thread.
+ *
+ * Asynchronous queues are an exception from most other GLib data
+ * structures, as they can be used simultaneously from multiple threads
+ * without explicit locking and they bring their own builtin reference
+ * counting. This is because the nature of an asynchronous queue is that
+ * it will always be used by at least 2 concurrent threads.
+ *
+ * For using an asynchronous queue you first have to create one with
+ * g_async_queue_new(). #GAsyncQueue structs are reference counted,
+ * use g_async_queue_ref() and g_async_queue_unref() to manage your
+ * references.
+ *
+ * A thread which wants to send a message to that queue simply calls
+ * g_async_queue_push() to push the message to the queue.
+ *
+ * A thread which is expecting messages from an asynchronous queue
+ * simply calls g_async_queue_pop() for that queue. If no message is
+ * available in the queue at that point, the thread is now put to sleep
+ * until a message arrives. The message will be removed from the queue
+ * and returned. The functions g_async_queue_try_pop() and
+ * g_async_queue_timeout_pop() can be used to only check for the presence
+ * of messages or to only wait a certain time for messages respectively.
+ *
+ * For almost every function there exist two variants, one that locks
+ * the queue and one that doesn't. That way you can hold the queue lock
+ * (acquire it with g_async_queue_lock() and release it with
+ * g_async_queue_unlock()) over multiple queue accessing instructions.
+ * This can be necessary to ensure the integrity of the queue, but should
+ * only be used when really necessary, as it can make your life harder
+ * if used unwisely. Normally you should only use the locking function
+ * variants (those without the _unlocked suffix).
+ *
+ * In many cases, it may be more convenient to use #GThreadPool when
+ * you need to distribute work to a set of worker threads instead of
+ * using #GAsyncQueue manually. #GThreadPool uses a GAsyncQueue
+ * internally.
+ */
+
+/**
+ * GAsyncQueue:
+ *
+ * The GAsyncQueue struct is an opaque data structure which represents
+ * an asynchronous queue. It should only be accessed through the
+ * g_async_queue_* functions.
+ */
struct _GAsyncQueue
{
- GMutex *mutex;
- GCond *cond;
- GQueue *queue;
+ GMutex mutex;
+ GCond cond;
+ GQueue queue;
+ GDestroyNotify item_free_func;
guint waiting_threads;
- guint ref_count;
+ gint ref_count;
};
-GAsyncQueue*
-g_async_queue_new ()
+typedef struct
{
- GAsyncQueue* retval = g_new (GAsyncQueue, 1);
- retval->mutex = g_mutex_new ();
- retval->cond = g_cond_new ();
- retval->queue = g_queue_new ();
- retval->waiting_threads = 0;
- retval->ref_count = 1;
- return retval;
+ GCompareDataFunc func;
+ gpointer user_data;
+} SortData;
+
+/**
+ * g_async_queue_new:
+ *
+ * Creates a new asynchronous queue.
+ *
+ * Returns: a new #GAsyncQueue. Free with g_async_queue_unref()
+ */
+GAsyncQueue *
+g_async_queue_new (void)
+{
+ return g_async_queue_new_full (NULL);
}
-void
+/**
+ * g_async_queue_new_full:
+ * @item_free_func: function to free queue elements
+ *
+ * Creates a new asynchronous queue and sets up a destroy notify
+ * function that is used to free any remaining queue items when
+ * the queue is destroyed after the final unref.
+ *
+ * Returns: a new #GAsyncQueue. Free with g_async_queue_unref()
+ *
+ * Since: 2.16
+ */
+GAsyncQueue *
+g_async_queue_new_full (GDestroyNotify item_free_func)
+{
+ GAsyncQueue *queue;
+
+ queue = g_new (GAsyncQueue, 1);
+ g_mutex_init (&queue->mutex);
+ g_cond_init (&queue->cond);
+ g_queue_init (&queue->queue);
+ queue->waiting_threads = 0;
+ queue->ref_count = 1;
+ queue->item_free_func = item_free_func;
+
+ return queue;
+}
+
+/**
+ * g_async_queue_ref:
+ * @queue: a #GAsyncQueue
+ *
+ * Increases the reference count of the asynchronous @queue by 1.
+ * You do not need to hold the lock to call this function.
+ *
+ * Returns: the @queue that was passed in (since 2.6)
+ */
+GAsyncQueue *
g_async_queue_ref (GAsyncQueue *queue)
{
- g_return_if_fail (queue);
- g_return_if_fail (queue->ref_count > 0);
-
- g_mutex_lock (queue->mutex);
- queue->ref_count++;
- g_mutex_unlock (queue->mutex);
+ g_return_val_if_fail (queue, NULL);
+
+ g_atomic_int_inc (&queue->ref_count);
+
+ return queue;
}
-void
+/**
+ * g_async_queue_ref_unlocked:
+ * @queue: a #GAsyncQueue
+ *
+ * Increases the reference count of the asynchronous @queue by 1.
+ *
+ * Deprecated: 2.8: Reference counting is done atomically.
+ * so g_async_queue_ref() can be used regardless of the @queue's
+ * lock.
+ */
+void
g_async_queue_ref_unlocked (GAsyncQueue *queue)
{
g_return_if_fail (queue);
- g_return_if_fail (queue->ref_count > 0);
-
- queue->ref_count++;
+
+ g_atomic_int_inc (&queue->ref_count);
}
-void
+/**
+ * g_async_queue_unref_and_unlock:
+ * @queue: a #GAsyncQueue
+ *
+ * Decreases the reference count of the asynchronous @queue by 1
+ * and releases the lock. This function must be called while holding
+ * the @queue's lock. If the reference count went to 0, the @queue
+ * will be destroyed and the memory allocated will be freed.
+ *
+ * Deprecated: 2.8: Reference counting is done atomically.
+ * so g_async_queue_unref() can be used regardless of the @queue's
+ * lock.
+ */
+void
g_async_queue_unref_and_unlock (GAsyncQueue *queue)
{
- gboolean stop;
-
g_return_if_fail (queue);
- g_return_if_fail (queue->ref_count > 0);
- queue->ref_count--;
- stop = (queue->ref_count == 0);
- g_mutex_unlock (queue->mutex);
-
- if (stop)
- {
- g_return_if_fail (queue->waiting_threads == 0);
- g_mutex_free (queue->mutex);
- g_cond_free (queue->cond);
- g_queue_free (queue->queue);
- g_free (queue);
- }
+ g_mutex_unlock (&queue->mutex);
+ g_async_queue_unref (queue);
}
-void
+/**
+ * g_async_queue_unref:
+ * @queue: a #GAsyncQueue.
+ *
+ * Decreases the reference count of the asynchronous @queue by 1.
+ *
+ * If the reference count went to 0, the @queue will be destroyed
+ * and the memory allocated will be freed. So you are not allowed
+ * to use the @queue afterwards, as it might have disappeared.
+ * You do not need to hold the lock to call this function.
+ */
+void
g_async_queue_unref (GAsyncQueue *queue)
{
g_return_if_fail (queue);
- g_return_if_fail (queue->ref_count > 0);
- g_mutex_lock (queue->mutex);
- g_async_queue_unref_and_unlock (queue);
+ if (g_atomic_int_dec_and_test (&queue->ref_count))
+ {
+ g_return_if_fail (queue->waiting_threads == 0);
+ g_mutex_clear (&queue->mutex);
+ g_cond_clear (&queue->cond);
+ if (queue->item_free_func)
+ g_queue_foreach (&queue->queue, (GFunc) queue->item_free_func, NULL);
+ g_queue_clear (&queue->queue);
+ g_free (queue);
+ }
}
+/**
+ * g_async_queue_lock:
+ * @queue: a #GAsyncQueue
+ *
+ * Acquires the @queue's lock. If another thread is already
+ * holding the lock, this call will block until the lock
+ * becomes available.
+ *
+ * Call g_async_queue_unlock() to drop the lock again.
+ *
+ * While holding the lock, you can only call the
+ * g_async_queue_*_unlocked() functions on @queue. Otherwise,
+ * deadlock may occur.
+ */
void
g_async_queue_lock (GAsyncQueue *queue)
{
g_return_if_fail (queue);
- g_return_if_fail (queue->ref_count > 0);
- g_mutex_lock (queue->mutex);
+ g_mutex_lock (&queue->mutex);
}
-void
+/**
+ * g_async_queue_unlock:
+ * @queue: a #GAsyncQueue
+ *
+ * Releases the queue's lock.
+ *
+ * Calling this function when you have not acquired
+ * the with g_async_queue_lock() leads to undefined
+ * behaviour.
+ */
+void
g_async_queue_unlock (GAsyncQueue *queue)
{
g_return_if_fail (queue);
- g_return_if_fail (queue->ref_count > 0);
- g_mutex_unlock (queue->mutex);
+ g_mutex_unlock (&queue->mutex);
}
+/**
+ * g_async_queue_push:
+ * @queue: a #GAsyncQueue
+ * @data: @data to push into the @queue
+ *
+ * Pushes the @data into the @queue. @data must not be %NULL.
+ */
void
-g_async_queue_push (GAsyncQueue* queue, gpointer data)
+g_async_queue_push (GAsyncQueue *queue,
+ gpointer data)
{
g_return_if_fail (queue);
- g_return_if_fail (queue->ref_count > 0);
g_return_if_fail (data);
- g_mutex_lock (queue->mutex);
+ g_mutex_lock (&queue->mutex);
g_async_queue_push_unlocked (queue, data);
- g_mutex_unlock (queue->mutex);
+ g_mutex_unlock (&queue->mutex);
}
+/**
+ * g_async_queue_push_unlocked:
+ * @queue: a #GAsyncQueue
+ * @data: @data to push into the @queue
+ *
+ * Pushes the @data into the @queue. @data must not be %NULL.
+ *
+ * This function must be called while holding the @queue's lock.
+ */
void
-g_async_queue_push_unlocked (GAsyncQueue* queue, gpointer data)
+g_async_queue_push_unlocked (GAsyncQueue *queue,
+ gpointer data)
{
g_return_if_fail (queue);
- g_return_if_fail (queue->ref_count > 0);
g_return_if_fail (data);
- g_queue_push_head (queue->queue, data);
- g_cond_signal (queue->cond);
+ g_queue_push_head (&queue->queue, data);
+ if (queue->waiting_threads > 0)
+ g_cond_signal (&queue->cond);
+}
+
+/**
+ * g_async_queue_push_sorted:
+ * @queue: a #GAsyncQueue
+ * @data: the @data to push into the @queue
+ * @func: the #GCompareDataFunc is used to sort @queue
+ * @user_data: user data passed to @func.
+ *
+ * Inserts @data into @queue using @func to determine the new
+ * position.
+ *
+ * This function requires that the @queue is sorted before pushing on
+ * new elements, see g_async_queue_sort().
+ *
+ * This function will lock @queue before it sorts the queue and unlock
+ * it when it is finished.
+ *
+ * For an example of @func see g_async_queue_sort().
+ *
+ * Since: 2.10
+ */
+void
+g_async_queue_push_sorted (GAsyncQueue *queue,
+ gpointer data,
+ GCompareDataFunc func,
+ gpointer user_data)
+{
+ g_return_if_fail (queue != NULL);
+
+ g_mutex_lock (&queue->mutex);
+ g_async_queue_push_sorted_unlocked (queue, data, func, user_data);
+ g_mutex_unlock (&queue->mutex);
+}
+
+static gint
+g_async_queue_invert_compare (gpointer v1,
+ gpointer v2,
+ SortData *sd)
+{
+ return -sd->func (v1, v2, sd->user_data);
+}
+
+/**
+ * g_async_queue_push_sorted_unlocked:
+ * @queue: a #GAsyncQueue
+ * @data: the @data to push into the @queue
+ * @func: the #GCompareDataFunc is used to sort @queue
+ * @user_data: user data passed to @func.
+ *
+ * Inserts @data into @queue using @func to determine the new
+ * position.
+ *
+ * The sort function @func is passed two elements of the @queue.
+ * It should return 0 if they are equal, a negative value if the
+ * first element should be higher in the @queue or a positive value
+ * if the first element should be lower in the @queue than the second
+ * element.
+ *
+ * This function requires that the @queue is sorted before pushing on
+ * new elements, see g_async_queue_sort().
+ *
+ * This function must be called while holding the @queue's lock.
+ *
+ * For an example of @func see g_async_queue_sort().
+ *
+ * Since: 2.10
+ */
+void
+g_async_queue_push_sorted_unlocked (GAsyncQueue *queue,
+ gpointer data,
+ GCompareDataFunc func,
+ gpointer user_data)
+{
+ SortData sd;
+
+ g_return_if_fail (queue != NULL);
+
+ sd.func = func;
+ sd.user_data = user_data;
+
+ g_queue_insert_sorted (&queue->queue,
+ data,
+ (GCompareDataFunc)g_async_queue_invert_compare,
+ &sd);
+ if (queue->waiting_threads > 0)
+ g_cond_signal (&queue->cond);
}
static gpointer
-g_async_queue_pop_intern_unlocked (GAsyncQueue* queue, gboolean try,
- GTimeVal *end_time)
+g_async_queue_pop_intern_unlocked (GAsyncQueue *queue,
+ gboolean wait,
+ gint64 end_time)
{
gpointer retval;
- if (!g_queue_peek_tail (queue->queue))
+ if (!g_queue_peek_tail_link (&queue->queue) && wait)
{
- if (try)
- return NULL;
- if (!end_time)
+ queue->waiting_threads++;
+ while (!g_queue_peek_tail_link (&queue->queue))
{
- queue->waiting_threads++;
- while (!g_queue_peek_tail (queue->queue))
- g_cond_wait(queue->cond, queue->mutex);
- queue->waiting_threads--;
- }
- else
- {
- queue->waiting_threads++;
- while (!g_queue_peek_tail (queue->queue))
- if (!g_cond_timed_wait (queue->cond, queue->mutex, end_time))
- break;
- queue->waiting_threads--;
- if (!g_queue_peek_tail (queue->queue))
- return NULL;
+ if (end_time == -1)
+ g_cond_wait (&queue->cond, &queue->mutex);
+ else
+ {
+ if (!g_cond_wait_until (&queue->cond, &queue->mutex, end_time))
+ break;
+ }
}
+ queue->waiting_threads--;
}
- retval = g_queue_pop_tail (queue->queue);
+ retval = g_queue_pop_tail (&queue->queue);
- g_assert (retval);
+ g_assert (retval || !wait || end_time > 0);
return retval;
}
+/**
+ * g_async_queue_pop:
+ * @queue: a #GAsyncQueue
+ *
+ * Pops data from the @queue. If @queue is empty, this function
+ * blocks until data becomes available.
+ *
+ * Returns: data from the queue
+ */
gpointer
-g_async_queue_pop (GAsyncQueue* queue)
+g_async_queue_pop (GAsyncQueue *queue)
{
gpointer retval;
g_return_val_if_fail (queue, NULL);
- g_return_val_if_fail (queue->ref_count > 0, NULL);
- g_mutex_lock (queue->mutex);
- retval = g_async_queue_pop_intern_unlocked (queue, FALSE, NULL);
- g_mutex_unlock (queue->mutex);
+ g_mutex_lock (&queue->mutex);
+ retval = g_async_queue_pop_intern_unlocked (queue, TRUE, -1);
+ g_mutex_unlock (&queue->mutex);
return retval;
}
+/**
+ * g_async_queue_pop_unlocked:
+ * @queue: a #GAsyncQueue
+ *
+ * Pops data from the @queue. If @queue is empty, this function
+ * blocks until data becomes available.
+ *
+ * This function must be called while holding the @queue's lock.
+ *
+ * Returns: data from the queue.
+ */
gpointer
-g_async_queue_pop_unlocked (GAsyncQueue* queue)
+g_async_queue_pop_unlocked (GAsyncQueue *queue)
{
g_return_val_if_fail (queue, NULL);
- g_return_val_if_fail (queue->ref_count > 0, NULL);
- return g_async_queue_pop_intern_unlocked (queue, FALSE, NULL);
+ return g_async_queue_pop_intern_unlocked (queue, TRUE, -1);
}
+/**
+ * g_async_queue_try_pop:
+ * @queue: a #GAsyncQueue
+ *
+ * Tries to pop data from the @queue. If no data is available,
+ * %NULL is returned.
+ *
+ * Returns: data from the queue or %NULL, when no data is
+ * available immediately.
+ */
gpointer
-g_async_queue_try_pop (GAsyncQueue* queue)
+g_async_queue_try_pop (GAsyncQueue *queue)
{
gpointer retval;
g_return_val_if_fail (queue, NULL);
- g_return_val_if_fail (queue->ref_count > 0, NULL);
- g_mutex_lock (queue->mutex);
- retval = g_async_queue_pop_intern_unlocked (queue, TRUE, NULL);
- g_mutex_unlock (queue->mutex);
+ g_mutex_lock (&queue->mutex);
+ retval = g_async_queue_pop_intern_unlocked (queue, FALSE, -1);
+ g_mutex_unlock (&queue->mutex);
return retval;
}
+/**
+ * g_async_queue_try_pop_unlocked:
+ * @queue: a #GAsyncQueue
+ *
+ * Tries to pop data from the @queue. If no data is available,
+ * %NULL is returned.
+ *
+ * This function must be called while holding the @queue's lock.
+ *
+ * Returns: data from the queue or %NULL, when no data is
+ * available immediately.
+ */
gpointer
-g_async_queue_try_pop_unlocked (GAsyncQueue* queue)
+g_async_queue_try_pop_unlocked (GAsyncQueue *queue)
{
g_return_val_if_fail (queue, NULL);
- g_return_val_if_fail (queue->ref_count > 0, NULL);
- return g_async_queue_pop_intern_unlocked (queue, TRUE, NULL);
+ return g_async_queue_pop_intern_unlocked (queue, FALSE, -1);
}
+/**
+ * g_async_queue_timeout_pop:
+ * @queue: a #GAsyncQueue
+ * @timeout: the number of microseconds to wait
+ *
+ * Pops data from the @queue. If the queue is empty, blocks for
+ * @timeout microseconds, or until data becomes available.
+ *
+ * If no data is received before the timeout, %NULL is returned.
+ *
+ * Returns: data from the queue or %NULL, when no data is
+ * received before the timeout.
+ */
gpointer
-g_async_queue_timed_pop (GAsyncQueue* queue, GTimeVal *end_time)
+g_async_queue_timeout_pop (GAsyncQueue *queue,
+ guint64 timeout)
{
+ gint64 end_time = g_get_monotonic_time () + timeout;
+ gpointer retval;
+
+ g_mutex_lock (&queue->mutex);
+ retval = g_async_queue_pop_intern_unlocked (queue, TRUE, end_time);
+ g_mutex_unlock (&queue->mutex);
+
+ return retval;
+}
+
+/**
+ * g_async_queue_timeout_pop_unlocked:
+ * @queue: a #GAsyncQueue
+ * @timeout: the number of microseconds to wait
+ *
+ * Pops data from the @queue. If the queue is empty, blocks for
+ * @timeout microseconds, or until data becomes available.
+ *
+ * If no data is received before the timeout, %NULL is returned.
+ *
+ * This function must be called while holding the @queue's lock.
+ *
+ * Returns: data from the queue or %NULL, when no data is
+ * received before the timeout.
+ */
+gpointer
+g_async_queue_timeout_pop_unlocked (GAsyncQueue *queue,
+ guint64 timeout)
+{
+ gint64 end_time = g_get_monotonic_time () + timeout;
+
+ return g_async_queue_pop_intern_unlocked (queue, TRUE, end_time);
+}
+
+/**
+ * g_async_queue_timed_pop:
+ * @queue: a #GAsyncQueue
+ * @end_time: a #GTimeVal, determining the final time
+ *
+ * Pops data from the @queue. If the queue is empty, blocks until
+ * @end_time or until data becomes available.
+ *
+ * If no data is received before @end_time, %NULL is returned.
+ *
+ * To easily calculate @end_time, a combination of g_get_current_time()
+ * and g_time_val_add() can be used.
+ *
+ * Returns: data from the queue or %NULL, when no data is
+ * received before @end_time.
+ *
+ * Deprecated: use g_async_queue_timeout_pop().
+ */
+gpointer
+g_async_queue_timed_pop (GAsyncQueue *queue,
+ GTimeVal *end_time)
+{
+ gint64 m_end_time;
gpointer retval;
g_return_val_if_fail (queue, NULL);
- g_return_val_if_fail (queue->ref_count > 0, NULL);
- g_mutex_lock (queue->mutex);
- retval = g_async_queue_pop_intern_unlocked (queue, FALSE, end_time);
- g_mutex_unlock (queue->mutex);
+ if (end_time != NULL)
+ {
+ m_end_time = g_get_monotonic_time () +
+ ((gint64) end_time->tv_sec * G_USEC_PER_SEC + end_time->tv_usec - g_get_real_time ());
+ }
+ else
+ m_end_time = -1;
+
+ g_mutex_lock (&queue->mutex);
+ retval = g_async_queue_pop_intern_unlocked (queue, TRUE, m_end_time);
+ g_mutex_unlock (&queue->mutex);
- return retval;
+ return retval;
}
+/**
+ * g_async_queue_timed_pop_unlocked:
+ * @queue: a #GAsyncQueue
+ * @end_time: a #GTimeVal, determining the final time
+ *
+ * Pops data from the @queue. If the queue is empty, blocks until
+ * @end_time or until data becomes available.
+ *
+ * If no data is received before @end_time, %NULL is returned.
+ *
+ * To easily calculate @end_time, a combination of g_get_current_time()
+ * and g_time_val_add() can be used.
+ *
+ * This function must be called while holding the @queue's lock.
+ *
+ * Returns: data from the queue or %NULL, when no data is
+ * received before @end_time.
+ *
+ * Deprecated: use g_async_queue_timeout_pop_unlocked().
+ */
gpointer
-g_async_queue_timed_pop_unlocked (GAsyncQueue* queue, GTimeVal *end_time)
+g_async_queue_timed_pop_unlocked (GAsyncQueue *queue,
+ GTimeVal *end_time)
{
+ gint64 m_end_time;
+
g_return_val_if_fail (queue, NULL);
- g_return_val_if_fail (queue->ref_count > 0, NULL);
- return g_async_queue_pop_intern_unlocked (queue, FALSE, end_time);
+ if (end_time != NULL)
+ {
+ m_end_time = g_get_monotonic_time () +
+ ((gint64) end_time->tv_sec * G_USEC_PER_SEC + end_time->tv_usec - g_get_real_time ());
+ }
+ else
+ m_end_time = -1;
+
+ return g_async_queue_pop_intern_unlocked (queue, TRUE, m_end_time);
}
+/**
+ * g_async_queue_length:
+ * @queue: a #GAsyncQueue.
+ *
+ * Returns the length of the queue.
+ *
+ * Actually this function returns the number of data items in
+ * the queue minus the number of waiting threads, so a negative
+ * value means waiting threads, and a positive value means available
+ * entries in the @queue. A return value of 0 could mean n entries
+ * in the queue and n threads waiting. This can happen due to locking
+ * of the queue or due to scheduling.
+ *
+ * Returns: the length of the @queue
+ */
gint
-g_async_queue_length_unlocked (GAsyncQueue* queue)
+g_async_queue_length (GAsyncQueue *queue)
{
+ gint retval;
+
g_return_val_if_fail (queue, 0);
- g_return_val_if_fail (queue->ref_count > 0, 0);
- return queue->queue->length - queue->waiting_threads;
+ g_mutex_lock (&queue->mutex);
+ retval = queue->queue.length - queue->waiting_threads;
+ g_mutex_unlock (&queue->mutex);
+
+ return retval;
}
+/**
+ * g_async_queue_length_unlocked:
+ * @queue: a #GAsyncQueue
+ *
+ * Returns the length of the queue.
+ *
+ * Actually this function returns the number of data items in
+ * the queue minus the number of waiting threads, so a negative
+ * value means waiting threads, and a positive value means available
+ * entries in the @queue. A return value of 0 could mean n entries
+ * in the queue and n threads waiting. This can happen due to locking
+ * of the queue or due to scheduling.
+ *
+ * This function must be called while holding the @queue's lock.
+ *
+ * Returns: the length of the @queue.
+ */
gint
-g_async_queue_length(GAsyncQueue* queue)
+g_async_queue_length_unlocked (GAsyncQueue *queue)
{
- glong retval;
-
g_return_val_if_fail (queue, 0);
- g_return_val_if_fail (queue->ref_count > 0, 0);
- g_mutex_lock (queue->mutex);
- retval = queue->queue->length - queue->waiting_threads;
- g_mutex_unlock (queue->mutex);
+ return queue->queue.length - queue->waiting_threads;
+}
- return retval;
+/**
+ * g_async_queue_sort:
+ * @queue: a #GAsyncQueue
+ * @func: the #GCompareDataFunc is used to sort @queue
+ * @user_data: user data passed to @func
+ *
+ * Sorts @queue using @func.
+ *
+ * The sort function @func is passed two elements of the @queue.
+ * It should return 0 if they are equal, a negative value if the
+ * first element should be higher in the @queue or a positive value
+ * if the first element should be lower in the @queue than the second
+ * element.
+ *
+ * This function will lock @queue before it sorts the queue and unlock
+ * it when it is finished.
+ *
+ * If you were sorting a list of priority numbers to make sure the
+ * lowest priority would be at the top of the queue, you could use:
+ * |[<!-- language="C" -->
+ * gint32 id1;
+ * gint32 id2;
+ *
+ * id1 = GPOINTER_TO_INT (element1);
+ * id2 = GPOINTER_TO_INT (element2);
+ *
+ * return (id1 > id2 ? +1 : id1 == id2 ? 0 : -1);
+ * ]|
+ *
+ * Since: 2.10
+ */
+void
+g_async_queue_sort (GAsyncQueue *queue,
+ GCompareDataFunc func,
+ gpointer user_data)
+{
+ g_return_if_fail (queue != NULL);
+ g_return_if_fail (func != NULL);
+
+ g_mutex_lock (&queue->mutex);
+ g_async_queue_sort_unlocked (queue, func, user_data);
+ g_mutex_unlock (&queue->mutex);
}
+/**
+ * g_async_queue_sort_unlocked:
+ * @queue: a #GAsyncQueue
+ * @func: the #GCompareDataFunc is used to sort @queue
+ * @user_data: user data passed to @func
+ *
+ * Sorts @queue using @func.
+ *
+ * The sort function @func is passed two elements of the @queue.
+ * It should return 0 if they are equal, a negative value if the
+ * first element should be higher in the @queue or a positive value
+ * if the first element should be lower in the @queue than the second
+ * element.
+ *
+ * This function must be called while holding the @queue's lock.
+ *
+ * Since: 2.10
+ */
+void
+g_async_queue_sort_unlocked (GAsyncQueue *queue,
+ GCompareDataFunc func,
+ gpointer user_data)
+{
+ SortData sd;
+
+ g_return_if_fail (queue != NULL);
+ g_return_if_fail (func != NULL);
+
+ sd.func = func;
+ sd.user_data = user_data;
+
+ g_queue_sort (&queue->queue,
+ (GCompareDataFunc)g_async_queue_invert_compare,
+ &sd);
+}
+
+/*
+ * Private API
+ */
+
+GMutex *
+_g_async_queue_get_mutex (GAsyncQueue *queue)
+{
+ g_return_val_if_fail (queue, NULL);
+
+ return &queue->mutex;
+}
projects / platform / upstream / glib.git / blobdiff