/**
* g_thread_pool_push:
* @pool: a #GThreadPool
* @data: a new task for @pool
* @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.
*
* 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)
{
GRealThreadPool *real;
gboolean result;
real = (GRealThreadPool*) pool;
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 */
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_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, or %NULL
*
* 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 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.
* 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);
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 ();
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;
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;
if (!g_thread_pool_start_thread (retval, &local_error))
{
g_propagate_error (error, local_error);
break;
}
}
g_async_queue_unlock (retval->queue);
}
return (GThreadPool*) retval;
}
/**
* g_thread_pool_set_max_threads:
* @pool: a #GThreadPool
* @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().
* 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.
*
* 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)
{
GRealThreadPool *real;
gint to_start;
gboolean result;
real = (GRealThreadPool*) pool;
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;
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;
}
/**
* 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);
}
