RmBuffer *rm_buffer_get(RmBufferPool *pool) {
RmBuffer *buffer = NULL;
g_mutex_lock(&pool->lock);
{
while(!buffer) {
buffer = rm_util_slist_pop(&pool->stack, NULL);
if (!buffer && pool->avail_buffers > 0) {
buffer = rm_buffer_new(pool);
}
if (!buffer) {
if(!pool->mem_warned) {
rm_log_warning_line(
"read buffer limit reached - waiting for "
"processing to catch up");
pool->mem_warned = true;
}
g_cond_wait(&pool->change, &pool->lock);
}
}
pool->avail_buffers--;
}
g_mutex_unlock(&pool->lock);
rm_assert_gentle(buffer);
return buffer;
}
/** @brief RmMDSDevice worker thread
**/
static void rm_mds_factory(RmMDSDevice *device, RmMDS *mds) {
/* rm_mds_factory processes tasks from device->task_list.
* After completing one pass of the device, returns self to the
* mds->pool threadpool. */
gint processed = 0;
g_mutex_lock(&device->lock);
{
/* check for empty queues - if so then wait a little while before giving up */
if(!device->sorted_tasks && !device->unsorted_tasks && device->ref_count > 0) {
/* timed wait for signal from rm_mds_push_task_impl() */
gint64 end_time = g_get_monotonic_time() + MDS_EMPTYQUEUE_SLEEP_US;
g_cond_wait_until(&device->cond, &device->lock, end_time);
}
/* sort and merge task lists */
if(device->unsorted_tasks) {
if(mds->prioritiser) {
device->sorted_tasks = g_slist_concat(
g_slist_sort_with_data(device->unsorted_tasks,
(GCompareDataFunc)rm_mds_compare,
(RmMDSSortFunc)mds->prioritiser),
device->sorted_tasks);
} else {
device->sorted_tasks =
g_slist_concat(device->unsorted_tasks, device->sorted_tasks);
}
device->unsorted_tasks = NULL;
}
}
g_mutex_unlock(&device->lock);
/* process tasks from device->sorted_tasks */
RmMDSTask *task = NULL;
while(processed < mds->pass_quota && (task = rm_util_slist_pop(&device->sorted_tasks, &device->lock))) {
if(mds->func(task->task_data, mds->user_data)) {
/* task succeeded; update counters */
++processed;
}
rm_mds_task_free(task);
}
if(rm_mds_device_ref(device, 0) > 0) {
/* return self to pool for further processing */
if(processed == 0) {
/* stalled queue; chill for a bit */
g_usleep(1000);
}
rm_util_thread_pool_push(mds->pool, device);
} else if(g_atomic_int_dec_and_test(&device->threads)) {
/* free self and signal to rm_mds_free() */
g_mutex_lock(&mds->lock);
{
rm_log_debug_line("Freeing device %" LLU " (pointer %p)", (RmOff)device->disk,
device);
g_hash_table_remove(mds->disks, GINT_TO_POINTER(device->disk));
rm_mds_device_free(device);
g_cond_signal(&mds->cond);
}
g_mutex_unlock(&mds->lock);
}
}
