*/
#include "u_queue.h"
+
+#include "c11/threads.h"
+
+#include "util/os_time.h"
#include "util/u_string.h"
+#include "util/u_thread.h"
+#include "u_process.h"
-static void util_queue_killall_and_wait(struct util_queue *queue);
+/* Define 256MB */
+#define S_256MB (256 * 1024 * 1024)
+
+static void
+util_queue_kill_threads(struct util_queue *queue, unsigned keep_num_threads,
+ bool finish_locked);
/****************************************************************************
* Wait for all queues to assert idle when exit() is called.
mtx_lock(&exit_mutex);
/* Wait for all queues to assert idle. */
LIST_FOR_EACH_ENTRY(iter, &queue_list, head) {
- util_queue_killall_and_wait(iter);
+ util_queue_kill_threads(iter, 0, false);
}
mtx_unlock(&exit_mutex);
}
static void
global_init(void)
{
- LIST_INITHEAD(&queue_list);
+ list_inithead(&queue_list);
atexit(atexit_handler);
}
call_once(&atexit_once_flag, global_init);
mtx_lock(&exit_mutex);
- LIST_ADD(&queue->head, &queue_list);
+ list_add(&queue->head, &queue_list);
mtx_unlock(&exit_mutex);
}
mtx_lock(&exit_mutex);
LIST_FOR_EACH_ENTRY_SAFE(iter, tmp, &queue_list, head) {
if (iter == queue) {
- LIST_DEL(&iter->head);
+ list_del(&iter->head);
break;
}
}
* util_queue_fence
*/
-static void
+#ifdef UTIL_QUEUE_FENCE_FUTEX
+static bool
+do_futex_fence_wait(struct util_queue_fence *fence,
+ bool timeout, int64_t abs_timeout)
+{
+ uint32_t v = fence->val;
+ struct timespec ts;
+ ts.tv_sec = abs_timeout / (1000*1000*1000);
+ ts.tv_nsec = abs_timeout % (1000*1000*1000);
+
+ while (v != 0) {
+ if (v != 2) {
+ v = p_atomic_cmpxchg(&fence->val, 1, 2);
+ if (v == 0)
+ return true;
+ }
+
+ int r = futex_wait(&fence->val, 2, timeout ? &ts : NULL);
+ if (timeout && r < 0) {
+ if (errno == ETIMEDOUT)
+ return false;
+ }
+
+ v = fence->val;
+ }
+
+ return true;
+}
+
+void
+_util_queue_fence_wait(struct util_queue_fence *fence)
+{
+ do_futex_fence_wait(fence, false, 0);
+}
+
+bool
+_util_queue_fence_wait_timeout(struct util_queue_fence *fence,
+ int64_t abs_timeout)
+{
+ return do_futex_fence_wait(fence, true, abs_timeout);
+}
+
+#endif
+
+#ifdef UTIL_QUEUE_FENCE_STANDARD
+void
util_queue_fence_signal(struct util_queue_fence *fence)
{
mtx_lock(&fence->mutex);
}
void
-util_queue_fence_wait(struct util_queue_fence *fence)
+_util_queue_fence_wait(struct util_queue_fence *fence)
{
mtx_lock(&fence->mutex);
while (!fence->signalled)
mtx_unlock(&fence->mutex);
}
+bool
+_util_queue_fence_wait_timeout(struct util_queue_fence *fence,
+ int64_t abs_timeout)
+{
+ /* This terrible hack is made necessary by the fact that we really want an
+ * internal interface consistent with os_time_*, but cnd_timedwait is spec'd
+ * to be relative to the TIME_UTC clock.
+ */
+ int64_t rel = abs_timeout - os_time_get_nano();
+
+ if (rel > 0) {
+ struct timespec ts;
+
+ timespec_get(&ts, TIME_UTC);
+
+ ts.tv_sec += abs_timeout / (1000*1000*1000);
+ ts.tv_nsec += abs_timeout % (1000*1000*1000);
+ if (ts.tv_nsec >= (1000*1000*1000)) {
+ ts.tv_sec++;
+ ts.tv_nsec -= (1000*1000*1000);
+ }
+
+ mtx_lock(&fence->mutex);
+ while (!fence->signalled) {
+ if (cnd_timedwait(&fence->cond, &fence->mutex, &ts) != thrd_success)
+ break;
+ }
+ mtx_unlock(&fence->mutex);
+ }
+
+ return fence->signalled;
+}
+
void
util_queue_fence_init(struct util_queue_fence *fence)
{
util_queue_fence_destroy(struct util_queue_fence *fence)
{
assert(fence->signalled);
+
+ /* Ensure that another thread is not in the middle of
+ * util_queue_fence_signal (having set the fence to signalled but still
+ * holding the fence mutex).
+ *
+ * A common contract between threads is that as soon as a fence is signalled
+ * by thread A, thread B is allowed to destroy it. Since
+ * util_queue_fence_is_signalled does not lock the fence mutex (for
+ * performance reasons), we must do so here.
+ */
+ mtx_lock(&fence->mutex);
+ mtx_unlock(&fence->mutex);
+
cnd_destroy(&fence->cond);
mtx_destroy(&fence->mutex);
}
+#endif
/****************************************************************************
* util_queue implementation
free(input);
- if (queue->name) {
- char name[16];
- util_snprintf(name, sizeof(name), "%s:%i", queue->name, thread_index);
- u_thread_setname(name);
- }
-
- if (queue->flags & UTIL_QUEUE_INIT_USE_MINIMUM_PRIORITY) {
-#if defined(__linux__)
- struct sched_param sched_param = {0};
-
- /* The nice() function can only set a maximum of 19.
- * SCHED_IDLE is the same as nice = 20.
- *
- * Note that Linux only allows decreasing the priority. The original
- * priority can't be restored.
+#ifdef HAVE_PTHREAD_SETAFFINITY
+ if (queue->flags & UTIL_QUEUE_INIT_SET_FULL_THREAD_AFFINITY) {
+ /* Don't inherit the thread affinity from the parent thread.
+ * Set the full mask.
*/
- pthread_setschedparam(queue->threads[thread_index], SCHED_IDLE,
- &sched_param);
+ cpu_set_t cpuset;
+ CPU_ZERO(&cpuset);
+ for (unsigned i = 0; i < CPU_SETSIZE; i++)
+ CPU_SET(i, &cpuset);
+
+ pthread_setaffinity_np(pthread_self(), sizeof(cpuset), &cpuset);
+ }
#endif
+
+ if (strlen(queue->name) > 0) {
+ char name[16];
+ snprintf(name, sizeof(name), "%s%i", queue->name, thread_index);
+ u_thread_setname(name);
}
while (1) {
assert(queue->num_queued >= 0 && queue->num_queued <= queue->max_jobs);
/* wait if the queue is empty */
- while (!queue->kill_threads && queue->num_queued == 0)
+ while (thread_index < queue->num_threads && queue->num_queued == 0)
cnd_wait(&queue->has_queued_cond, &queue->lock);
- if (queue->kill_threads) {
+ /* only kill threads that are above "num_threads" */
+ if (thread_index >= queue->num_threads) {
mtx_unlock(&queue->lock);
break;
}
util_queue_fence_signal(job.fence);
if (job.cleanup)
job.cleanup(job.job, thread_index);
+
+ queue->total_jobs_size -= job.job_size;
}
}
- /* signal remaining jobs before terminating */
+ /* signal remaining jobs if all threads are being terminated */
mtx_lock(&queue->lock);
- for (unsigned i = queue->read_idx; i != queue->write_idx;
- i = (i + 1) % queue->max_jobs) {
- if (queue->jobs[i].job) {
- util_queue_fence_signal(queue->jobs[i].fence);
- queue->jobs[i].job = NULL;
+ if (queue->num_threads == 0) {
+ for (unsigned i = queue->read_idx; i != queue->write_idx;
+ i = (i + 1) % queue->max_jobs) {
+ if (queue->jobs[i].job) {
+ util_queue_fence_signal(queue->jobs[i].fence);
+ queue->jobs[i].job = NULL;
+ }
}
+ queue->read_idx = queue->write_idx;
+ queue->num_queued = 0;
}
- queue->read_idx = queue->write_idx;
- queue->num_queued = 0;
mtx_unlock(&queue->lock);
return 0;
}
+static bool
+util_queue_create_thread(struct util_queue *queue, unsigned index)
+{
+ struct thread_input *input =
+ (struct thread_input *) malloc(sizeof(struct thread_input));
+ input->queue = queue;
+ input->thread_index = index;
+
+ queue->threads[index] = u_thread_create(util_queue_thread_func, input);
+
+ if (!queue->threads[index]) {
+ free(input);
+ return false;
+ }
+
+ if (queue->flags & UTIL_QUEUE_INIT_USE_MINIMUM_PRIORITY) {
+#if defined(__linux__) && defined(SCHED_IDLE)
+ struct sched_param sched_param = {0};
+
+ /* The nice() function can only set a maximum of 19.
+ * SCHED_IDLE is the same as nice = 20.
+ *
+ * Note that Linux only allows decreasing the priority. The original
+ * priority can't be restored.
+ */
+ pthread_setschedparam(queue->threads[index], SCHED_IDLE, &sched_param);
+#endif
+ }
+ return true;
+}
+
+void
+util_queue_adjust_num_threads(struct util_queue *queue, unsigned num_threads)
+{
+ num_threads = MIN2(num_threads, queue->max_threads);
+ num_threads = MAX2(num_threads, 1);
+
+ mtx_lock(&queue->finish_lock);
+ unsigned old_num_threads = queue->num_threads;
+
+ if (num_threads == old_num_threads) {
+ mtx_unlock(&queue->finish_lock);
+ return;
+ }
+
+ if (num_threads < old_num_threads) {
+ util_queue_kill_threads(queue, num_threads, true);
+ mtx_unlock(&queue->finish_lock);
+ return;
+ }
+
+ /* Create threads.
+ *
+ * We need to update num_threads first, because threads terminate
+ * when thread_index < num_threads.
+ */
+ queue->num_threads = num_threads;
+ for (unsigned i = old_num_threads; i < num_threads; i++) {
+ if (!util_queue_create_thread(queue, i))
+ break;
+ }
+ mtx_unlock(&queue->finish_lock);
+}
+
bool
util_queue_init(struct util_queue *queue,
const char *name,
{
unsigned i;
+ /* Form the thread name from process_name and name, limited to 13
+ * characters. Characters 14-15 are reserved for the thread number.
+ * Character 16 should be 0. Final form: "process:name12"
+ *
+ * If name is too long, it's truncated. If any space is left, the process
+ * name fills it.
+ */
+ const char *process_name = util_get_process_name();
+ int process_len = process_name ? strlen(process_name) : 0;
+ int name_len = strlen(name);
+ const int max_chars = sizeof(queue->name) - 1;
+
+ name_len = MIN2(name_len, max_chars);
+
+ /* See if there is any space left for the process name, reserve 1 for
+ * the colon. */
+ process_len = MIN2(process_len, max_chars - name_len - 1);
+ process_len = MAX2(process_len, 0);
+
memset(queue, 0, sizeof(*queue));
- queue->name = name;
- queue->num_threads = num_threads;
+
+ if (process_len) {
+ snprintf(queue->name, sizeof(queue->name), "%.*s:%s",
+ process_len, process_name, name);
+ } else {
+ snprintf(queue->name, sizeof(queue->name), "%s", name);
+ }
+
queue->flags = flags;
+ queue->max_threads = num_threads;
+ queue->num_threads = num_threads;
queue->max_jobs = max_jobs;
queue->jobs = (struct util_queue_job*)
goto fail;
(void) mtx_init(&queue->lock, mtx_plain);
+ (void) mtx_init(&queue->finish_lock, mtx_plain);
queue->num_queued = 0;
cnd_init(&queue->has_queued_cond);
/* start threads */
for (i = 0; i < num_threads; i++) {
- struct thread_input *input =
- (struct thread_input *) malloc(sizeof(struct thread_input));
- input->queue = queue;
- input->thread_index = i;
-
- queue->threads[i] = u_thread_create(util_queue_thread_func, input);
-
- if (!queue->threads[i]) {
- free(input);
-
+ if (!util_queue_create_thread(queue, i)) {
if (i == 0) {
/* no threads created, fail */
goto fail;
}
static void
-util_queue_killall_and_wait(struct util_queue *queue)
+util_queue_kill_threads(struct util_queue *queue, unsigned keep_num_threads,
+ bool finish_locked)
{
unsigned i;
/* Signal all threads to terminate. */
+ if (!finish_locked)
+ mtx_lock(&queue->finish_lock);
+
+ if (keep_num_threads >= queue->num_threads) {
+ mtx_unlock(&queue->finish_lock);
+ return;
+ }
+
mtx_lock(&queue->lock);
- queue->kill_threads = 1;
+ unsigned old_num_threads = queue->num_threads;
+ /* Setting num_threads is what causes the threads to terminate.
+ * Then cnd_broadcast wakes them up and they will exit their function.
+ */
+ queue->num_threads = keep_num_threads;
cnd_broadcast(&queue->has_queued_cond);
mtx_unlock(&queue->lock);
- for (i = 0; i < queue->num_threads; i++)
+ for (i = keep_num_threads; i < old_num_threads; i++)
thrd_join(queue->threads[i], NULL);
- queue->num_threads = 0;
+
+ if (!finish_locked)
+ mtx_unlock(&queue->finish_lock);
}
void
util_queue_destroy(struct util_queue *queue)
{
- util_queue_killall_and_wait(queue);
+ util_queue_kill_threads(queue, 0, false);
remove_from_atexit_list(queue);
cnd_destroy(&queue->has_space_cond);
cnd_destroy(&queue->has_queued_cond);
+ mtx_destroy(&queue->finish_lock);
mtx_destroy(&queue->lock);
free(queue->jobs);
free(queue->threads);
void *job,
struct util_queue_fence *fence,
util_queue_execute_func execute,
- util_queue_execute_func cleanup)
+ util_queue_execute_func cleanup,
+ const size_t job_size)
{
struct util_queue_job *ptr;
- assert(fence->signalled);
-
mtx_lock(&queue->lock);
- if (queue->kill_threads) {
+ if (queue->num_threads == 0) {
mtx_unlock(&queue->lock);
/* well no good option here, but any leaks will be
* short-lived as things are shutting down..
return;
}
- fence->signalled = false;
+ util_queue_fence_reset(fence);
assert(queue->num_queued >= 0 && queue->num_queued <= queue->max_jobs);
- /* if the queue is full, wait until there is space */
- while (queue->num_queued == queue->max_jobs)
- cnd_wait(&queue->has_space_cond, &queue->lock);
+ if (queue->num_queued == queue->max_jobs) {
+ if (queue->flags & UTIL_QUEUE_INIT_RESIZE_IF_FULL &&
+ queue->total_jobs_size + job_size < S_256MB) {
+ /* If the queue is full, make it larger to avoid waiting for a free
+ * slot.
+ */
+ unsigned new_max_jobs = queue->max_jobs + 8;
+ struct util_queue_job *jobs =
+ (struct util_queue_job*)calloc(new_max_jobs,
+ sizeof(struct util_queue_job));
+ assert(jobs);
+
+ /* Copy all queued jobs into the new list. */
+ unsigned num_jobs = 0;
+ unsigned i = queue->read_idx;
+
+ do {
+ jobs[num_jobs++] = queue->jobs[i];
+ i = (i + 1) % queue->max_jobs;
+ } while (i != queue->write_idx);
+
+ assert(num_jobs == queue->num_queued);
+
+ free(queue->jobs);
+ queue->jobs = jobs;
+ queue->read_idx = 0;
+ queue->write_idx = num_jobs;
+ queue->max_jobs = new_max_jobs;
+ } else {
+ /* Wait until there is a free slot. */
+ while (queue->num_queued == queue->max_jobs)
+ cnd_wait(&queue->has_space_cond, &queue->lock);
+ }
+ }
ptr = &queue->jobs[queue->write_idx];
assert(ptr->job == NULL);
ptr->fence = fence;
ptr->execute = execute;
ptr->cleanup = cleanup;
+ ptr->job_size = job_size;
+
queue->write_idx = (queue->write_idx + 1) % queue->max_jobs;
+ queue->total_jobs_size += ptr->job_size;
queue->num_queued++;
cnd_signal(&queue->has_queued_cond);
util_queue_fence_wait(fence);
}
+static void
+util_queue_finish_execute(void *data, int num_thread)
+{
+ util_barrier *barrier = data;
+ util_barrier_wait(barrier);
+}
+
+/**
+ * Wait until all previously added jobs have completed.
+ */
+void
+util_queue_finish(struct util_queue *queue)
+{
+ util_barrier barrier;
+ struct util_queue_fence *fences;
+
+ /* If 2 threads were adding jobs for 2 different barries at the same time,
+ * a deadlock would happen, because 1 barrier requires that all threads
+ * wait for it exclusively.
+ */
+ mtx_lock(&queue->finish_lock);
+
+ /* The number of threads can be changed to 0, e.g. by the atexit handler. */
+ if (!queue->num_threads) {
+ mtx_unlock(&queue->finish_lock);
+ return;
+ }
+
+ fences = malloc(queue->num_threads * sizeof(*fences));
+ util_barrier_init(&barrier, queue->num_threads);
+
+ for (unsigned i = 0; i < queue->num_threads; ++i) {
+ util_queue_fence_init(&fences[i]);
+ util_queue_add_job(queue, &barrier, &fences[i],
+ util_queue_finish_execute, NULL, 0);
+ }
+
+ for (unsigned i = 0; i < queue->num_threads; ++i) {
+ util_queue_fence_wait(&fences[i]);
+ util_queue_fence_destroy(&fences[i]);
+ }
+ mtx_unlock(&queue->finish_lock);
+
+ util_barrier_destroy(&barrier);
+
+ free(fences);
+}
+
int64_t
util_queue_get_thread_time_nano(struct util_queue *queue, unsigned thread_index)
{