X-Git-Url: https://repo.jachan.dev/qemu.git/blobdiff_plain/9176e8fb8f78206bd4039f001aca0d931a47d663..36a43ea83b4426344592523fd560e5f76c4867c4:/thread-pool.c diff --git a/thread-pool.c b/thread-pool.c index 5025567817..03ba0b02a4 100644 --- a/thread-pool.c +++ b/thread-pool.c @@ -14,15 +14,14 @@ * Contributions after 2012-01-13 are licensed under the terms of the * GNU GPL, version 2 or (at your option) any later version. */ +#include "qemu/osdep.h" #include "qemu-common.h" #include "qemu/queue.h" #include "qemu/thread.h" -#include "qemu/osdep.h" -#include "block/coroutine.h" +#include "qemu/coroutine.h" #include "trace.h" -#include "block/block_int.h" -#include "qemu/event_notifier.h" #include "block/thread-pool.h" +#include "qemu/main-loop.h" static void do_spawn_thread(ThreadPool *pool); @@ -32,11 +31,10 @@ enum ThreadState { THREAD_QUEUED, THREAD_ACTIVE, THREAD_DONE, - THREAD_CANCELED, }; struct ThreadPoolElement { - BlockDriverAIOCB common; + BlockAIOCB common; ThreadPool *pool; ThreadPoolFunc *func; void *arg; @@ -56,10 +54,9 @@ struct ThreadPoolElement { }; struct ThreadPool { - EventNotifier notifier; AioContext *ctx; + QEMUBH *completion_bh; QemuMutex lock; - QemuCond check_cancel; QemuCond worker_stopped; QemuSemaphore sem; int max_threads; @@ -74,7 +71,6 @@ struct ThreadPool { int idle_threads; int new_threads; /* backlog of threads we need to create */ int pending_threads; /* threads created but not running yet */ - int pending_cancellations; /* whether we need a cond_broadcast */ bool stopping; }; @@ -114,11 +110,8 @@ static void *worker_thread(void *opaque) req->state = THREAD_DONE; qemu_mutex_lock(&pool->lock); - if (pool->pending_cancellations) { - qemu_cond_broadcast(&pool->check_cancel); - } - event_notifier_set(&pool->notifier); + qemu_bh_schedule(pool->completion_bh); } pool->cur_threads--; @@ -139,7 +132,7 @@ static void do_spawn_thread(ThreadPool *pool) pool->new_threads--; pool->pending_threads++; - qemu_thread_create(&t, worker_thread, pool, QEMU_THREAD_DETACHED); + qemu_thread_create(&t, "worker", worker_thread, pool, QEMU_THREAD_DETACHED); } static void spawn_thread_bh_fn(void *opaque) @@ -167,37 +160,40 @@ static void spawn_thread(ThreadPool *pool) } } -static void event_notifier_ready(EventNotifier *notifier) +static void thread_pool_completion_bh(void *opaque) { - ThreadPool *pool = container_of(notifier, ThreadPool, notifier); + ThreadPool *pool = opaque; ThreadPoolElement *elem, *next; - event_notifier_test_and_clear(notifier); restart: QLIST_FOREACH_SAFE(elem, &pool->head, all, next) { - if (elem->state != THREAD_CANCELED && elem->state != THREAD_DONE) { + if (elem->state != THREAD_DONE) { continue; } - if (elem->state == THREAD_DONE) { - trace_thread_pool_complete(pool, elem, elem->common.opaque, - elem->ret); - } - if (elem->state == THREAD_DONE && elem->common.cb) { - QLIST_REMOVE(elem, all); + + trace_thread_pool_complete(pool, elem, elem->common.opaque, + elem->ret); + QLIST_REMOVE(elem, all); + + if (elem->common.cb) { /* Read state before ret. */ smp_rmb(); + + /* Schedule ourselves in case elem->common.cb() calls aio_poll() to + * wait for another request that completed at the same time. + */ + qemu_bh_schedule(pool->completion_bh); + elem->common.cb(elem->common.opaque, elem->ret); - qemu_aio_release(elem); + qemu_aio_unref(elem); goto restart; } else { - /* remove the request */ - QLIST_REMOVE(elem, all); - qemu_aio_release(elem); + qemu_aio_unref(elem); } } } -static void thread_pool_cancel(BlockDriverAIOCB *acb) +static void thread_pool_cancel(BlockAIOCB *acb) { ThreadPoolElement *elem = (ThreadPoolElement *)acb; ThreadPool *pool = elem->pool; @@ -213,26 +209,31 @@ static void thread_pool_cancel(BlockDriverAIOCB *acb) */ qemu_sem_timedwait(&pool->sem, 0) == 0) { QTAILQ_REMOVE(&pool->request_list, elem, reqs); - elem->state = THREAD_CANCELED; - event_notifier_set(&pool->notifier); - } else { - pool->pending_cancellations++; - while (elem->state != THREAD_CANCELED && elem->state != THREAD_DONE) { - qemu_cond_wait(&pool->check_cancel, &pool->lock); - } - pool->pending_cancellations--; + qemu_bh_schedule(pool->completion_bh); + + elem->state = THREAD_DONE; + elem->ret = -ECANCELED; } + qemu_mutex_unlock(&pool->lock); } +static AioContext *thread_pool_get_aio_context(BlockAIOCB *acb) +{ + ThreadPoolElement *elem = (ThreadPoolElement *)acb; + ThreadPool *pool = elem->pool; + return pool->ctx; +} + static const AIOCBInfo thread_pool_aiocb_info = { .aiocb_size = sizeof(ThreadPoolElement), - .cancel = thread_pool_cancel, + .cancel_async = thread_pool_cancel, + .get_aio_context = thread_pool_get_aio_context, }; -BlockDriverAIOCB *thread_pool_submit_aio(ThreadPool *pool, +BlockAIOCB *thread_pool_submit_aio(ThreadPool *pool, ThreadPoolFunc *func, void *arg, - BlockDriverCompletionFunc *cb, void *opaque) + BlockCompletionFunc *cb, void *opaque) { ThreadPoolElement *req; @@ -291,10 +292,9 @@ static void thread_pool_init_one(ThreadPool *pool, AioContext *ctx) } memset(pool, 0, sizeof(*pool)); - event_notifier_init(&pool->notifier, false); pool->ctx = ctx; + pool->completion_bh = aio_bh_new(ctx, thread_pool_completion_bh, pool); qemu_mutex_init(&pool->lock); - qemu_cond_init(&pool->check_cancel); qemu_cond_init(&pool->worker_stopped); qemu_sem_init(&pool->sem, 0); pool->max_threads = 64; @@ -302,8 +302,6 @@ static void thread_pool_init_one(ThreadPool *pool, AioContext *ctx) QLIST_INIT(&pool->head); QTAILQ_INIT(&pool->request_list); - - aio_set_event_notifier(ctx, &pool->notifier, event_notifier_ready); } ThreadPool *thread_pool_new(AioContext *ctx) @@ -337,11 +335,9 @@ void thread_pool_free(ThreadPool *pool) qemu_mutex_unlock(&pool->lock); - aio_set_event_notifier(pool->ctx, &pool->notifier, NULL); + qemu_bh_delete(pool->completion_bh); qemu_sem_destroy(&pool->sem); - qemu_cond_destroy(&pool->check_cancel); qemu_cond_destroy(&pool->worker_stopped); qemu_mutex_destroy(&pool->lock); - event_notifier_cleanup(&pool->notifier); g_free(pool); }