From patchwork Tue Sep 17 17:13:20 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vladimir Sementsov-Ogievskiy X-Patchwork-Id: 1163520 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=virtuozzo.com Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 46XqV20Bkkz9s4Y for ; Wed, 18 Sep 2019 03:14:32 +1000 (AEST) Received: from localhost ([::1]:48766 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iAH3c-0006rx-5h for incoming@patchwork.ozlabs.org; Tue, 17 Sep 2019 13:14:28 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:50647) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iAH2g-0006lt-Tq for qemu-devel@nongnu.org; Tue, 17 Sep 2019 13:13:32 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1iAH2f-00033L-Ir for qemu-devel@nongnu.org; Tue, 17 Sep 2019 13:13:30 -0400 Received: from relay.sw.ru ([185.231.240.75]:55314) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1iAH2c-000303-N7; Tue, 17 Sep 2019 13:13:26 -0400 Received: from [10.94.3.0] (helo=kvm.qa.sw.ru) by relay.sw.ru with esmtp (Exim 4.92.2) (envelope-from ) id 1iAH2Z-0003rq-NJ; Tue, 17 Sep 2019 20:13:23 +0300 From: Vladimir Sementsov-Ogievskiy To: qemu-block@nongnu.org Date: Tue, 17 Sep 2019 20:13:20 +0300 Message-Id: <20190917171322.4127-2-vsementsov@virtuozzo.com> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190917171322.4127-1-vsementsov@virtuozzo.com> References: <20190917171322.4127-1-vsementsov@virtuozzo.com> MIME-Version: 1.0 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 185.231.240.75 Subject: [Qemu-devel] [PATCH v9 1/3] qemu-coroutine-sleep: introduce qemu_co_sleep_wake X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kwolf@redhat.com, vsementsov@virtuozzo.com, qemu-devel@nongnu.org, mreitz@redhat.com, stefanha@redhat.com, den@openvz.org Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" Introduce a function to gracefully wake a coroutine sleeping in qemu_co_sleep_ns(). Signed-off-by: Vladimir Sementsov-Ogievskiy Reviewed-by: Kevin Wolf Reviewed-by: Eric Blake --- include/qemu/coroutine.h | 23 +++++++++++++++-- util/qemu-coroutine-sleep.c | 51 +++++++++++++++++++++++++++---------- 2 files changed, 59 insertions(+), 15 deletions(-) diff --git a/include/qemu/coroutine.h b/include/qemu/coroutine.h index 9801e7f5a4..8d55663062 100644 --- a/include/qemu/coroutine.h +++ b/include/qemu/coroutine.h @@ -273,10 +273,29 @@ void qemu_co_rwlock_wrlock(CoRwlock *lock); */ void qemu_co_rwlock_unlock(CoRwlock *lock); +typedef struct QemuCoSleepState QemuCoSleepState; + +/** + * Yield the coroutine for a given duration. During this yield, @sleep_state + * (if not NULL) is set to an opaque pointer, which may be used for + * qemu_co_sleep_wake(). Be careful, the pointer is set back to zero when the + * timer fires. Don't save the obtained value to other variables and don't call + * qemu_co_sleep_wake from another aio context. + */ +void coroutine_fn qemu_co_sleep_ns_wakeable(QEMUClockType type, int64_t ns, + QemuCoSleepState **sleep_state); +static inline void coroutine_fn qemu_co_sleep_ns(QEMUClockType type, int64_t ns) +{ + qemu_co_sleep_ns_wakeable(type, ns, NULL); +} + /** - * Yield the coroutine for a given duration + * Wake a coroutine if it is sleeping in qemu_co_sleep_ns. The timer will be + * deleted. @sleep_state must be the variable whose address was given to + * qemu_co_sleep_ns() and should be checked to be non-NULL before calling + * qemu_co_sleep_wake(). */ -void coroutine_fn qemu_co_sleep_ns(QEMUClockType type, int64_t ns); +void qemu_co_sleep_wake(QemuCoSleepState *sleep_state); /** * Yield until a file descriptor becomes readable diff --git a/util/qemu-coroutine-sleep.c b/util/qemu-coroutine-sleep.c index 4bfdd30cbf..ae91b92b6e 100644 --- a/util/qemu-coroutine-sleep.c +++ b/util/qemu-coroutine-sleep.c @@ -17,31 +17,56 @@ #include "qemu/timer.h" #include "block/aio.h" -static void co_sleep_cb(void *opaque) -{ - Coroutine *co = opaque; +static const char *qemu_co_sleep_ns__scheduled = "qemu_co_sleep_ns"; + +struct QemuCoSleepState { + Coroutine *co; + QEMUTimer *ts; + QemuCoSleepState **user_state_pointer; +}; +void qemu_co_sleep_wake(QemuCoSleepState *sleep_state) +{ /* Write of schedule protected by barrier write in aio_co_schedule */ - atomic_set(&co->scheduled, NULL); - aio_co_wake(co); + const char *scheduled = atomic_cmpxchg(&sleep_state->co->scheduled, + qemu_co_sleep_ns__scheduled, NULL); + + assert(scheduled == qemu_co_sleep_ns__scheduled); + if (sleep_state->user_state_pointer) { + *sleep_state->user_state_pointer = NULL; + } + timer_del(sleep_state->ts); + aio_co_wake(sleep_state->co); } -void coroutine_fn qemu_co_sleep_ns(QEMUClockType type, int64_t ns) +static void co_sleep_cb(void *opaque) +{ + qemu_co_sleep_wake(opaque); +} + +void coroutine_fn qemu_co_sleep_ns_wakeable(QEMUClockType type, int64_t ns, + QemuCoSleepState **sleep_state) { AioContext *ctx = qemu_get_current_aio_context(); - QEMUTimer *ts; - Coroutine *co = qemu_coroutine_self(); + QemuCoSleepState state = { + .co = qemu_coroutine_self(), + .ts = aio_timer_new(ctx, type, SCALE_NS, co_sleep_cb, &state), + .user_state_pointer = sleep_state, + }; - const char *scheduled = atomic_cmpxchg(&co->scheduled, NULL, __func__); + const char *scheduled = atomic_cmpxchg(&state.co->scheduled, NULL, + qemu_co_sleep_ns__scheduled); if (scheduled) { fprintf(stderr, "%s: Co-routine was already scheduled in '%s'\n", __func__, scheduled); abort(); } - ts = aio_timer_new(ctx, type, SCALE_NS, co_sleep_cb, co); - timer_mod(ts, qemu_clock_get_ns(type) + ns); + + if (sleep_state) { + *sleep_state = &state; + } + timer_mod(state.ts, qemu_clock_get_ns(type) + ns); qemu_coroutine_yield(); - timer_del(ts); - timer_free(ts); + timer_free(state.ts); }