diff options
| -rw-r--r-- | aio-posix.c | 9 | ||||
| -rw-r--r-- | aio-win32.c | 8 | ||||
| -rw-r--r-- | include/block/aio.h | 13 |
3 files changed, 24 insertions, 6 deletions
diff --git a/aio-posix.c b/aio-posix.c index 296cd9b140..4abec38866 100644 --- a/aio-posix.c +++ b/aio-posix.c @@ -238,6 +238,7 @@ bool aio_poll(AioContext *ctx, bool blocking) bool progress; int64_t timeout; + aio_context_acquire(ctx); was_dispatching = ctx->dispatching; progress = false; @@ -267,7 +268,13 @@ bool aio_poll(AioContext *ctx, bool blocking) timeout = blocking ? aio_compute_timeout(ctx) : 0; /* wait until next event */ + if (timeout) { + aio_context_release(ctx); + } ret = qemu_poll_ns((GPollFD *)pollfds, npfd, timeout); + if (timeout) { + aio_context_acquire(ctx); + } /* if we have any readable fds, dispatch event */ if (ret > 0) { @@ -286,5 +293,7 @@ bool aio_poll(AioContext *ctx, bool blocking) } aio_set_dispatching(ctx, was_dispatching); + aio_context_release(ctx); + return progress; } diff --git a/aio-win32.c b/aio-win32.c index e6f4cedf48..233d8f5d79 100644 --- a/aio-win32.c +++ b/aio-win32.c @@ -283,6 +283,7 @@ bool aio_poll(AioContext *ctx, bool blocking) int count; int timeout; + aio_context_acquire(ctx); have_select_revents = aio_prepare(ctx); if (have_select_revents) { blocking = false; @@ -323,7 +324,13 @@ bool aio_poll(AioContext *ctx, bool blocking) timeout = blocking ? qemu_timeout_ns_to_ms(aio_compute_timeout(ctx)) : 0; + if (timeout) { + aio_context_release(ctx); + } ret = WaitForMultipleObjects(count, events, FALSE, timeout); + if (timeout) { + aio_context_acquire(ctx); + } aio_set_dispatching(ctx, true); if (first && aio_bh_poll(ctx)) { @@ -349,5 +356,6 @@ bool aio_poll(AioContext *ctx, bool blocking) progress |= timerlistgroup_run_timers(&ctx->tlg); aio_set_dispatching(ctx, was_dispatching); + aio_context_release(ctx); return progress; } diff --git a/include/block/aio.h b/include/block/aio.h index 0dc7a258e2..d2bb423de1 100644 --- a/include/block/aio.h +++ b/include/block/aio.h @@ -118,13 +118,14 @@ void aio_context_ref(AioContext *ctx); void aio_context_unref(AioContext *ctx); /* Take ownership of the AioContext. If the AioContext will be shared between - * threads, a thread must have ownership when calling aio_poll(). + * threads, and a thread does not want to be interrupted, it will have to + * take ownership around calls to aio_poll(). Otherwise, aio_poll() + * automatically takes care of calling aio_context_acquire and + * aio_context_release. * - * Note that multiple threads calling aio_poll() means timers, BHs, and - * callbacks may be invoked from a different thread than they were registered - * from. Therefore, code must use AioContext acquire/release or use - * fine-grained synchronization to protect shared state if other threads will - * be accessing it simultaneously. + * Access to timers and BHs from a thread that has not acquired AioContext + * is possible. Access to callbacks for now must be done while the AioContext + * is owned by the thread (FIXME). */ void aio_context_acquire(AioContext *ctx); |