X-Git-Url: https://repo.jachan.dev/qemu.git/blobdiff_plain/eabc977973103527bbb8fed69c91cfaa6691f8ab..7df9381b7aa56c897e344f3bfe43bf5848bbd3e0:/async.c

diff --git a/async.c b/async.c
index a232192148..d4dd2cc799 100644
--- a/async.c
+++ b/async.c
@@ -22,6 +22,7 @@
  * THE SOFTWARE.
  */
 
+#include "qemu/osdep.h"
 #include "qemu-common.h"
 #include "block/aio.h"
 #include "block/thread-pool.h"
@@ -59,6 +60,11 @@ QEMUBH *aio_bh_new(AioContext *ctx, QEMUBHFunc *cb, void *opaque)
     return bh;
 }
 
+void aio_bh_call(QEMUBH *bh)
+{
+    bh->cb(bh->opaque);
+}
+
 /* Multiple occurrences of aio_bh_poll cannot be called concurrently */
 int aio_bh_poll(AioContext *ctx)
 {
@@ -79,10 +85,12 @@ int aio_bh_poll(AioContext *ctx)
          * aio_notify again if necessary.
          */
         if (!bh->deleted && atomic_xchg(&bh->scheduled, 0)) {
-            if (!bh->idle)
+            /* Idle BHs and the notify BH don't count as progress */
+            if (!bh->idle && bh != ctx->notify_dummy_bh) {
                 ret = 1;
+            }
             bh->idle = 0;
-            bh->cb(bh->opaque);
+            aio_bh_call(bh);
         }
     }
 
@@ -203,6 +211,8 @@ aio_ctx_check(GSource *source)
     QEMUBH *bh;
 
     atomic_and(&ctx->notify_me, ~1);
+    aio_notify_accept(ctx);
+
     for (bh = ctx->first_bh; bh; bh = bh->next) {
         if (!bh->deleted && bh->scheduled) {
             return true;
@@ -228,8 +238,22 @@ aio_ctx_finalize(GSource     *source)
 {
     AioContext *ctx = (AioContext *) source;
 
+    qemu_bh_delete(ctx->notify_dummy_bh);
     thread_pool_free(ctx->thread_pool);
-    aio_set_event_notifier(ctx, &ctx->notifier, NULL);
+
+    qemu_mutex_lock(&ctx->bh_lock);
+    while (ctx->first_bh) {
+        QEMUBH *next = ctx->first_bh->next;
+
+        /* qemu_bh_delete() must have been called on BHs in this AioContext */
+        assert(ctx->first_bh->deleted);
+
+        g_free(ctx->first_bh);
+        ctx->first_bh = next;
+    }
+    qemu_mutex_unlock(&ctx->bh_lock);
+
+    aio_set_event_notifier(ctx, &ctx->notifier, false, NULL);
     event_notifier_cleanup(&ctx->notifier);
     rfifolock_destroy(&ctx->lock);
     qemu_mutex_destroy(&ctx->bh_lock);
@@ -265,6 +289,14 @@ void aio_notify(AioContext *ctx)
     smp_mb();
     if (ctx->notify_me) {
         event_notifier_set(&ctx->notifier);
+        atomic_mb_set(&ctx->notified, true);
+    }
+}
+
+void aio_notify_accept(AioContext *ctx)
+{
+    if (atomic_xchg(&ctx->notified, false)) {
+        event_notifier_test_and_clear(&ctx->notifier);
     }
 }
 
@@ -275,31 +307,54 @@ static void aio_timerlist_notify(void *opaque)
 
 static void aio_rfifolock_cb(void *opaque)
 {
+    AioContext *ctx = opaque;
+
     /* Kick owner thread in case they are blocked in aio_poll() */
-    aio_notify(opaque);
+    qemu_bh_schedule(ctx->notify_dummy_bh);
+}
+
+static void notify_dummy_bh(void *opaque)
+{
+    /* Do nothing, we were invoked just to force the event loop to iterate */
+}
+
+static void event_notifier_dummy_cb(EventNotifier *e)
+{
 }
 
 AioContext *aio_context_new(Error **errp)
 {
     int ret;
     AioContext *ctx;
+    Error *local_err = NULL;
+
     ctx = (AioContext *) g_source_new(&aio_source_funcs, sizeof(AioContext));
+    aio_context_setup(ctx, &local_err);
+    if (local_err) {
+        error_propagate(errp, local_err);
+        goto fail;
+    }
     ret = event_notifier_init(&ctx->notifier, false);
     if (ret < 0) {
-        g_source_destroy(&ctx->source);
         error_setg_errno(errp, -ret, "Failed to initialize event notifier");
-        return NULL;
+        goto fail;
     }
     g_source_set_can_recurse(&ctx->source, true);
     aio_set_event_notifier(ctx, &ctx->notifier,
+                           false,
                            (EventNotifierHandler *)
-                           event_notifier_test_and_clear);
+                           event_notifier_dummy_cb);
     ctx->thread_pool = NULL;
     qemu_mutex_init(&ctx->bh_lock);
     rfifolock_init(&ctx->lock, aio_rfifolock_cb, ctx);
     timerlistgroup_init(&ctx->tlg, aio_timerlist_notify, ctx);
 
+    ctx->notify_dummy_bh = aio_bh_new(ctx, notify_dummy_bh, NULL);
+
     return ctx;
+fail:
+    g_source_destroy(&ctx->source);
+    return NULL;
 }
 
 void aio_context_ref(AioContext *ctx)