migration/postcopy: mis->have_listen_thread check will never be touched

[mirror_qemu.git] / util / async.c

diff --git a/util/async.c b/util/async.c
index 0e1bd8780ae323280bbe4caf5c29d48002b2c3c0..ca83e32c7fa13d18f09cf2b921cb1f79c2cc2918 100644 (file)
--- a/util/async.c
+++ b/util/async.c
@@ -25,7 +25,6 @@
 
 #include "qemu/osdep.h"
 #include "qapi/error.h"
-#include "qemu-common.h"
 #include "block/aio.h"
 #include "block/thread-pool.h"
 #include "qemu/main-loop.h"
@@ -298,6 +297,7 @@ aio_ctx_finalize(GSource     *source)
     qemu_rec_mutex_destroy(&ctx->lock);
     qemu_lockcnt_destroy(&ctx->list_lock);
     timerlistgroup_deinit(&ctx->tlg);
+    aio_context_destroy(ctx);
 }
 
 static GSourceFuncs aio_source_funcs = {
@@ -322,14 +322,22 @@ ThreadPool *aio_get_thread_pool(AioContext *ctx)
 }
 
 #ifdef CONFIG_LINUX_AIO
-LinuxAioState *aio_get_linux_aio(AioContext *ctx)
+LinuxAioState *aio_setup_linux_aio(AioContext *ctx, Error **errp)
 {
     if (!ctx->linux_aio) {
-        ctx->linux_aio = laio_init();
-        laio_attach_aio_context(ctx->linux_aio, ctx);
+        ctx->linux_aio = laio_init(errp);
+        if (ctx->linux_aio) {
+            laio_attach_aio_context(ctx->linux_aio, ctx);
+        }
     }
     return ctx->linux_aio;
 }
+
+LinuxAioState *aio_get_linux_aio(AioContext *ctx)
+{
+    assert(ctx->linux_aio);
+    return ctx->linux_aio;
+}
 #endif
 
 void aio_notify(AioContext *ctx)
@@ -346,7 +354,11 @@ void aio_notify(AioContext *ctx)
 
 void aio_notify_accept(AioContext *ctx)
 {
-    if (atomic_xchg(&ctx->notified, false)) {
+    if (atomic_xchg(&ctx->notified, false)
+#ifdef WIN32
+        || true
+#endif
+    ) {
         event_notifier_test_and_clear(&ctx->notifier);
     }
 }
@@ -388,7 +400,10 @@ static void co_schedule_bh_cb(void *opaque)
         QSLIST_REMOVE_HEAD(&straight, co_scheduled_next);
         trace_aio_co_schedule_bh_cb(ctx, co);
         aio_context_acquire(ctx);
-        qemu_coroutine_enter(co);
+
+        /* Protected by write barrier in qemu_aio_coroutine_enter */
+        atomic_set(&co->scheduled, NULL);
+        qemu_aio_coroutine_enter(ctx, co);
         aio_context_release(ctx);
     }
 }
@@ -438,9 +453,27 @@ fail:
 void aio_co_schedule(AioContext *ctx, Coroutine *co)
 {
     trace_aio_co_schedule(ctx, co);
+    const char *scheduled = atomic_cmpxchg(&co->scheduled, NULL,
+                                           __func__);
+
+    if (scheduled) {
+        fprintf(stderr,
+                "%s: Co-routine was already scheduled in '%s'\n",
+                __func__, scheduled);
+        abort();
+    }
+
+    /* The coroutine might run and release the last ctx reference before we
+     * invoke qemu_bh_schedule().  Take a reference to keep ctx alive until
+     * we're done.
+     */
+    aio_context_ref(ctx);
+
     QSLIST_INSERT_HEAD_ATOMIC(&ctx->scheduled_coroutines,
                               co, co_scheduled_next);
     qemu_bh_schedule(ctx->co_schedule_bh);
+
+    aio_context_unref(ctx);
 }
 
 void aio_co_wake(struct Coroutine *co)