qdev: use device_class_set_parent_realize/unrealize/reset()

[qemu.git] / util / qemu-coroutine.c

diff --git a/util/qemu-coroutine.c b/util/qemu-coroutine.c
index 72412e564939013c8183d558199f3df45fb23b84..9eff7fd450a33e489f955495f5438dd35124d30f 100644 (file)
--- a/util/qemu-coroutine.c
+++ b/util/qemu-coroutine.c
@@ -102,12 +102,26 @@ static void coroutine_delete(Coroutine *co)
     qemu_coroutine_delete(co);
 }
 
-void qemu_coroutine_enter(Coroutine *co)
+void qemu_aio_coroutine_enter(AioContext *ctx, Coroutine *co)
 {
     Coroutine *self = qemu_coroutine_self();
     CoroutineAction ret;
 
-    trace_qemu_coroutine_enter(self, co, co->entry_arg);
+    /* Cannot rely on the read barrier for co in aio_co_wake(), as there are
+     * callers outside of aio_co_wake() */
+    const char *scheduled = atomic_mb_read(&co->scheduled);
+
+    trace_qemu_aio_coroutine_enter(ctx, self, co, co->entry_arg);
+
+    /* if the Coroutine has already been scheduled, entering it again will
+     * cause us to enter it twice, potentially even after the coroutine has
+     * been deleted */
+    if (scheduled) {
+        fprintf(stderr,
+                "%s: Co-routine was already scheduled in '%s'\n",
+                __func__, scheduled);
+        abort();
+    }
 
     if (co->caller) {
         fprintf(stderr, "Co-routine re-entered recursively\n");
@@ -115,7 +129,7 @@ void qemu_coroutine_enter(Coroutine *co)
     }
 
     co->caller = self;
-    co->ctx = qemu_get_current_aio_context();
+    co->ctx = ctx;
 
     /* Store co->ctx before anything that stores co.  Matches
      * barrier in aio_co_wake and qemu_co_mutex_wake.
@@ -126,6 +140,11 @@ void qemu_coroutine_enter(Coroutine *co)
 
     qemu_co_queue_run_restart(co);
 
+    /* Beware, if ret == COROUTINE_YIELD and qemu_co_queue_run_restart()
+     * has started any other coroutine, "co" might have been reentered
+     * and even freed by now!  So be careful and do not touch it.
+     */
+
     switch (ret) {
     case COROUTINE_YIELD:
         return;
@@ -139,6 +158,11 @@ void qemu_coroutine_enter(Coroutine *co)
     }
 }
 
+void qemu_coroutine_enter(Coroutine *co)
+{
+    qemu_aio_coroutine_enter(qemu_get_current_aio_context(), co);
+}
+
 void qemu_coroutine_enter_if_inactive(Coroutine *co)
 {
     if (!qemu_coroutine_entered(co)) {