Merge remote-tracking branch 'remotes/vivier2/tags/trivial-branch-pull-request' into...

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

diff --git a/util/qemu-coroutine-sleep.c b/util/qemu-coroutine-sleep.c
index b35db56356dd90f05a89d57ab293b1db8a6156ac..ae91b92b6e78dfbb570d5321d282aca4bce52e26 100644 (file)
--- a/util/qemu-coroutine-sleep.c
+++ b/util/qemu-coroutine-sleep.c
@@ -11,31 +11,62 @@
  *
  */
 
+#include "qemu/osdep.h"
 #include "qemu/coroutine.h"
+#include "qemu/coroutine_int.h"
 #include "qemu/timer.h"
 #include "block/aio.h"
 
-typedef struct CoSleepCB {
-    QEMUTimer *ts;
+static const char *qemu_co_sleep_ns__scheduled = "qemu_co_sleep_ns";
+
+struct QemuCoSleepState {
     Coroutine *co;
-} CoSleepCB;
+    QEMUTimer *ts;
+    QemuCoSleepState **user_state_pointer;
+};
 
-static void co_sleep_cb(void *opaque)
+void qemu_co_sleep_wake(QemuCoSleepState *sleep_state)
 {
-    CoSleepCB *sleep_cb = opaque;
+    /* Write of schedule protected by barrier write in aio_co_schedule */
+    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);
+}
 
-    qemu_coroutine_enter(sleep_cb->co, NULL);
+static void co_sleep_cb(void *opaque)
+{
+    qemu_co_sleep_wake(opaque);
 }
 
-void coroutine_fn co_aio_sleep_ns(AioContext *ctx, QEMUClockType type,
-                                  int64_t ns)
+void coroutine_fn qemu_co_sleep_ns_wakeable(QEMUClockType type, int64_t ns,
+                                            QemuCoSleepState **sleep_state)
 {
-    CoSleepCB sleep_cb = {
+    AioContext *ctx = qemu_get_current_aio_context();
+    QemuCoSleepState state = {
         .co = qemu_coroutine_self(),
+        .ts = aio_timer_new(ctx, type, SCALE_NS, co_sleep_cb, &state),
+        .user_state_pointer = sleep_state,
     };
-    sleep_cb.ts = aio_timer_new(ctx, type, SCALE_NS, co_sleep_cb, &sleep_cb);
-    timer_mod(sleep_cb.ts, qemu_clock_get_ns(type) + ns);
+
+    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();
+    }
+
+    if (sleep_state) {
+        *sleep_state = &state;
+    }
+    timer_mod(state.ts, qemu_clock_get_ns(type) + ns);
     qemu_coroutine_yield();
-    timer_del(sleep_cb.ts);
-    timer_free(sleep_cb.ts);
+    timer_free(state.ts);
 }