i8259: Switch to per-PIC IRQ update

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

diff --git a/qemu-coroutine-lock.c b/qemu-coroutine-lock.c
index abaa1f796702736e64e0823ea068b0d69632c7fe..2a385a3bb8f510bd817273bb5f7a2067d423b1ee 100644 (file)
--- a/qemu-coroutine-lock.c
+++ b/qemu-coroutine-lock.c
@@ -30,14 +30,10 @@
 
 static QTAILQ_HEAD(, Coroutine) unlock_bh_queue =
     QTAILQ_HEAD_INITIALIZER(unlock_bh_queue);
-
-struct unlock_bh {
-    QEMUBH *bh;
-};
+static QEMUBH* unlock_bh;
 
 static void qemu_co_queue_next_bh(void *opaque)
 {
-    struct unlock_bh *unlock_bh = opaque;
     Coroutine *next;
 
     trace_qemu_co_queue_next_bh();
@@ -45,14 +41,15 @@ static void qemu_co_queue_next_bh(void *opaque)
         QTAILQ_REMOVE(&unlock_bh_queue, next, co_queue_next);
         qemu_coroutine_enter(next, NULL);
     }
-
-    qemu_bh_delete(unlock_bh->bh);
-    qemu_free(unlock_bh);
 }
 
 void qemu_co_queue_init(CoQueue *queue)
 {
     QTAILQ_INIT(&queue->entries);
+
+    if (!unlock_bh) {
+        unlock_bh = qemu_bh_new(qemu_co_queue_next_bh, NULL);
+    }
 }
 
 void coroutine_fn qemu_co_queue_wait(CoQueue *queue)
@@ -65,7 +62,6 @@ void coroutine_fn qemu_co_queue_wait(CoQueue *queue)
 
 bool qemu_co_queue_next(CoQueue *queue)
 {
-    struct unlock_bh *unlock_bh;
     Coroutine *next;
 
     next = QTAILQ_FIRST(&queue->entries);
@@ -73,10 +69,7 @@ bool qemu_co_queue_next(CoQueue *queue)
         QTAILQ_REMOVE(&queue->entries, next, co_queue_next);
         QTAILQ_INSERT_TAIL(&unlock_bh_queue, next, co_queue_next);
         trace_qemu_co_queue_next(next);
-
-        unlock_bh = qemu_malloc(sizeof(*unlock_bh));
-        unlock_bh->bh = qemu_bh_new(qemu_co_queue_next_bh, unlock_bh);
-        qemu_bh_schedule(unlock_bh->bh);
+        qemu_bh_schedule(unlock_bh);
     }
 
     return (next != NULL);
@@ -122,3 +115,47 @@ void coroutine_fn qemu_co_mutex_unlock(CoMutex *mutex)
 
     trace_qemu_co_mutex_unlock_return(mutex, self);
 }
+
+void qemu_co_rwlock_init(CoRwlock *lock)
+{
+    memset(lock, 0, sizeof(*lock));
+    qemu_co_queue_init(&lock->queue);
+}
+
+void qemu_co_rwlock_rdlock(CoRwlock *lock)
+{
+    while (lock->writer) {
+        qemu_co_queue_wait(&lock->queue);
+    }
+    lock->reader++;
+}
+
+void qemu_co_rwlock_unlock(CoRwlock *lock)
+{
+    assert(qemu_in_coroutine());
+    if (lock->writer) {
+        lock->writer = false;
+        while (!qemu_co_queue_empty(&lock->queue)) {
+            /*
+             * Wakeup every body. This will include some
+             * writers too.
+             */
+            qemu_co_queue_next(&lock->queue);
+        }
+    } else {
+        lock->reader--;
+        assert(lock->reader >= 0);
+        /* Wakeup only one waiting writer */
+        if (!lock->reader) {
+            qemu_co_queue_next(&lock->queue);
+        }
+    }
+}
+
+void qemu_co_rwlock_wrlock(CoRwlock *lock)
+{
+    while (lock->writer || lock->reader) {
+        qemu_co_queue_wait(&lock->queue);
+    }
+    lock->writer = true;
+}