aio: convert from RFifoLock to QemuRecMutex

It is simpler and a bit faster, and QEMU does not need the contention
callbacks (and thus the fairness) anymore.

Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <1477565348-5458-21-git-send-email-pbonzini@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>

2 files changed, 1 insertions, 56 deletions

diff --git a/include/block/aio.h b/include/block/aio.h
index 8e1885b..c7ae27c 100644
--- a/include/block/aio.h
+++ b/include/block/aio.h
@@ -18,7 +18,6 @@
 #include "qemu/queue.h"
 #include "qemu/event_notifier.h"
 #include "qemu/thread.h"
-#include "qemu/rfifolock.h"
 #include "qemu/timer.h"
 
 typedef struct BlockAIOCB BlockAIOCB;
@@ -54,7 +53,7 @@ struct AioContext {
     GSource source;
 
     /* Protects all fields from multi-threaded access */
-    RFifoLock lock;
+    QemuRecMutex lock;
 
     /* The list of registered AIO handlers */
     QLIST_HEAD(, AioHandler) aio_handlers;
diff --git a/include/qemu/rfifolock.h b/include/qemu/rfifolock.h
deleted file mode 100644
index b23ab53..0000000
--- a/include/qemu/rfifolock.h
+++ /dev/null
@@ -1,54 +0,0 @@
-/*
- * Recursive FIFO lock
- *
- * Copyright Red Hat, Inc. 2013
- *
- * Authors:
- *  Stefan Hajnoczi   <stefanha@redhat.com>
- *
- * This work is licensed under the terms of the GNU GPL, version 2 or later.
- * See the COPYING file in the top-level directory.
- *
- */
-
-#ifndef QEMU_RFIFOLOCK_H
-#define QEMU_RFIFOLOCK_H
-
-#include "qemu/thread.h"
-
-/* Recursive FIFO lock
- *
- * This lock provides more features than a plain mutex:
- *
- * 1. Fairness - enforces FIFO order.
- * 2. Nesting - can be taken recursively.
- * 3. Contention callback - optional, called when thread must wait.
- *
- * The recursive FIFO lock is heavyweight so prefer other synchronization
- * primitives if you do not need its features.
- */
-typedef struct {
-    QemuMutex lock;             /* protects all fields */
-
-    /* FIFO order */
-    unsigned int head;          /* active ticket number */
-    unsigned int tail;          /* waiting ticket number */
-    QemuCond cond;              /* used to wait for our ticket number */
-
-    /* Nesting */
-    QemuThread owner_thread;    /* thread that currently has ownership */
-    unsigned int nesting;       /* amount of nesting levels */
-
-    /* Contention callback */
-    void (*cb)(void *);         /* called when thread must wait, with ->lock
-                                 * held so it may not recursively lock/unlock
-                                 */
-    void *cb_opaque;
-} RFifoLock;
-
-void rfifolock_init(RFifoLock *r, void (*cb)(void *), void *opaque);
-void rfifolock_destroy(RFifoLock *r);
-void rfifolock_lock(RFifoLock *r);
-void rfifolock_unlock(RFifoLock *r);
-
-#endif /* QEMU_RFIFOLOCK_H */