[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Qemu-devel] [PATCH 2/4] seqlock: add QemuLockable support
From: |
Paolo Bonzini |
Subject: |
[Qemu-devel] [PATCH 2/4] seqlock: add QemuLockable support |
Date: |
Mon, 20 Aug 2018 17:09:01 +0200 |
A shortcut when the seqlock write is protected by a spinlock or any mutex
other than the BQL.
Signed-off-by: Paolo Bonzini <address@hidden>
---
include/qemu/seqlock.h | 20 ++++++++++++++++++++
1 file changed, 20 insertions(+)
diff --git a/include/qemu/seqlock.h b/include/qemu/seqlock.h
index c367516708..fd408b7ec5 100644
--- a/include/qemu/seqlock.h
+++ b/include/qemu/seqlock.h
@@ -16,6 +16,7 @@
#include "qemu/atomic.h"
#include "qemu/thread.h"
+#include "qemu/lockable.h"
typedef struct QemuSeqLock QemuSeqLock;
@@ -45,6 +46,25 @@ static inline void seqlock_write_end(QemuSeqLock *sl)
atomic_set(&sl->sequence, sl->sequence + 1);
}
+/* Lock out other writers and update the count. */
+static inline void seqlock_write_lock_impl(QemuSeqLock *sl, QemuLockable *lock)
+{
+ qemu_lockable_lock(lock);
+ seqlock_write_begin(sl);
+}
+#define seqlock_write_lock(sl, lock) \
+ seqlock_write_lock_impl(sl, QEMU_MAKE_LOCKABLE(lock))
+
+/* Lock out other writers and update the count. */
+static inline void seqlock_write_unlock_impl(QemuSeqLock *sl, QemuLockable
*lock)
+{
+ qemu_lockable_unlock(lock);
+ seqlock_write_begin(sl);
+}
+#define seqlock_write_unlock(sl, lock) \
+ seqlock_write_unlock_impl(sl, QEMU_MAKE_LOCKABLE(lock))
+
+
static inline unsigned seqlock_read_begin(const QemuSeqLock *sl)
{
/* Always fail if a write is in progress. */
--
2.17.1