From ed3327eb5d7f1df9b2c5a8f3628e37c45c4f9fba Mon Sep 17 00:00:00 2001

Message-Id: <ed3327eb5d7f1df9b2c5a8f3628e37c45c4f9fba.1391615407.git.jdenemar@redhat.com>

From: "Daniel P. Berrange" <berrange@redhat.com>

Date: Tue, 4 Feb 2014 06:23:06 -0700

Subject: [PATCH] Add a read/write lock implementation

https://bugzilla.redhat.com/show_bug.cgi?id=1034807

Add virRWLock backed up by a POSIX rwlock primitive

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>

(cherry picked from commit c065984b58000a44c90588198d222a314ac532fd)

Signed-off-by: Jiri Denemark <jdenemar@redhat.com>

---

 src/libvirt_private.syms    |  5 +++++

 src/util/virthread.h        | 10 ++++++++++

 src/util/virthreadpthread.c | 33 +++++++++++++++++++++++++++++++++

 src/util/virthreadpthread.h |  4 ++++

 src/util/virthreadwin32.c   | 19 +++++++++++++++++++

 src/util/virthreadwin32.h   |  4 ++++

 6 files changed, 75 insertions(+)

diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms

index 22df5a9..fa56bfd 100644

--- a/src/libvirt_private.syms

+++ b/src/libvirt_private.syms

@@ -1975,6 +1975,11 @@ virMutexInitRecursive;

 virMutexLock;

 virMutexUnlock;

 virOnce;

+virRWLockDestroy;

+virRWLockInit;

+virRWLockRead;

+virRWLockUnlock;

+virRWLockWrite;

 virThreadCancel;

 virThreadCreate;

 virThreadID;

diff --git a/src/util/virthread.h b/src/util/virthread.h

index 84d3bdc..7015d60 100644

--- a/src/util/virthread.h

+++ b/src/util/virthread.h

@@ -28,6 +28,9 @@

 typedef struct virMutex virMutex;

 typedef virMutex *virMutexPtr;

+typedef struct virRWLock virRWLock;

+typedef virRWLock *virRWLockPtr;

+

 typedef struct virCond virCond;

 typedef virCond *virCondPtr;

@@ -89,6 +92,13 @@ void virMutexLock(virMutexPtr m);

 void virMutexUnlock(virMutexPtr m);

+int virRWLockInit(virRWLockPtr m) ATTRIBUTE_RETURN_CHECK;

+void virRWLockDestroy(virRWLockPtr m);

+

+void virRWLockRead(virRWLockPtr m);

+void virRWLockWrite(virRWLockPtr m);

+void virRWLockUnlock(virRWLockPtr m);

+

 int virCondInit(virCondPtr c) ATTRIBUTE_RETURN_CHECK;

 int virCondDestroy(virCondPtr c);

diff --git a/src/util/virthreadpthread.c b/src/util/virthreadpthread.c

index ca841e4..38b6454 100644

--- a/src/util/virthreadpthread.c

+++ b/src/util/virthreadpthread.c

@@ -91,6 +91,39 @@ void virMutexUnlock(virMutexPtr m)

 }

+int virRWLockInit(virRWLockPtr m)

+{

+    int ret;

+    ret = pthread_rwlock_init(&m->lock, NULL);

+    if (ret != 0) {

+        errno = ret;

+        return -1;

+    }

+    return 0;

+}

+

+void virRWLockDestroy(virRWLockPtr m)

+{

+    pthread_rwlock_destroy(&m->lock);

+}

+

+

+void virRWLockRead(virRWLockPtr m)

+{

+    pthread_rwlock_rdlock(&m->lock);

+}

+

+void virRWLockWrite(virRWLockPtr m)

+{

+    pthread_rwlock_wrlock(&m->lock);

+}

+

+

+void virRWLockUnlock(virRWLockPtr m)

+{

+    pthread_rwlock_unlock(&m->lock);

+}

+

 int virCondInit(virCondPtr c)

 {

     int ret;

diff --git a/src/util/virthreadpthread.h b/src/util/virthreadpthread.h

index b9f1319..cb607d0 100644

--- a/src/util/virthreadpthread.h

+++ b/src/util/virthreadpthread.h

@@ -27,6 +27,10 @@ struct virMutex {

     pthread_mutex_t lock;

 };

+struct virRWLock {

+    pthread_rwlock_t lock;

+};

+

 struct virCond {

     pthread_cond_t cond;

 };

diff --git a/src/util/virthreadwin32.c b/src/util/virthreadwin32.c

index 5d6277f..a9e2353 100644

--- a/src/util/virthreadwin32.c

+++ b/src/util/virthreadwin32.c

@@ -123,6 +123,25 @@ void virMutexUnlock(virMutexPtr m)

 }

+int virRWLockInit(virRWLockPtr m ATTRIBUTE_UNUSED)

+{

+    errno = ENOSYS;

+    return -1;

+}

+

+void virRWLockDestroy(virRWLockPtr m ATTRIBUTE_UNUSED)

+{}

+

+

+void virRWLockRead(virRWLockPtr m ATTRIBUTE_UNUSED)

+{}

+

+void virRWLockWrite(virRWLockPtr m ATTRIBUTE_UNUSED)

+{}

+

+

+void virRWLockUnlock(virRWLockPtr m ATTRIBUTE_UNUSED)

+{}

 int virCondInit(virCondPtr c)

 {

diff --git a/src/util/virthreadwin32.h b/src/util/virthreadwin32.h

index 645031b..31d9444 100644

--- a/src/util/virthreadwin32.h

+++ b/src/util/virthreadwin32.h

@@ -30,6 +30,10 @@ struct virMutex {

     HANDLE lock;

 };

+struct virRWLock {

+    bool ignored;

+};

+

 struct virCond {

     virMutex lock;

     size_t nwaiters;

-- 

1.8.5.3