[libvirt] [PATCH 02/21] Implement a RWLock primitive for drivers to use
Daniel Veillard
veillard at redhat.com
Wed Oct 28 16:15:05 UTC 2009
On Fri, Oct 23, 2009 at 02:05:31PM +0100, Daniel P. Berrange wrote:
> This implements a thin wrapper around the pthread_rwlock
> primitives. No impl is provided for Win32 at this time
> since it is rather hard, and none of our code yet requires
> it on Win32
>
> * src/util/threads.h: Add virRWLockInit, virRWLockDestroy,
> virRWLockRead, virRWLockWrite, virRWLockUnlock APIs
> * src/util/threads-pthread.h: define virRWLock struct
> * src/util/threads-pthread.c: Implement RWLock APIs
> ---
> src/libvirt_private.syms | 6 ++++++
> src/util/threads-pthread.c | 30 ++++++++++++++++++++++++++++++
> src/util/threads-pthread.h | 4 ++++
> src/util/threads.h | 10 ++++++++++
> 4 files changed, 50 insertions(+), 0 deletions(-)
>
> diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
> index bd9d84a..6ed562d 100644
> --- a/src/libvirt_private.syms
> +++ b/src/libvirt_private.syms
> @@ -426,6 +426,12 @@ virCondWait;
> virCondSignal;
> virCondBroadcast;
>
> +virRWLockInit;
> +virRWLockDestroy;
> +virRWLockRead;
> +virRWLockWrite;
> +virRWLockUnlock;
> +
> # util.h
> virFileReadAll;
> virFileWriteStr;
> diff --git a/src/util/threads-pthread.c b/src/util/threads-pthread.c
> index 4e00bc5..2052c0a 100644
> --- a/src/util/threads-pthread.c
> +++ b/src/util/threads-pthread.c
> @@ -57,6 +57,36 @@ void virMutexUnlock(virMutexPtr m)
> }
>
>
> +int virRWLockInit(virRWLockPtr m)
> +{
> + if (pthread_rwlock_init(&m->lock, NULL) != 0) {
> + errno = EINVAL;
> + 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);
> +}
> +
> +
Hum it's a small patch, but I would rather fix those function to not
be void when the underlying pthread_ counterpart can actually fail.
IMHO we should report errors coming from the thread library (whichever
is used on a given platform).
Daniel
--
Daniel Veillard | libxml Gnome XML XSLT toolkit http://xmlsoft.org/
daniel at veillard.com | Rpmfind RPM search engine http://rpmfind.net/
http://veillard.com/ | virtualization library http://libvirt.org/
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