From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([140.186.70.92]:56447) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Qm6sG-0003nV-39 for qemu-devel@nongnu.org; Wed, 27 Jul 2011 12:22:21 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Qm6sF-0001Uy-9h for qemu-devel@nongnu.org; Wed, 27 Jul 2011 12:22:20 -0400 Received: from e23smtp08.au.ibm.com ([202.81.31.141]:54301) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Qm6sE-0001Ui-NT for qemu-devel@nongnu.org; Wed, 27 Jul 2011 12:22:19 -0400 Received: from d23relay04.au.ibm.com (d23relay04.au.ibm.com [202.81.31.246]) by e23smtp08.au.ibm.com (8.14.4/8.13.1) with ESMTP id p6RGH1PT024336 for ; Thu, 28 Jul 2011 02:17:01 +1000 Received: from d23av01.au.ibm.com (d23av01.au.ibm.com [9.190.234.96]) by d23relay04.au.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id p6RGLPdF393322 for ; Thu, 28 Jul 2011 02:21:30 +1000 Received: from d23av01.au.ibm.com (loopback [127.0.0.1]) by d23av01.au.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id p6RGM54k018876 for ; Thu, 28 Jul 2011 02:22:05 +1000 From: "Aneesh Kumar K.V" Date: Wed, 27 Jul 2011 21:51:51 +0530 Message-Id: <1311783711-8129-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> Subject: [Qemu-devel] [PATCH -V2] coroutine: Add CoRwlock support List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org, Kevin Wolf Cc: aliguori@us.ibm.com, "Aneesh Kumar K.V" Signed-off-by: Aneesh Kumar K.V --- qemu-coroutine-lock.c | 44 ++++++++++++++++++++++++++++++++++++++++++++ qemu-coroutine.h | 12 ++++++++++++ 2 files changed, 56 insertions(+), 0 deletions(-) diff --git a/qemu-coroutine-lock.c b/qemu-coroutine-lock.c index 5071fb8..b7d01d1 100644 --- a/qemu-coroutine-lock.c +++ b/qemu-coroutine-lock.c @@ -115,3 +115,47 @@ void 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; +} diff --git a/qemu-coroutine.h b/qemu-coroutine.h index 71cfa5a..a9735fb 100644 --- a/qemu-coroutine.h +++ b/qemu-coroutine.h @@ -17,6 +17,7 @@ #include #include "qemu-queue.h" +#include "qemu-thread.h" /** * Coroutines are a mechanism for stack switching and can be used for @@ -114,4 +115,15 @@ void qemu_co_mutex_init(CoMutex *mutex); void qemu_co_mutex_lock(CoMutex *mutex); void qemu_co_mutex_unlock(CoMutex *mutex); +typedef struct CoRwlock { + bool writer; + int reader; + CoQueue queue; +} CoRwlock; + +void qemu_co_rwlock_init(CoRwlock *lock); +void qemu_co_rwlock_rdlock(CoRwlock *lock); +void qemu_co_rwlock_wrlock(CoRwlock *lock); +void qemu_co_rwlock_unlock(CoRwlock *lock); + #endif /* QEMU_COROUTINE_H */ -- 1.7.4.1