From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:50109) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZMXpb-0000ts-9s for qemu-devel@nongnu.org; Tue, 04 Aug 2015 04:44:20 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZMXpZ-00030i-Ki for qemu-devel@nongnu.org; Tue, 04 Aug 2015 04:44:19 -0400 Received: from mail.ispras.ru ([83.149.199.45]:56229) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZMXpZ-00030a-Cn for qemu-devel@nongnu.org; Tue, 04 Aug 2015 04:44:17 -0400 From: Pavel Dovgalyuk Date: Tue, 04 Aug 2015 11:44:17 +0300 Message-ID: <20150804084417.7280.90011.stgit@PASHA-ISP> In-Reply-To: <20150804084345.7280.75100.stgit@PASHA-ISP> References: <20150804084345.7280.75100.stgit@PASHA-ISP> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Subject: [Qemu-devel] [PATCH v16 05/21] replay: introduce mutex to protect the replay log List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: peter.maydell@linaro.org, peter.crosthwaite@xilinx.com, igor.rubinov@gmail.com, alex.bennee@linaro.org, mark.burton@greensocs.com, real@ispras.ru, batuzovk@ispras.ru, maria.klimushenkova@ispras.ru, pavel.dovgaluk@ispras.ru, pbonzini@redhat.com, hines@cert.org, fred.konrad@greensocs.com This mutex will protect read/write operations for replay log. Using mutex is necessary because most of the events consist of several fields stored in the log. The mutex will help to avoid races. Reviewed-by: Paolo Bonzini Signed-off-by: Pavel Dovgalyuk --- replay/replay-internal.c | 27 +++++++++++++++++++++++++++ replay/replay-internal.h | 7 +++++++ 2 files changed, 34 insertions(+), 0 deletions(-) diff --git a/replay/replay-internal.c b/replay/replay-internal.c index 04efeee..b2ee141 100755 --- a/replay/replay-internal.c +++ b/replay/replay-internal.c @@ -17,6 +17,13 @@ unsigned int replay_data_kind = -1; static unsigned int replay_has_unread_data; +/* Mutex to protect reading and writing events to the log. + replay_data_kind and replay_has_unread_data are also protected + by this mutex. + It also protects replay events queue which stores events to be + written or read to the log. */ +static QemuMutex lock; + /* File for replay writing */ FILE *replay_file; @@ -153,3 +160,23 @@ void replay_finish_event(void) replay_has_unread_data = 0; replay_fetch_data_kind(); } + +void replay_mutex_init(void) +{ + qemu_mutex_init(&lock); +} + +void replay_mutex_destroy(void) +{ + qemu_mutex_destroy(&lock); +} + +void replay_mutex_lock(void) +{ + qemu_mutex_lock(&lock); +} + +void replay_mutex_unlock(void) +{ + qemu_mutex_unlock(&lock); +} diff --git a/replay/replay-internal.h b/replay/replay-internal.h index 17600de..8a0de0d 100755 --- a/replay/replay-internal.h +++ b/replay/replay-internal.h @@ -33,6 +33,13 @@ int64_t replay_get_qword(void); void replay_get_array(uint8_t *buf, size_t *size); void replay_get_array_alloc(uint8_t **buf, size_t *size); +/* Mutex functions for protecting replay log file */ + +void replay_mutex_init(void); +void replay_mutex_destroy(void); +void replay_mutex_lock(void); +void replay_mutex_unlock(void); + /*! Checks error status of the file. */ void replay_check_error(void);