diff options
| author | Alex Bennée <alex.bennee@linaro.org> | 2018-02-27 12:52:42 +0300 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2018-03-12 16:12:50 +0100 |
| commit | a36544d34c8b7e483386d29f9716ca9f4caad9fb (patch) | |
| tree | a1682c57aa3a90ab2ff16741891773a9af0318a5 | |
| parent | 180d30bebeff8e3687b50bd55d44e6a5a83bc4da (diff) | |
replay: make locking visible outside replay code
The replay_mutex_lock/unlock/locked functions are now going to be used
for ensuring lock-step behaviour between the two threads. Make them
public API functions and also provide stubs for non-QEMU builds on
common paths.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Pavel Dovgalyuk <pavel.dovgaluk@ispras.ru>
Message-Id: <20180227095242.1060.16601.stgit@pasha-VirtualBox>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| -rw-r--r-- | include/sysemu/replay.h | 13 | ||||
| -rw-r--r-- | replay/replay-internal.c | 2 | ||||
| -rw-r--r-- | replay/replay-internal.h | 6 | ||||
| -rw-r--r-- | stubs/replay.c | 8 |
4 files changed, 25 insertions, 4 deletions
diff --git a/include/sysemu/replay.h b/include/sysemu/replay.h index 401de12130..3ced6bc231 100644 --- a/include/sysemu/replay.h +++ b/include/sysemu/replay.h @@ -48,6 +48,19 @@ extern ReplayMode replay_mode; /* Name of the initial VM snapshot */ extern char *replay_snapshot; +/* Replay locking + * + * The locks are needed to protect the shared structures and log file + * when doing record/replay. They also are the main sync-point between + * the main-loop thread and the vCPU thread. This was a role + * previously filled by the BQL which has been busy trying to reduce + * its impact across the code. This ensures blocks of events stay + * sequential and reproducible. + */ + +void replay_mutex_lock(void); +void replay_mutex_unlock(void); + /* Replay process control functions */ /*! Enables recording or saving event log with specified parameters */ diff --git a/replay/replay-internal.c b/replay/replay-internal.c index 0d7e1d6bc4..7cdefeaa04 100644 --- a/replay/replay-internal.c +++ b/replay/replay-internal.c @@ -181,7 +181,7 @@ void replay_mutex_destroy(void) qemu_mutex_destroy(&lock); } -static bool replay_mutex_locked(void) +bool replay_mutex_locked(void) { return replay_locked; } diff --git a/replay/replay-internal.h b/replay/replay-internal.h index 8e4c701751..41eee66e9b 100644 --- a/replay/replay-internal.h +++ b/replay/replay-internal.h @@ -100,12 +100,12 @@ 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 */ +/* Mutex functions for protecting replay log file and ensuring + * synchronisation between vCPU and main-loop threads. */ void replay_mutex_init(void); void replay_mutex_destroy(void); -void replay_mutex_lock(void); -void replay_mutex_unlock(void); +bool replay_mutex_locked(void); /*! Checks error status of the file. */ void replay_check_error(void); diff --git a/stubs/replay.c b/stubs/replay.c index 9c8aa48c9c..04279abb2c 100644 --- a/stubs/replay.c +++ b/stubs/replay.c @@ -72,3 +72,11 @@ uint64_t blkreplay_next_id(void) { return 0; } + +void replay_mutex_lock(void) +{ +} + +void replay_mutex_unlock(void) +{ +} |