Commit a36544d3 authored by Alex Bennée's avatar Alex Bennée Committed by Paolo Bonzini
Browse files

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: default avatarAlex Bennée <alex.bennee@linaro.org>
Signed-off-by: default avatarPavel Dovgalyuk <pavel.dovgaluk@ispras.ru>
Message-Id: <20180227095242.1060.16601.stgit@pasha-VirtualBox>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 180d30be

include/sysemu/replay.h

+13 −0
Original line number Diff line number Diff line
@@ -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 */

replay/replay-internal.c

+1 −1
Original line number Diff line number Diff line
@@ -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;

}

replay/replay-internal.h

+3 −3
Original line number Diff line number Diff line
@@ -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);

stubs/replay.c

+8 −0
Original line number Diff line number Diff line
@@ -72,3 +72,11 @@ uint64_t blkreplay_next_id(void) 
{

    return 0;

}



void replay_mutex_lock(void)

{

}



void replay_mutex_unlock(void)

{

}