On Thu, 2021-08-05 at 14:24 +0100, Daniel P. Berrangé wrote:
On Thu, Aug 05, 2021 at 03:08:50PM +0200, Tim Wiederhake wrote:
`pthread_mutex_destroy`, `pthread_mutex_lock` and `pthread_mutex_unlock` return an error code that is currently ignored.
Add debug information if one of these operations failed, e.g. when there is an attempt to destroy a still locked mutex or unlock and already unlocked mutex.
We ignore the errors because in practice we found impls don't return any error code when using PTHREAD_MUTEX_NORMAL - it would require use of PTHREAD_MUTEX_ERRORCHECK.
Did you actually see errors returned for real ?
Yes. Please note that I apprently copy-pasted the wrong link in the cover letter. The pipeline for this series is correct (https://gitlab.com/twiederh/libvirt/-/pipelines/348505233), the pipeline for only patches 5, 6, 7 that demonstrate the non-zero return values of pthread_mutex_{lock,unlock,destroy} is here: https://gitlab.com/twiederh/libvirt/-/pipelines/348505770 Regards, Tim
Signed-off-by: Tim Wiederhake <twiederh@redhat.com> --- src/util/virthread.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-)
diff --git a/src/util/virthread.c b/src/util/virthread.c index e89c1a09fb..f64dbee9e9 100644 --- a/src/util/virthread.c +++ b/src/util/virthread.c @@ -35,7 +35,10 @@ #include "viralloc.h" #include "virthreadjob.h" +#include "virlog.h" +#define VIR_FROM_THIS VIR_FROM_THREAD +VIR_LOG_INIT("util.thread"); int virOnce(virOnceControl *once, virOnceFunc init) { @@ -83,17 +86,23 @@ int virMutexInitRecursive(virMutex *m) void virMutexDestroy(virMutex *m) { - pthread_mutex_destroy(&m->lock); + if (pthread_mutex_destroy(&m->lock)) { + VIR_WARN("Failed to destroy mutex=%p", m); + } } void virMutexLock(virMutex *m) { - pthread_mutex_lock(&m->lock); + if (pthread_mutex_lock(&m->lock)) { + VIR_WARN("Failed to lock mutex=%p", m); + } } void virMutexUnlock(virMutex *m) { - pthread_mutex_unlock(&m->lock); + if (pthread_mutex_unlock(&m->lock)) { + VIR_WARN("Failed to unlock mutex=%p", m); + } } -- 2.31.1
Regards, Daniel