Re: [libvirt] [PATCH 1/2] qemu: simplify monitor callbacks

The next patch will change reference counting idioms; consolidating this pattern now makes the next patch smaller (touch only the new macro rather than every caller). * src/qemu/qemu_monitor.c (QEMU_MONITOR_CALLBACK): New helper. (qemuMonitorGetDiskSecret, qemuMonitorEmitShutdown) (qemuMonitorEmitReset, qemuMonitorEmitPowerdown) (qemuMonitorEmitStop, qemuMonitorEmitRTCChange) (qemuMonitorEmitWatchdog, qemuMonitorEmitIOError) (qemuMonitorEmitGraphics): Use it to reduce duplication. --- > > We should probably annotate qemuMonitorUnref() (and similar functions) > > with ATTRIBUTE_RETURN_CHECK too > I'm working on that now... And here we go; this exercise didn't find any more unsafe instances.  src/qemu/qemu_monitor.c |   80 +++++++++++++----------------------------------  1 files changed, 22 insertions(+), 58 deletions(-) diff --git a/src/qemu/qemu_monitor.c b/src/qemu/qemu_monitor.c index dc08594..fd02ca0 100644 --- a/src/qemu/qemu_monitor.c +++ b/src/qemu/qemu_monitor.c @@ -754,6 +754,15 @@ int qemuMonitorHMPCommandWithFd(qemuMonitorPtr mon,         return qemuMonitorTextCommandWithFd(mon, cmd, scm_fd, reply);  } +/* Ensure proper locking around callbacks; assumes mon and ret are in + * scope.  */ +#define QEMU_MONITOR_CALLBACK(callback, ...)         \ +    qemuMonitorRef(mon);                             \ +    qemuMonitorUnlock(mon);                          \ +    if (mon->cb && mon->cb->callback)                \ +        ret = (mon->cb->callback)(mon, __VA_ARGS__); \ +    qemuMonitorLock(mon);                            \ +    qemuMonitorUnref(mon)