Re: [libvirt] [PATCH 12/15] Allow timeouts waiting for QEMU job lock

Some monitor commands may take a very long time to complete. It is not desirable to block other incoming API calls forever. With this change, if an existing API call is holding the job lock, additional API calls will not wait forever. They will time out after a short period of time, allowing application to retry later. * include/libvirt/virterror.h, src/util/virterror.c: Add new VIR_ERR_OPERATION_TIMEOUT error code * src/qemu/qemu_driver.c: Change to a timed condition variable wait for acquiring the monitor job lock

+/* Give up waiting for mutex after 30 seconds */ +//#define QEMU_JOB_WAIT_TIME (1000ull * 30) +#define QEMU_JOB_WAIT_TIME (1000ull * 3) static int qemuDomainObjBeginJob(virDomainObjPtr obj) ATTRIBUTE_RETURN_CHECK; static int qemuDomainObjBeginJob(virDomainObjPtr obj) { qemuDomainObjPrivatePtr priv = obj->privateData; + struct timeval now; + unsigned long long then; + + if (gettimeofday(&now, NULL) < 0) { + virReportSystemError(NULL, errno, "%s", + _("cannot get time of day")); + return -1; + } + then = (now.tv_sec * 1000ull) + (now.tv_usec / 1000); + then += QEMU_JOB_WAIT_TIME;