Re: [libvirt] [PATCH v2]daemon: Fix a crash during virNetlinkEventServiceStopAll
HI peter, Could you help me to review it ? I sent it about two months ago. thanks, haitao On 6/12/19 3:18 PM, Liu Haitao wrote: When reboot the host, a core dump file would be generated. The call traces are: Note.In this case, the main thread is thread 5. (gdb) thread 5 [Switching to thread 5 (LWP 4142)] (gdb) bt 0 0x7f00a6838273 in futex_wait_cancelable (private=, expected=0, futex_word=0x7f004c0125c0) at /usr/src/debug/glibc/2.24-r0/git/sysdeps/unix/sysv/linux/futex-internal.h:88 1 __pthread_cond_wait_common (abstime=0x0, mutex=0x7f004c012540, cond=0x7f004c012598) at /usr/src/debug/glibc/2.24-r0/git/nptl/pthread_cond_wait.c:502 2 __pthread_cond_wait (cond=0x7f004c012598, mutex=0x7f004c012540) at /usr/src/debug/glibc/2.24-r0/git/nptl/pthread_cond_wait.c:655 3 0x7f00aa467246 in virCondWait (c=, m=) at /usr/src/debug/libvirt/5.3.0-r0/libvirt-5.3.0/src/util/virthread.c:154 4 0x7f00aa467eb0 in virThreadPoolFree (pool=) at /usr/src/debug/libvirt/5.3.0-r0/libvirt-5.3.0/src/util/virthreadpool.c:286 5 0x7f0074349f9d in qemuStateCleanup () at /usr/src/debug/libvirt/5.3.0-r0/libvirt-5.3.0/src/qemu/qemu_driver.c:1036 6 0x7f00aa5e9486 in virStateCleanup () at /usr/src/debug/libvirt/5.3.0-r0/libvirt-5.3.0/src/libvirt.c:682 7 0x55a687ab86a4 in main (argc=, argv=) at /usr/src/debug/libvirt/5.3.0-r0/libvirt-5.3.0/src/remote/remote_daemon.c:1473 (gdb) thread 1 [Switching to thread 1 (LWP 4403)] (gdb) bt 0 __GI___pthread_mutex_lock (mutex=mutex@entry=0x0) at /usr/src/debug/glibc/2.24-r0/git/nptl/pthread_mutex_lock.c:67 1 0x7f00aa467165 in virMutexLock (m=m@entry=0x0) at /usr/src/debug/libvirt/5.3.0-r0/libvirt-5.3.0/src/util/virthread.c:89 2 0x7f00aa43c0f9 in virNetlinkEventServerLock (driver=) at /usr/src/debug/libvirt/5.3.0-r0/libvirt-5.3.0/src/util/virnetlink.c:799 3 virNetlinkEventRemoveClient (watch=watch@entry=0, macaddr=macaddr@entry=0x7f0088014944, protocol=protocol@entry=0) at /usr/src/debug/libvirt/5.3.0-r0/libvirt-5.3.0/src/util/virnetlink.c:1197 4 0x7f00aa4341df in virNetDevMacVLanDeleteWithVPortProfile ( ifname=, macaddr=macaddr@entry=0x7f0088014944, linkdev=0x7f0088014920 "eth1", mode=mode@entry=1, virtPortProfile=virtPortProfile@entry=0x0, stateDir=stateDir@entry=0x7f004c12fa90 "/var/run/libvirt/qemu") at /usr/src/debug/libvirt/5.3.0-r0/libvirt-5.3.0/src/util/virnetdevmacvlan.c:1112 5 0x7f0074312251 in qemuProcessStop (driver=driver@entry=0x7f004c0ecef0, vm=vm@entry=0x7f0088000b00, reason=reason@entry=VIR_DOMAIN_SHUTOFF_SHUTDOWN, asyncJob=asyncJob@entry=QEMU_ASYNC_JOB_NONE, flags=) at /usr/src/debug/libvirt/5.3.0-r0/libvirt-5.3.0/src/qemu/qemu_process.c:7291 6 0x7f007437a5ea in processMonitorEOFEvent (vm=0x7f0088000b00, driver=0x7f004c0ecef0) at /usr/src/debug/libvirt/5.3.0-r0/libvirt-5.3.0/src/qemu/qemu_driver.c:4756 7 qemuProcessEventHandler (data=0x55a687d6df10, opaque=0x7f004c0ecef0) at /usr/src/debug/libvirt/5.3.0-r0/libvirt-5.3.0/src/qemu/qemu_driver.c:4859 8 0x7f00aa467c5b in virThreadPoolWorker ( opaque=opaque@entry=0x55a687d6c110) at /usr/src/debug/libvirt/5.3.0-r0/libvirt-5.3.0/src/util/virthreadpool.c:163 9 0x7f00aa466fe8 in virThreadHelper (data=) at /usr/src/debug/libvirt/5.3.0-r0/libvirt-5.3.0/src/util/virthread.c:206 10 0x7f00a68323f4 in start_thread (arg=0x7f00699df700) at /usr/src/debug/glibc/2.24-r0/git/nptl/pthread_create.c:456 11 0x7f00a616e10f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:105 1. The execution flow of main thread (Thread 5 LWP 4142): main() -->virNetDaemonRun() -->virNetDaemonClose(dmn) //cleanup -->virNetlinkEventServiceStopAll() -->virStateCleanup() -->qemuStateCleanup() -->virThreadPoolFree() -->__pthread_cond_wait() virNetDaemonRun() -->virEventRunDefaultImpl -->virEventPollRunOnce -->virEventPollDispatchHandles -->qemuMonitorIO -->qemuProcessHandleMonitorEOF -->processEvent->eventType = QEMU_PROCESS_EVENT_MONITOR_EOF -->virThreadPoolSendJob() After typing reboot command on the host, the main thread would send an event message to another thread. Here it would let thread 1 to handle the shutdown of qemu process. But it could not be executed immediately. virNetlinkEventServiceStopAll() --> virNetlinkEventServiceStop() --> server[protocol] = NULL; // set server to null IN virNetlinkEventServiceStopAll(), some variables related to network are freed, like (static virNetlinkEventSrvPrivatePtr server). virStateCleanup() -->qemuStateCleanup() -->virThreadPoolFree() -->__pthread_cond_wait() In virThreadPoolFree() it will wait other thread to end up. 2. The execution flow of thread 5 (LWP 4403): qemuProcessStop()
Re: [libvirt] [PATCH v2]daemon: Fix a crash during virNetlinkEventServiceStopAll
Hi guys, Could you help me to review it ? thanks, haitao On 2019/6/12 15:18, Liu Haitao wrote: When reboot the host, a core dump file would be generated. The call traces are: Note.In this case, the main thread is thread 5. (gdb) thread 5 [Switching to thread 5 (LWP 4142)] (gdb) bt 0 0x7f00a6838273 in futex_wait_cancelable (private=, expected=0, futex_word=0x7f004c0125c0) at /usr/src/debug/glibc/2.24-r0/git/sysdeps/unix/sysv/linux/futex-internal.h:88 1 __pthread_cond_wait_common (abstime=0x0, mutex=0x7f004c012540, cond=0x7f004c012598) at /usr/src/debug/glibc/2.24-r0/git/nptl/pthread_cond_wait.c:502 2 __pthread_cond_wait (cond=0x7f004c012598, mutex=0x7f004c012540) at /usr/src/debug/glibc/2.24-r0/git/nptl/pthread_cond_wait.c:655 3 0x7f00aa467246 in virCondWait (c=, m=) at /usr/src/debug/libvirt/5.3.0-r0/libvirt-5.3.0/src/util/virthread.c:154 4 0x7f00aa467eb0 in virThreadPoolFree (pool=) at /usr/src/debug/libvirt/5.3.0-r0/libvirt-5.3.0/src/util/virthreadpool.c:286 5 0x7f0074349f9d in qemuStateCleanup () at /usr/src/debug/libvirt/5.3.0-r0/libvirt-5.3.0/src/qemu/qemu_driver.c:1036 6 0x7f00aa5e9486 in virStateCleanup () at /usr/src/debug/libvirt/5.3.0-r0/libvirt-5.3.0/src/libvirt.c:682 7 0x55a687ab86a4 in main (argc=, argv=) at /usr/src/debug/libvirt/5.3.0-r0/libvirt-5.3.0/src/remote/remote_daemon.c:1473 (gdb) thread 1 [Switching to thread 1 (LWP 4403)] (gdb) bt 0 __GI___pthread_mutex_lock (mutex=mutex@entry=0x0) at /usr/src/debug/glibc/2.24-r0/git/nptl/pthread_mutex_lock.c:67 1 0x7f00aa467165 in virMutexLock (m=m@entry=0x0) at /usr/src/debug/libvirt/5.3.0-r0/libvirt-5.3.0/src/util/virthread.c:89 2 0x7f00aa43c0f9 in virNetlinkEventServerLock (driver=) at /usr/src/debug/libvirt/5.3.0-r0/libvirt-5.3.0/src/util/virnetlink.c:799 3 virNetlinkEventRemoveClient (watch=watch@entry=0, macaddr=macaddr@entry=0x7f0088014944, protocol=protocol@entry=0) at /usr/src/debug/libvirt/5.3.0-r0/libvirt-5.3.0/src/util/virnetlink.c:1197 4 0x7f00aa4341df in virNetDevMacVLanDeleteWithVPortProfile ( ifname=, macaddr=macaddr@entry=0x7f0088014944, linkdev=0x7f0088014920 "eth1", mode=mode@entry=1, virtPortProfile=virtPortProfile@entry=0x0, stateDir=stateDir@entry=0x7f004c12fa90 "/var/run/libvirt/qemu") at /usr/src/debug/libvirt/5.3.0-r0/libvirt-5.3.0/src/util/virnetdevmacvlan.c:1112 5 0x7f0074312251 in qemuProcessStop (driver=driver@entry=0x7f004c0ecef0, vm=vm@entry=0x7f0088000b00, reason=reason@entry=VIR_DOMAIN_SHUTOFF_SHUTDOWN, asyncJob=asyncJob@entry=QEMU_ASYNC_JOB_NONE, flags=) at /usr/src/debug/libvirt/5.3.0-r0/libvirt-5.3.0/src/qemu/qemu_process.c:7291 6 0x7f007437a5ea in processMonitorEOFEvent (vm=0x7f0088000b00, driver=0x7f004c0ecef0) at /usr/src/debug/libvirt/5.3.0-r0/libvirt-5.3.0/src/qemu/qemu_driver.c:4756 7 qemuProcessEventHandler (data=0x55a687d6df10, opaque=0x7f004c0ecef0) at /usr/src/debug/libvirt/5.3.0-r0/libvirt-5.3.0/src/qemu/qemu_driver.c:4859 8 0x7f00aa467c5b in virThreadPoolWorker ( opaque=opaque@entry=0x55a687d6c110) at /usr/src/debug/libvirt/5.3.0-r0/libvirt-5.3.0/src/util/virthreadpool.c:163 9 0x7f00aa466fe8 in virThreadHelper (data=) at /usr/src/debug/libvirt/5.3.0-r0/libvirt-5.3.0/src/util/virthread.c:206 10 0x7f00a68323f4 in start_thread (arg=0x7f00699df700) at /usr/src/debug/glibc/2.24-r0/git/nptl/pthread_create.c:456 11 0x7f00a616e10f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:105 1. The execution flow of main thread (Thread 5 LWP 4142): main() -->virNetDaemonRun() -->virNetDaemonClose(dmn) //cleanup -->virNetlinkEventServiceStopAll() -->virStateCleanup() -->qemuStateCleanup() -->virThreadPoolFree() -->__pthread_cond_wait() virNetDaemonRun() -->virEventRunDefaultImpl -->virEventPollRunOnce -->virEventPollDispatchHandles -->qemuMonitorIO -->qemuProcessHandleMonitorEOF -->processEvent->eventType = QEMU_PROCESS_EVENT_MONITOR_EOF -->virThreadPoolSendJob() After typing reboot command on the host, the main thread would send an event message to another thread. Here it would let thread 1 to handle the shutdown of qemu process. But it could not be executed immediately. virNetlinkEventServiceStopAll() --> virNetlinkEventServiceStop() --> server[protocol] = NULL; // set server to null IN virNetlinkEventServiceStopAll(), some variables related to network are freed, like (static virNetlinkEventSrvPrivatePtr server). virStateCleanup() -->qemuStateCleanup() -->virThreadPoolFree() -->__pthread_cond_wait() In virThreadPoolFree() it will wait other thread to end up. 2. The execution flow of thread 5 (LWP 4403): qemuProcessStop() -->virNetDevMacVLanDeleteWithVPortProfile()
Re: [libvirt] [PATCH v2]daemon: Fix a crash during virNetlinkEventServiceStopAll
The steps to reproduce: 1. create a xml file including the following configuration. function='0x0' /> function='0x0'/> 2. ensure you systemd has supported core dump function 3. create and start vm with virsh command sysctl -w kernel.core_pattern=/core.%u.%e.%p brctl addbr ctrlbr0 virsh create vm.xml 4. when the vm has started up completely, reboot the host with the following command reboot -d Note, you must set one real Ethernet port(eth0,or eth1) to a direct mode in xml file. On 2019/6/12 15:18, Liu Haitao wrote: When reboot the host, a core dump file would be generated. The call traces are: Note.In this case, the main thread is thread 5. (gdb) thread 5 [Switching to thread 5 (LWP 4142)] (gdb) bt 0 0x7f00a6838273 in futex_wait_cancelable (private=, expected=0, futex_word=0x7f004c0125c0) at /usr/src/debug/glibc/2.24-r0/git/sysdeps/unix/sysv/linux/futex-internal.h:88 1 __pthread_cond_wait_common (abstime=0x0, mutex=0x7f004c012540, cond=0x7f004c012598) at /usr/src/debug/glibc/2.24-r0/git/nptl/pthread_cond_wait.c:502 2 __pthread_cond_wait (cond=0x7f004c012598, mutex=0x7f004c012540) at /usr/src/debug/glibc/2.24-r0/git/nptl/pthread_cond_wait.c:655 3 0x7f00aa467246 in virCondWait (c=, m=) at /usr/src/debug/libvirt/5.3.0-r0/libvirt-5.3.0/src/util/virthread.c:154 4 0x7f00aa467eb0 in virThreadPoolFree (pool=) at /usr/src/debug/libvirt/5.3.0-r0/libvirt-5.3.0/src/util/virthreadpool.c:286 5 0x7f0074349f9d in qemuStateCleanup () at /usr/src/debug/libvirt/5.3.0-r0/libvirt-5.3.0/src/qemu/qemu_driver.c:1036 6 0x7f00aa5e9486 in virStateCleanup () at /usr/src/debug/libvirt/5.3.0-r0/libvirt-5.3.0/src/libvirt.c:682 7 0x55a687ab86a4 in main (argc=, argv=) at /usr/src/debug/libvirt/5.3.0-r0/libvirt-5.3.0/src/remote/remote_daemon.c:1473 (gdb) thread 1 [Switching to thread 1 (LWP 4403)] (gdb) bt 0 __GI___pthread_mutex_lock (mutex=mutex@entry=0x0) at /usr/src/debug/glibc/2.24-r0/git/nptl/pthread_mutex_lock.c:67 1 0x7f00aa467165 in virMutexLock (m=m@entry=0x0) at /usr/src/debug/libvirt/5.3.0-r0/libvirt-5.3.0/src/util/virthread.c:89 2 0x7f00aa43c0f9 in virNetlinkEventServerLock (driver=) at /usr/src/debug/libvirt/5.3.0-r0/libvirt-5.3.0/src/util/virnetlink.c:799 3 virNetlinkEventRemoveClient (watch=watch@entry=0, macaddr=macaddr@entry=0x7f0088014944, protocol=protocol@entry=0) at /usr/src/debug/libvirt/5.3.0-r0/libvirt-5.3.0/src/util/virnetlink.c:1197 4 0x7f00aa4341df in virNetDevMacVLanDeleteWithVPortProfile ( ifname=, macaddr=macaddr@entry=0x7f0088014944, linkdev=0x7f0088014920 "eth1", mode=mode@entry=1, virtPortProfile=virtPortProfile@entry=0x0, stateDir=stateDir@entry=0x7f004c12fa90 "/var/run/libvirt/qemu") at /usr/src/debug/libvirt/5.3.0-r0/libvirt-5.3.0/src/util/virnetdevmacvlan.c:1112 5 0x7f0074312251 in qemuProcessStop (driver=driver@entry=0x7f004c0ecef0, vm=vm@entry=0x7f0088000b00, reason=reason@entry=VIR_DOMAIN_SHUTOFF_SHUTDOWN, asyncJob=asyncJob@entry=QEMU_ASYNC_JOB_NONE, flags=) at /usr/src/debug/libvirt/5.3.0-r0/libvirt-5.3.0/src/qemu/qemu_process.c:7291 6 0x7f007437a5ea in processMonitorEOFEvent (vm=0x7f0088000b00, driver=0x7f004c0ecef0) at /usr/src/debug/libvirt/5.3.0-r0/libvirt-5.3.0/src/qemu/qemu_driver.c:4756 7 qemuProcessEventHandler (data=0x55a687d6df10, opaque=0x7f004c0ecef0) at /usr/src/debug/libvirt/5.3.0-r0/libvirt-5.3.0/src/qemu/qemu_driver.c:4859 8 0x7f00aa467c5b in virThreadPoolWorker ( opaque=opaque@entry=0x55a687d6c110) at /usr/src/debug/libvirt/5.3.0-r0/libvirt-5.3.0/src/util/virthreadpool.c:163 9 0x7f00aa466fe8 in virThreadHelper (data=) at /usr/src/debug/libvirt/5.3.0-r0/libvirt-5.3.0/src/util/virthread.c:206 10 0x7f00a68323f4 in start_thread (arg=0x7f00699df700) at /usr/src/debug/glibc/2.24-r0/git/nptl/pthread_create.c:456 11 0x7f00a616e10f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:105 1. The execution flow of main thread (Thread 5 LWP 4142): main() -->virNetDaemonRun() -->virNetDaemonClose(dmn) //cleanup -->virNetlinkEventServiceStopAll() -->virStateCleanup() -->qemuStateCleanup() -->virThreadPoolFree() -->__pthread_cond_wait() virNetDaemonRun() -->virEventRunDefaultImpl -->virEventPollRunOnce -->virEventPollDispatchHandles -->qemuMonitorIO -->qemuProcessHandleMonitorEOF -->processEvent->eventType = QEMU_PROCESS_EVENT_MONITOR_EOF -->virThreadPoolSendJob() After typing reboot command on the host, the main thread would send an event message to another thread. Here it would let thread 1 to handle the shutdown of qemu process. But it could not be executed immediately.
[libvirt] [PATCH v2]daemon: Fix a crash during virNetlinkEventServiceStopAll
When reboot the host, a core dump file would be generated. The call traces are: Note.In this case, the main thread is thread 5. (gdb) thread 5 [Switching to thread 5 (LWP 4142)] (gdb) bt 0 0x7f00a6838273 in futex_wait_cancelable (private=, expected=0, futex_word=0x7f004c0125c0) at /usr/src/debug/glibc/2.24-r0/git/sysdeps/unix/sysv/linux/futex-internal.h:88 1 __pthread_cond_wait_common (abstime=0x0, mutex=0x7f004c012540, cond=0x7f004c012598) at /usr/src/debug/glibc/2.24-r0/git/nptl/pthread_cond_wait.c:502 2 __pthread_cond_wait (cond=0x7f004c012598, mutex=0x7f004c012540) at /usr/src/debug/glibc/2.24-r0/git/nptl/pthread_cond_wait.c:655 3 0x7f00aa467246 in virCondWait (c=, m=) at /usr/src/debug/libvirt/5.3.0-r0/libvirt-5.3.0/src/util/virthread.c:154 4 0x7f00aa467eb0 in virThreadPoolFree (pool=) at /usr/src/debug/libvirt/5.3.0-r0/libvirt-5.3.0/src/util/virthreadpool.c:286 5 0x7f0074349f9d in qemuStateCleanup () at /usr/src/debug/libvirt/5.3.0-r0/libvirt-5.3.0/src/qemu/qemu_driver.c:1036 6 0x7f00aa5e9486 in virStateCleanup () at /usr/src/debug/libvirt/5.3.0-r0/libvirt-5.3.0/src/libvirt.c:682 7 0x55a687ab86a4 in main (argc=, argv=) at /usr/src/debug/libvirt/5.3.0-r0/libvirt-5.3.0/src/remote/remote_daemon.c:1473 (gdb) thread 1 [Switching to thread 1 (LWP 4403)] (gdb) bt 0 __GI___pthread_mutex_lock (mutex=mutex@entry=0x0) at /usr/src/debug/glibc/2.24-r0/git/nptl/pthread_mutex_lock.c:67 1 0x7f00aa467165 in virMutexLock (m=m@entry=0x0) at /usr/src/debug/libvirt/5.3.0-r0/libvirt-5.3.0/src/util/virthread.c:89 2 0x7f00aa43c0f9 in virNetlinkEventServerLock (driver=) at /usr/src/debug/libvirt/5.3.0-r0/libvirt-5.3.0/src/util/virnetlink.c:799 3 virNetlinkEventRemoveClient (watch=watch@entry=0, macaddr=macaddr@entry=0x7f0088014944, protocol=protocol@entry=0) at /usr/src/debug/libvirt/5.3.0-r0/libvirt-5.3.0/src/util/virnetlink.c:1197 4 0x7f00aa4341df in virNetDevMacVLanDeleteWithVPortProfile ( ifname=, macaddr=macaddr@entry=0x7f0088014944, linkdev=0x7f0088014920 "eth1", mode=mode@entry=1, virtPortProfile=virtPortProfile@entry=0x0, stateDir=stateDir@entry=0x7f004c12fa90 "/var/run/libvirt/qemu") at /usr/src/debug/libvirt/5.3.0-r0/libvirt-5.3.0/src/util/virnetdevmacvlan.c:1112 5 0x7f0074312251 in qemuProcessStop (driver=driver@entry=0x7f004c0ecef0, vm=vm@entry=0x7f0088000b00, reason=reason@entry=VIR_DOMAIN_SHUTOFF_SHUTDOWN, asyncJob=asyncJob@entry=QEMU_ASYNC_JOB_NONE, flags=) at /usr/src/debug/libvirt/5.3.0-r0/libvirt-5.3.0/src/qemu/qemu_process.c:7291 6 0x7f007437a5ea in processMonitorEOFEvent (vm=0x7f0088000b00, driver=0x7f004c0ecef0) at /usr/src/debug/libvirt/5.3.0-r0/libvirt-5.3.0/src/qemu/qemu_driver.c:4756 7 qemuProcessEventHandler (data=0x55a687d6df10, opaque=0x7f004c0ecef0) at /usr/src/debug/libvirt/5.3.0-r0/libvirt-5.3.0/src/qemu/qemu_driver.c:4859 8 0x7f00aa467c5b in virThreadPoolWorker ( opaque=opaque@entry=0x55a687d6c110) at /usr/src/debug/libvirt/5.3.0-r0/libvirt-5.3.0/src/util/virthreadpool.c:163 9 0x7f00aa466fe8 in virThreadHelper (data=) at /usr/src/debug/libvirt/5.3.0-r0/libvirt-5.3.0/src/util/virthread.c:206 10 0x7f00a68323f4 in start_thread (arg=0x7f00699df700) at /usr/src/debug/glibc/2.24-r0/git/nptl/pthread_create.c:456 11 0x7f00a616e10f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:105 1. The execution flow of main thread (Thread 5 LWP 4142): main() -->virNetDaemonRun() -->virNetDaemonClose(dmn) //cleanup -->virNetlinkEventServiceStopAll() -->virStateCleanup() -->qemuStateCleanup() -->virThreadPoolFree() -->__pthread_cond_wait() virNetDaemonRun() -->virEventRunDefaultImpl -->virEventPollRunOnce -->virEventPollDispatchHandles -->qemuMonitorIO -->qemuProcessHandleMonitorEOF -->processEvent->eventType = QEMU_PROCESS_EVENT_MONITOR_EOF -->virThreadPoolSendJob() After typing reboot command on the host, the main thread would send an event message to another thread. Here it would let thread 1 to handle the shutdown of qemu process. But it could not be executed immediately. virNetlinkEventServiceStopAll() --> virNetlinkEventServiceStop() --> server[protocol] = NULL; // set server to null IN virNetlinkEventServiceStopAll(), some variables related to network are freed, like (static virNetlinkEventSrvPrivatePtr server). virStateCleanup() -->qemuStateCleanup() -->virThreadPoolFree() -->__pthread_cond_wait() In virThreadPoolFree() it will wait other thread to end up. 2. The execution flow of thread 5 (LWP 4403): qemuProcessStop() -->virNetDevMacVLanDeleteWithVPortProfile() -->virNetlinkEventRemoveClient() --> srv = server[protocol] Although the main thread had sent the message
