[libvirt-users] Thread-safety issues with vbox driver ?

Hi, I'm experiencing weird things with the vbox driver when using multiple threads. Following is the snippet of code I experience problems with /*****************************************************/ #include <stdlib.h> #include <stdio.h> #include <pthread.h> #include <libvirt/libvirt.h> void *create_and_destroy(void *arg) { virDomainPtr dom = (virDomainPtr)arg; char buf[VIR_UUID_STRING_BUFLEN]; virDomainGetUUIDString(dom, buf); if (virDomainCreate(dom) != 0) { printf("failed to start %s\n", buf); goto end; } printf("%s started\n", buf); if (virDomainDestroy(dom) != 0) { printf("failed to destroy %s\n", buf); } printf("%s destroyed\n", buf); end: virDomainFree(dom); pthread_exit(NULL); } int main(int argc, char **argv) { virConnectPtr conn = virConnectOpen("vbox:///session"); int i; int count = virConnectNumOfDefinedDomains(conn); char **names = malloc(count * sizeof(char *)); virConnectListDefinedDomains(conn, names, count); virDomainPtr *doms = malloc(count * sizeof(virDomainPtr)); for (i = 0 ; i < count ; ++i) { doms[i] = virDomainLookupByName(conn, names[i]); } pthread_t *threads = malloc(count * sizeof(pthread_t)); pthread_attr_t attr; pthread_attr_init(&attr); pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_JOINABLE); for (i = 0 ; i < count ; ++i) { pthread_create(&threads[i], &attr, create_and_destroy, (void *)doms[i]); } pthread_attr_destroy(&attr); for (i = 0 ; i < count ; ++i) { pthread_join(threads[i], NULL); } virConnectClose(conn); pthread_exit(NULL); } /************************************************/ Here is the output of the program with 2 defined domains: Sometimes the first domain really fails to start, but sometimes it starts correctly but libvirt reports an error. Sometimes domains aren't destroyed but libvirt reports no error at all. If there is only one domain, no problem occurs at all. I also tried the same code (ie with multiple domains) but with only one thread and it works well. I managed to reproduce these issues with libvirt 0.9.4, 0.9.7, using VirtualBox 4.0 and 4.1. -- Jean-Baptiste ROUAULT Ingénieur R&D - diateam : Architectes de l'information Phone : +33 (0)9 53 16 02 70 Fax : +33 (0)2 98 050 051