Re: [Libvirt-cim] [PATCH] Workaround to fix race condition around libvirt init

# HG changeset patch # User Sharad Mishra&lt;snmishra(a)us.ibm.com&gt; # Date 1314379933 25200 # Node ID a42b68361ed9cb4f7d6f15de5b58ccc68e88ef38 # Parent a346baf140d64177a9dc1066677c307ee6518236 Workaround to fix race condition around libvirt init. This patch fixes the race condition caused when mutiple threads try to start a VM. This patch also fixes the issue of incorrect mem allocation for VSSD property - emulator. Signed-off-by: Sharad Mishra&lt;snmishra(a)us.ibm.com&gt; diff --git a/libxkutil/misc_util.c b/libxkutil/misc_util.c --- a/libxkutil/misc_util.c +++ b/libxkutil/misc_util.c @@ -28,6 +28,7 @@ #include<stdbool.h> #include<stdarg.h> #include<unistd.h> +#include<pthread.h> #include<libvirt/libvirt.h> #include<libvirt/virterror.h> @@ -45,6 +46,9 @@ #include "misc_util.h" #include "cs_util.h" +static pthread_mutex_t libvirt_mutex = PTHREAD_MUTEX_INITIALIZER; +/* libvirt library not initialized */ +static int libvirt_initialized = 0; #define URI_ENV "HYPURI" @@ -114,11 +118,15 @@ CU_DEBUG("Connecting to libvirt with uri `%s'", uri); + pthread_mutex_lock(&libvirt_mutex); + if (is_read_only()) conn = virConnectOpenReadOnly(uri); else conn = virConnectOpen(uri); + pthread_mutex_unlock(&libvirt_mutex); + if (!conn) { CU_DEBUG("Unable to connect to `%s'", uri); return NULL; @@ -530,7 +538,19 @@ bool libvirt_cim_init(void) { - return virInitialize() == 0; + int ret=0; + + /* double-check lock pattern used for performance reasons */ + if (0 == libvirt_initialized) { + pthread_mutex_lock(&libvirt_mutex); + if (0 == libvirt_initialized) { + ret = virInitialize(); + if (ret == 0) + libvirt_initialized=1; + } + pthread_mutex_unlock(&libvirt_mutex); + } + return (ret == 0); }

bool check_refs_pfx_match(const CMPIObjectPath *refa, diff --git a/src/Virt_VirtualSystemManagementService.c b/src/Virt_VirtualSystemManagementService.c --- a/src/Virt_VirtualSystemManagementService.c +++ b/src/Virt_VirtualSystemManagementService.c @@ -188,6 +188,20 @@ return 1; } +static bool make_space(struct virt_device **list, int cur, int new) +{ + struct virt_device *tmp; + + tmp = calloc(cur + new, sizeof(*tmp)); + if (tmp == NULL) + return false; + + memcpy(tmp, *list, sizeof(*tmp) * cur); + *list = tmp; + + return true; +} +