[libvirt] [PATCH 4/6] qemu: use virObject to manage reference-counting for qemu monitor
Hu Tao
hutao at cn.fujitsu.com
Wed Apr 6 07:19:55 UTC 2011
---
src/qemu/qemu_domain.c | 30 ++-----------
src/qemu/qemu_migration.c | 2 -
src/qemu/qemu_monitor.c | 109 ++++++++++++++++++++++++--------------------
src/qemu/qemu_monitor.h | 4 +-
src/qemu/qemu_process.c | 32 +++++++-------
5 files changed, 81 insertions(+), 96 deletions(-)
diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c
index 3a3c953..d11dc5f 100644
--- a/src/qemu/qemu_domain.c
+++ b/src/qemu/qemu_domain.c
@@ -560,9 +560,8 @@ void qemuDomainObjEnterMonitor(virDomainObjPtr obj)
{
qemuDomainObjPrivatePtr priv = obj->privateData;
- qemuMonitorLock(priv->mon);
- qemuMonitorRef(priv->mon);
virDomainObjUnlock(obj);
+ qemuMonitorLock(priv->mon);
}
@@ -573,18 +572,9 @@ void qemuDomainObjEnterMonitor(virDomainObjPtr obj)
void qemuDomainObjExitMonitor(virDomainObjPtr obj)
{
qemuDomainObjPrivatePtr priv = obj->privateData;
- int refs;
-
- refs = qemuMonitorUnref(priv->mon);
-
- if (refs > 0)
- qemuMonitorUnlock(priv->mon);
+ qemuMonitorUnlock(priv->mon);
virDomainObjLock(obj);
-
- if (refs == 0) {
- priv->mon = NULL;
- }
}
@@ -601,10 +591,8 @@ void qemuDomainObjEnterMonitorWithDriver(struct qemud_driver *driver,
{
qemuDomainObjPrivatePtr priv = obj->privateData;
- qemuMonitorLock(priv->mon);
- qemuMonitorRef(priv->mon);
virDomainObjUnlock(obj);
- qemuDriverUnlock(driver);
+ qemuMonitorLock(priv->mon);
}
@@ -617,19 +605,9 @@ void qemuDomainObjExitMonitorWithDriver(struct qemud_driver *driver,
virDomainObjPtr obj)
{
qemuDomainObjPrivatePtr priv = obj->privateData;
- int refs;
-
- refs = qemuMonitorUnref(priv->mon);
-
- if (refs > 0)
- qemuMonitorUnlock(priv->mon);
- qemuDriverLock(driver);
+ qemuMonitorUnlock(priv->mon);
virDomainObjLock(obj);
-
- if (refs == 0) {
- priv->mon = NULL;
- }
}
void qemuDomainObjEnterRemoteWithDriver(struct qemud_driver *driver,
diff --git a/src/qemu/qemu_migration.c b/src/qemu/qemu_migration.c
index 462e6be..6af2e24 100644
--- a/src/qemu/qemu_migration.c
+++ b/src/qemu/qemu_migration.c
@@ -224,11 +224,9 @@ qemuMigrationWaitForCompletion(struct qemud_driver *driver, virDomainObjPtr vm)
}
virDomainObjUnlock(vm);
- qemuDriverUnlock(driver);
nanosleep(&ts, NULL);
- qemuDriverLock(driver);
virDomainObjLock(vm);
}
diff --git a/src/qemu/qemu_monitor.c b/src/qemu/qemu_monitor.c
index 2d28f8d..98c55e7 100644
--- a/src/qemu/qemu_monitor.c
+++ b/src/qemu/qemu_monitor.c
@@ -37,6 +37,7 @@
#include "memory.h"
#include "logging.h"
#include "files.h"
+#include "virobject.h"
#define VIR_FROM_THIS VIR_FROM_QEMU
@@ -44,11 +45,10 @@
#define DEBUG_RAW_IO 0
struct _qemuMonitor {
+ virObject obj;
virMutex lock; /* also used to protect fd */
virCond notify;
- int refs;
-
int fd;
int watch;
int hasSendFD;
@@ -203,35 +203,61 @@ void qemuMonitorUnlock(qemuMonitorPtr mon)
}
-static void qemuMonitorFree(qemuMonitorPtr mon)
+static void doMonitorFree(virObjectPtr obj)
{
+ qemuMonitorPtr mon = (qemuMonitorPtr)obj;
+
VIR_DEBUG("mon=%p", mon);
if (mon->cb && mon->cb->destroy)
(mon->cb->destroy)(mon, mon->vm);
- if (virCondDestroy(&mon->notify) < 0)
- {}
+ ignore_value(virCondDestroy(&mon->notify));
virMutexDestroy(&mon->lock);
VIR_FREE(mon->buffer);
VIR_FREE(mon);
}
-int qemuMonitorRef(qemuMonitorPtr mon)
+static qemuMonitorPtr qemuMonitorAlloc(void)
{
- mon->refs++;
- return mon->refs;
-}
+ qemuMonitorPtr mon;
-int qemuMonitorUnref(qemuMonitorPtr mon)
-{
- mon->refs--;
+ if (VIR_ALLOC(mon) < 0) {
+ virReportOOMError();
+ return NULL;
+ }
- if (mon->refs == 0) {
- qemuMonitorUnlock(mon);
- qemuMonitorFree(mon);
- return 0;
+ if (virObjectInit(&mon->obj, doMonitorFree)) {
+ VIR_FREE(mon);
+ return NULL;
+ }
+
+ if (virMutexInit(&mon->lock) < 0) {
+ qemuReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+ _("cannot initialize monitor mutex"));
+ VIR_FREE(mon);
+ return NULL;
}
- return mon->refs;
+ if (virCondInit(&mon->notify) < 0) {
+ qemuReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+ _("cannot initialize monitor condition"));
+ virMutexDestroy(&mon->lock);
+ VIR_FREE(mon);
+ return NULL;
+ }
+
+ mon->fd = -1;
+
+ return mon;
+}
+
+void qemuMonitorRef(qemuMonitorPtr mon)
+{
+ virObjectRef(&mon->obj);
+}
+
+void qemuMonitorUnref(qemuMonitorPtr mon)
+{
+ virObjectUnref(&mon->obj);
}
static void
@@ -239,9 +265,7 @@ qemuMonitorUnwatch(void *monitor)
{
qemuMonitorPtr mon = monitor;
- qemuMonitorLock(mon);
- if (qemuMonitorUnref(mon) > 0)
- qemuMonitorUnlock(mon);
+ qemuMonitorUnref(mon);
}
static int
@@ -521,7 +545,6 @@ qemuMonitorIO(int watch, int fd, int events, void *opaque) {
/* lock access to the monitor and protect fd */
qemuMonitorLock(mon);
- qemuMonitorRef(mon);
#if DEBUG_IO
VIR_DEBUG("Monitor %p I/O on watch %d fd %d events %d", mon, watch, fd, events);
#endif
@@ -598,13 +621,11 @@ qemuMonitorIO(int watch, int fd, int events, void *opaque) {
/* Make sure anyone waiting wakes up now */
virCondSignal(&mon->notify);
- if (qemuMonitorUnref(mon) > 0)
- qemuMonitorUnlock(mon);
+ qemuMonitorUnlock(mon);
VIR_DEBUG("Triggering EOF callback error? %d", failed);
(eofNotify)(mon, vm, failed);
} else {
- if (qemuMonitorUnref(mon) > 0)
- qemuMonitorUnlock(mon);
+ qemuMonitorUnlock(mon);
}
}
@@ -623,30 +644,13 @@ qemuMonitorOpen(virDomainObjPtr vm,
return NULL;
}
- if (VIR_ALLOC(mon) < 0) {
- virReportOOMError();
+ mon = qemuMonitorAlloc();
+ if (!mon)
return NULL;
- }
- if (virMutexInit(&mon->lock) < 0) {
- qemuReportError(VIR_ERR_INTERNAL_ERROR, "%s",
- _("cannot initialize monitor mutex"));
- VIR_FREE(mon);
- return NULL;
- }
- if (virCondInit(&mon->notify) < 0) {
- qemuReportError(VIR_ERR_INTERNAL_ERROR, "%s",
- _("cannot initialize monitor condition"));
- virMutexDestroy(&mon->lock);
- VIR_FREE(mon);
- return NULL;
- }
- mon->fd = -1;
- mon->refs = 1;
mon->vm = vm;
mon->json = json;
mon->cb = cb;
- qemuMonitorLock(mon);
switch (config->type) {
case VIR_DOMAIN_CHR_TYPE_UNIX:
@@ -679,20 +683,25 @@ qemuMonitorOpen(virDomainObjPtr vm,
}
+ /* mon will be accessed by qemuMonitorIO which is called in
+ * event thread, so ref it before passing it to the thread.
+ *
+ * Note: mon is unrefed in qemuMonitorUnwatch
+ */
+ qemuMonitorRef(mon);
if ((mon->watch = virEventAddHandle(mon->fd,
VIR_EVENT_HANDLE_HANGUP |
VIR_EVENT_HANDLE_ERROR |
VIR_EVENT_HANDLE_READABLE,
qemuMonitorIO,
mon, qemuMonitorUnwatch)) < 0) {
+ qemuMonitorUnref(mon);
qemuReportError(VIR_ERR_INTERNAL_ERROR, "%s",
_("unable to register monitor events"));
goto cleanup;
}
- qemuMonitorRef(mon);
VIR_DEBUG("New mon %p fd =%d watch=%d", mon, mon->fd, mon->watch);
- qemuMonitorUnlock(mon);
return mon;
@@ -703,8 +712,8 @@ cleanup:
* so kill the callbacks now.
*/
mon->cb = NULL;
- qemuMonitorUnlock(mon);
qemuMonitorClose(mon);
+ qemuMonitorUnref(mon);
return NULL;
}
@@ -724,8 +733,8 @@ void qemuMonitorClose(qemuMonitorPtr mon)
VIR_FORCE_CLOSE(mon->fd);
}
- if (qemuMonitorUnref(mon) > 0)
- qemuMonitorUnlock(mon);
+ qemuMonitorUnlock(mon);
+ qemuMonitorUnref(mon);
}
@@ -778,7 +787,7 @@ int qemuMonitorHMPCommandWithFd(qemuMonitorPtr mon,
if ((mon)->cb && (mon)->cb->callback) \
(ret) = ((mon)->cb->callback)(mon, __VA_ARGS__); \
qemuMonitorLock(mon); \
- ignore_value(qemuMonitorUnref(mon)); \
+ qemuMonitorUnref(mon); \
} while (0)
int qemuMonitorGetDiskSecret(qemuMonitorPtr mon,
diff --git a/src/qemu/qemu_monitor.h b/src/qemu/qemu_monitor.h
index c90219b..4498c49 100644
--- a/src/qemu/qemu_monitor.h
+++ b/src/qemu/qemu_monitor.h
@@ -132,8 +132,8 @@ int qemuMonitorCheckHMP(qemuMonitorPtr mon, const char *cmd);
void qemuMonitorLock(qemuMonitorPtr mon);
void qemuMonitorUnlock(qemuMonitorPtr mon);
-int qemuMonitorRef(qemuMonitorPtr mon);
-int qemuMonitorUnref(qemuMonitorPtr mon) ATTRIBUTE_RETURN_CHECK;
+void qemuMonitorRef(qemuMonitorPtr mon);
+void qemuMonitorUnref(qemuMonitorPtr mon);
/* These APIs are for use by the internal Text/JSON monitor impl code only */
int qemuMonitorSend(qemuMonitorPtr mon,
diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c
index 244b22a..4b9087f 100644
--- a/src/qemu/qemu_process.c
+++ b/src/qemu/qemu_process.c
@@ -107,7 +107,6 @@ qemuProcessHandleMonitorEOF(qemuMonitorPtr mon ATTRIBUTE_UNUSED,
VIR_DEBUG("Received EOF on %p '%s'", vm, vm->def->name);
- qemuDriverLock(driver);
virDomainObjLock(vm);
if (!virDomainObjIsActive(vm)) {
@@ -133,15 +132,17 @@ qemuProcessHandleMonitorEOF(qemuMonitorPtr mon ATTRIBUTE_UNUSED,
qemuProcessStop(driver, vm, 0);
qemuAuditDomainStop(vm, hasError ? "failed" : "shutdown");
- if (!vm->persistent)
+ if (!vm->persistent) {
+ qemuDriverLock(driver);
virDomainRemoveInactive(&driver->domains, vm);
- else
- virDomainObjUnlock(vm);
+ qemuDriverUnlock(driver);
+ }
+
+ virDomainObjUnlock(vm);
if (event) {
qemuDomainEventQueue(driver, event);
}
- qemuDriverUnlock(driver);
}
@@ -602,8 +603,10 @@ static void qemuProcessHandleMonitorDestroy(qemuMonitorPtr mon,
virDomainObjLock(vm);
priv = vm->privateData;
- if (priv->mon == mon)
+ if (priv->mon == mon) {
priv->mon = NULL;
+ qemuMonitorUnref(mon);
+ }
virDomainObjUnlock(vm);
virDomainObjUnref(vm);
}
@@ -633,19 +636,11 @@ qemuConnectMonitor(struct qemud_driver *driver, virDomainObjPtr vm)
goto error;
}
- /* Hold an extra reference because we can't allow 'vm' to be
- * deleted while the monitor is active */
- virDomainObjRef(vm);
-
priv->mon = qemuMonitorOpen(vm,
priv->monConfig,
priv->monJSON,
&monitorCallbacks);
- /* Safe to ignore value since ref count was incremented above */
- if (priv->mon == NULL)
- virDomainObjUnref(vm);
-
if (virSecurityManagerClearSocketLabel(driver->securityManager, vm) < 0) {
VIR_ERROR(_("Failed to clear security context for monitor for %s"),
vm->def->name);
@@ -657,6 +652,7 @@ qemuConnectMonitor(struct qemud_driver *driver, virDomainObjPtr vm)
goto error;
}
+ qemuMonitorRef(priv->mon);
qemuDomainObjEnterMonitorWithDriver(driver, vm);
ret = qemuMonitorSetCapabilities(priv->mon);
@@ -2471,8 +2467,12 @@ void qemuProcessStop(struct qemud_driver *driver,
_("Failed to send SIGTERM to %s (%d)"),
vm->def->name, vm->pid);
- if (priv->mon)
- qemuMonitorClose(priv->mon);
+ if (priv->mon) {
+ qemuMonitorPtr mon = priv->mon;
+ priv->mon = NULL;
+ qemuMonitorClose(mon);
+ qemuMonitorUnref(mon);
+ }
if (priv->monConfig) {
if (priv->monConfig->type == VIR_DOMAIN_CHR_TYPE_UNIX)
--
1.7.3.1
--
Thanks,
Hu Tao
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