Follows the pattern used in the QEMU driver for managing multiple,
simultaneous jobs within the driver.
Signed-off-by: Jim Fehlig jfeh...@suse.com
---
V2:
Add ATTRIBUTE_RETURN_CHECK to libxlDomainObjEndJob
src/libxl/libxl_domain.c | 128 +++
src/libxl/libxl_domain.h | 38 ++
2 files changed, 166 insertions(+)
diff --git a/src/libxl/libxl_domain.c b/src/libxl/libxl_domain.c
index eb2e50e..fdc4661 100644
--- a/src/libxl/libxl_domain.c
+++ b/src/libxl/libxl_domain.c
@@ -30,10 +30,18 @@
#include virerror.h
#include virlog.h
#include virstring.h
+#include virtime.h
#define VIR_FROM_THIS VIR_FROM_LIBXL
+VIR_ENUM_IMPL(libxlDomainJob, LIBXL_JOB_LAST,
+ none,
+ query,
+ destroy,
+ modify,
+);
+
/* Object used to store info related to libxl event registrations */
typedef struct _libxlEventHookInfo libxlEventHookInfo;
typedef libxlEventHookInfo *libxlEventHookInfoPtr;
@@ -284,6 +292,119 @@ static const libxl_osevent_hooks libxl_event_callbacks = {
.timeout_deregister = libxlDomainObjTimeoutDeregisterEventHook,
};
+static int
+libxlDomainObjInitJob(libxlDomainObjPrivatePtr priv)
+{
+memset(priv-job, 0, sizeof(priv-job));
+
+if (virCondInit(priv-job.cond) 0)
+return -1;
+
+return 0;
+}
+
+static void
+libxlDomainObjResetJob(libxlDomainObjPrivatePtr priv)
+{
+struct libxlDomainJobObj *job = priv-job;
+
+job-active = LIBXL_JOB_NONE;
+job-owner = 0;
+}
+
+static void
+libxlDomainObjFreeJob(libxlDomainObjPrivatePtr priv)
+{
+ignore_value(virCondDestroy(priv-job.cond));
+}
+
+/* Give up waiting for mutex after 30 seconds */
+#define LIBXL_JOB_WAIT_TIME (1000ull * 30)
+
+/*
+ * obj must be locked before calling, libxlDriverPrivatePtr must NOT be locked
+ *
+ * This must be called by anything that will change the VM state
+ * in any way
+ *
+ * Upon successful return, the object will have its ref count increased,
+ * successful calls must be followed by EndJob eventually
+ */
+int
+libxlDomainObjBeginJob(libxlDriverPrivatePtr driver ATTRIBUTE_UNUSED,
+ virDomainObjPtr obj,
+ enum libxlDomainJob job)
+{
+libxlDomainObjPrivatePtr priv = obj-privateData;
+unsigned long long now;
+unsigned long long then;
+
+if (virTimeMillisNow(now) 0)
+return -1;
+then = now + LIBXL_JOB_WAIT_TIME;
+
+virObjectRef(obj);
+
+while (priv-job.active) {
+VIR_DEBUG(Wait normal job condition for starting job: %s,
+ libxlDomainJobTypeToString(job));
+if (virCondWaitUntil(priv-job.cond, obj-parent.lock, then) 0)
+goto error;
+}
+
+libxlDomainObjResetJob(priv);
+
+VIR_DEBUG(Starting job: %s, libxlDomainJobTypeToString(job));
+priv-job.active = job;
+priv-job.owner = virThreadSelfID();
+
+return 0;
+
+error:
+VIR_WARN(Cannot start job (%s) for domain %s;
+ current job is (%s) owned by (%d),
+ libxlDomainJobTypeToString(job),
+ obj-def-name,
+ libxlDomainJobTypeToString(priv-job.active),
+ priv-job.owner);
+
+if (errno == ETIMEDOUT)
+virReportError(VIR_ERR_OPERATION_TIMEOUT,
+ %s, _(cannot acquire state change lock));
+else
+virReportSystemError(errno,
+ %s, _(cannot acquire job mutex));
+
+virObjectUnref(obj);
+return -1;
+}
+
+/*
+ * obj must be locked before calling
+ *
+ * To be called after completing the work associated with the
+ * earlier libxlDomainBeginJob() call
+ *
+ * Returns true if the remaining reference count on obj is
+ * non-zero, false if the reference count has dropped to zero
+ * and obj is disposed.
+ */
+bool
+libxlDomainObjEndJob(libxlDriverPrivatePtr driver ATTRIBUTE_UNUSED,
+ virDomainObjPtr obj)
+{
+libxlDomainObjPrivatePtr priv = obj-privateData;
+enum libxlDomainJob job = priv-job.active;
+
+VIR_DEBUG(Stopping job: %s,
+ libxlDomainJobTypeToString(job));
+
+libxlDomainObjResetJob(priv);
+virCondSignal(priv-job.cond);
+
+return virObjectUnref(obj);
+}
+
static void *
libxlDomainObjPrivateAlloc(void)
{
@@ -300,6 +421,12 @@ libxlDomainObjPrivateAlloc(void)
return NULL;
}
+if (libxlDomainObjInitJob(priv) 0) {
+virChrdevFree(priv-devs);
+virObjectUnref(priv);
+return NULL;
+}
+
return priv;
}
@@ -311,6 +438,7 @@ libxlDomainObjPrivateDispose(void *obj)
if (priv-deathW)
libxl_evdisable_domain_death(priv-ctx, priv-deathW);
+libxlDomainObjFreeJob(priv);
virChrdevFree(priv-devs);
libxl_ctx_free(priv-ctx);
if (priv-logger_file)
diff --git a/src/libxl/libxl_domain.h b/src/libxl/libxl_domain.h
index 8565820..0a29d38 100644
--- a/src/libxl/libxl_domain.h
+++ b/src/libxl/libxl_domain.h
@@ -30,6 +30,31 @@
# include libxl_conf.h
