On 07.02.2014 04:53, Jim Fehlig wrote:
Follows the pattern used in the QEMU driver for managing multiple,
simultaneous jobs within the driver.
Signed-off-by: Jim Fehlig <jfehlig@xxxxxxxx>
---
src/libxl/libxl_domain.c | 128 +++++++++++++++++++++++++++++++++++++++++++++++
src/libxl/libxl_domain.h | 37 ++++++++++++++
2 files changed, 165 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..4decc40 100644
--- a/src/libxl/libxl_domain.h
+++ b/src/libxl/libxl_domain.h
@@ -30,6 +30,31 @@
# include "libxl_conf.h"
# include "virchrdev.h"
+# define JOB_MASK(job) (1 << (job - 1))
+# define DEFAULT_JOB_MASK \
+ (JOB_MASK(LIBXL_JOB_DESTROY) | \
+ JOB_MASK(LIBXL_JOB_ABORT))
+
+/* Only 1 job is allowed at any time
+ * A job includes *all* libxl.so api, even those just querying
+ * information, not merely actions */
+enum libxlDomainJob {
+ LIBXL_JOB_NONE = 0, /* Always set to 0 for easy if (jobActive) conditions */
+ LIBXL_JOB_QUERY, /* Doesn't change any state */
+ LIBXL_JOB_DESTROY, /* Destroys the domain (cannot be masked out) */
+ LIBXL_JOB_MODIFY, /* May change state */
+
+ LIBXL_JOB_LAST
+};
+VIR_ENUM_DECL(libxlDomainJob)
+
+
+struct libxlDomainJobObj {
+ virCond cond; /* Use to coordinate jobs */
+ enum libxlDomainJob active; /* Currently running job */
+ int owner; /* Thread which set current job */
+};
+
typedef struct _libxlDomainObjPrivate libxlDomainObjPrivate;
typedef libxlDomainObjPrivate *libxlDomainObjPrivatePtr;
struct _libxlDomainObjPrivate {
@@ -43,6 +68,8 @@ struct _libxlDomainObjPrivate {
/* console */
virChrdevsPtr devs;
libxl_evgen_domain_death *deathW;
+
+ struct libxlDomainJobObj job;
};
@@ -53,4 +80,14 @@ extern virDomainDefParserConfig libxlDomainDefParserConfig;
int
libxlDomainObjPrivateInitCtx(virDomainObjPtr vm);
+int
+libxlDomainObjBeginJob(libxlDriverPrivatePtr driver,
+ virDomainObjPtr obj,
+ enum libxlDomainJob job)
+ ATTRIBUTE_RETURN_CHECK;
+
+bool
+libxlDomainObjEndJob(libxlDriverPrivatePtr driver,
+ virDomainObjPtr obj);
+
#endif /* LIBXL_DOMAIN_H */
ACK
Michal
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