[libvirt] [PATCH 2/8] Return count of callbacks when registering callbacks
Daniel P. Berrange
berrange at redhat.com
Wed Dec 14 00:38:19 UTC 2011
From: "Daniel P. Berrange" <berrange at redhat.com>
When registering a callback for a particular event some callers
need to know how many callbacks already exist for that event.
While it is possible to ask for a count, this is not free from
race conditions when threaded. Thus the API for registering
callbacks should return the count of callbacks
* src/conf/domain_event.c, src/conf/domain_event.h,
src/libvirt_private.syms: Return count of callbacks when
registering callbacks
* src/libxl/libxl_driver.c, src/libxl/libxl_driver.c,
src/qemu/qemu_driver.c, src/remote/remote_driver.c,
src/remote/remote_driver.c, src/uml/uml_driver.c,
src/vbox/vbox_tmpl.c, src/xen/xen_driver.c: Update
for change in APIs
---
src/conf/domain_event.c | 23 ++++++++++++++++++-----
src/conf/domain_event.h | 3 ++-
src/libvirt_private.syms | 2 +-
src/libxl/libxl_driver.c | 15 ++++++++-------
src/lxc/lxc_driver.c | 15 ++++++++-------
src/qemu/qemu_driver.c | 15 ++++++++-------
src/remote/remote_driver.c | 33 ++++++++++++++++-----------------
src/test/test_driver.c | 15 ++++++++-------
src/uml/uml_driver.c | 15 ++++++++-------
src/vbox/vbox_tmpl.c | 15 ++++++++-------
src/xen/xen_driver.c | 13 +++++++------
11 files changed, 92 insertions(+), 72 deletions(-)
diff --git a/src/conf/domain_event.c b/src/conf/domain_event.c
index 0e481cf..00c5dbf 100644
--- a/src/conf/domain_event.c
+++ b/src/conf/domain_event.c
@@ -357,7 +357,7 @@ virDomainEventCallbackListAdd(virConnectPtr conn,
return virDomainEventCallbackListAddID(conn, cbList, NULL,
VIR_DOMAIN_EVENT_ID_LIFECYCLE,
VIR_DOMAIN_EVENT_CALLBACK(callback),
- opaque, freecb);
+ opaque, freecb, NULL);
}
@@ -368,6 +368,7 @@ virDomainEventCallbackListAdd(virConnectPtr conn,
* @eventID: the event ID
* @callback: the callback to add
* @opaque: opaque data tio pass to callback
+ * @callbackID: filled with callback ID
*
* Internal function to add a callback from a virDomainEventCallbackListPtr
*/
@@ -378,10 +379,12 @@ virDomainEventCallbackListAddID(virConnectPtr conn,
int eventID,
virConnectDomainEventGenericCallback callback,
void *opaque,
- virFreeCallback freecb)
+ virFreeCallback freecb,
+ int *callbackID)
{
virDomainEventCallbackPtr event;
int i;
+ int ret = 0;
/* Check incoming */
if ( !cbList ) {
@@ -427,7 +430,17 @@ virDomainEventCallbackListAddID(virConnectPtr conn,
event->callbackID = cbList->nextID++;
- return event->callbackID;
+ for (i = 0 ; i < cbList->count ; i++) {
+ if (cbList->callbacks[i]->eventID == VIR_DOMAIN_EVENT_ID_LIFECYCLE &&
+ cbList->callbacks[i]->conn == conn &&
+ !cbList->callbacks[i]->deleted)
+ ret++;
+ }
+
+ if (callbackID)
+ *callbackID = event->callbackID;
+
+ return ret;
no_memory:
virReportOOMError();
@@ -1364,9 +1377,9 @@ virDomainEventStateDeregister(virConnectPtr conn,
* @callbackID: ID of the function to remove from event
*
* Unregister the function @callbackID with connection @conn,
- * from @state, for lifecycle events.
+ * from @state, for events.
*
- * Returns: the number of lifecycle callbacks still registered, or -1 on error
+ * Returns: the number of callbacks still registered, or -1 on error
*/
int
virDomainEventStateDeregisterID(virConnectPtr conn,
diff --git a/src/conf/domain_event.h b/src/conf/domain_event.h
index 10a55b0..83656e6 100644
--- a/src/conf/domain_event.h
+++ b/src/conf/domain_event.h
@@ -80,7 +80,8 @@ int virDomainEventCallbackListAddID(virConnectPtr conn,
int eventID,
virConnectDomainEventGenericCallback cb,
void *opaque,
- virFreeCallback freecb)
+ virFreeCallback freecb,
+ int *callbackID)
ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(5);
diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
index a81c230..3d1d7d2 100644
--- a/src/libvirt_private.syms
+++ b/src/libvirt_private.syms
@@ -510,7 +510,7 @@ virDomainEventRebootNew;
virDomainEventRebootNewFromDom;
virDomainEventRebootNewFromObj;
virDomainEventStateDeregister;
-virDomainEventStateDeregisterAny;
+virDomainEventStateDeregisterID;
virDomainEventStateFlush;
virDomainEventStateFree;
virDomainEventStateNew;
diff --git a/src/libxl/libxl_driver.c b/src/libxl/libxl_driver.c
index 7cc32ad..46504dc 100644
--- a/src/libxl/libxl_driver.c
+++ b/src/libxl/libxl_driver.c
@@ -3851,10 +3851,11 @@ libxlDomainEventRegisterAny(virConnectPtr conn, virDomainPtr dom, int eventID,
int ret;
libxlDriverLock(driver);
- ret = virDomainEventCallbackListAddID(conn,
- driver->domainEventState->callbacks,
- dom, eventID, callback, opaque,
- freecb);
+ if (virDomainEventCallbackListAddID(conn,
+ driver->domainEventState->callbacks,
+ dom, eventID, callback, opaque,
+ freecb, &ret) < 0)
+ ret = -1;
libxlDriverUnlock(driver);
return ret;
@@ -3868,9 +3869,9 @@ libxlDomainEventDeregisterAny(virConnectPtr conn, int callbackID)
int ret;
libxlDriverLock(driver);
- ret = virDomainEventStateDeregisterAny(conn,
- driver->domainEventState,
- callbackID);
+ ret = virDomainEventStateDeregisterID(conn,
+ driver->domainEventState,
+ callbackID);
libxlDriverUnlock(driver);
return ret;
diff --git a/src/lxc/lxc_driver.c b/src/lxc/lxc_driver.c
index b16cfd8..6b17c75 100644
--- a/src/lxc/lxc_driver.c
+++ b/src/lxc/lxc_driver.c
@@ -2164,10 +2164,11 @@ lxcDomainEventRegisterAny(virConnectPtr conn,
int ret;
lxcDriverLock(driver);
- ret = virDomainEventCallbackListAddID(conn,
- driver->domainEventState->callbacks,
- dom, eventID,
- callback, opaque, freecb);
+ if (virDomainEventCallbackListAddID(conn,
+ driver->domainEventState->callbacks,
+ dom, eventID,
+ callback, opaque, freecb, &ret) < 0)
+ ret = -1;
lxcDriverUnlock(driver);
return ret;
@@ -2182,9 +2183,9 @@ lxcDomainEventDeregisterAny(virConnectPtr conn,
int ret;
lxcDriverLock(driver);
- ret = virDomainEventStateDeregisterAny(conn,
- driver->domainEventState,
- callbackID);
+ ret = virDomainEventStateDeregisterID(conn,
+ driver->domainEventState,
+ callbackID);
lxcDriverUnlock(driver);
return ret;
diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index 10a289e..7423340 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -8180,10 +8180,11 @@ qemuDomainEventRegisterAny(virConnectPtr conn,
int ret;
qemuDriverLock(driver);
- ret = virDomainEventCallbackListAddID(conn,
- driver->domainEventState->callbacks,
- dom, eventID,
- callback, opaque, freecb);
+ if (virDomainEventCallbackListAddID(conn,
+ driver->domainEventState->callbacks,
+ dom, eventID,
+ callback, opaque, freecb, &ret) < 0)
+ ret = -1;
qemuDriverUnlock(driver);
return ret;
@@ -8198,9 +8199,9 @@ qemuDomainEventDeregisterAny(virConnectPtr conn,
int ret;
qemuDriverLock(driver);
- ret = virDomainEventStateDeregisterAny(conn,
- driver->domainEventState,
- callbackID);
+ ret = virDomainEventStateDeregisterID(conn,
+ driver->domainEventState,
+ callbackID);
qemuDriverUnlock(driver);
return ret;
diff --git a/src/remote/remote_driver.c b/src/remote/remote_driver.c
index ff2d4b4..a0cf7d3 100644
--- a/src/remote/remote_driver.c
+++ b/src/remote/remote_driver.c
@@ -3120,6 +3120,7 @@ static int remoteDomainEventRegister(virConnectPtr conn,
{
int rv = -1;
struct private_data *priv = conn->privateData;
+ int count;
remoteDriverLock(priv);
@@ -3128,15 +3129,13 @@ static int remoteDomainEventRegister(virConnectPtr conn,
goto done;
}
- if (virDomainEventCallbackListAdd(conn, priv->domainEventState->callbacks,
- callback, opaque, freecb) < 0) {
+ if ((count = virDomainEventCallbackListAdd(conn, priv->domainEventState->callbacks,
+ callback, opaque, freecb)) < 0) {
remoteError(VIR_ERR_RPC, "%s", _("adding cb to list"));
goto done;
}
- if (virDomainEventCallbackListCountID(conn,
- priv->domainEventState->callbacks,
- VIR_DOMAIN_EVENT_ID_LIFECYCLE) == 1) {
+ if (count == 1) {
/* Tell the server when we are the first callback deregistering */
if (call (conn, priv, 0, REMOTE_PROC_DOMAIN_EVENTS_REGISTER,
(xdrproc_t) xdr_void, (char *) NULL,
@@ -3760,6 +3759,7 @@ static int remoteDomainEventRegisterAny(virConnectPtr conn,
struct private_data *priv = conn->privateData;
remote_domain_events_register_any_args args;
int callbackID;
+ int count;
remoteDriverLock(priv);
@@ -3768,19 +3768,18 @@ static int remoteDomainEventRegisterAny(virConnectPtr conn,
goto done;
}
- if ((callbackID = virDomainEventCallbackListAddID(conn,
- priv->domainEventState->callbacks,
- dom, eventID,
- callback, opaque, freecb)) < 0) {
- remoteError(VIR_ERR_RPC, "%s", _("adding cb to list"));
- goto done;
+ if ((count = virDomainEventCallbackListAddID(conn,
+ priv->domainEventState->callbacks,
+ dom, eventID,
+ callback, opaque, freecb,
+ &callbackID)) < 0) {
+ remoteError(VIR_ERR_RPC, "%s", _("adding cb to list"));
+ goto done;
}
/* If this is the first callback for this eventID, we need to enable
* events on the server */
- if (virDomainEventCallbackListCountID(conn,
- priv->domainEventState->callbacks,
- eventID) == 1) {
+ if (count == 1) {
args.eventID = eventID;
if (call (conn, priv, 0, REMOTE_PROC_DOMAIN_EVENTS_REGISTER_ANY,
@@ -3818,9 +3817,9 @@ static int remoteDomainEventDeregisterAny(virConnectPtr conn,
goto done;
}
- if (virDomainEventStateDeregisterAny(conn,
- priv->domainEventState,
- callbackID) < 0)
+ if (virDomainEventStateDeregisterID(conn,
+ priv->domainEventState,
+ callbackID) < 0)
goto done;
/* If that was the last callback for this eventID, we need to disable
diff --git a/src/test/test_driver.c b/src/test/test_driver.c
index 89f7df1..f32990b 100644
--- a/src/test/test_driver.c
+++ b/src/test/test_driver.c
@@ -5469,10 +5469,11 @@ testDomainEventRegisterAny(virConnectPtr conn,
int ret;
testDriverLock(driver);
- ret = virDomainEventCallbackListAddID(conn,
- driver->domainEventState->callbacks,
- dom, eventID,
- callback, opaque, freecb);
+ if (virDomainEventCallbackListAddID(conn,
+ driver->domainEventState->callbacks,
+ dom, eventID,
+ callback, opaque, freecb, &ret) < 0)
+ ret = -1;
testDriverUnlock(driver);
return ret;
@@ -5486,9 +5487,9 @@ testDomainEventDeregisterAny(virConnectPtr conn,
int ret;
testDriverLock(driver);
- ret = virDomainEventStateDeregisterAny(conn,
- driver->domainEventState,
- callbackID);
+ ret = virDomainEventStateDeregisterID(conn,
+ driver->domainEventState,
+ callbackID);
testDriverUnlock(driver);
return ret;
diff --git a/src/uml/uml_driver.c b/src/uml/uml_driver.c
index faea313..420488d 100644
--- a/src/uml/uml_driver.c
+++ b/src/uml/uml_driver.c
@@ -2483,10 +2483,11 @@ umlDomainEventRegisterAny(virConnectPtr conn,
int ret;
umlDriverLock(driver);
- ret = virDomainEventCallbackListAddID(conn,
- driver->domainEventState->callbacks,
- dom, eventID,
- callback, opaque, freecb);
+ if (virDomainEventCallbackListAddID(conn,
+ driver->domainEventState->callbacks,
+ dom, eventID,
+ callback, opaque, freecb, &ret) < 0)
+ ret = -1;
umlDriverUnlock(driver);
return ret;
@@ -2501,9 +2502,9 @@ umlDomainEventDeregisterAny(virConnectPtr conn,
int ret;
umlDriverLock(driver);
- ret = virDomainEventStateDeregisterAny(conn,
- driver->domainEventState,
- callbackID);
+ ret = virDomainEventStateDeregisterID(conn,
+ driver->domainEventState,
+ callbackID);
umlDriverUnlock(driver);
return ret;
diff --git a/src/vbox/vbox_tmpl.c b/src/vbox/vbox_tmpl.c
index 7f13f90..670de9c 100644
--- a/src/vbox/vbox_tmpl.c
+++ b/src/vbox/vbox_tmpl.c
@@ -7280,13 +7280,14 @@ static int vboxDomainEventRegisterAny(virConnectPtr conn,
* later you can iterate over them
*/
- ret = virDomainEventCallbackListAddID(conn, data->domainEvents->callbacks,
- dom, eventID,
- callback, opaque, freecb);
+ if (virDomainEventCallbackListAddID(conn, data->domainEvents->callbacks,
+ dom, eventID,
+ callback, opaque, freecb, &ret) < 0)
+ ret = -1;
VIR_DEBUG("virDomainEventCallbackListAddID (ret = %d) ( conn: %p, "
- "data->domainEvents->callbacks: %p, callback: %p, opaque: %p, "
- "freecb: %p )", ret, conn, data->domainEvents->callbacks, callback,
- opaque, freecb);
+ "data->domainEvents->callbacks: %p, callback: %p, opaque: %p, "
+ "freecb: %p )", ret, conn, data->domainEvents->callbacks, callback,
+ opaque, freecb);
}
}
@@ -7312,7 +7313,7 @@ static int vboxDomainEventDeregisterAny(virConnectPtr conn,
*/
vboxDriverLock(data);
- cnt = virDomainEventStateDeregisterAny(conn, data->domainEvents,
+ cnt = virDomainEventStateDeregisterID(conn, data->domainEvents,
callbackID);
if (data->vboxCallback && cnt == 0) {
diff --git a/src/xen/xen_driver.c b/src/xen/xen_driver.c
index 8c47ad5..b11dd9e 100644
--- a/src/xen/xen_driver.c
+++ b/src/xen/xen_driver.c
@@ -1897,9 +1897,10 @@ xenUnifiedDomainEventRegisterAny(virConnectPtr conn,
return -1;
}
- ret = virDomainEventCallbackListAddID(conn, priv->domainEvents->callbacks,
- dom, eventID,
- callback, opaque, freefunc);
+ if (virDomainEventCallbackListAddID(conn, priv->domainEvents->callbacks,
+ dom, eventID,
+ callback, opaque, freefunc, &ret) < 0)
+ ret = -1;
xenUnifiedUnlock(priv);
return (ret);
@@ -1919,9 +1920,9 @@ xenUnifiedDomainEventDeregisterAny(virConnectPtr conn,
return -1;
}
- ret = virDomainEventStateDeregisterAny(conn,
- priv->domainEvents,
- callbackID);
+ ret = virDomainEventStateDeregisterID(conn,
+ priv->domainEvents,
+ callbackID);
xenUnifiedUnlock(priv);
return ret;
--
1.7.7.4
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