Clarify semantic of nparams argument of virDomainGetSchedulerType

Some drivers assumed it can be NULL (e.g. qemu and lxc) and check it
before assigning to it, other drivers assumed it must be non-NULL
(e.g. test and esx) and just assigned to it.

Unify this to nparams being optional and document it.

diff --git a/src/esx/esx_driver.c b/src/esx/esx_driver.c
index bb9d60a44a871ce2c020f937291fdf86f9eaa2ff..7fe5446839f035aa38960b43e15955c0c7ddc921 100644 (file)
--- a/src/esx/esx_driver.c
+++ b/src/esx/esx_driver.c
@@ -3513,7 +3513,9 @@ esxDomainGetSchedulerType(virDomainPtr domain ATTRIBUTE_UNUSED, int *nparams)
         return NULL;
     }
 
-    *nparams = 3; /* reservation, limit, shares */
+    if (nparams != NULL) {
+        *nparams = 3; /* reservation, limit, shares */
+    }
 
     return type;
 }

diff --git a/src/libvirt.c b/src/libvirt.c
index 56b1257b821b3e3e0bc9828879a69bb3d884127c..45bc9b072ea8155c5deeccbfabb1c9e604073f1e 100644 (file)
--- a/src/libvirt.c
+++ b/src/libvirt.c
@@ -4973,9 +4973,10 @@ error:
 /**
  * virDomainGetSchedulerType:
  * @domain: pointer to domain object
- * @nparams: number of scheduler parameters(return value)
+ * @nparams: pointer to number of scheduler parameters, can be NULL
+ *           (return value)
  *
- * Get the scheduler type.
+ * Get the scheduler type and the number of scheduler parameters.
  *
  * Returns NULL in case of error. The caller must free the returned string.
  */

diff --git a/src/libxl/libxl_driver.c b/src/libxl/libxl_driver.c
index 5cc9362deff0cb144ed6a76b9ae7252935a78270..6b2d806b012ca9e6c843524738a88c9b938b176c 100644 (file)
--- a/src/libxl/libxl_driver.c
+++ b/src/libxl/libxl_driver.c
@@ -2396,14 +2396,16 @@ libxlDomainGetSchedulerType(virDomainPtr dom, int *nparams)
         goto cleanup;
     }
 
-    *nparams = 0;
+    if (nparams)
+        *nparams = 0;
     switch(sched_id) {
     case XEN_SCHEDULER_SEDF:
         ret = strdup("sedf");
         break;
     case XEN_SCHEDULER_CREDIT:
         ret = strdup("credit");
-        *nparams = XEN_SCHED_CREDIT_NPARAM;
+        if (nparams)
+            *nparams = XEN_SCHED_CREDIT_NPARAM;
         break;
     case XEN_SCHEDULER_CREDIT2:
         ret = strdup("credit2");

diff --git a/src/test/test_driver.c b/src/test/test_driver.c
index eadd587b6f0354a4f882c838907075f8c5ce674f..e716c98f64cbf0a0fcc6404cae9430ec3e7726aa 100644 (file)
--- a/src/test/test_driver.c
+++ b/src/test/test_driver.c
@@ -2624,7 +2624,9 @@ static char *testDomainGetSchedulerType(virDomainPtr domain ATTRIBUTE_UNUSED,
 {
     char *type = NULL;
 
-    *nparams = 1;
+    if (nparams)
+        *nparams = 1;
+
     type = strdup("fair");
     if (!type)
         virReportOOMError();

diff --git a/src/xen/xend_internal.c b/src/xen/xend_internal.c
index dfa03423488966cfdccfd8aa7c8890795b04dd60..359d5f497216511fec3ea10ac149e5eb155a307a 100644 (file)
--- a/src/xen/xend_internal.c
+++ b/src/xen/xend_internal.c
@@ -3531,8 +3531,7 @@ xenDaemonGetSchedulerType(virDomainPtr domain, int *nparams)
     const char *ret = NULL;
     char *schedulertype = NULL;
 
-    if ((domain == NULL) || (domain->conn == NULL) || (domain->name == NULL)
-        || (nparams == NULL)) {
+    if (domain->conn == NULL || domain->name == NULL) {
         virXendError(VIR_ERR_INVALID_ARG, __FUNCTION__);
         return NULL;
     }
@@ -3562,14 +3561,16 @@ xenDaemonGetSchedulerType(virDomainPtr domain, int *nparams)
             virReportOOMError();
             goto error;
         }
-        *nparams = XEN_SCHED_CRED_NPARAM;
+        if (nparams)
+            *nparams = XEN_SCHED_CRED_NPARAM;
     } else if (STREQ (ret, "sedf")) {
         schedulertype = strdup("sedf");
         if (schedulertype == NULL){
             virReportOOMError();
             goto error;
         }
-        *nparams = XEN_SCHED_SEDF_NPARAM;
+        if (nparams)
+            *nparams = XEN_SCHED_SEDF_NPARAM;
     } else {
         virXendError(VIR_ERR_INTERNAL_ERROR, "%s", _("Unknown scheduler"));
         goto error;

diff --git a/src/xenapi/xenapi_driver.c b/src/xenapi/xenapi_driver.c
index 13b9161e094b7492cd5a9c3ec49eef4fa0f85fb2..6f642084233febbcc1a7d91bdc83de87ae880f79 100644 (file)
--- a/src/xenapi/xenapi_driver.c
+++ b/src/xenapi/xenapi_driver.c
@@ -1767,7 +1767,9 @@ static char *
 xenapiDomainGetSchedulerType (virDomainPtr dom ATTRIBUTE_UNUSED, int *nparams)
 {
     char *result = NULL;
-    *nparams = 0;
+
+    if (nparams)
+        *nparams = 0;
     if (!(result = strdup("credit")))
         virReportOOMError();
     return result;