[libvirt] [PATCHv6 3/6] virNodeGetCPUStats: Implement public API
virNodeGetCPUStats: Implement public API
Signed-off-by: Minoru Usui <usui(a)mxm.nes.nec.co.jp>
---
src/libvirt.c | 85 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 85 insertions(+), 0 deletions(-)
diff --git a/src/libvirt.c b/src/libvirt.c
index ff16c48..937d8ab 100644
--- a/src/libvirt.c
+++ b/src/libvirt.c
@@ -4967,6 +4967,91 @@ error:
}
/**
+ * virNodeGetCPUStats:
+ * @conn: pointer to the hypervisor connection.
+ * @params: pointer to node cpu time parameter objects
+ * @nparams: number of node cpu time parameter (this value should be same or
+ * less than the number of parameters supported)
+ * @flags: currently unused, for future extension. always pass 0.
+ *
+ * This function provides cpu time statistics of the node.
+ * The @params array will be filled with the values equal to the number of
+ * parameters suggested by @nparams
+ *
+ * As the value of @nparams is dynamic, call the API setting @nparams to 0 and
+ * @params as NULL, the API returns the number of parameters supported by the
+ * HV by updating @nparams on SUCCESS. The caller should then allocate @params
+ * array, i.e. (sizeof(@virCPUStats) * @nparams) bytes and call
+ * the API again.
+ *
+ * Here is the sample code snippet:
+ *
+ * if ((virNodeGetCPUStats(conn, NULL, &nparams, 0) == 0) &&
+ * (nparams != 0)) {
+ * params = vshMalloc(ctl, sizeof(virCPUStats) * nparams);
+ * memset(params, 0, sizeof(virCPUStats) * nparams);
+ * if (virNodeGetCPUStats(conn, params, &nparams, 0)) {
+ * vshError(ctl, "%s", _("Unable to get node cpu stats"));
+ * goto error;
+ * }
+ * }
+ *
+ * This function doesn't requires privileged access to the hypervisor.
+ * This function expects the caller to allocate the @params.
+ *
+ * CPU time Statistics:
+ *
+ * VIR_NODE_CPU_STATS_KERNEL:
+ * The cumulative CPU time which spends by kernel,
+ * when the node booting up.(nanoseconds)
+ * VIR_NODE_CPU_STATS_USER:
+ * The cumulative CPU time which spends by user processes,
+ * when the node booting up.(nanoseconds)
+ * VIR_NODE_CPU_STATS_IDLE:
+ * The cumulative idle CPU time, when the node booting up.(nanoseconds)
+ * VIR_NODE_CPU_STATS_IOWAIT:
+ * The cumulative I/O wait CPU time, when the node booting up.(nanoseconds)
+ * VIR_NODE_CPU_STATS_UTILIZATION:
+ * The CPU utilization. The usage value is in percent and 100%
+ * represents all CPUs on the server.
+ *
+ * Returns -1 in case of error, 0 in case of success.
+ */
+int virNodeGetCPUStats (virConnectPtr conn,
+ virCPUStatsPtr params,
+ int *nparams, unsigned int flags)
+{
+ VIR_DEBUG("conn=%p, params=%p, nparams=%d, flags=%u",
+ conn, params, nparams ? *nparams : -1, flags);
+
+ virResetLastError();
+
+ if (!VIR_IS_CONNECT(conn)) {
+ virLibConnError(VIR_ERR_INVALID_CONN, __FUNCTION__);
+ virDispatchError(NULL);
+ return -1;
+ }
+
+ if ((nparams == NULL) || (*nparams < 0)) {
+ virLibConnError(VIR_ERR_INVALID_ARG, __FUNCTION__);
+ goto error;
+ }
+
+ if (conn->driver->nodeGetCPUStats) {
+ int ret;
+ ret = conn->driver->nodeGetCPUStats (conn, params, nparams, flags);
+ if (ret < 0)
+ goto error;
+ return ret;
+ }
+ virLibConnError(VIR_ERR_NO_SUPPORT, __FUNCTION__);
+
+error:
+ virDispatchError(conn);
+ return -1;
+}
+
+/**
* virNodeGetFreeMemory:
* @conn: pointer to the hypervisor connection
*
--
1.7.1