Support discovery and group management in rdc_lib

The rdc.h is modified for new discovery and grouping APIs.

The RdcGroupSettingsImpl.cc is added to implement the GPU group and
the field group management.

The RdcMetricFetcherImpl.cc is added to fetch the metrics from
rocm_smi_lib. Currently, only support power, memory, GPU utilization,
temperature, GPU clock, total device and device name.

A new example field_value_example.cc is added to demo how to record
the fields and retrieve data from cache.

Change-Id: I57acfa048fe9b3d848e2d441e768b3a63ccae3f8

example/job_stats_example.cc

@@ -94,15 +94,8 @@ int main(int, char **) {
     // (2) start the recording. Set the sample frequency to once per second, the
     // max keep age to one hour and the maximum number of samples to
     // keep to unlimited.
-    result = rdc_watch_job_fields(rdc_handle, group_id, 1000000, 3600, 0);
-    if (result != RDC_ST_OK) {
-        std::cout << "Error watch job fileds. Return: "
-            << rdc_status_string(result);
-        goto cleanup;
-    }
-
-    // (3) Start a Slurm job on this group
-    result = rdc_job_start_stats(rdc_handle, group_id, job_id);
+    result = rdc_job_start_stats(rdc_handle, group_id,
+        job_id, 1000000, 3600, 0);
     if (result != RDC_ST_OK) {
         std::cout << "Error start job stats. Return: "
             << rdc_status_string(result);
@@ -126,7 +119,7 @@ int main(int, char **) {
         usleep(5000000);  // sleep 5 seconds before fetch the stats
     }
 
-    // (4) stop the Slurm job, which will stop the watch
+    // (3) stop the Slurm job, which will stop the watch
     // We do not have to stop the job to get stats. The rdc_job_get_stats can be
     // called at any time before stop
     result = rdc_job_stop_stats(rdc_handle, job_id);
@@ -136,7 +129,7 @@ int main(int, char **) {
         goto cleanup;
     }
 
-    // (5) Get the stats
+    // (4) Get the stats
     rdc_job_info_t job_info;
     result = rdc_job_get_stats(rdc_handle, job_id, &job_info);
 
@@ -178,7 +171,7 @@ int main(int, char **) {
         std::cout << "No data for job stats found." << std::endl;
     }
 
-    // Cleanup consists of shutting down DCGM.
+    // Cleanup consists of shutting down RDC.
     cleanup:
     std::cout << "Cleaning up.\n";
     if (standalone)