Modified c downstream api to support transmission of info needed by power policy (acr)

lib/downstream_api.c

-#include "nrm.h"
+/* Filename: downstream.c
+ *
+ * Description: This file contains the implementation of downstream API to
+ * transmit application context information to NRM.
+ *
+ * The application context information transmitted is used to monitor
+ * application progress and/or invoke power policies to improve energy
+ * efficiency at the node level.
+ */
+
+#include "downstream_api.h"
 #include<zmq.h>
 #include<stdio.h>
 #include<unistd.h>
@@ -10,7 +20,7 @@ int nrm_init(struct nrm_context *ctxt, const char *uuid)
 {
     assert(ctxt != NULL);
     assert(uuid != NULL);
-    char *uri = getenv(NRM_ENV_URI);
+    const char *uri = getenv(NRM_ENV_URI);
     if(uri == NULL)
         uri = NRM_DEFAULT_URI;
     ctxt->container_uuid = getenv("ARGO_CONTAINER_UUID");
@@ -50,7 +60,8 @@ int nrm_send_progress(struct nrm_context *ctxt, unsigned long progress)
     long long int timediff = (now.tv_nsec - ctxt->time.tv_nsec) +
                  1e9* (now.tv_sec - ctxt->time.tv_sec);
     ctxt->acc += progress;
-    if(timediff > NRM_RATELIMIT_THRESHOLD) {
+    if(timediff > NRM_RATELIMIT_THRESHOLD) 
+    {
         snprintf(buf, 512, NRM_PROGRESS_FORMAT, ctxt->acc, ctxt->app_uuid);
         int err = zmq_send(ctxt->socket, buf, strnlen(buf, 512), 0);
         assert(err > 0);
@@ -59,3 +70,24 @@ int nrm_send_progress(struct nrm_context *ctxt, unsigned long progress)
     ctxt->time = now;
     return 0;
 }
+
+int nrm_invoke_power_policy(struct nrm_context *ctxt, int cpu, double 
+        startCompute, double endCompute, double startBarrier, double 
+        endBarrier)
+{
+    char buf[512];
+    struct timespec now;
+    clock_gettime(CLOCK_REALTIME, &now);
+    long long int timediff = (now.tv_nsec - ctxt->time.tv_nsec) +
+                 1e9* (now.tv_sec - ctxt->time.tv_sec);
+
+    if(timediff > NRM_RATELIMIT_THRESHOLD) 
+    {
+        snprintf(buf, 512, NRM_POWER_POLICY_FORMAT, cpu, startCompute, 
+                endCompute, startBarrier, endBarrier, ctxt->app_uuid);
+        int err = zmq_send(ctxt->socket, buf, strnlen(buf, 512), 0);
+        assert(err > 0);
+    }
+    ctxt->time = now;
+    return 0;  
+}

lib/downstream_api.h

+/* Filename: downstream_api.h
+ *
+ * Includes required headers, functions and parameters used by NRM downstream 
+ * interface
+ *
+ */
+
 #ifndef NRM_H
 #define NRM_H 1
 
@@ -21,11 +28,15 @@ struct nrm_context {
 
 #define NRM_START_FORMAT "{\"type\":\"application\", \"event\":\"start\", \"container\": \"%s\", \"uuid\": \"%s\", \"progress\": true, \"threads\": null}"
 #define NRM_PROGRESS_FORMAT "{\"type\":\"application\", \"event\":\"progress\", \"payload\": \"%lu\", \"uuid\": \"%s\"}"
+#define NRM_POWER_POLICY_FORMAT "{\"type\":\"application\", \"event\":\"power_policy\", \"cpu\": \"%d\", \"startcompute\": \"%lf\", \"endcompute\": \"%lf\", \"startbarrier\": \"%lf\", \"endbarrier\": \"%lf\", \"uuid\": \"%s\"}"
 #define NRM_EXIT_FORMAT "{\"type\":\"application\", \"event\":\"exit\", \"uuid\": \"%s\"}"
 
 int nrm_init(struct nrm_context *, const char *);
 int nrm_fini(struct nrm_context *);
 
 int nrm_send_progress(struct nrm_context *, unsigned long);
+int nrm_invoke_power_policy(struct nrm_context *ctxt, int cpu, double 
+        startCompute, double endCompute, double startBarrier, double 
+        endBarrier);
 
 #endif