Add a naive L2 shared option for comm techs bench

communication_techniques/src/main.c

@@ -1,3 +1,5 @@
+#define _GNU_SOURCE
+
 #include <stdio.h>
 #include <stdlib.h>
 #include <pthread.h>
@@ -17,6 +19,7 @@ static long nb_cache_lines = 0;
 static long nb_prod = 0;
 static long size_buf = 1;
 static char *calculation_lib = NULL;
+static int shared = 0;
 
 void usage(char *argv[])
 {
@@ -106,6 +109,7 @@ int analyse_options(int argc, char *argv[])
 				}
 				break;
 			case 's' :
+				shared = 1;
 				/* TODO: shared L2 cache */
 				break;
 			case '?' :
@@ -129,6 +133,11 @@ int analyse_options(int argc, char *argv[])
 		fprintf(stderr, "You must give the number of producers\n");
 		return -1;
 	}
+	if (shared && (nb_prod > 1))
+	{
+		fprintf(stderr, "Too many producers to fit with the consumer in processors which share a same cache\n");
+		return -1;
+	}
 	return 0;
 }
 
@@ -136,6 +145,20 @@ void *producer(void *unused)
 {
 	int i, j, k;
 
+	if (shared)
+	{
+		pthread_t tid;
+		cpu_set_t cpuset;
+
+		tid = pthread_self();
+		CPU_ZERO(&cpuset);
+		CPU_SET(1, &cpuset);
+		if (pthread_setaffinity_np(tid, sizeof(cpu_set_t), &cpuset))
+		{
+			perror("pthread_setaffinity_np");
+			return NULL;
+		}
+	}
 	printf("Registering: %p !\n", (void*) pthread_self());
 	add_sender();
 	k = (uintptr_t) pthread_self();
@@ -161,6 +184,20 @@ void onMessage(uintptr_t val)
 
 void *receptor(void *a)
 {
+	if (shared)
+	{
+		pthread_t tid;
+		cpu_set_t cpuset;
+
+		tid = pthread_self();
+		CPU_ZERO(&cpuset);
+		CPU_SET(1, &cpuset);
+		if (pthread_setaffinity_np(tid, sizeof(cpu_set_t), &cpuset))
+		{
+			perror("pthread_setaffinity_np");
+			return NULL;
+		}
+	}
 	reception(onMessage);
 	return NULL;
 }