communication techniques bench: add c_cache_comm

communication_techniques/include/c_cache_comm.h

@@ -0,0 +1,45 @@
+#ifndef _SPECIFIC_COMM_H_
+#define _SPECIFIC_COMM_H_ 1
+
+#include <stdint.h>
+
+/* Non standard include */
+#include <common_comm.h>
+
+/* This is not an error, we need this two-macro system */
+#define toString(x) doStringification(x)
+#define doStringification(x) #x
+
+struct comm_channel
+{
+	volatile void *buf[2 * BUF_SIZE / sizeof(void *)] __attribute__ ((aligned (CACHE_LINE_SIZE)));
+	volatile int  state __attribute__ ((aligned (CACHE_LINE_SIZE)));
+	int  idx __attribute__ ((aligned (CACHE_LINE_SIZE)));
+};
+
+struct thread_comm
+{
+	struct comm_channel *channel;
+	int receiver_idx;
+};
+
+extern struct thread_comm *tcomms;
+extern __thread struct comm_channel channel;
+
+__BEGIN_DECLS
+
+void init_thread_comm(void);
+static inline void send(void **addr)
+{
+	channel.buf[channel.idx++] = addr;
+	channel.idx %= 2 * BUF_SIZE / sizeof(void *);
+	if (!(channel.idx % (BUF_SIZE / sizeof(void *))))
+	{
+		while (channel.state);
+		channel.state = 1;
+	}
+}
+
+__END_DECLS
+
+#endif

communication_techniques/src/c_cache.c

@@ -0,0 +1,62 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <pthread.h>
+
+/* Non standard include */
+#include <common_comm.h>
+#include <specific_comm.h>
+
+
+__thread struct comm_channel channel;
+
+void init_thread_comm(void)
+{
+	static int i = 0;
+	static pthread_mutex_t i_lock = PTHREAD_MUTEX_INITIALIZER;
+	int i_local;
+
+	pthread_mutex_lock(&i_lock);
+	i_local = i;
+	pthread_mutex_unlock(&i_lock);
+	tcomms[i].receiver_idx = 0;
+	tcomms[i].channel = &channel;
+	tcomms[i].channel->state = 0;
+	tcomms[i].channel->idx = 0;
+	pthread_mutex_lock(&i_lock);
+	i++;
+	pthread_mutex_unlock(&i_lock);
+}
+
+char *dstr="buffer transition\n";
+
+void reception(void (*on_receive)(volatile void *))
+{
+	/* printf("Activate the consumer...\n"); */
+	while (cont)
+	{
+		int i;
+
+		for (i = 0; i < nb_prod; i++)
+		{
+			if(tcomms[i].channel->state)
+			{
+				int j, n;
+				/* 
+				 * cur->receiver_idx point to the last cache
+				 * line we have read. We go to the next cache
+				 * line "+ (CACHE_LINE_SIZE >> 2)" (because
+				 * the line is full of integer (2^2 octets)
+				 * and then if we are after the second cache
+				 * line we correct the pointer to point to
+				 * the first one (this is done by the modulo)
+				 */
+				j = tcomms[i].receiver_idx;
+				n = tcomms[i].receiver_idx + (BUF_SIZE / sizeof(void *));
+				tcomms[i].receiver_idx = n % ((2 * BUF_SIZE) / sizeof(void *));
+				for(; j<n; j++)
+					on_receive(tcomms[i].channel->buf[j]);
+				tcomms[i].channel->state = 0;
+			}
+		}
+	}
+}