X-Git-Url: http://rtime.felk.cvut.cz/gitweb/can-benchmark.git/blobdiff_plain/87ae560edb2ef5f1b6b2029a3fe7c0259c45ffb1..e3e90bc84127a14b7de6a827c087a1c51da70bdc:/recvmmsg/can_recvmmsg.c

diff --git a/recvmmsg/can_recvmmsg.c b/recvmmsg/can_recvmmsg.c
index 4dee5f1..7e21c65 100644
--- a/recvmmsg/can_recvmmsg.c
+++ b/recvmmsg/can_recvmmsg.c
@@ -16,11 +16,13 @@
 #include <time.h>
 #include <stdbool.h>
 
-#define CHECK(cmd) do { if ((cmd) == -1) { perror(#cmd); exit(1); } } while (0)
+#define STRINGIFY(val) #val
+#define TOSTRING(val) STRINGIFY(val)
+#define CHECK(cmd) ({ int ret = (cmd); if (ret == -1) { perror(#cmd " line " TOSTRING(__LINE__)); exit(1); }; ret; })
 
 char *dev = "vcan0";
 int count = 10000;
-enum { READ, RECVMMSG } recv_method = READ;
+enum { READWRITE, MMSG } method = READWRITE;
 bool quiet = false;
 
 /* Subtract the `struct timespec' values X and Y,
@@ -29,25 +31,18 @@ bool quiet = false;
 
 int
 timespec_subtract (struct timespec *result,
-		   struct timespec *x,
-		   struct timespec *y)
+		   const struct timespec *x,
+		   const struct timespec *y)
 {
-	/* Perform the carry for the later subtraction by updating Y. */
-	if (x->tv_nsec < y->tv_nsec) {
-		int num_sec = (y->tv_nsec - x->tv_nsec) / 1000000000 + 1;
-		y->tv_nsec -= 1000000000 * num_sec;
-		y->tv_sec += num_sec;
-	}
-	if (x->tv_nsec - y->tv_nsec > 1000000000) {
-		int num_sec = (x->tv_nsec - y->tv_nsec) / 1000000000;
-		y->tv_nsec += 1000000000 * num_sec;
-		y->tv_sec -= num_sec;
-	}
+	int carry = (x->tv_nsec < y->tv_nsec);
+
+	result->tv_sec = x->tv_sec - y->tv_sec - carry;
+	result->tv_nsec = x->tv_nsec + carry*1000000000 - y->tv_nsec;
 
-	/* Compute the time remaining to wait.
-	   `tv_nsec' is certainly positive. */
-	result->tv_sec = x->tv_sec - y->tv_sec;
-	result->tv_nsec = x->tv_nsec - y->tv_nsec;
+/* 	printf("%ld.%09ld - %ld.%09ld = %ld.%09ld\n", */
+/* 	       x->tv_sec, x->tv_nsec, */
+/* 	       y->tv_sec, y->tv_nsec, */
+/* 	       result->tv_sec, result->tv_nsec); */
 
 	/* Return 1 if result is negative. */
 	return x->tv_sec < y->tv_sec;
@@ -61,7 +56,7 @@ void benchmark()
 	struct ifreq ifr;
 	struct can_frame cf;
 	int ret, i;
-	struct timespec t, t1, t2;
+	struct timespec ttx, trx, t1, t2;
 
 	ss = socket(PF_CAN, SOCK_RAW, CAN_RAW);
 	sr = socket(PF_CAN, SOCK_RAW, CAN_RAW);
@@ -81,17 +76,43 @@ void benchmark()
 	memset(&cf, 0, sizeof(cf));
 	cf.can_dlc = 8;
 
-	if (!quiet) fprintf(stderr, "Sending %d frames\n", count);
-	for (i = 0; i < count; i++) {
-		ret = write(ss, &cf, sizeof(cf));
-		if (ret != sizeof(cf)) {
-			perror("write");
-			exit(1);
+	switch (method) {
+	case READWRITE: {
+		if (!quiet) fprintf(stderr, "Sending %d frames via write()\n", count);
+		clock_gettime(CLOCK_MONOTONIC, &t1);
+		for (i = 0; i < count; i++) {
+			ret = write(ss, &cf, sizeof(cf));
+			if (ret != sizeof(cf)) {
+				perror("write");
+				exit(1);
+			}
 		}
+		clock_gettime(CLOCK_MONOTONIC, &t2);
+		break;
+	}
+	case MMSG: {
+		if (!quiet) fprintf(stderr, "Sending %d frames via sendmmsg()\n", count);
+		struct mmsghdr msgs[count];
+		struct iovec iovecs[count];
+		memset(msgs, 0, sizeof(msgs));
+		memset(iovecs, 0, sizeof(iovecs));
+		for (i = 0; i < count; i++) {
+			iovecs[i].iov_base         = &cf;
+			iovecs[i].iov_len          = sizeof(cf);
+			msgs[i].msg_hdr.msg_iov    = &iovecs[i];
+			msgs[i].msg_hdr.msg_iovlen = 1;
+		}
+		clock_gettime(CLOCK_MONOTONIC, &t1);
+		for (i = 0; i < count; i += ret)
+			ret = CHECK(sendmmsg(ss, &msgs[i], count - i, 0));
+		clock_gettime(CLOCK_MONOTONIC, &t2);
+		break;
+	}
 	}
+	timespec_subtract(&ttx, &t2, &t1);
 
-	switch (recv_method) {
-	case READ: {
+	switch (method) {
+	case READWRITE: {
 		if (!quiet) fprintf(stderr, "Receiving %d frames with read()\n", count);
 		clock_gettime(CLOCK_MONOTONIC, &t1);
 		for (i = 0; i < count; i++) {
@@ -106,7 +127,7 @@ void benchmark()
 		//fprintf(stderr, "\n");
 		break;
 	}
-	case RECVMMSG: {
+	case MMSG: {
 		if (!quiet) fprintf(stderr, "Receiving %d frames with recvmmsg()\n", count);
 		struct mmsghdr msgs[count];
 		struct iovec iovecs[count];
@@ -133,8 +154,9 @@ void benchmark()
 		break;
 	}
 	}
-	timespec_subtract(&t, &t2, &t1);
-	printf("%d us\n", t.tv_nsec/1000);
+	timespec_subtract(&trx, &t2, &t1);
+	printf("tx %ld rx %ld [us]\n", ttx.tv_sec*1000000 + ttx.tv_nsec/1000,
+		       	      	       trx.tv_sec*1000000 + trx.tv_nsec/1000);
 }
 
 int main(int argc, char *argv[])
@@ -147,10 +169,10 @@ int main(int argc, char *argv[])
 			count = atoi(optarg);
 			break;
 		case 'm':
-			recv_method = RECVMMSG;
+			method = MMSG;
 			break;
 		case 'r':
-			recv_method = READ;
+			method = READWRITE;
 			break;
 		case 'q':
 			quiet = true;