add tridge's ping_pong.c to the utils folder

Michael

(This used to be ctdb commit fe59ecb697fb4686ad8ea2fe4ec1cc7b4629e74f)

1 files changed, 176 insertions, 0 deletions

diff --git a/ctdb/utils/ping_pong/ping_pong.c b/ctdb/utils/ping_pong/ping_pong.c
new file mode 100644
index 00000000000..8511d957e5f
--- /dev/null
+++ b/ctdb/utils/ping_pong/ping_pong.c
@@ -0,0 +1,176 @@
+/*
+  this measures the ping-pong byte range lock latency. It is
+  especially useful on a cluster of nodes sharing a common lock
+  manager as it will give some indication of the lock managers
+  performance under stress
+
+  tridge@samba.org, February 2002
+
+*/
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/time.h>
+#include <time.h>
+#include <errno.h>
+#include <string.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <getopt.h>
+#include <sys/mman.h>
+
+static struct timeval tp1,tp2;
+
+static int do_reads, do_writes, use_mmap;
+
+static void start_timer()
+{
+	gettimeofday(&tp1,NULL);
+}
+
+static double end_timer()
+{
+	gettimeofday(&tp2,NULL);
+	return (tp2.tv_sec + (tp2.tv_usec*1.0e-6)) - 
+		(tp1.tv_sec + (tp1.tv_usec*1.0e-6));
+}
+
+/* lock a byte range in a open file */
+static int lock_range(int fd, int offset, int len)
+{
+	struct flock lock;
+
+	lock.l_type = F_WRLCK;
+	lock.l_whence = SEEK_SET;
+	lock.l_start = offset;
+	lock.l_len = len;
+	lock.l_pid = 0;
+	
+	return fcntl(fd,F_SETLKW,&lock);
+}
+
+/* unlock a byte range in a open file */
+static int unlock_range(int fd, int offset, int len)
+{
+	struct flock lock;
+
+	lock.l_type = F_UNLCK;
+	lock.l_whence = SEEK_SET;
+	lock.l_start = offset;
+	lock.l_len = len;
+	lock.l_pid = 0;
+	
+	return fcntl(fd,F_SETLKW,&lock);
+}
+
+/* run the ping pong test on fd */
+static void ping_pong(int fd, int num_locks)
+{
+	unsigned count = 0;
+	int i=0, loops=0;
+	unsigned char *val;
+	unsigned char incr=0, last_incr=0;
+	unsigned char *p = NULL;
+
+	ftruncate(fd, num_locks+1);
+
+	if (use_mmap) {
+		p = mmap(NULL, num_locks+1, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);
+	}
+
+	val = (unsigned char *)calloc(num_locks+1, sizeof(unsigned char));
+
+	start_timer();	
+
+	lock_range(fd, 0, 1);
+	i = 0;
+
+	while (1) {
+		if (lock_range(fd, (i+1) % num_locks, 1) != 0) {
+			printf("lock at %d failed! - %s\n",
+			       (i+1) % num_locks, strerror(errno));
+		}
+		if (do_reads) {
+			unsigned char c;
+			if (use_mmap) {
+				c = p[i];
+			} if (pread(fd, &c, 1, i) != 1) {
+				printf("read failed at %d\n", i);
+			}
+			incr = c - val[i];
+			val[i] = c;
+		}
+		if (do_writes) {
+			char c = val[i] + 1;
+			if (use_mmap) {
+				p[i] = c;
+			} else if (pwrite(fd, &c, 1, i) != 1) {
+				printf("write failed at %d\n", i);
+			}
+		}
+		if (unlock_range(fd, i, 1) != 0) {
+			printf("unlock at %d failed! - %s\n",
+			       i, strerror(errno));
+		}
+		i = (i+1) % num_locks;
+		count++;
+		if (loops > num_locks && incr != last_incr) {
+			last_incr = incr;
+			printf("data increment = %u\n", incr);
+			fflush(stdout);
+		}
+		if (end_timer() > 1.0) {
+			printf("%8u locks/sec\r", 
+			       (unsigned)(2*count/end_timer()));
+			fflush(stdout);
+			start_timer();
+			count=0;
+		}
+		loops++;
+	}
+}
+
+int main(int argc, char *argv[])
+{
+	char *fname;
+	int fd, num_locks;
+	int c;
+
+	while ((c = getopt(argc, argv, "rwm")) != -1) {
+		switch (c){
+		case 'w':
+			do_writes = 1;
+			break;
+		case 'r':
+			do_reads = 1;
+			break;
+		case 'm':
+			use_mmap = 1;
+			break;
+		default:
+			fprintf(stderr, "Unknown option '%c'\n", c);
+			exit(1);
+		}
+	}
+
+	argv += optind;
+	argc -= optind;
+
+	if (argc < 2) {
+		printf("ping_pong [options] <file> <num_locks>\n");
+		printf("           -r    do reads\n");
+		printf("           -w    do writes\n");
+		printf("           -m    use mmap\n");
+		exit(1);
+	}
+
+	fname = argv[0];
+	num_locks = atoi(argv[1]);
+
+	fd = open(fname, O_CREAT|O_RDWR, 0600);
+	if (fd == -1) exit(1);
+
+	ping_pong(fd, num_locks);
+
+	return 0;
+}