Improve timing of tests; avoid wrapping tv_usec and tv_sec problems; better rounding...

[nbd.git] / nbd-tester-client.c

diff --git a/nbd-tester-client.c b/nbd-tester-client.c
index 1ead4f1..7c1cb75 100644 (file)
--- a/nbd-tester-client.c
+++ b/nbd-tester-client.c
@@ -56,6 +56,32 @@ typedef enum {
        CONNECTION_CLOSE_FAST,
 } CLOSE_TYPE;
 
+int timeval_subtract (struct timeval *result, struct timeval *x,
+                     struct timeval *y) {
+       if (x->tv_usec < y->tv_usec) {
+               int nsec = (y->tv_usec - x->tv_usec) / 1000000 + 1;
+               y->tv_usec -= 1000000 * nsec;
+               y->tv_sec += nsec;
+       }
+       
+       if (x->tv_usec - y->tv_usec > 1000000) {
+               int nsec = (x->tv_usec - y->tv_usec) / 1000000;
+               y->tv_usec += 1000000 * nsec;
+               y->tv_sec -= nsec;
+       }
+       
+       result->tv_sec = x->tv_sec - y->tv_sec;
+       result->tv_usec = x->tv_usec - y->tv_usec;
+       
+       return x->tv_sec < y->tv_sec;
+}
+
+double timeval_diff_to_double (struct timeval * x, struct timeval * y) {
+       struct timeval r;
+       timeval_subtract(&r, x, y);
+       return r.tv_sec * 1.0 + r.tv_usec/1000000.0;
+}
+
 static inline int read_all(int f, void *buf, size_t len) {
        ssize_t res;
        size_t retval=0;
@@ -311,8 +337,8 @@ int throughput_test(gchar* hostname, int port, char* name, int sock,
        struct timeval tv;
        struct timeval start;
        struct timeval stop;
-       float timespan;
-       int speed;
+       double timespan;
+       double speed;
        char speedchar[2] = { '\0', '\0' };
        int retval=0;
        size_t tmp;
@@ -401,21 +427,21 @@ int throughput_test(gchar* hostname, int port, char* name, int sock,
                snprintf(errstr, errstr_len, "Could not measure end time: %s", strerror(errno));
                goto err_open;
        }
-       timespan=(float)(stop.tv_sec-start.tv_sec+(stop.tv_usec-start.tv_usec))/(float)1000000;
-       speed=(int)(size/timespan);
+       timespan=timeval_diff_to_double(&stop, &start);
+       speed=size/timespan;
        if(speed>1024) {
-               speed>>=10;
+               speed=speed/1024.0;
                speedchar[0]='K';
        }
        if(speed>1024) {
-               speed>>=10;
+               speed=speed/1024.0;
                speedchar[0]='M';
        }
        if(speed>1024) {
-               speed>>=10;
+               speed=speed/1024.0;
                speedchar[0]='G';
        }
-       g_message("%d: Throughput %s test complete. Took %.3f seconds to complete, %d%siB/s", (int)getpid(), write?"write":"read", timespan, speed, speedchar);
+       g_message("%d: Throughput %s test complete. Took %.3f seconds to complete, %.3f%sib/s", (int)getpid(), write?"write":"read", timespan, speed, speedchar);
 
 err_open:
        if(close_sock) {