From 8d0bce22e9d657bd916c69516fde6c8f2fd2433a Mon Sep 17 00:00:00 2001 From: David Woodhouse Date: Fri, 10 Aug 2007 14:40:01 +0800 Subject: Fine-tine the TX timing for serve_image. It just busy-waits until it's time to send the next packet now. Which sucks, but gives us good timing for debugging. Needs work (and actually if we have hrtimers we probably _can_ sleep and still have proper timing). Signed-off-by: David Woodhouse --- serve_image.c | 60 +++++++++++++++++++++++++++++++++++++++++++++++++++-------- 1 file changed, 52 insertions(+), 8 deletions(-) (limited to 'serve_image.c') diff --git a/serve_image.c b/serve_image.c index b1875b1..d2e3390 100644 --- a/serve_image.c +++ b/serve_image.c @@ -11,6 +11,7 @@ #include #include #include +#include #include "crc32.h" #include "mcast_image.h" @@ -28,8 +29,6 @@ int main(int argc, char **argv) int rfd; struct stat st; int writeerrors = 0; - long usec_per_tick = 1000000 / sysconf(_SC_CLK_TCK); - long delay_accum = 0; uint32_t erasesize; unsigned char parbuf[PKT_SIZE]; unsigned char *image, *blockptr; @@ -37,6 +36,8 @@ int main(int argc, char **argv) uint32_t block_ofs; int nr_blocks; uint32_t droppoint = -1; + struct timeval then, now, nextpkt; + long time_msecs; if (argc == 6) { tx_rate = atol(argv[5]) * 1024; @@ -52,7 +53,7 @@ int main(int argc, char **argv) (strrchr(argv[0], '/')?:argv[0]-1)+1); exit(1); } - pkt_delay = (PKT_SIZE * 1000000) / tx_rate; + pkt_delay = (sizeof(pktbuf) * 1000000) / tx_rate; printf("Inter-packet delay (avg): %dµs\n", pkt_delay); printf("Transmit rate: %d KiB/s\n", tx_rate / 1024); @@ -108,14 +109,20 @@ int main(int argc, char **argv) exit(1); } - nr_blocks = st.st_size / erasesize; + printf("Checking CRC...."); + pktbuf.hdr.resend = 0; pktbuf.hdr.totcrc = htonl(crc32(-1, image, st.st_size)); pktbuf.hdr.nr_blocks = htonl(nr_blocks); pktbuf.hdr.blocksize = htonl(erasesize); + printf("%08x\n", ntohl(pktbuf.hdr.totcrc)); + + gettimeofday(&then, NULL); + nextpkt = then; + blockptr = image; for (block_nr = 0; block_nr < nr_blocks; block_nr++) { @@ -133,7 +140,15 @@ int main(int argc, char **argv) len = PKT_SIZE; if (block_ofs == erasesize) { - printf("\rSending parity block: %08x", block_nr * erasesize); + gettimeofday(&now, NULL); + + time_msecs = (now.tv_sec - then.tv_sec) * 1000; + time_msecs += ((int)(now.tv_usec - then.tv_usec)) / 1000; + + printf("\rSending parity block: %08x (%ld KiB/s) ", + block_nr * erasesize, + (block_ofs + (block_nr * (erasesize+sizeof(pktbuf)))) / 1024 * 1000 / time_msecs); + len = PKT_SIZE; memcpy(pktbuf.data, parbuf, PKT_SIZE); } else { @@ -164,7 +179,6 @@ int main(int argc, char **argv) continue; } - if (write(sock, &pktbuf, sizeof(pktbuf.hdr)+len) < 0) { perror("write"); writeerrors++; @@ -175,18 +189,48 @@ int main(int argc, char **argv) } else writeerrors = 0; + do { + gettimeofday(&now, NULL); + } while (now.tv_sec < nextpkt.tv_sec || + (now.tv_sec == nextpkt.tv_sec && + now.tv_usec < nextpkt.tv_usec)); + + nextpkt.tv_usec = now.tv_usec + pkt_delay; + if (nextpkt.tv_usec > 1000000) { + nextpkt.tv_sec += nextpkt.tv_usec / 1000000; + nextpkt.tv_usec %= 1000000; + } +#if 0 /* Delay, if we are so far ahead of ourselves that we have at least one tick to wait. */ + + gettimeofday(&now, NULL); + nextpkt.tv_usec = now.tv_usec + + /* Add to pkt_delay if necessary */ delay_accum += pkt_delay; + delay_accum -= (now.tv_usec - blkthen.tv_usec); + delay_accum -= 1000000 * (now.tv_sec - blkthen.tv_sec); + if (delay_accum < 0) + delay_accum = 0; + blkthen = now; + if (delay_accum >= usec_per_tick) { usleep(delay_accum); + delay_accum = 0; - } + } printf("delay_accum %ld\n", delay_accum); +#endif } } munmap(image, st.st_size); close(rfd); close(sock); - printf("\n"); + gettimeofday(&now, NULL); + + time_msecs = (now.tv_sec - then.tv_sec) * 1000; + time_msecs += ((int)(now.tv_usec - then.tv_usec)) / 1000; + printf("\n%d KiB sent in %ldms (%ld KiB/s)\n", + nr_blocks * (erasesize+sizeof(pktbuf)) / 1024, time_msecs, + nr_blocks * (erasesize+sizeof(pktbuf)) / 1024 * 1000 / time_msecs); return 0; } -- cgit v1.2.3