X-Git-Url: https://mattmccutchen.net/rsync/rsync.git/blobdiff_plain/880da0072e01453a6a7329ce402d35093bce2618..e681e8206641ec61d3ef8918f15351e8d84ccf4f:/io.c diff --git a/io.c b/io.c index 3349b83b..66fd4c82 100644 --- a/io.c +++ b/io.c @@ -390,6 +390,33 @@ unsigned char read_byte(int f) } +/** + * Sleep after writing to limit I/O bandwidth usage. + * + * @todo Rather than sleeping after each write, it might be better to + * use some kind of averaging. The current algorithm seems to always + * use a bit less bandwidth than specified, because it doesn't make up + * for slow periods. But arguably this is a feature. In addition, we + * ought to take the time used to write the data into account. + **/ +static void sleep_for_bwlimit(int bytes_written) +{ + struct timeval tv; + + if (!bwlimit) + return; + + assert(bytes_written > 0); + assert(bwlimit > 0); + + tv.tv_usec = bytes_written * 1000 / bwlimit; + tv.tv_sec = tv.tv_usec / 1000000; + tv.tv_usec = tv.tv_usec % 1000000; + + select(0, NULL, NULL, NULL, tv); +} + + /** * Write len bytes to the file descriptor @p fd. * @@ -464,24 +491,13 @@ static void writefd_unbuffered(int fd,char *buf,size_t len) * across the stream */ io_multiplexing_close(); rprintf(FERROR, RSYNC_NAME - ": error writing %d unbuffered bytes" - " - exiting: %s\n", len, + ": writefd_unbuffered failed to write %ld bytes: %s\n", + (long) len, strerror(errno)); exit_cleanup(RERR_STREAMIO); } - /* Sleep after writing to limit I/O bandwidth */ - if (bwlimit) - { - tv.tv_sec = 0; - tv.tv_usec = ret * 1000 / bwlimit; - while (tv.tv_usec > 1000000) - { - tv.tv_sec++; - tv.tv_usec -= 1000000; - } - select(0, NULL, NULL, NULL, &tv); - } + sleep_for_bwlimit(ret); total += ret;