diff options
Diffstat (limited to 'libbb/bb_do_delay.c')
| -rw-r--r-- | libbb/bb_do_delay.c | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/libbb/bb_do_delay.c b/libbb/bb_do_delay.c index 3dbf032db..9a84fa24b 100644 --- a/libbb/bb_do_delay.c +++ b/libbb/bb_do_delay.c @@ -36,6 +36,7 @@ void FAST_FUNC sleep1(void) void FAST_FUNC msleep(unsigned ms) { +#if 0 /* 1. usleep(n) is not guaranteed by standards to accept n >= 1000000 * 2. multiplication in usleep(ms * 1000) can overflow if ms > 4294967 * (sleep of ~71.5 minutes) @@ -46,4 +47,21 @@ void FAST_FUNC msleep(unsigned ms) ms -= 500; } usleep(ms * 1000); +#else +//usleep is often implemented as a call to nanosleep. +//Simply do the same to implement msleep. +//it's marginally larger, but wakes your CPU less often: +//function old new delta +//msleep 45 52 +7 + struct timespec ts; + ts.tv_sec = ms / 1000; + ts.tv_nsec = (ms % 1000) * 1000000; + /* + * If a signal has non-default handler, nanosleep returns early. + * Our version of msleep doesn't return early + * if interrupted by such signals: + */ + while (nanosleep(&ts, &ts) != 0) + continue; +#endif } |