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) | |||
36 | 36 | ||
37 | void FAST_FUNC msleep(unsigned ms) | 37 | void FAST_FUNC msleep(unsigned ms) |
38 | { | 38 | { |
39 | #if 0 | ||
39 | /* 1. usleep(n) is not guaranteed by standards to accept n >= 1000000 | 40 | /* 1. usleep(n) is not guaranteed by standards to accept n >= 1000000 |
40 | * 2. multiplication in usleep(ms * 1000) can overflow if ms > 4294967 | 41 | * 2. multiplication in usleep(ms * 1000) can overflow if ms > 4294967 |
41 | * (sleep of ~71.5 minutes) | 42 | * (sleep of ~71.5 minutes) |
@@ -46,4 +47,21 @@ void FAST_FUNC msleep(unsigned ms) | |||
46 | ms -= 500; | 47 | ms -= 500; |
47 | } | 48 | } |
48 | usleep(ms * 1000); | 49 | usleep(ms * 1000); |
50 | #else | ||
51 | //usleep is often implemented as a call to nanosleep. | ||
52 | //Simply do the same to implement msleep. | ||
53 | //it's marginally larger, but wakes your CPU less often: | ||
54 | //function old new delta | ||
55 | //msleep 45 52 +7 | ||
56 | struct timespec ts; | ||
57 | ts.tv_sec = ms / 1000; | ||
58 | ts.tv_nsec = (ms % 1000) * 1000000; | ||
59 | /* | ||
60 | * If a signal has non-default handler, nanosleep returns early. | ||
61 | * Our version of msleep doesn't return early | ||
62 | * if interrupted by such signals: | ||
63 | */ | ||
64 | while (nanosleep(&ts, &ts) != 0) | ||
65 | continue; | ||
66 | #endif | ||
49 | } | 67 | } |