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Diffstat (limited to 'manual/time.texi')
| -rw-r--r-- | manual/time.texi | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/manual/time.texi b/manual/time.texi index 7a5cd655c0..c2b2378da8 100644 --- a/manual/time.texi +++ b/manual/time.texi @@ -1455,6 +1455,42 @@ On the GNU system, it is safe to use @code{sleep} and @code{SIGALRM} in the same program, because @code{sleep} does not work by means of @code{SIGALRM}. +@comment time.h +@comment POSIX.1 +@deftypefun int nanosleep (const struct timespec *@var{requested_time}, struct timespec *@var{remaining}) +If the resolution of seconds is not enough the @code{nanosleep} function +can be used. As the name suggests the sleeping period can be specified +in nanoseconds. The actual period of waiting time might be longer since +the requested time in the @var{requested_time} parameter is rounded up +to the next integer multiple of the actual resolution of the system. + +If the function returns because the time has elapsed the return value is +zero. If the function return @math{-1} the global variable @var{errno} +is set to the following values: + +@table @code +@item EINTR +The call was interrupted because a signal was delivered to the thread. +If the @var{remaining} parameter is not the null pointer the structure +pointed to by @var{remaining} is updated to contain the remaining time. + +@item EINVAL +The nanosecond value in the @var{requested_time} parameter contains an +illegal value. Either the value is negative or greater than or equal to +1000 million. +@end table + +This function is a cancelation point in multi-threaded programs. This +is a problem if the thread allocates some resources (like memory, file +descriptors, semaphores or whatever) at the time @code{nanosleep} is +called. If the thread gets canceled these resources stay allocated +until the program ends. To avoid this calls to @code{nanosleep} should +be protected using cancelation handlers. +@c ref pthread_cleanup_push / pthread_cleanup_pop + +The @code{nanosleep} function is declared in @file{time.h}. +@end deftypefun + @node Resource Usage @section Resource Usage |