diff options
Diffstat (limited to 'manual/time.texi')
| -rw-r--r-- | manual/time.texi | 151 |
1 files changed, 51 insertions, 100 deletions
diff --git a/manual/time.texi b/manual/time.texi index dccb979955..33aa221428 100644 --- a/manual/time.texi +++ b/manual/time.texi @@ -76,9 +76,8 @@ One way to represent an elapsed time is with a simple arithmetic data type, as with the following function to compute the elapsed time between two calendar times. This function is declared in @file{time.h}. -@comment time.h -@comment ISO @deftypefun double difftime (time_t @var{time1}, time_t @var{time0}) +@standards{ISO, time.h} @safety{@prelim{}@mtsafe{}@assafe{}@acsafe{}} The @code{difftime} function returns the number of seconds of elapsed time between calendar time @var{time1} and calendar time @var{time0}, as @@ -96,9 +95,8 @@ you can use them for your own purposes too. They're exactly the same except that one has a resolution in microseconds, and the other, newer one, is in nanoseconds. -@comment sys/time.h -@comment BSD @deftp {Data Type} {struct timeval} +@standards{BSD, sys/time.h} @cindex timeval The @code{struct timeval} structure represents an elapsed time. It is declared in @file{sys/time.h} and has the following members: @@ -115,9 +113,8 @@ million. @end table @end deftp -@comment sys/time.h -@comment POSIX.1 @deftp {Data Type} {struct timespec} +@standards{POSIX.1, sys/time.h} @cindex timespec The @code{struct timespec} structure represents an elapsed time. It is declared in @file{time.h} and has the following members: @@ -229,24 +226,21 @@ track of CPU time. It's common for the internal processor clock to have a resolution somewhere between a hundredth and millionth of a second. -@comment time.h -@comment ISO @deftypevr Macro int CLOCKS_PER_SEC +@standards{ISO, time.h} The value of this macro is the number of clock ticks per second measured by the @code{clock} function. POSIX requires that this value be one million independent of the actual resolution. @end deftypevr -@comment time.h -@comment ISO @deftp {Data Type} clock_t +@standards{ISO, time.h} This is the type of the value returned by the @code{clock} function. Values of type @code{clock_t} are numbers of clock ticks. @end deftp -@comment time.h -@comment ISO @deftypefun clock_t clock (void) +@standards{ISO, time.h} @safety{@prelim{}@mtsafe{}@assafe{}@acsafe{}} @c On Hurd, this calls task_info twice and adds user and system time @c from both basic and thread time info structs. On generic posix, @@ -270,9 +264,8 @@ include the header file @file{sys/times.h} to use this facility. @cindex CPU time @pindex sys/times.h -@comment sys/times.h -@comment POSIX.1 @deftp {Data Type} {struct tms} +@standards{POSIX.1, sys/times.h} The @code{tms} structure is used to return information about process times. It contains at least the following members: @@ -307,16 +300,14 @@ these are the actual amounts of time; not relative to any event. @xref{Creating a Process}. @end deftp -@comment time.h -@comment POSIX.1 @deftypevr Macro int CLK_TCK +@standards{POSIX.1, time.h} This is an obsolete name for the number of clock ticks per second. Use @code{sysconf (_SC_CLK_TCK)} instead. @end deftypevr -@comment sys/times.h -@comment POSIX.1 @deftypefun clock_t times (struct tms *@var{buffer}) +@standards{POSIX.1, sys/times.h} @safety{@prelim{}@mtsafe{}@assafe{}@acsafe{}} @c On HURD, this calls task_info twice, for basic and thread times info, @c adding user and system times into tms, and then gettimeofday, to @@ -395,9 +386,8 @@ These facilities are declared in the header file @file{time.h}. @pindex time.h @cindex epoch -@comment time.h -@comment ISO @deftp {Data Type} time_t +@standards{ISO, time.h} This is the data type used to represent simple time. Sometimes, it also represents an elapsed time. When interpreted as a calendar time value, it represents the number of seconds elapsed since 00:00:00 on January 1, @@ -419,9 +409,8 @@ The function @code{difftime} tells you the elapsed time between two simple calendar times, which is not always as easy to compute as just subtracting. @xref{Elapsed Time}. -@comment time.h -@comment ISO @deftypefun time_t time (time_t *@var{result}) +@standards{ISO, time.h} @safety{@prelim{}@mtsafe{}@assafe{}@acsafe{}} The @code{time} function returns the current calendar time as a value of type @code{time_t}. If the argument @var{result} is not a null pointer, @@ -432,9 +421,9 @@ current calendar time is not available, the value @c The GNU C library implements stime() with a call to settimeofday() on @c Linux. -@comment time.h -@comment SVID, XPG @deftypefun int stime (const time_t *@var{newtime}) +@standards{SVID, time.h} +@standards{XPG, time.h} @safety{@prelim{}@mtsafe{}@assafe{}@acsafe{}} @c On unix, this is implemented in terms of settimeofday. @code{stime} sets the system clock, i.e., it tells the system that the @@ -470,9 +459,8 @@ functions and the associated data types described in this section are declared in @file{sys/time.h}. @pindex sys/time.h -@comment sys/time.h -@comment BSD @deftp {Data Type} {struct timezone} +@standards{BSD, sys/time.h} The @code{struct timezone} structure is used to hold minimal information about the local time zone. It has the following members: @@ -488,9 +476,8 @@ The @code{struct timezone} type is obsolete and should never be used. Instead, use the facilities described in @ref{Time Zone Functions}. @end deftp -@comment sys/time.h -@comment BSD @deftypefun int gettimeofday (struct timeval *@var{tp}, struct timezone *@var{tzp}) +@standards{BSD, sys/time.h} @safety{@prelim{}@mtsafe{}@assafe{}@acsafe{}} @c On most GNU/Linux systems this is a direct syscall, but the posix/ @c implementation (not used on GNU/Linux or GNU/Hurd) relies on time and @@ -517,9 +504,8 @@ Instead, use the facilities described in @ref{Time Zone Functions}. @end table @end deftypefun -@comment sys/time.h -@comment BSD @deftypefun int settimeofday (const struct timeval *@var{tp}, const struct timezone *@var{tzp}) +@standards{BSD, sys/time.h} @safety{@prelim{}@mtsafe{}@assafe{}@acsafe{}} @c On HURD, it calls host_set_time with a privileged port. On other @c unix systems, it's a syscall. @@ -561,9 +547,8 @@ The operating system does not support setting time zone information, and @end deftypefun @c On Linux, GNU libc implements adjtime() as a call to adjtimex(). -@comment sys/time.h -@comment BSD @deftypefun int adjtime (const struct timeval *@var{delta}, struct timeval *@var{olddelta}) +@standards{BSD, sys/time.h} @safety{@prelim{}@mtsafe{}@assafe{}@acsafe{}} @c On hurd and mach, call host_adjust_time with a privileged port. On @c Linux, it's implemented in terms of adjtimex. On other unixen, it's @@ -603,9 +588,8 @@ and @code{adjtime} functions are derived from BSD. Symbols for the following function are declared in @file{sys/timex.h}. -@comment sys/timex.h -@comment GNU @deftypefun int adjtimex (struct timex *@var{timex}) +@standards{GNU, sys/timex.h} @safety{@prelim{}@mtsafe{}@assafe{}@acsafe{}} @c It's a syscall, only available on linux. @@ -634,9 +618,8 @@ zone, and it also indicates which time zone that is. The symbols in this section are declared in the header file @file{time.h}. -@comment time.h -@comment ISO @deftp {Data Type} {struct tm} +@standards{ISO, time.h} This is the data type used to represent a broken-down time. The structure contains at least the following members, which can appear in any order. @@ -702,9 +685,8 @@ GNU extension, and is not visible in a strict @w{ISO C} environment. @end deftp -@comment time.h -@comment ISO @deftypefun {struct tm *} localtime (const time_t *@var{time}) +@standards{ISO, time.h} @safety{@prelim{}@mtunsafe{@mtasurace{:tmbuf} @mtsenv{} @mtslocale{}}@asunsafe{@ascuheap{} @asulock{}}@acunsafe{@aculock{} @acsmem{} @acsfd{}}} @c Calls tz_convert with a static buffer. @c localtime @mtasurace:tmbuf @mtsenv @mtslocale @ascuheap @asulock @aculock @acsmem @acsfd @@ -730,9 +712,8 @@ Using the @code{localtime} function is a big problem in multi-threaded programs. The result is returned in a static buffer and this is used in all threads. POSIX.1c introduced a variant of this function. -@comment time.h -@comment POSIX.1c @deftypefun {struct tm *} localtime_r (const time_t *@var{time}, struct tm *@var{resultp}) +@standards{POSIX.1c, time.h} @safety{@prelim{}@mtsafe{@mtsenv{} @mtslocale{}}@asunsafe{@ascuheap{} @asulock{}}@acunsafe{@aculock{} @acsmem{} @acsfd{}}} @c localtime_r @mtsenv @mtslocale @ascuheap @asulock @aculock @acsmem @acsfd @c tz_convert(use_localtime) @mtsenv @mtslocale @ascuheap @asulock @aculock @acsmem @acsfd @@ -827,9 +808,8 @@ object the result was written into, i.e., it returns @var{resultp}. @end deftypefun -@comment time.h -@comment ISO @deftypefun {struct tm *} gmtime (const time_t *@var{time}) +@standards{ISO, time.h} @safety{@prelim{}@mtunsafe{@mtasurace{:tmbuf} @mtsenv{} @mtslocale{}}@asunsafe{@ascuheap{} @asulock{}}@acunsafe{@aculock{} @acsmem{} @acsfd{}}} @c gmtime @mtasurace:tmbuf @mtsenv @mtslocale @ascuheap @asulock @aculock @acsmem @acsfd @c tz_convert dup @mtsenv @mtslocale @ascuheap @asulock @aculock @acsmem @acsfd @@ -843,9 +823,8 @@ As for the @code{localtime} function we have the problem that the result is placed in a static variable. POSIX.1c also provides a replacement for @code{gmtime}. -@comment time.h -@comment POSIX.1c @deftypefun {struct tm *} gmtime_r (const time_t *@var{time}, struct tm *@var{resultp}) +@standards{POSIX.1c, time.h} @safety{@prelim{}@mtsafe{@mtsenv{} @mtslocale{}}@asunsafe{@ascuheap{} @asulock{}}@acunsafe{@aculock{} @acsmem{} @acsfd{}}} @c You'd think tz_convert could avoid some safety issues with @c !use_localtime, but no such luck: tzset_internal will always bring @@ -863,9 +842,8 @@ object the result was written into, i.e., it returns @var{resultp}. @end deftypefun -@comment time.h -@comment ISO @deftypefun time_t mktime (struct tm *@var{brokentime}) +@standards{ISO, time.h} @safety{@prelim{}@mtsafe{@mtsenv{} @mtslocale{}}@asunsafe{@ascuheap{} @asulock{}}@acunsafe{@aculock{} @acsmem{} @acsfd{}}} @c mktime @mtsenv @mtslocale @ascuheap @asulock @aculock @acsmem @acsfd @c passes a static localtime_offset to mktime_internal; it is read @@ -913,9 +891,8 @@ of @var{brokentime}'s initial @code{tm_gmtoff} and @code{tm_zone} members. @xref{Time Zone Functions}. @end deftypefun -@comment time.h -@comment ??? @deftypefun time_t timelocal (struct tm *@var{brokentime}) +@standards{???, time.h} @safety{@prelim{}@mtsafe{@mtsenv{} @mtslocale{}}@asunsafe{@ascuheap{} @asulock{}}@acunsafe{@aculock{} @acsmem{} @acsfd{}}} @c Alias to mktime. @@ -928,9 +905,8 @@ available. @code{timelocal} is rather rare. @end deftypefun -@comment time.h -@comment ??? @deftypefun time_t timegm (struct tm *@var{brokentime}) +@standards{???, time.h} @safety{@prelim{}@mtsafe{@mtsenv{} @mtslocale{}}@asunsafe{@ascuheap{} @asulock{}}@acunsafe{@aculock{} @acsmem{} @acsfd{}}} @c timegm @mtsenv @mtslocale @ascuheap @asulock @aculock @acsmem @acsfd @c gmtime_offset triggers the same caveats as localtime_offset in mktime. @@ -1002,9 +978,8 @@ system clock from the true calendar time. @end table @end deftp -@comment sys/timex.h -@comment GNU @deftypefun int ntp_gettime (struct ntptimeval *@var{tptr}) +@standards{GNU, sys/timex.h} @safety{@prelim{}@mtsafe{}@assafe{}@acsafe{}} @c Wrapper for adjtimex. The @code{ntp_gettime} function sets the structure pointed to by @@ -1121,9 +1096,8 @@ exceeded the threshold. @end table @end deftp -@comment sys/timex.h -@comment GNU @deftypefun int ntp_adjtime (struct timex *@var{tptr}) +@standards{GNU, sys/timex.h} @safety{@prelim{}@mtsafe{}@assafe{}@acsafe{}} @c Alias to adjtimex syscall. The @code{ntp_adjtime} function sets the structure specified by @@ -1177,9 +1151,8 @@ The functions described in this section format calendar time values as strings. These functions are declared in the header file @file{time.h}. @pindex time.h -@comment time.h -@comment ISO @deftypefun {char *} asctime (const struct tm *@var{brokentime}) +@standards{ISO, time.h} @safety{@prelim{}@mtunsafe{@mtasurace{:asctime} @mtslocale{}}@asunsafe{}@acsafe{}} @c asctime @mtasurace:asctime @mtslocale @c Uses a static buffer. @@ -1207,9 +1180,8 @@ overwritten by subsequent calls to @code{asctime} or @code{ctime}. string.) @end deftypefun -@comment time.h -@comment POSIX.1c @deftypefun {char *} asctime_r (const struct tm *@var{brokentime}, char *@var{buffer}) +@standards{POSIX.1c, time.h} @safety{@prelim{}@mtsafe{@mtslocale{}}@assafe{}@acsafe{}} @c asctime_r @mtslocale @c asctime_internal dup @mtslocale @@ -1224,9 +1196,8 @@ it returns @code{NULL}. @end deftypefun -@comment time.h -@comment ISO @deftypefun {char *} ctime (const time_t *@var{time}) +@standards{ISO, time.h} @safety{@prelim{}@mtunsafe{@mtasurace{:tmbuf} @mtasurace{:asctime} @mtsenv{} @mtslocale{}}@asunsafe{@ascuheap{} @asulock{}}@acunsafe{@aculock{} @acsmem{} @acsfd{}}} @c ctime @mtasurace:tmbuf @mtasurace:asctime @mtsenv @mtslocale @ascuheap @asulock @aculock @acsmem @acsfd @c localtime dup @mtasurace:tmbuf @mtsenv @mtslocale @ascuheap @asulock @aculock @acsmem @acsfd @@ -1243,9 +1214,8 @@ Calling @code{ctime} also sets the current time zone as if @code{tzset} were called. @xref{Time Zone Functions}. @end deftypefun -@comment time.h -@comment POSIX.1c @deftypefun {char *} ctime_r (const time_t *@var{time}, char *@var{buffer}) +@standards{POSIX.1c, time.h} @safety{@prelim{}@mtsafe{@mtsenv{} @mtslocale{}}@asunsafe{@ascuheap{} @asulock{}}@acunsafe{@aculock{} @acsmem{} @acsfd{}}} @c ctime_r @mtsenv @mtslocale @ascuheap @asulock @aculock @acsmem @acsfd @c localtime_r dup @mtsenv @mtslocale @ascuheap @asulock @aculock @acsmem @acsfd @@ -1264,9 +1234,8 @@ it returns @code{NULL}. @end deftypefun -@comment time.h -@comment ISO @deftypefun size_t strftime (char *@var{s}, size_t @var{size}, const char *@var{template}, const struct tm *@var{brokentime}) +@standards{ISO, time.h} @safety{@prelim{}@mtsafe{@mtsenv{} @mtslocale{}}@asunsafe{@asucorrupt{} @ascuheap{} @asulock{} @ascudlopen{}}@acunsafe{@acucorrupt{} @aculock{} @acsmem{} @acsfd{}}} @c strftime @mtsenv @mtslocale @asucorrupt @ascuheap @asulock @ascudlopen @acucorrupt @aculock @acsmem @acsfd @c strftime_l @mtsenv @mtslocale @asucorrupt @ascuheap @asulock @ascudlopen @acucorrupt @aculock @acsmem @acsfd @@ -1648,9 +1617,8 @@ members. @xref{Time Zone Functions}. For an example of @code{strftime}, see @ref{Time Functions Example}. @end deftypefun -@comment time.h -@comment ISO/Amend1 @deftypefun size_t wcsftime (wchar_t *@var{s}, size_t @var{size}, const wchar_t *@var{template}, const struct tm *@var{brokentime}) +@standards{ISO/Amend1, time.h} @safety{@prelim{}@mtsafe{@mtsenv{} @mtslocale{}}@asunsafe{@asucorrupt{} @ascuheap{} @asulock{} @ascudlopen{}}@acunsafe{@acucorrupt{} @aculock{} @acsmem{} @acsfd{}}} @c wcsftime @mtsenv @mtslocale @asucorrupt @ascuheap @asulock @ascudlopen @acucorrupt @aculock @acsmem @acsfd @c wcsftime_l @mtsenv @mtslocale @asucorrupt @ascuheap @asulock @ascudlopen @acucorrupt @aculock @acsmem @acsfd @@ -1745,9 +1713,8 @@ used in software since it is better known. Its interface and implementation are heavily influenced by the @code{getdate} function, which is defined and implemented in terms of calls to @code{strptime}. -@comment time.h -@comment XPG4 @deftypefun {char *} strptime (const char *@var{s}, const char *@var{fmt}, struct tm *@var{tp}) +@standards{XPG4, time.h} @safety{@prelim{}@mtsafe{@mtsenv{} @mtslocale{}}@asunsafe{@ascuheap{} @asulock{}}@acunsafe{@aculock{} @acsmem{} @acsfd{}}} @c strptime @mtsenv @mtslocale @ascuheap @asulock @aculock @acsmem @acsfd @c strptime_internal @mtsenv @mtslocale @ascuheap @asulock @aculock @acsmem @acsfd @@ -2155,9 +2122,8 @@ in multi-threaded programs or libraries, since it returns a pointer to a static variable, and uses a global variable and global state (an environment variable). -@comment time.h -@comment Unix98 @defvar getdate_err +@standards{Unix98, time.h} This variable of type @code{int} contains the error code of the last unsuccessful call to @code{getdate}. Defined values are: @@ -2184,9 +2150,8 @@ in a @code{time_t} variable. @end table @end defvar -@comment time.h -@comment Unix98 @deftypefun {struct tm *} getdate (const char *@var{string}) +@standards{Unix98, time.h} @safety{@prelim{}@mtunsafe{@mtasurace{:getdate} @mtsenv{} @mtslocale{}}@asunsafe{@ascuheap{} @asulock{}}@acunsafe{@aculock{} @acsmem{} @acsfd{}}} @c getdate @mtasurace:getdate @mtsenv @mtslocale @ascuheap @asulock @aculock @acsmem @acsfd @c getdate_r dup @mtsenv @mtslocale @ascuheap @asulock @aculock @acsmem @acsfd @@ -2298,9 +2263,8 @@ any arbitrary file and chances are high that with some bogus input (such as a binary file) the program will crash. @end deftypefun -@comment time.h -@comment GNU @deftypefun int getdate_r (const char *@var{string}, struct tm *@var{tp}) +@standards{GNU, time.h} @safety{@prelim{}@mtsafe{@mtsenv{} @mtslocale{}}@asunsafe{@ascuheap{} @asulock{}}@acunsafe{@aculock{} @acsmem{} @acsfd{}}} @c getdate_r @mtsenv @mtslocale @ascuheap @asulock @aculock @acsmem @acsfd @c getenv dup @mtsenv @@ -2528,9 +2492,8 @@ community of volunteers and put in the public domain. @node Time Zone Functions @subsection Functions and Variables for Time Zones -@comment time.h -@comment POSIX.1 @deftypevar {char *} tzname [2] +@standards{POSIX.1, time.h} The array @code{tzname} contains two strings, which are the standard names of the pair of time zones (standard and Daylight Saving) that the user has selected. @code{tzname[0]} is the name of @@ -2558,9 +2521,8 @@ lead to trouble. @end deftypevar -@comment time.h -@comment POSIX.1 @deftypefun void tzset (void) +@standards{POSIX.1, time.h} @safety{@prelim{}@mtsafe{@mtsenv{} @mtslocale{}}@asunsafe{@ascuheap{} @asulock{}}@acunsafe{@aculock{} @acsmem{} @acsfd{}}} @c tzset @mtsenv @mtslocale @ascuheap @asulock @aculock @acsmem @acsfd @c libc_lock_lock dup @asulock @aculock @@ -2577,9 +2539,8 @@ The following variables are defined for compatibility with System V Unix. Like @code{tzname}, these variables are set by calling @code{tzset} or the other time conversion functions. -@comment time.h -@comment SVID @deftypevar {long int} timezone +@standards{SVID, time.h} This contains the difference between UTC and the latest local standard time, in seconds west of UTC. For example, in the U.S. Eastern time zone, the value is @code{5*60*60}. Unlike the @code{tm_gmtoff} member @@ -2589,9 +2550,8 @@ to use @code{tm_gmtoff}, since it contains the correct offset even when it is not the latest one. @end deftypevar -@comment time.h -@comment SVID @deftypevar int daylight +@standards{SVID, time.h} This variable has a nonzero value if Daylight Saving Time rules apply. A nonzero value does not necessarily mean that Daylight Saving Time is now in effect; it means only that Daylight Saving Time is sometimes in @@ -2683,9 +2643,8 @@ simpler interface for setting the real-time timer. @pindex unistd.h @pindex sys/time.h -@comment sys/time.h -@comment BSD @deftp {Data Type} {struct itimerval} +@standards{BSD, sys/time.h} This structure is used to specify when a timer should expire. It contains the following members: @table @code @@ -2701,9 +2660,8 @@ the alarm is disabled. The @code{struct timeval} data type is described in @ref{Elapsed Time}. @end deftp -@comment sys/time.h -@comment BSD @deftypefun int setitimer (int @var{which}, const struct itimerval *@var{new}, struct itimerval *@var{old}) +@standards{BSD, sys/time.h} @safety{@prelim{}@mtsafe{@mtstimer{}}@assafe{}@acsafe{}} @c This function is marked with @mtstimer because the same set of timers @c is shared by all threads of a process, so calling it in one thread @@ -2730,9 +2688,8 @@ The timer period is too large. @end table @end deftypefun -@comment sys/time.h -@comment BSD @deftypefun int getitimer (int @var{which}, struct itimerval *@var{old}) +@standards{BSD, sys/time.h} @safety{@prelim{}@mtsafe{}@assafe{}@acsafe{}} The @code{getitimer} function stores information about the timer specified by @var{which} in the structure pointed at by @var{old}. @@ -2741,31 +2698,27 @@ The return value and error conditions are the same as for @code{setitimer}. @end deftypefun @vtable @code -@comment sys/time.h -@comment BSD @item ITIMER_REAL +@standards{BSD, sys/time.h} This constant can be used as the @var{which} argument to the @code{setitimer} and @code{getitimer} functions to specify the real-time timer. -@comment sys/time.h -@comment BSD @item ITIMER_VIRTUAL +@standards{BSD, sys/time.h} This constant can be used as the @var{which} argument to the @code{setitimer} and @code{getitimer} functions to specify the virtual timer. -@comment sys/time.h -@comment BSD @item ITIMER_PROF +@standards{BSD, sys/time.h} This constant can be used as the @var{which} argument to the @code{setitimer} and @code{getitimer} functions to specify the profiling timer. @end vtable -@comment unistd.h -@comment POSIX.1 @deftypefun {unsigned int} alarm (unsigned int @var{seconds}) +@standards{POSIX.1, unistd.h} @safety{@prelim{}@mtsafe{@mtstimer{}}@assafe{}@acsafe{}} @c Wrapper for setitimer. The @code{alarm} function sets the real-time timer to expire in @@ -2824,9 +2777,8 @@ signals, use @code{select} (@pxref{Waiting for I/O}) and don't specify any descriptors to wait for. @c !!! select can get EINTR; using SA_RESTART makes sleep win too. -@comment unistd.h -@comment POSIX.1 @deftypefun {unsigned int} sleep (unsigned int @var{seconds}) +@standards{POSIX.1, unistd.h} @safety{@prelim{}@mtunsafe{@mtascusig{:SIGCHLD/linux}}@asunsafe{}@acunsafe{}} @c On Mach, it uses ports and calls time. On generic posix, it calls @c nanosleep. On Linux, it temporarily blocks SIGCHLD, which is MT- and @@ -2872,9 +2824,8 @@ On @gnusystems{}, 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}) +@standards{POSIX.1, time.h} @safety{@prelim{}@mtsafe{}@assafe{}@acsafe{}} @c On Linux, it's a syscall. On Mach, it calls gettimeofday and uses @c ports. |