diff options
Diffstat (limited to 'sysdeps/posix/clock_getres.c')
| -rw-r--r-- | sysdeps/posix/clock_getres.c | 111 |
1 files changed, 60 insertions, 51 deletions
diff --git a/sysdeps/posix/clock_getres.c b/sysdeps/posix/clock_getres.c index a2d4666..f4dc21f 100644 --- a/sysdeps/posix/clock_getres.c +++ b/sysdeps/posix/clock_getres.c @@ -1,4 +1,5 @@ -/* Copyright (C) 1999, 2000, 2001, 2003 Free Software Foundation, Inc. +/* clock_getres -- Get the resolution of a POSIX clockid_t. + Copyright (C) 1999, 2000, 2001, 2003, 2004 Free Software Foundation, Inc. This file is part of the GNU C Library. The GNU C Library is free software; you can redistribute it and/or @@ -24,11 +25,55 @@ #include <libc-internal.h> -#if HP_TIMING_AVAIL && !defined HANDLED_CPUTIME -/* Clock frequency of the processor. */ -static long int nsec; +#if HP_TIMING_AVAIL +static long int nsec; /* Clock frequency of the processor. */ + +static inline int +hp_timing_getres (struct timespec *res) +{ + if (__builtin_expect (nsec == 0, 0)) + { + hp_timing_t freq; + + /* This can only happen if we haven't initialized the `nsec' + variable yet. Do this now. We don't have to protect this + code against multiple execution since all of them should + lead to the same result. */ + freq = __get_clockfreq (); + if (__builtin_expect (freq == 0, 0)) + /* Something went wrong. */ + return -1; + + nsec = MAX (UINT64_C (1000000000) / freq, 1); + } + + /* Fill in the values. + The seconds are always zero (unless we have a 1Hz machine). */ + res->tv_sec = 0; + res->tv_nsec = nsec; + + return 0; +} #endif +static inline int +realtime_getres (struct timespec *res) +{ + long int clk_tck = sysconf (_SC_CLK_TCK); + + if (__builtin_expect (clk_tck != -1, 1)) + { + /* This implementation assumes that the realtime clock has a + resolution higher than 1 second. This is the case for any + reasonable implementation. */ + res->tv_sec = 0; + res->tv_nsec = 1000000000 / clk_tck; + return 0; + } + + return -1; +} + /* Get resolution of clock. */ int @@ -38,69 +83,33 @@ clock_getres (clockid_t clock_id, struct timespec *res) switch (clock_id) { -#define HANDLE_REALTIME \ - do { \ - long int clk_tck = sysconf (_SC_CLK_TCK); \ - \ - if (__builtin_expect (clk_tck != -1, 1)) \ - { \ - /* This implementation assumes that the realtime clock has a \ - resolution higher than 1 second. This is the case for any \ - reasonable implementation. */ \ - res->tv_sec = 0; \ - res->tv_nsec = 1000000000 / clk_tck; \ - \ - retval = 0; \ - } \ - } while (0) - #ifdef SYSDEP_GETRES SYSDEP_GETRES; #endif #ifndef HANDLED_REALTIME case CLOCK_REALTIME: - HANDLE_REALTIME; + retval = realtime_getres (res); break; #endif /* handled REALTIME */ default: +#ifdef SYSDEP_GETRES_CPU + SYSDEP_GETRES_CPU; +#endif #if HP_TIMING_AVAIL if ((clock_id & ((1 << CLOCK_IDFIELD_SIZE) - 1)) - != CLOCK_THREAD_CPUTIME_ID) + == CLOCK_THREAD_CPUTIME_ID) + retval = hp_timing_getres (res); + else #endif - { - __set_errno (EINVAL); - break; - } + __set_errno (EINVAL); + break; #if HP_TIMING_AVAIL && !defined HANDLED_CPUTIME - /* FALLTHROUGH. */ case CLOCK_PROCESS_CPUTIME_ID: - { - if (__builtin_expect (nsec == 0, 0)) - { - hp_timing_t freq; - - /* This can only happen if we haven't initialized the `freq' - variable yet. Do this now. We don't have to protect this - code against multiple execution since all of them should - lead to the same result. */ - freq = __get_clockfreq (); - if (__builtin_expect (freq == 0, 0)) - /* Something went wrong. */ - break; - - nsec = MAX (UINT64_C (1000000000) / freq, 1); - } - - /* File in the values. The seconds are always zero (unless we - have a 1Hz machine). */ - res->tv_sec = 0; - res->tv_nsec = nsec; - - retval = 0; - } + case CLOCK_THREAD_CPUTIME_ID: + retval = hp_timing_getres (res); break; #endif } |