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authorAustin Foxley <austinf@cetoncorp.com>2009-10-17 14:42:01 -0700
committerAustin Foxley <austinf@cetoncorp.com>2009-10-17 14:42:01 -0700
commita202cf6f119f41532b60ad28bc48746b535fd34c (patch)
tree03e96b87732058543d681803a829ee02238e5ab9 /librt/clock_gettime.c
parent93e6d12ea06dc489cde0d96f78d623410703d33e (diff)
librt additions that are now possible with nptl
* clock_getcpuclockid, clock_gettime, clock_nanosleep, mq_receive, mq_send, mq_timedreceive, mq_timedsend, _SC_MONOTONIC_CLOCK Signed-off-by: Austin Foxley <austinf@cetoncorp.com>
Diffstat (limited to 'librt/clock_gettime.c')
-rw-r--r--librt/clock_gettime.c301
1 files changed, 301 insertions, 0 deletions
diff --git a/librt/clock_gettime.c b/librt/clock_gettime.c
new file mode 100644
index 000000000..8308329b2
--- /dev/null
+++ b/librt/clock_gettime.c
@@ -0,0 +1,301 @@
+/* clock_gettime -- Get current time from a POSIX clockid_t. Linux version.
+ Copyright (C) 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
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, write to the Free
+ Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+ 02111-1307 USA. */
+
+#include <sysdep.h>
+#include <errno.h>
+#include <time.h>
+#include "kernel-posix-cpu-timers.h"
+#include <bits/kernel-features.h>
+
+
+#define SYSCALL_GETTIME \
+ retval = INLINE_SYSCALL (clock_gettime, 2, clock_id, tp); \
+ break
+
+#ifdef __ASSUME_POSIX_TIMERS
+
+/* This means the REALTIME and MONOTONIC clock are definitely
+ supported in the kernel. */
+# define SYSDEP_GETTIME \
+ SYSDEP_GETTIME_CPUTIME \
+ case CLOCK_REALTIME: \
+ case CLOCK_MONOTONIC: \
+ SYSCALL_GETTIME
+
+# define __libc_missing_posix_timers 0
+#elif defined __NR_clock_gettime
+/* Is the syscall known to exist? */
+int __libc_missing_posix_timers attribute_hidden;
+
+static inline int
+maybe_syscall_gettime (clockid_t clock_id, struct timespec *tp)
+{
+ int e = EINVAL;
+
+ if (!__libc_missing_posix_timers)
+ {
+ INTERNAL_SYSCALL_DECL (err);
+ int r = INTERNAL_SYSCALL (clock_gettime, err, 2, clock_id, tp);
+ if (!INTERNAL_SYSCALL_ERROR_P (r, err))
+ return 0;
+
+ e = INTERNAL_SYSCALL_ERRNO (r, err);
+ if (e == ENOSYS)
+ {
+ __libc_missing_posix_timers = 1;
+ e = EINVAL;
+ }
+ }
+
+ return e;
+}
+
+/* The REALTIME and MONOTONIC clock might be available. Try the
+ syscall first. */
+# define SYSDEP_GETTIME \
+ SYSDEP_GETTIME_CPUTIME \
+ case CLOCK_REALTIME: \
+ case CLOCK_MONOTONIC: \
+ retval = maybe_syscall_gettime (clock_id, tp); \
+ if (retval == 0) \
+ break; \
+ /* Fallback code. */ \
+ if (retval == EINVAL && clock_id == CLOCK_REALTIME) \
+ retval = realtime_gettime (tp); \
+ else \
+ { \
+ __set_errno (retval); \
+ retval = -1; \
+ } \
+ break;
+#endif
+
+#ifdef __NR_clock_gettime
+/* We handled the REALTIME clock here. */
+# define HANDLED_REALTIME 1
+# define HANDLED_CPUTIME 1
+
+# if __ASSUME_POSIX_CPU_TIMERS > 0
+
+# define SYSDEP_GETTIME_CPU SYSCALL_GETTIME
+# define SYSDEP_GETTIME_CPUTIME /* Default catches them too. */
+
+# else
+
+int __libc_missing_posix_cpu_timers attribute_hidden;
+
+static int
+maybe_syscall_gettime_cpu (clockid_t clock_id, struct timespec *tp)
+{
+ int e = EINVAL;
+
+ if (!__libc_missing_posix_cpu_timers)
+ {
+ INTERNAL_SYSCALL_DECL (err);
+ int r = INTERNAL_SYSCALL (clock_gettime, err, 2, clock_id, tp);
+ if (!INTERNAL_SYSCALL_ERROR_P (r, err))
+ return 0;
+
+ e = INTERNAL_SYSCALL_ERRNO (r, err);
+# ifndef __ASSUME_POSIX_TIMERS
+ if (e == ENOSYS)
+ {
+ __libc_missing_posix_timers = 1;
+ __libc_missing_posix_cpu_timers = 1;
+ e = EINVAL;
+ }
+ else
+# endif
+ {
+ if (e == EINVAL)
+ {
+ /* Check whether the kernel supports CPU clocks at all.
+ If not, record it for the future. */
+ r = INTERNAL_SYSCALL (clock_getres, err, 2,
+ MAKE_PROCESS_CPUCLOCK (0, CPUCLOCK_SCHED),
+ NULL);
+ if (INTERNAL_SYSCALL_ERROR_P (r, err))
+ __libc_missing_posix_cpu_timers = 1;
+ }
+ }
+ }
+
+ return e;
+}
+
+# define SYSDEP_GETTIME_CPU \
+ retval = maybe_syscall_gettime_cpu (clock_id, tp); \
+ if (retval == 0) \
+ break; \
+ if (retval != EINVAL || !__libc_missing_posix_cpu_timers) \
+ { \
+ __set_errno (retval); \
+ retval = -1; \
+ break; \
+ } \
+ retval = -1 /* Otherwise continue on to the HP_TIMING version. */;
+
+static inline int
+maybe_syscall_gettime_cputime (clockid_t clock_id, struct timespec *tp)
+{
+ return maybe_syscall_gettime_cpu
+ (clock_id == CLOCK_THREAD_CPUTIME_ID
+ ? MAKE_THREAD_CPUCLOCK (0, CPUCLOCK_SCHED)
+ : MAKE_PROCESS_CPUCLOCK (0, CPUCLOCK_SCHED),
+ tp);
+}
+
+# define SYSDEP_GETTIME_CPUTIME \
+ case CLOCK_PROCESS_CPUTIME_ID: \
+ case CLOCK_THREAD_CPUTIME_ID: \
+ retval = maybe_syscall_gettime_cputime (clock_id, tp); \
+ if (retval == 0) \
+ break; \
+ if (retval != EINVAL || !__libc_missing_posix_cpu_timers) \
+ { \
+ __set_errno (retval); \
+ retval = -1; \
+ break; \
+ } \
+ retval = hp_timing_gettime (clock_id, tp); \
+ break;
+# if !HP_TIMING_AVAIL
+# define hp_timing_gettime(clock_id, tp) (__set_errno (EINVAL), -1)
+# endif
+
+# endif
+#endif
+
+#include <errno.h>
+#include <stdint.h>
+#include <time.h>
+#include <sys/time.h>
+#include <libc-internal.h>
+#include <ldsodefs.h>
+
+
+#if HP_TIMING_AVAIL
+/* Clock frequency of the processor. We make it a 64-bit variable
+ because some jokers are already playing with processors with more
+ than 4GHz. */
+static hp_timing_t freq;
+
+
+/* This function is defined in the thread library. */
+extern int __pthread_clock_gettime (clockid_t clock_id, hp_timing_t freq,
+ struct timespec *tp)
+ __attribute__ ((__weak__));
+
+static int
+hp_timing_gettime (clockid_t clock_id, struct timespec *tp)
+{
+ hp_timing_t tsc;
+
+ if (__builtin_expect (freq == 0, 0))
+ {
+ /* 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. */
+ return -1;
+ }
+
+ if (clock_id != CLOCK_PROCESS_CPUTIME_ID
+ && __pthread_clock_gettime != NULL)
+ return __pthread_clock_gettime (clock_id, freq, tp);
+
+ /* Get the current counter. */
+ HP_TIMING_NOW (tsc);
+
+ /* Compute the offset since the start time of the process. */
+ tsc -= GL(dl_cpuclock_offset);
+
+ /* Compute the seconds. */
+ tp->tv_sec = tsc / freq;
+
+ /* And the nanoseconds. This computation should be stable until
+ we get machines with about 16GHz frequency. */
+ tp->tv_nsec = ((tsc % freq) * UINT64_C (1000000000)) / freq;
+
+ return 0;
+}
+#endif
+
+
+static inline int
+realtime_gettime (struct timespec *tp)
+{
+ struct timeval tv;
+ int retval = gettimeofday (&tv, NULL);
+ if (retval == 0)
+ /* Convert into `timespec'. */
+ TIMEVAL_TO_TIMESPEC (&tv, tp);
+ return retval;
+}
+
+librt_hidden_proto (clock_gettime)
+/* Get current value of CLOCK and store it in TP. */
+int
+clock_gettime (clockid_t clock_id, struct timespec *tp)
+{
+ int retval = -1;
+#ifndef HANDLED_REALTIME
+ struct timeval tv;
+#endif
+
+ switch (clock_id)
+ {
+#ifdef SYSDEP_GETTIME
+ SYSDEP_GETTIME;
+#endif
+
+#ifndef HANDLED_REALTIME
+ case CLOCK_REALTIME:
+ retval = gettimeofday (&tv, NULL);
+ if (retval == 0)
+ TIMEVAL_TO_TIMESPEC (&tv, tp);
+ break;
+#endif
+
+ default:
+#ifdef SYSDEP_GETTIME_CPU
+ SYSDEP_GETTIME_CPU;
+#endif
+#if HP_TIMING_AVAIL
+ if ((clock_id & ((1 << CLOCK_IDFIELD_SIZE) - 1))
+ == CLOCK_THREAD_CPUTIME_ID)
+ retval = hp_timing_gettime (clock_id, tp);
+ else
+#endif
+ __set_errno (EINVAL);
+ break;
+
+#if HP_TIMING_AVAIL && !defined HANDLED_CPUTIME
+ case CLOCK_PROCESS_CPUTIME_ID:
+ retval = hp_timing_gettime (clock_id, tp);
+ break;
+#endif
+ }
+
+ return retval;
+}
+librt_hidden_def (clock_gettime)