1 /* Copyright (C) 2003, 2004, 2005 Free Software Foundation, Inc.
2    This file is part of the GNU C Library.
3 
4    The GNU C Library is free software; you can redistribute it and/or
5    modify it under the terms of the GNU Lesser General Public
6    License as published by the Free Software Foundation; either
7    version 2.1 of the License, or (at your option) any later version.
8 
9    The GNU C Library is distributed in the hope that it will be useful,
10    but WITHOUT ANY WARRANTY; without even the implied warranty of
11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
12    Lesser General Public License for more details.
13 
14    You should have received a copy of the GNU Lesser General Public
15    License along with the GNU C Library; if not, see
16    <http://www.gnu.org/licenses/>.  */
17 
18 #include <time.h>
19 #include <errno.h>
20 
21 #include <sysdep-cancel.h>
22 #include <bits/kernel-features.h>
23 #include "kernel-posix-cpu-timers.h"
24 
25 
26 #ifdef __ASSUME_POSIX_TIMERS
27 /* We can simply use the syscall.  The CPU clocks are not supported
28    with this function.  */
29 int
clock_nanosleep(clockid_t clock_id,int flags,const struct timespec * req,struct timespec * rem)30 clock_nanosleep (clockid_t clock_id, int flags, const struct timespec *req,
31 		 struct timespec *rem)
32 {
33   INTERNAL_SYSCALL_DECL (err);
34   int r;
35 
36   if (clock_id == CLOCK_THREAD_CPUTIME_ID)
37     return EINVAL;
38   if (clock_id == CLOCK_PROCESS_CPUTIME_ID)
39     clock_id = MAKE_PROCESS_CPUCLOCK (0, CPUCLOCK_SCHED);
40 
41   if (SINGLE_THREAD_P)
42     r = INTERNAL_SYSCALL (clock_nanosleep, err, 4, clock_id, flags, req, rem);
43   else
44     {
45       int oldstate = LIBC_CANCEL_ASYNC ();
46 
47       r = INTERNAL_SYSCALL (clock_nanosleep, err, 4, clock_id, flags, req,
48 			    rem);
49 
50       LIBC_CANCEL_RESET (oldstate);
51     }
52 
53   return (INTERNAL_SYSCALL_ERROR_P (r, err)
54 	  ? INTERNAL_SYSCALL_ERRNO (r, err) : 0);
55 }
56 
57 #else
58 # ifdef __NR_clock_nanosleep
59 /* Is the syscall known to exist?  */
60 extern int __libc_missing_posix_timers attribute_hidden;
61 
62 /* The REALTIME and MONOTONIC clock might be available.  Try the
63    syscall first.  */
64 #  define SYSDEP_NANOSLEEP \
65   if (!__libc_missing_posix_timers)					      \
66     {									      \
67       clockid_t syscall_clockid;					      \
68       INTERNAL_SYSCALL_DECL (err);					      \
69 									      \
70       if (clock_id == CLOCK_THREAD_CPUTIME_ID)				      \
71 	return EINVAL;							      \
72       if (clock_id == CLOCK_PROCESS_CPUTIME_ID)				      \
73 	syscall_clockid = MAKE_PROCESS_CPUCLOCK (0, CPUCLOCK_SCHED);	      \
74       else								      \
75 	syscall_clockid = clock_id;					      \
76 									      \
77       int oldstate = LIBC_CANCEL_ASYNC ();				      \
78 									      \
79       int r = INTERNAL_SYSCALL (clock_nanosleep, err, 4,		      \
80 				syscall_clockid, flags, req, rem);	      \
81 									      \
82       LIBC_CANCEL_RESET (oldstate);					      \
83 									      \
84       if (!INTERNAL_SYSCALL_ERROR_P (r, err))				      \
85 	return 0;							      \
86 									      \
87       if (INTERNAL_SYSCALL_ERRNO (r, err) != ENOSYS)			      \
88 	return INTERNAL_SYSCALL_ERRNO (r, err);				      \
89 									      \
90       __libc_missing_posix_timers = 1;					      \
91     }
92 # endif
93 
94 # include <sysdeps/unix/clock_nanosleep.c>
95 #endif
96