1 | /* clock_nanosleep - high-resolution sleep with specifiable clock. |
2 | Copyright (C) 2002-2022 Free Software Foundation, Inc. |
3 | This file is part of the GNU C Library. |
4 | |
5 | The GNU C Library is free software; you can redistribute it and/or |
6 | modify it under the terms of the GNU Lesser General Public |
7 | License as published by the Free Software Foundation; either |
8 | version 2.1 of the License, or (at your option) any later version. |
9 | |
10 | The GNU C Library is distributed in the hope that it will be useful, |
11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
13 | Lesser General Public License for more details. |
14 | |
15 | You should have received a copy of the GNU Lesser General Public |
16 | License along with the GNU C Library; if not, see |
17 | <https://www.gnu.org/licenses/>. */ |
18 | |
19 | #include <errno.h> |
20 | #include <mach.h> |
21 | #include <time.h> |
22 | #include <unistd.h> |
23 | #include <posix-timer.h> |
24 | #include <shlib-compat.h> |
25 | #include <sysdep-cancel.h> |
26 | |
27 | static int |
28 | nanosleep_call (const struct timespec *req, struct timespec *rem) |
29 | { |
30 | mach_port_t recv; |
31 | struct timespec before; |
32 | error_t err; |
33 | |
34 | const mach_msg_timeout_t ms |
35 | = req->tv_sec * 1000 |
36 | + (req->tv_nsec + 999999) / 1000000; |
37 | |
38 | recv = __mach_reply_port (); |
39 | |
40 | if (rem != NULL) |
41 | __clock_gettime (CLOCK_REALTIME, &before); |
42 | |
43 | int cancel_oldtype = LIBC_CANCEL_ASYNC(); |
44 | err = __mach_msg (NULL, MACH_RCV_MSG|MACH_RCV_TIMEOUT|MACH_RCV_INTERRUPT, |
45 | 0, 0, recv, ms, MACH_PORT_NULL); |
46 | LIBC_CANCEL_RESET (cancel_oldtype); |
47 | |
48 | __mach_port_destroy (mach_task_self (), recv); |
49 | |
50 | if (err == EMACH_RCV_INTERRUPTED) |
51 | { |
52 | if (rem != NULL) |
53 | { |
54 | struct timespec after, elapsed; |
55 | __clock_gettime (CLOCK_REALTIME, &after); |
56 | timespec_sub (diff: &elapsed, left: &after, right: &before); |
57 | timespec_sub (diff: rem, left: req, right: &elapsed); |
58 | } |
59 | |
60 | return EINTR; |
61 | } |
62 | |
63 | return 0; |
64 | } |
65 | |
66 | int |
67 | __clock_nanosleep (clockid_t clock_id, int flags, const struct timespec *req, |
68 | struct timespec *rem) |
69 | { |
70 | if (clock_id != CLOCK_REALTIME |
71 | || !valid_nanoseconds (ns: req->tv_nsec) |
72 | || (flags != 0 && flags != TIMER_ABSTIME)) |
73 | return EINVAL; |
74 | |
75 | struct timespec now; |
76 | |
77 | /* If we got an absolute time, remap it. */ |
78 | if (flags == TIMER_ABSTIME) |
79 | { |
80 | long int nsec; |
81 | long int sec; |
82 | |
83 | /* Make sure we use safe data types. */ |
84 | assert (sizeof (sec) >= sizeof (now.tv_sec)); |
85 | |
86 | /* Get the current time for this clock. */ |
87 | if (__clock_gettime (clock_id, &now) != 0) |
88 | return errno; |
89 | |
90 | /* Compute the difference. */ |
91 | nsec = req->tv_nsec - now.tv_nsec; |
92 | sec = req->tv_sec - now.tv_sec - (nsec < 0); |
93 | if (sec < 0) |
94 | /* The time has already elapsed. */ |
95 | return 0; |
96 | |
97 | now.tv_sec = sec; |
98 | now.tv_nsec = nsec + (nsec < 0 ? 1000000000 : 0); |
99 | |
100 | /* From now on this is our time. */ |
101 | req = &now; |
102 | |
103 | /* Make sure we are not modifying the struct pointed to by REM. */ |
104 | rem = NULL; |
105 | } |
106 | |
107 | return nanosleep_call (req, rem); |
108 | } |
109 | libc_hidden_def (__clock_nanosleep) |
110 | versioned_symbol (libc, __clock_nanosleep, clock_nanosleep, GLIBC_2_17); |
111 | /* clock_nanosleep moved to libc in version 2.17; |
112 | old binaries may expect the symbol version it had in librt. */ |
113 | #if SHLIB_COMPAT (libc, GLIBC_2_2, GLIBC_2_17) |
114 | strong_alias (__clock_nanosleep, __clock_nanosleep_2); |
115 | compat_symbol (libc, __clock_nanosleep_2, clock_nanosleep, GLIBC_2_2); |
116 | #endif |
117 | |