diff options
| -rw-r--r-- | support/Makefile | 1 | ||||
| -rw-r--r-- | support/support.h | 11 | ||||
| -rw-r--r-- | support/support_create_timer.c | 69 |
3 files changed, 81 insertions, 0 deletions
diff --git a/support/Makefile b/support/Makefile index f3ebaa8..278f462 100644 --- a/support/Makefile +++ b/support/Makefile @@ -50,6 +50,7 @@ libsupport-routines = \ support_chroot \ support_copy_file \ support_copy_file_range \ + support_create_timer \ support_descriptor_supports_holes \ support_descriptors \ support_enter_mount_namespace \ diff --git a/support/support.h b/support/support.h index 874204b..9ec8ecb 100644 --- a/support/support.h +++ b/support/support.h @@ -24,6 +24,7 @@ #define SUPPORT_H #include <stdbool.h> +#include <stdint.h> #include <stddef.h> #include <sys/cdefs.h> /* For mode_t. */ @@ -153,6 +154,16 @@ extern bool support_select_modifies_timeout (void); tv_usec larger than 1000000. */ extern bool support_select_normalizes_timeout (void); +/* Create a timer that trigger after SEC seconds and NSEC nanoseconds. If + REPEAT is true the timer will repeat indefinitely. If CALLBACK is not + NULL, the function will be called when the timer expires; otherwise a + dummy empty function is used instead. + This is implemented with POSIX per-process timer with SIGEV_SIGNAL. */ +timer_t support_create_timer (uint64_t sec, long int nsec, bool repeat, + void (*callback)(int)); +/* Disable the timer TIMER. */ +void support_delete_timer (timer_t timer); + __END_DECLS #endif /* SUPPORT_H */ diff --git a/support/support_create_timer.c b/support/support_create_timer.c new file mode 100644 index 0000000..c93aaa5 --- /dev/null +++ b/support/support_create_timer.c @@ -0,0 +1,69 @@ +/* Create a periodic timer. + Copyright (C) 2021 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, see + <https://www.gnu.org/licenses/>. */ + +#include <support/check.h> +#include <support/support.h> +#include <support/xsignal.h> +#include <time.h> + +static void +dummy_alrm_handler (int sig) +{ +} + +timer_t +support_create_timer (uint64_t sec, long int nsec, bool repeat, + void (*callback)(int)) +{ + struct sigaction sa; + sa.sa_handler = callback != NULL ? callback : dummy_alrm_handler; + sigemptyset (&sa.sa_mask); + sa.sa_flags = 0; + xsigaction (SIGALRM, &sa, NULL); + + struct sigevent ev = { + .sigev_notify = SIGEV_SIGNAL, + .sigev_signo = SIGALRM + }; + timer_t timerid; + int r = timer_create (CLOCK_REALTIME, &ev, &timerid); + if (r == -1) + FAIL_EXIT1 ("timer_create: %m"); + + /* Single timer with 0.1s. */ + struct itimerspec its = + { + { .tv_sec = repeat ? sec : 0, .tv_nsec = repeat ? nsec : 0 }, + { .tv_sec = sec, .tv_nsec = nsec } + }; + r = timer_settime (timerid, 0, &its, NULL); + if (r == -1) + FAIL_EXIT1 ("timer_settime: %m"); + + return timerid; +} + +/* Disable the timer TIMER. */ +void +support_delete_timer (timer_t timer) +{ + int r = timer_delete (timer); + if (r == -1) + FAIL_EXIT1 ("timer_delete: %m"); + xsignal (SIGALRM, SIG_DFL); +} |