From ea4d8939af7204bc6ca76144354ef4d70189eaa3 Mon Sep 17 00:00:00 2001 From: Harald Welte Date: Sun, 3 Dec 2017 16:13:39 +0100 Subject: Add osmo_timerfd_* functions for osmo_fd-wrapped timerfd Linux offers file descriptor based periodic (interval) timers, which can achieve a higher precision than our userspace based timers and which can be slave'd to CLOCK_MONOTINIC or other clock sources. Let's add some code for osmo_fd wrapped versions that integrate well with our select() abstraction. The code has been used in osmo-bts-trx since June 2017 (change-id I51b19adde14ebb7ef3bb863d45e06243c323e22e), and I'm just renaming and moving it to libosmocore here. After a merge, the osmo-bts implementations can be removed in favor if this one. Change-Id: Ibeffba7c997252c003723bcd5d14122c4ded2fe7 --- src/select.c | 66 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 66 insertions(+) (limited to 'src') diff --git a/src/select.c b/src/select.c index 1c62e011..0b115c61 100644 --- a/src/select.c +++ b/src/select.c @@ -30,6 +30,7 @@ #include #include #include +#include #include #include @@ -270,6 +271,71 @@ struct osmo_fd *osmo_fd_get_by_fd(int fd) return NULL; } +#ifdef HAVE_SYS_TIMERFD_H +#include + +/*! disable the osmocom-wrapped timerfd */ +int osmo_timerfd_disable(struct osmo_fd *ofd) +{ + const struct itimerspec its_null = { + .it_value = { 0, 0 }, + .it_interval = { 0, 0 }, + }; + return timerfd_settime(ofd->fd, 0, &its_null, NULL); +} + +/*! schedule the osmcoom-wrapped timerfd to occur first at \a first, then periodically at \a interval + * \param[in] ofd Osmocom wrapped timerfd + * \param[in] first Relative time at which the timer should first execute (NULL = \a interval) + * \param[in] interval Time interval at which subsequent timer shall fire + * \returns 0 on success; negative on error */ +int osmo_timerfd_schedule(struct osmo_fd *ofd, const struct timespec *first, + const struct timespec *interval) +{ + struct itimerspec its; + + if (ofd->fd < 0) + return -EINVAL; + + /* first expiration */ + if (first) + its.it_value = *first; + else + its.it_value = *interval; + /* repeating interval */ + its.it_interval = *interval; + + return timerfd_settime(ofd->fd, 0, &its, NULL); +} + +/*! setup osmocom-wrapped timerfd + * \param[inout] ofd Osmocom-wrapped timerfd on which to operate + * \param[in] cb Call-back function called when timerfd becomes readable + * \param[in] data Opaque data to be passed on to call-back + * \returns 0 on success; negative on error + * + * We simply initialize the data structures here, but do not yet + * schedule the timer. + */ +int osmo_timerfd_setup(struct osmo_fd *ofd, int (*cb)(struct osmo_fd *, unsigned int), void *data) +{ + ofd->cb = cb; + ofd->data = data; + ofd->when = BSC_FD_READ; + + if (ofd->fd < 0) { + ofd->fd = timerfd_create(CLOCK_MONOTONIC, TFD_NONBLOCK); + if (ofd->fd < 0) + return ofd->fd; + + osmo_fd_register(ofd); + } + return 0; +} + +#endif /* HAVE_SYS_TIMERFD_H */ + + /*! @} */ #endif /* _HAVE_SYS_SELECT_H */ -- cgit v1.2.3