From ec381af90208a5675183202cf05078eac208edfb Mon Sep 17 00:00:00 2001 From: Rich Felker Date: Tue, 2 Aug 2011 21:11:36 -0400 Subject: unify and overhaul timed futex waits new features: - FUTEX_WAIT_BITSET op will be used for timed waits if available. this saves a call to clock_gettime. - error checking for the timespec struct is now inside __timedwait so it doesn't need to be duplicated everywhere. cond_timedwait still needs to duplicate it to avoid unlocking the mutex, though. - pushing and popping the cancellation handler is delegated to __timedwait, and cancellable/non-cancellable waits are unified. --- src/thread/__timedwait.c | 53 +++++++++++++++++++++++++++++++++++------------- 1 file changed, 39 insertions(+), 14 deletions(-) (limited to 'src/thread/__timedwait.c') diff --git a/src/thread/__timedwait.c b/src/thread/__timedwait.c index b1d3af23..931675eb 100644 --- a/src/thread/__timedwait.c +++ b/src/thread/__timedwait.c @@ -1,23 +1,48 @@ +#include #include #include #include "futex.h" #include "syscall.h" -int __timedwait(volatile int *addr, int val, clockid_t clk, const struct timespec *at, int priv) +static int do_wait(volatile int *addr, int val, clockid_t clk, const struct timespec *at, int cp, int priv) { - int r; - struct timespec to; - if (at) { - clock_gettime(clk, &to); - to.tv_sec = at->tv_sec - to.tv_sec; - if ((to.tv_nsec = at->tv_nsec - to.tv_nsec) < 0) { - to.tv_sec--; - to.tv_nsec += 1000000000; - } - if (to.tv_sec < 0) return ETIMEDOUT; + int r, flag = 0; + struct timespec to, *top=0; + + if (!at) goto notimeout; + if (at->tv_nsec >= 1000000000UL) + return EINVAL; + if (clk == CLOCK_REALTIME || clk == CLOCK_MONOTONIC) { + if (clk == CLOCK_REALTIME) flag = FUTEX_CLOCK_REALTIME; + if (cp) r = -__syscall_cp(SYS_futex, addr, FUTEX_WAIT_BITSET|flag, val, at, 0, -1); + else r = -__syscall(SYS_futex, addr, FUTEX_WAIT_BITSET|flag, val, at, 0, -1); + if (r != ENOSYS) goto done; } - if (priv) priv = 128; priv=0; - r = -__syscall(SYS_futex, (long)addr, FUTEX_WAIT | priv, val, at ? (long)&to : 0); - if (r == ETIMEDOUT || r == EINTR) return r; + if (clock_gettime(clk, &to)) return EINVAL; + to.tv_sec = at->tv_sec - to.tv_sec; + if ((to.tv_nsec = at->tv_nsec - to.tv_nsec) < 0) { + to.tv_sec--; + to.tv_nsec += 1000000000; + } + if (to.tv_sec < 0) return ETIMEDOUT; + top = &to; +notimeout: + if (cp) r = -__syscall_cp(SYS_futex, addr, FUTEX_WAIT, val, top); + else r = -__syscall(SYS_futex, addr, FUTEX_WAIT, val, top); +done: + if (r == EINTR || r == EINVAL || r == ETIMEDOUT) return r; return 0; } + +int __timedwait(volatile int *addr, int val, clockid_t clk, const struct timespec *at, void (*cleanup)(void *), void *arg, int priv) +{ + int r; + if (cleanup) { + pthread_cleanup_push(cleanup, arg); + r = do_wait(addr, val, clk, at, 1, priv); + pthread_cleanup_pop(0); + } else { + r = do_wait(addr, val, clk, at, 0, priv); + } + return r; +} -- cgit v1.2.1