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path: root/src/thread/__timedwait.c
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2011-08-07simplify unified timed wait code, drop support for newer methodRich Felker1-31/+28
the new absolute-time-based wait kernelside was hard to get right and basically just code duplication. it could only improve "performance" when waiting, and even then, the improvement was just slight drop in cpu usage during a wait. actually, with vdso clock_gettime, the "old" way will be even faster than the "new" way if the time has already expired, since it will not invoke any syscalls. it can determine entirely in userspace that it needs to return ETIMEDOUT.
2011-08-03timedwait: play it safe for nowRich Felker1-1/+1
it's unclear whether EINVAL or ENOSYS is used when the operation is not supported, so check for both...
2011-08-02correctly handle old kernels without FUTEX_WAIT_BITSETRich Felker1-1/+1
futex returns EINVAL, not ENOSYS, when op is not supported. unfortunately this looks just like EINVAL from other causes, and we end up running the fallback code and getting EINVAL again. fortunately this case should be rare since correct code should not generate EINVAL anyway.
2011-08-02unify and overhaul timed futex waitsRich Felker1-14/+39
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.
2011-04-17overhaul pthread cancellationRich Felker1-1/+1
this patch improves the correctness, simplicity, and size of cancellation-related code. modulo any small errors, it should now be completely conformant, safe, and resource-leak free. the notion of entering and exiting cancellation-point context has been completely eliminated and replaced with alternative syscall assembly code for cancellable syscalls. the assembly is responsible for setting up execution context information (stack pointer and address of the syscall instruction) which the cancellation signal handler can use to determine whether the interrupted code was in a cancellable state. these changes eliminate race conditions in the previous generation of cancellation handling code (whereby a cancellation request received just prior to the syscall would not be processed, leaving the syscall to block, potentially indefinitely), and remedy an issue where non-cancellable syscalls made from signal handlers became cancellable if the signal handler interrupted a cancellation point. x86_64 asm is untested and may need a second try to get it right.
2011-04-06consistency: change all remaining syscalls to use SYS_ rather than __NR_ prefixRich Felker1-1/+1
2011-04-06major semaphore improvements (performance and correctness)Rich Felker1-1/+1
1. make sem_[timed]wait interruptible by signals, per POSIX 2. keep a waiter count in order to avoid unnecessary futex wake syscalls
2011-03-19if returning errno value directly from a syscall, we need to negate it.Rich Felker1-1/+1
2011-03-19syscall overhaul part two - unify public and internal syscall interfaceRich Felker1-2/+1
with this patch, the syscallN() functions are no longer needed; a variadic syscall() macro allows syscalls with anywhere from 0 to 6 arguments to be made with a single macro name. also, manually casting each non-integer argument with (long) is no longer necessary; the casts are hidden in the macros. some source files which depended on being able to define the old macro SYSCALL_RETURNS_ERRNO have been modified to directly use __syscall() instead of syscall(). references to SYSCALL_SIGSET_SIZE and SYSCALL_LL have also been changed. x86_64 has not been tested, and may need a follow-up commit to fix any minor bugs/oversights.
2011-03-16don't expose EAGAIN, etc. from timed futex wait to callerRich Felker1-1/+4
2011-02-12initial check-in, version 0.5.0v0.5.0Rich Felker1-0/+21