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path: root/src/time/timer_create.c
AgeCommit message (Collapse)AuthorLines
2011-08-12more efficient signal blocking for timer threadsRich Felker-4/+4
due to the barrier, it's safe just to block signals in the new thread, rather than blocking and unblocking in the parent thread.
2011-08-11normal exit from timer thread should run dtors, restore cancel stateRich Felker-1/+1
2011-08-11block signals in timer threadsRich Felker-0/+4
if a timer thread leaves signals unblocked, any future attempt by the main thread to prevent the process from being terminated by blocking signals will fail, since the signal can still be delivered to the timer thread.
2011-05-07optimize compound-literal sigset_t's not to contain useless hurd bitsRich Felker-1/+1
2011-05-07overhaul implementation-internal signal protectionsRich Felker-2/+1
the new approach relies on the fact that the only ways to create sigset_t objects without invoking UB are to use the sig*set() functions, or from the masks returned by sigprocmask, sigaction, etc. or in the ucontext_t argument to a signal handler. thus, as long as sigfillset and sigaddset avoid adding the "protected" signals, there is no way the application will ever obtain a sigset_t including these bits, and thus no need to add the overhead of checking/clearing them when sigprocmask or sigaction is called. note that the old code actually *failed* to remove the bits from sa_mask when sigaction was called. the new implementations are also significantly smaller, simpler, and faster due to ignoring the useless "GNU HURD signals" 65-1024, which are not used and, if there's any sanity in the world, never will be used.
2011-04-14use a separate signal from SIGCANCEL for SIGEV_THREAD timersRich Felker-7/+25
otherwise we cannot support an application's desire to use asynchronous cancellation within the callback function. this change also slightly debloats pthread_create.c.
2011-04-09run pthread tsd destructors when a timer thread pretends to exitRich Felker-0/+6
2011-04-09greatly improve SIGEV_THREAD timersRich Felker-14/+14
calling pthread_exit from, or pthread_cancel on, the timer callback thread will no longer destroy the timer.
2011-04-06fix signal-based timers with null sigevent argumentRich Felker-19/+14
since timer_create is no longer allocating a structure for the timer_t and simply using the kernel timer id, it was impossible to specify the timer_t as the argument to the signal handler. the solution is to pass the null sigevent pointer on to the kernel, rather than filling it in userspace, so that the kernel does the right thing. however, that precludes the clever timerid-versus-threadid encoding we were doing. instead, just assume timerids are below 1M and thread pointers are above 1M. (in perspective: timerids are sequentially allocated and seem limited to 32k, and thread pointers are at roughly 3G.)
2011-04-03timer threads should sleep and stay asleep... a long timeRich Felker-1/+1
2011-04-03revert to deleting kernel-level timer from cancellation handlerRich Felker-0/+8
this is necessary in order to avoid breaking timer_getoverrun in the last run of the timer event handler, if it has not yet finished.
2011-04-03simplify calling of timer signal handlerRich Felker-3/+1
2011-03-30avoid all malloc/free in timer creation/destructionRich Felker-20/+4
instead of allocating a userspace structure for signal-based timers, simply use the kernel timer id. we use the fact that thread pointers will always be zero in the low bit (actually more) to encode integer timerid values as pointers. also, this change ensures that the timer_destroy syscall has completed before the library timer_destroy function returns, in case it matters.
2011-03-30optimize timer creation and possibly protect against some minor racesRich Felker-14/+19
the major idea of this patch is not to depend on having the timer pointer delivered to the signal handler, and instead use the thread pointer to get the callback function address and argument. this way, the parent thread can make the timer_create syscall while the child thread is starting, and it should never have to block waiting for the barrier.
2011-03-29reorder timer initialization so that timer_create does not depend on freeRich Felker-8/+16
this allows small programs which only create times, but never delete them, to use simple_malloc instead of the full malloc.
2011-03-29implement POSIX timersRich Felker-0/+110
this implementation is superior to the glibc/nptl implementation, in that it gives true realtime behavior. there is no risk of timer expiration events being lost due to failed thread creation or failed malloc, because the thread is created as time creation time, and reused until the timer is deleted.