X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Frts%2FItimer.c;h=50be88dd799a68605bb14085b69b9d21db44e2c2;hb=3160a6546bf6e57d0d5ef7bc084fcbcb10297ff6;hp=cb7df627ed030c53946f5d86a336e646ac4a6a65;hpb=90a6918a3cb4901ecc64d810a6a4eb54d572c0bf;p=ghc-hetmet.git diff --git a/ghc/rts/Itimer.c b/ghc/rts/Itimer.c index cb7df62..50be88d 100644 --- a/ghc/rts/Itimer.c +++ b/ghc/rts/Itimer.c @@ -1,5 +1,4 @@ /* ----------------------------------------------------------------------------- - * $Id: Itimer.c,v 1.11 2000/03/20 09:42:49 andy Exp $ * * (c) The GHC Team, 1995-1999 * @@ -17,13 +16,11 @@ * Hence, we use the old-fashioned @setitimer@ that just about everyone seems * to support. So much for standards. */ - -#if !defined(_AIX) -# define NON_POSIX_SOURCE -#endif - #include "Rts.h" +#include "RtsFlags.h" +#include "Timer.h" #include "Itimer.h" +#include "Proftimer.h" #include "Schedule.h" /* As recommended in the autoconf manual */ @@ -38,191 +35,148 @@ # endif # endif -#if HAVE_WINDOWS_H -# include +#ifdef HAVE_SIGNAL_H +# include #endif - -lnat total_ticks = 0; -rtsBool do_prof_ticks = rtsFalse; -static -void -#if defined(mingw32_TARGET_OS) || (defined(cygwin32_TARGET_OS) && !defined(HAVE_SETITIMER)) -CALLBACK +/* Major bogosity: + * + * In the threaded RTS, we can't set the virtual timer because the + * thread which has the virtual timer might be sitting waiting for a + * capability, and the virtual timer only ticks in CPU time. + * + * So, possible solutions: + * + * (1) tick in realtime. Not very good, because this ticker is used for + * profiling, and this will give us unreliable time profiling + * results. Furthermore, this requires picking a single OS thread + * to be the timekeeper, which is a bad idea because the thread in + * question might just be making a temporary call into Haskell land. + * + * (2) save/restore the virtual timer around excursions into STG land. + * Sounds great, but I tried it and the resolution of the virtual timer + * isn't good enough (on Linux) - most of our excursions fall + * within the timer's resolution and we never make any progress. + * + * (3) have a virtual timer in every OS thread. Might be reasonable, + * because most of the time there is only ever one of these + * threads running, so it approximates a single virtual timer. + * But still quite bogus (and I got crashes when I tried this). + * + * For now, we're using (1), but this needs a better solution. --SDM + */ +#ifdef RTS_SUPPORTS_THREADS +#define ITIMER_FLAVOUR ITIMER_REAL +#define ITIMER_SIGNAL SIGALRM +#else +#define ITIMER_FLAVOUR ITIMER_VIRTUAL +#define ITIMER_SIGNAL SIGVTALRM #endif -handle_tick(int unused STG_UNUSED); - -/* ----------------------------------------------------------------------------- - Tick handler - - We use the ticker for two things: supporting threadDelay, and time - profiling. - - SMP note: this signal could be delivered to *any* thread. We have - to ensure that it doesn't matter which thread actually runs the - signal handler. - -------------------------------------------------------------------------- */ static -void -#if defined(mingw32_TARGET_OS) || (defined(cygwin32_TARGET_OS) && !defined(HAVE_SETITIMER)) -CALLBACK -#endif -handle_tick(int unused STG_UNUSED) +int +install_vtalrm_handler(TickProc handle_tick) { - total_ticks++; + struct sigaction action; -#ifdef PROFILING - if (do_prof_ticks == rtsTrue) { - CCS_TICK(CCCS); - } -#endif + action.sa_handler = handle_tick; + + sigemptyset(&action.sa_mask); + action.sa_flags = 0; - /* For threadDelay etc., see Select.c */ - ticks_since_select++; + return sigaction(ITIMER_SIGNAL, &action, NULL); } +int +startTicker(nat ms, TickProc handle_tick) +{ +# ifndef HAVE_SETITIMER + /* debugBelch("No virtual timer on this system\n"); */ + return -1; +# else + struct itimerval it; -/* - * Handling timer events under cygwin32 is not done with signal/setitimer. - * Instead of the two steps of first registering a signal handler to handle - * \tr{SIGVTALRM} and then start generating them via @setitimer()@, we use - * the Multimedia API (MM) and its @timeSetEvent@. (Internally, the MM API - * creates a separate thread that will notify the main thread of timer - * expiry). -- SOF 7/96 - * - * 11/98: if the cygwin DLL supports setitimer(), then use it instead. - */ + install_vtalrm_handler(handle_tick); -#if defined(mingw32_TARGET_OS) || (defined(cygwin32_TARGET_OS) && !defined(HAVE_SETITIMER)) + timestamp = getourtimeofday(); -/* - * Sigh - to avoid requiring anyone that wants to build ghc to have - * to augment the Win32 header files that comes with cygwinb20.1, - * include the missing MM API decls here inline. - * - * ToDo: check and remove these once the next version of cygwin is - * released. - */ -#define TIMERR_NOERROR 0 -#define TIMERR_NOCANDO 97 -#define TIME_PERIODIC 1 - -typedef UINT MMRESULT; -typedef void CALLBACK (*TIMECALLBACK) (UINT, UINT, DWORD, DWORD, DWORD); -typedef TIMECALLBACK *LPTIMECALLBACK; -MMRESULT STDCALL timeSetEvent(UINT, UINT, LPTIMECALLBACK, DWORD, UINT); -/* - vtalrm_handler is assigned and set up in Signals.c - - vtalrm_id (defined in Signals.c) holds - the system id for the current timer (used to - later block/kill it.) -*/ -extern nat vtalrm_id; -TIMECALLBACK *vtalrm_cback; - -nat -initialize_virtual_timer(nat ms) -{ -# ifdef PROFILING - /* On Win32 setups that don't have support for - setitimer(), we use the MultiMedia API's timer - support. - - As the delivery of ticks isn't free, we only - enable it if we really needed, i.e., when profiling. - (the RTS now also needs timer ticks to implement - threadDelay in non-profiling mode, but the pure - Win32 port doesn't support that.....yet.) - */ - unsigned int delay,vtalrm_id; - - delay = timeBeginPeriod(1); - if (delay == TIMERR_NOCANDO) { /* error of some sort. */ - return delay; - } - vtalrm_id = - timeSetEvent(ms, /* event every `delay' milliseconds. */ - 1, /* precision is within 5 millisecs. */ - (LPTIMECALLBACK)vtalrm_cback, - 0, - TIME_PERIODIC); + it.it_value.tv_sec = ms / 1000; + it.it_value.tv_usec = 1000 * (ms - (1000 * it.it_value.tv_sec)); + it.it_interval = it.it_value; + return (setitimer(ITIMER_FLAVOUR, &it, NULL)); # endif - return 0; } - -#else -nat -initialize_virtual_timer(nat ms) +int +stopTicker() { # ifndef HAVE_SETITIMER - /* fprintf(stderr, "No virtual timer on this system\n"); */ + /* debugBelch("No virtual timer on this system\n"); */ return -1; # else struct itimerval it; - - it.it_value.tv_sec = ms / 1000; - it.it_value.tv_usec = 1000 * (ms - (1000 * it.it_value.tv_sec)); + + it.it_value.tv_sec = 0; + it.it_value.tv_usec = 0; it.it_interval = it.it_value; - return (setitimer(ITIMER_VIRTUAL, &it, NULL)); + return (setitimer(ITIMER_FLAVOUR, &it, NULL)); # endif } -#endif /* !cygwin32_TARGET_OS */ - # if 0 /* This is a potential POSIX version */ -nat -initialize_virtual_timer(nat ms) +int +startTicker(nat ms) { struct sigevent se; struct itimerspec it; timer_t tid; + timestamp = getourtimeofday(); + se.sigev_notify = SIGEV_SIGNAL; - se.sigev_signo = SIGVTALRM; - se.sigev_value.sival_int = SIGVTALRM; + se.sigev_signo = ITIMER_SIGNAL; + se.sigev_value.sival_int = ITIMER_SIGNAL; if (timer_create(CLOCK_VIRTUAL, &se, &tid)) { barf("can't create virtual timer"); } it.it_value.tv_sec = ms / 1000; it.it_value.tv_nsec = 1000000 * (ms - 1000 * it.it_value.tv_sec); it.it_interval = it.it_value; - timer_settime(tid, TIMER_RELTIME, &it, NULL); + return timer_settime(tid, TIMER_RELTIME, &it, NULL); } -# endif -#if defined(mingw32_TARGET_OS) || (defined(cygwin32_TARGET_OS) && !defined(HAVE_SETITIMER)) int -install_vtalrm_handler(void) +stopTicker() { - vtalrm_cback = handle_tick; - return 0; -} - -#else -int -install_vtalrm_handler(void) -{ - struct sigaction action; - - action.sa_handler = handle_tick; + struct sigevent se; + struct itimerspec it; + timer_t tid; - sigemptyset(&action.sa_mask); - action.sa_flags = 0; + timestamp = getourtimeofday(); - return sigaction(SIGVTALRM, &action, NULL); + se.sigev_notify = SIGEV_SIGNAL; + se.sigev_signo = ITIMER_SIGNAL; + se.sigev_value.sival_int = ITIMER_SIGNAL; + if (timer_create(CLOCK_VIRTUAL, &se, &tid)) { + barf("can't create virtual timer"); + } + it.it_value.tv_sec = 0; + it.it_value.tv_nsec = 0; + it.it_interval = it.it_value; + return timer_settime(tid, TIMER_RELTIME, &it, NULL); } +# endif +#if 0 +/* Currently unused */ void block_vtalrm_signal(void) { sigset_t signals; sigemptyset(&signals); - sigaddset(&signals, SIGVTALRM); + sigaddset(&signals, ITIMER_SIGNAL); (void) sigprocmask(SIG_BLOCK, &signals, NULL); } @@ -233,16 +187,22 @@ unblock_vtalrm_signal(void) sigset_t signals; sigemptyset(&signals); - sigaddset(&signals, SIGVTALRM); + sigaddset(&signals, ITIMER_SIGNAL); (void) sigprocmask(SIG_UNBLOCK, &signals, NULL); } #endif -unsigned int +/* gettimeofday() takes around 1us on our 500MHz PIII. Since we're + * only calling it 50 times/s, it shouldn't have any great impact. + */ +nat getourtimeofday(void) { struct timeval tv; gettimeofday(&tv, (struct timezone *) NULL); - return (tv.tv_sec * 1000000 + tv.tv_usec); + // cast to nat because nat may be 64 bit when int is only 32 bit + return ((nat)tv.tv_sec * TICK_FREQUENCY + + (nat)tv.tv_usec * TICK_FREQUENCY / 1000000); } +