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Diffstat (limited to 'src/cmd/ksh93/sh/timers.c')
| -rw-r--r-- | src/cmd/ksh93/sh/timers.c | 248 |
1 files changed, 248 insertions, 0 deletions
diff --git a/src/cmd/ksh93/sh/timers.c b/src/cmd/ksh93/sh/timers.c new file mode 100644 index 0000000..d9ace52 --- /dev/null +++ b/src/cmd/ksh93/sh/timers.c @@ -0,0 +1,248 @@ +/*********************************************************************** +* * +* This software is part of the ast package * +* Copyright (c) 1982-2011 AT&T Intellectual Property * +* and is licensed under the * +* Eclipse Public License, Version 1.0 * +* by AT&T Intellectual Property * +* * +* A copy of the License is available at * +* http://www.eclipse.org/org/documents/epl-v10.html * +* (with md5 checksum b35adb5213ca9657e911e9befb180842) * +* * +* Information and Software Systems Research * +* AT&T Research * +* Florham Park NJ * +* * +* David Korn <dgk@research.att.com> * +* * +***********************************************************************/ +#pragma prototyped + +#include <ast.h> +#include <sig.h> +#include <error.h> +#include "fault.h" +#include "defs.h" +#include "FEATURE/sigfeatures" +#include "FEATURE/time" + +typedef struct _timer +{ + double wakeup; + double incr; + struct _timer *next; + void (*action)(void*); + void *handle; +} Timer_t; + +#define IN_ADDTIMEOUT 1 +#define IN_SIGALRM 2 +#define DEFER_SIGALRM 4 +#define SIGALRM_CALL 8 + +static Timer_t *tptop, *tpmin, *tpfree; +static char time_state; + +static double getnow(void) +{ + register double now; +#ifdef timeofday + struct timeval tp; + timeofday(&tp); + now = tp.tv_sec + 1.e-6*tp.tv_usec; + +#else + now = (double)time((time_t*)0); +#endif /* timeofday */ + return(now+.001); +} + +/* + * set an alarm for <t> seconds + */ +static double setalarm(register double t) +{ +#if defined(_lib_setitimer) && defined(ITIMER_REAL) + struct itimerval tnew, told; + tnew.it_value.tv_sec = t; + tnew.it_value.tv_usec = 1.e6*(t- (double)tnew.it_value.tv_sec); + if(t && tnew.it_value.tv_sec==0 && tnew.it_value.tv_usec<1000) + tnew.it_value.tv_usec = 1000; + tnew.it_interval.tv_sec = 0; + tnew.it_interval.tv_usec = 0; + if(setitimer(ITIMER_REAL,&tnew,&told) < 0) + errormsg(SH_DICT,ERROR_system(1),e_alarm); + t = told.it_value.tv_sec + 1.e-6*told.it_value.tv_usec; +#else + unsigned seconds = (unsigned)t; + if(t && seconds<1) + seconds=1; + t = (double)alarm(seconds); +#endif + return(t); +} + +/* signal handler for alarm call */ +static void sigalrm(int sig) +{ + register Timer_t *tp, *tplast, *tpold, *tpnext; + double now; + static double left; + NOT_USED(sig); + left = 0; + if(time_state&SIGALRM_CALL) + time_state &= ~SIGALRM_CALL; + else if(alarm(0)) + sh_fault(SIGALRM|SH_TRAP); + if(time_state) + { + if(time_state&IN_ADDTIMEOUT) + time_state |= DEFER_SIGALRM; + errno = EINTR; + return; + } + time_state |= IN_SIGALRM; + sigrelease(SIGALRM); + while(1) + { + now = getnow(); + tpold = tpmin = 0; + for(tplast=0,tp=tptop; tp; tp=tpnext) + { + tpnext = tp->next; + if(tp->action) + { + if(tp->wakeup <=now) + { + if(!tpold || tpold->wakeup>tp->wakeup) + tpold = tp; + } + else + { + if(!tpmin || tpmin->wakeup>tp->wakeup) + tpmin=tp; + } + tplast = tp; + } + else + { + if(tplast) + tplast->next = tp->next; + else + tptop = tp->next; + tp->next = tpfree; + tpfree = tp; + } + } + if((tp=tpold) && tp->incr) + { + while((tp->wakeup += tp->incr) <= now); + if(!tpmin || tpmin->wakeup>tp->wakeup) + tpmin=tp; + } + if(tpmin && (left==0 || (tp && tpmin->wakeup < (now+left)))) + { + if(left==0) + signal(SIGALRM,sigalrm); + left = setalarm(tpmin->wakeup-now); + if(left && (now+left) < tpmin->wakeup) + setalarm(left); + else + left=tpmin->wakeup-now; + } + if(tp) + { + void (*action)(void*); + action = tp->action; + if(!tp->incr) + tp->action = 0; + errno = EINTR; + time_state &= ~IN_SIGALRM; + (*action)(tp->handle); + time_state |= IN_SIGALRM; + } + else + break; + } + if(!tpmin) + signal(SIGALRM,(sh.sigflag[SIGALRM]&SH_SIGFAULT)?sh_fault:SIG_DFL); + time_state &= ~IN_SIGALRM; + errno = EINTR; +} + +static void oldalrm(void *handle) +{ + Handler_t fn = *(Handler_t*)handle; + free(handle); + (*fn)(SIGALRM); +} + +void *sh_timeradd(unsigned long msec,int flags,void (*action)(void*),void *handle) +{ + register Timer_t *tp; + double t; + Handler_t fn; + t = ((double)msec)/1000.; + if(t<=0 || !action) + return((void*)0); + if(tp=tpfree) + tpfree = tp->next; + else if(!(tp=(Timer_t*)malloc(sizeof(Timer_t)))) + return((void*)0); + tp->wakeup = getnow() + t; + tp->incr = (flags?t:0); + tp->action = action; + tp->handle = handle; + time_state |= IN_ADDTIMEOUT; + tp->next = tptop; + tptop = tp; + if(!tpmin || tp->wakeup < tpmin->wakeup) + { + tpmin = tp; + fn = (Handler_t)signal(SIGALRM,sigalrm); + if((t= setalarm(t))>0 && fn && fn!=(Handler_t)sigalrm) + { + Handler_t *hp = (Handler_t*)malloc(sizeof(Handler_t)); + if(hp) + { + *hp = fn; + sh_timeradd((long)(1000*t), 0, oldalrm, (void*)hp); + } + } + tp = tptop; + } + else if(tpmin && !tpmin->action) + time_state |= DEFER_SIGALRM; + time_state &= ~IN_ADDTIMEOUT; + if(time_state&DEFER_SIGALRM) + { + time_state=SIGALRM_CALL; + sigalrm(SIGALRM); + if(tp!=tptop) + tp=0; + } + return((void*)tp); +} + +/* + * delete timer <tp>. If <tp> is NULL, all timers are deleted + */ +void timerdel(void *handle) +{ + register Timer_t *tp = (Timer_t*)handle; + if(tp) + tp->action = 0; + else + { + for(tp=tptop; tp; tp=tp->next) + tp->action = 0; + if(tpmin) + { + tpmin = 0; + setalarm((double)0); + } + signal(SIGALRM,(sh.sigflag[SIGALRM]&SH_SIGFAULT)?sh_fault:SIG_DFL); + } +} + |