1#include <time.h>
  2#include <setjmp.h>
  3#include <limits.h>
  4#include "pthread_impl.h"
  5#include "atomic.h"
  6
  7struct ksigevent {
  8	union sigval sigev_value;
  9	int sigev_signo;
 10	int sigev_notify;
 11	int sigev_tid;
 12};
 13
 14struct start_args {
 15	pthread_barrier_t b;
 16	struct sigevent *sev;
 17};
 18
 19static void dummy_0()
 20{
 21}
 22weak_alias(dummy_0, __pthread_tsd_run_dtors);
 23
 24static void cleanup_fromsig(void *p)
 25{
 26	pthread_t self = __pthread_self();
 27	__pthread_tsd_run_dtors();
 28	self->cancel = 0;
 29	self->cancelbuf = 0;
 30	self->canceldisable = 0;
 31	self->cancelasync = 0;
 32	__reset_tls();
 33	longjmp(p, 1);
 34}
 35
 36static void *start(void *arg)
 37{
 38	pthread_t self = __pthread_self();
 39	struct start_args *args = arg;
 40	jmp_buf jb;
 41
 42	void (*notify)(union sigval) = args->sev->sigev_notify_function;
 43	union sigval val = args->sev->sigev_value;
 44
 45	pthread_barrier_wait(&args->b);
 46	if (self->cancel)
 47		return 0;
 48	for (;;) {
 49		siginfo_t si;
 50		while (sigwaitinfo(SIGTIMER_SET, &si) < 0);
 51		if (si.si_code == SI_TIMER && !setjmp(jb)) {
 52			pthread_cleanup_push(cleanup_fromsig, jb);
 53			notify(val);
 54			pthread_cleanup_pop(1);
 55		}
 56		if (self->timer_id < 0) break;
 57	}
 58	__syscall(SYS_timer_delete, self->timer_id & INT_MAX);
 59	return 0;
 60}
 61
 62int timer_create(clockid_t clk, struct sigevent *restrict evp, timer_t *restrict res)
 63{
 64	static volatile int init = 0;
 65	pthread_t td;
 66	pthread_attr_t attr;
 67	int r;
 68	struct start_args args;
 69	struct ksigevent ksev, *ksevp=0;
 70	int timerid;
 71	sigset_t set;
 72
 73	switch (evp ? evp->sigev_notify : SIGEV_SIGNAL) {
 74	case SIGEV_NONE:
 75	case SIGEV_SIGNAL:
 76	case SIGEV_THREAD_ID:
 77		if (evp) {
 78			ksev.sigev_value = evp->sigev_value;
 79			ksev.sigev_signo = evp->sigev_signo;
 80			ksev.sigev_notify = evp->sigev_notify;
 81			if (evp->sigev_notify == SIGEV_THREAD_ID)
 82				ksev.sigev_tid = evp->sigev_notify_thread_id;
 83			else
 84				ksev.sigev_tid = 0;
 85			ksevp = &ksev;
 86		}
 87		if (syscall(SYS_timer_create, clk, ksevp, &timerid) < 0)
 88			return -1;
 89		*res = (void *)(intptr_t)timerid;
 90		break;
 91	case SIGEV_THREAD:
 92		if (!init) {
 93			struct sigaction sa = { .sa_handler = SIG_DFL };
 94			__libc_sigaction(SIGTIMER, &sa, 0);
 95			a_store(&init, 1);
 96		}
 97		if (evp->sigev_notify_attributes)
 98			attr = *evp->sigev_notify_attributes;
 99		else
100			pthread_attr_init(&attr);
101		pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
102		pthread_barrier_init(&args.b, 0, 2);
103		args.sev = evp;
104
105		__block_app_sigs(&set);
106		__syscall(SYS_rt_sigprocmask, SIG_BLOCK, SIGTIMER_SET, 0, _NSIG/8);
107		r = pthread_create(&td, &attr, start, &args);
108		__restore_sigs(&set);
109		if (r) {
110			errno = r;
111			return -1;
112		}
113
114		ksev.sigev_value.sival_ptr = 0;
115		ksev.sigev_signo = SIGTIMER;
116		ksev.sigev_notify = SIGEV_THREAD_ID;
117		ksev.sigev_tid = td->tid;
118		if (syscall(SYS_timer_create, clk, &ksev, &timerid) < 0) {
119			timerid = -1;
120			td->cancel = 1;
121		}
122		td->timer_id = timerid;
123		pthread_barrier_wait(&args.b);
124		if (timerid < 0) return -1;
125		*res = (void *)(INTPTR_MIN | (uintptr_t)td>>1);
126		break;
127	default:
128		errno = EINVAL;
129		return -1;
130	}
131
132	return 0;
133}