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 volatile int b; 16 struct sigevent *sev; 17}; 18 19/* 20* barrier val: 21* 0: init state 22* 2: child thread arrive: when child thread is the first thread to arrive, will wait, otherwise, will wake 23* 3: parent thread arrive: when parent thread is the first thread to arrive, will wait, otherwise, will wake 24* 4: parent thread should wait for the child to finish synchronizing (state: CHILD_DONE) 25* 5: child thread done 26*/ 27enum ThreadState { 28 INIT_STATE = 0, 29 CHILD_ARRIVE = 2, 30 PARENT_ARRIVE, 31 PARENT_WAIT, 32 CHILD_DONE, 33}; 34 35static void dummy_0() 36{ 37} 38weak_alias(dummy_0, __pthread_tsd_run_dtors); 39 40static void cleanup_fromsig(void *p) 41{ 42 pthread_t self = __pthread_self(); 43 __pthread_tsd_run_dtors(); 44#ifdef FEATURE_PTHREAD_CANCEL 45 self->cancel = 0; 46 self->canceldisable = 0; 47 self->cancelasync = 0; 48#endif 49 self->cancelbuf = 0; 50 __reset_tls(); 51 longjmp(p, 1); 52} 53 54static void __child_sync(volatile int *barrier) 55{ 56 if (a_swap(barrier, CHILD_ARRIVE) == INIT_STATE) { 57 __wait(barrier, 0, CHILD_ARRIVE, 0); 58 } else { 59 __wake(barrier, 1, 0); 60 } 61 62 a_swap(barrier, CHILD_DONE); 63 __wake(barrier, 1, 0); 64} 65 66static void __parent_sync(volatile int *barrier) 67{ 68 if (a_swap(barrier, PARENT_ARRIVE) == CHILD_ARRIVE) { 69 __wake(barrier, 1, 0); 70 } else { 71 __wait(barrier, 0, PARENT_ARRIVE, 0); 72 } 73 74 if (a_swap(barrier, PARENT_WAIT) != CHILD_DONE) { 75 __wait(barrier, 0, PARENT_WAIT, 0); 76 } 77} 78 79static void *start(void *arg) 80{ 81 pthread_t self = __pthread_self(); 82 struct start_args *args = arg; 83 jmp_buf jb; 84 85 void (*notify)(union sigval) = args->sev->sigev_notify_function; 86 union sigval val = args->sev->sigev_value; 87 88 __child_sync(&args->b); 89#ifdef FEATURE_PTHREAD_CANCEL 90 if (self->cancel) 91 return 0; 92#endif 93 for (;;) { 94 siginfo_t si; 95 while (sigwaitinfo(SIGTIMER_SET, &si) < 0); 96 if (si.si_code == SI_TIMER && !setjmp(jb)) { 97#ifndef HWASAN_REMOVE_CLEANUP 98 pthread_cleanup_push(cleanup_fromsig, jb); 99#endif 100 notify(val); 101#ifndef HWASAN_REMOVE_CLEANUP 102 pthread_cleanup_pop(1); 103#endif 104 } 105 if (self->timer_id < 0) break; 106 } 107 __syscall(SYS_timer_delete, self->timer_id & INT_MAX); 108 return 0; 109} 110 111int timer_create(clockid_t clk, struct sigevent *restrict evp, timer_t *restrict res) 112{ 113 static volatile int init = 0; 114 pthread_t td; 115 pthread_attr_t attr; 116 int r; 117 struct start_args args; 118 struct ksigevent ksev, *ksevp=0; 119 int timerid; 120 sigset_t set; 121 122 switch (evp ? evp->sigev_notify : SIGEV_SIGNAL) { 123 case SIGEV_NONE: 124 case SIGEV_SIGNAL: 125 case SIGEV_THREAD_ID: 126 if (evp) { 127 ksev.sigev_value = evp->sigev_value; 128 ksev.sigev_signo = evp->sigev_signo; 129 ksev.sigev_notify = evp->sigev_notify; 130 if (evp->sigev_notify == SIGEV_THREAD_ID) 131 ksev.sigev_tid = evp->sigev_notify_thread_id; 132 else 133 ksev.sigev_tid = 0; 134 ksevp = &ksev; 135 } 136 if (syscall(SYS_timer_create, clk, ksevp, &timerid) < 0) 137 return -1; 138 *res = (void *)(intptr_t)timerid; 139 break; 140 case SIGEV_THREAD: 141 if (!init) { 142 struct sigaction sa = { .sa_handler = SIG_DFL }; 143 __libc_sigaction(SIGTIMER, &sa, 0); 144 a_store(&init, 1); 145 } 146 if (evp->sigev_notify_attributes) 147 attr = *evp->sigev_notify_attributes; 148 else 149 pthread_attr_init(&attr); 150 pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED); 151 a_store(&args.b, 0); 152 args.sev = evp; 153 154 __block_app_sigs(&set); 155 __syscall(SYS_rt_sigprocmask, SIG_BLOCK, SIGTIMER_SET, 0, _NSIG/8); 156 r = pthread_create(&td, &attr, start, &args); 157 __restore_sigs(&set); 158 if (r) { 159 errno = r; 160 return -1; 161 } 162 163 ksev.sigev_value.sival_ptr = 0; 164 ksev.sigev_signo = SIGTIMER; 165 ksev.sigev_notify = SIGEV_THREAD_ID; 166 ksev.sigev_tid = td->tid; 167 if (syscall(SYS_timer_create, clk, &ksev, &timerid) < 0) { 168 timerid = -1; 169#ifdef FEATURE_PTHREAD_CANCEL 170 td->cancel = 1; 171#endif 172 } 173 td->timer_id = timerid; 174 __parent_sync(&args.b); 175 if (timerid < 0) return -1; 176 *res = (void *)(INTPTR_MIN | (uintptr_t)td>>1); 177 break; 178 default: 179 errno = EINVAL; 180 return -1; 181 } 182 183 return 0; 184} 185