| #include <mqueue.h> |
| #include <pthread.h> |
| #include <errno.h> |
| #include <sys/socket.h> |
| #include <signal.h> |
| #include <unistd.h> |
| #include <semaphore.h> |
| #include "syscall.h" |
| |
| struct args { |
| sem_t sem; |
| int sock; |
| mqd_t mqd; |
| int err; |
| const struct sigevent *sev; |
| }; |
| |
| static void *start(void *p) |
| { |
| struct args *args = p; |
| char buf[32]; |
| ssize_t n; |
| int s = args->sock; |
| void (*func)(union sigval) = args->sev->sigev_notify_function; |
| union sigval val = args->sev->sigev_value; |
| struct sigevent sev2; |
| static const char zeros[32]; |
| int err; |
| |
| sev2.sigev_notify = SIGEV_THREAD; |
| sev2.sigev_signo = s; |
| sev2.sigev_value.sival_ptr = (void *)&zeros; |
| |
| args->err = err = -__syscall(SYS_mq_notify, args->mqd, &sev2); |
| sem_post(&args->sem); |
| if (err) return 0; |
| |
| pthread_detach(pthread_self()); |
| n = recv(s, buf, sizeof(buf), MSG_NOSIGNAL|MSG_WAITALL); |
| close(s); |
| if (n==sizeof buf && buf[sizeof buf - 1] == 1) |
| func(val); |
| return 0; |
| } |
| |
| int mq_notify(mqd_t mqd, const struct sigevent *sev) |
| { |
| struct args args = { .sev = sev }; |
| pthread_attr_t attr; |
| pthread_t td; |
| int s; |
| int cs; |
| sigset_t allmask, origmask; |
| |
| if (!sev || sev->sigev_notify != SIGEV_THREAD) |
| return syscall(SYS_mq_notify, mqd, sev); |
| |
| s = socket(AF_NETLINK, SOCK_RAW|SOCK_CLOEXEC, 0); |
| if (s < 0) return -1; |
| args.sock = s; |
| args.mqd = mqd; |
| |
| if (sev->sigev_notify_attributes) attr = *sev->sigev_notify_attributes; |
| else pthread_attr_init(&attr); |
| pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_JOINABLE); |
| sem_init(&args.sem, 0, 0); |
| |
| sigfillset(&allmask); |
| pthread_sigmask(SIG_BLOCK, &allmask, &origmask); |
| if (pthread_create(&td, &attr, start, &args)) { |
| __syscall(SYS_close, s); |
| pthread_sigmask(SIG_SETMASK, &origmask, 0); |
| errno = EAGAIN; |
| return -1; |
| } |
| pthread_sigmask(SIG_SETMASK, &origmask, 0); |
| |
| pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs); |
| sem_wait(&args.sem); |
| sem_destroy(&args.sem); |
| |
| if (args.err) { |
| __syscall(SYS_close, s); |
| pthread_join(td, 0); |
| pthread_setcancelstate(cs, 0); |
| errno = args.err; |
| return -1; |
| } |
| |
| pthread_setcancelstate(cs, 0); |
| return 0; |
| } |