libc-top-half/musl/src/aio/lio_listio.c

   1 #include <aio.h>
   2 #include <errno.h>
   3 #include <unistd.h>
   4 #include <string.h>
   5 #include "pthread_impl.h"
   6
   7 struct lio_state {
   8         struct sigevent *sev;
   9         int cnt;
  10         struct aiocb *cbs[];
  11 };
  12
  13 static int lio_wait(struct lio_state *st)
  14 {
  15         int i, err, got_err = 0;
  16         int cnt = st->cnt;
  17         struct aiocb **cbs = st->cbs;
  18
  19         for (;;) {
  20                 for (i=0; i<cnt; i++) {
  21                         if (!cbs[i]) continue;
  22                         err = aio_error(cbs[i]);
  23                         if (err==EINPROGRESS)
  24                                 break;
  25                         if (err) got_err=1;
  26                         cbs[i] = 0;
  27                 }
  28                 if (i==cnt) {
  29                         if (got_err) {
  30                                 errno = EIO;
  31                                 return -1;
  32                         }
  33                         return 0;
  34                 }
  35                 if (aio_suspend((void *)cbs, cnt, 0))
  36                         return -1;
  37         }
  38 }
  39
  40 static void notify_signal(struct sigevent *sev)
  41 {
  42         siginfo_t si = {
  43                 .si_signo = sev->sigev_signo,
  44                 .si_value = sev->sigev_value,
  45                 .si_code = SI_ASYNCIO,
  46                 .si_pid = getpid(),
  47                 .si_uid = getuid()
  48         };
  49         __syscall(SYS_rt_sigqueueinfo, si.si_pid, si.si_signo, &si);
  50 }
  51
  52 static void *wait_thread(void *p)
  53 {
  54         struct lio_state *st = p;
  55         struct sigevent *sev = st->sev;
  56         lio_wait(st);
  57         free(st);
  58         switch (sev->sigev_notify) {
  59         case SIGEV_SIGNAL:
  60                 notify_signal(sev);
  61                 break;
  62         case SIGEV_THREAD:
  63                 sev->sigev_notify_function(sev->sigev_value);
  64                 break;
  65         }
  66         return 0;
  67 }
  68
  69 int lio_listio(int mode, struct aiocb *restrict const *restrict cbs, int cnt, struct sigevent *restrict sev)
  70 {
  71         int i, ret;
  72         struct lio_state *st=0;
  73
  74         if (cnt < 0) {
  75                 errno = EINVAL;
  76                 return -1;
  77         }
  78
  79         if (mode == LIO_WAIT || (sev && sev->sigev_notify != SIGEV_NONE)) {
  80                 if (!(st = malloc(sizeof *st + cnt*sizeof *cbs))) {
  81                         errno = EAGAIN;
  82                         return -1;
  83                 }
  84                 st->cnt = cnt;
  85                 st->sev = sev;
  86                 memcpy(st->cbs, (void*) cbs, cnt*sizeof *cbs);
  87         }
  88
  89         for (i=0; i<cnt; i++) {
  90                 if (!cbs[i]) continue;
  91                 switch (cbs[i]->aio_lio_opcode) {
  92                 case LIO_READ:
  93                         ret = aio_read(cbs[i]);
  94                         break;
  95                 case LIO_WRITE:
  96                         ret = aio_write(cbs[i]);
  97                         break;
  98                 default:
  99                         continue;
 100                 }
 101                 if (ret) {
 102                         free(st);
 103                         errno = EAGAIN;
 104                         return -1;
 105                 }
 106         }
 107
 108         if (mode == LIO_WAIT) {
 109                 ret = lio_wait(st);
 110                 free(st);
 111                 return ret;
 112         }
 113
 114         if (st) {
 115                 pthread_attr_t a;
 116                 sigset_t set;
 117                 pthread_t td;
 118
 119                 if (sev->sigev_notify == SIGEV_THREAD) {
 120                         if (sev->sigev_notify_attributes)
 121                                 a = *sev->sigev_notify_attributes;
 122                         else
 123                                 pthread_attr_init(&a);
 124                 } else {
 125                         pthread_attr_init(&a);
 126                         pthread_attr_setstacksize(&a, PAGE_SIZE);
 127                         pthread_attr_setguardsize(&a, 0);
 128                 }
 129                 pthread_attr_setdetachstate(&a, PTHREAD_CREATE_DETACHED);
 130                 sigfillset(&set);
 131                 pthread_sigmask(SIG_BLOCK, &set, &set);
 132                 if (pthread_create(&td, &a, wait_thread, st)) {
 133                         free(st);
 134                         errno = EAGAIN;
 135                         return -1;
 136                 }
 137                 pthread_sigmask(SIG_SETMASK, &set, 0);
 138         }
 139
 140         return 0;
 141 }
 142
 143 weak_alias(lio_listio, lio_listio64);