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 #include "libc.h"
   7
   8 struct lio_state {
   9         struct sigevent *sev;
  10         int cnt;
  11         struct aiocb *cbs[];
  12 };
  13
  14 static int lio_wait(struct lio_state *st)
  15 {
  16         int i, err, got_err = 0;
  17         int cnt = st->cnt;
  18         struct aiocb **cbs = st->cbs;
  19
  20         for (;;) {
  21                 for (i=0; i<cnt; i++) {
  22                         if (!cbs[i]) continue;
  23                         err = aio_error(cbs[i]);
  24                         if (err==EINPROGRESS)
  25                                 break;
  26                         if (err) got_err=1;
  27                         cbs[i] = 0;
  28                 }
  29                 if (i==cnt) {
  30                         if (got_err) {
  31                                 errno = EIO;
  32                                 return -1;
  33                         }
  34                         return 0;
  35                 }
  36                 if (aio_suspend((void *)cbs, cnt, 0))
  37                         return -1;
  38         }
  39 }
  40
  41 static void notify_signal(struct sigevent *sev)
  42 {
  43         siginfo_t si = {
  44                 .si_signo = sev->sigev_signo,
  45                 .si_value = sev->sigev_value,
  46                 .si_code = SI_ASYNCIO,
  47                 .si_pid = getpid(),
  48                 .si_uid = getuid()
  49         };
  50         __syscall(SYS_rt_sigqueueinfo, si.si_pid, si.si_signo, &si);
  51 }
  52
  53 static void *wait_thread(void *p)
  54 {
  55         struct lio_state *st = p;
  56         struct sigevent *sev = st->sev;
  57         lio_wait(st);
  58         free(st);
  59         switch (sev->sigev_notify) {
  60         case SIGEV_SIGNAL:
  61                 notify_signal(sev);
  62                 break;
  63         case SIGEV_THREAD:
  64                 sev->sigev_notify_function(sev->sigev_value);
  65                 break;
  66         }
  67         return 0;
  68 }
  69
  70 int lio_listio(int mode, struct aiocb *restrict const *restrict cbs, int cnt, struct sigevent *restrict sev)
  71 {
  72         int i, ret;
  73         struct lio_state *st=0;
  74
  75         if (cnt < 0) {
  76                 errno = EINVAL;
  77                 return -1;
  78         }
  79
  80         if (mode == LIO_WAIT || (sev && sev->sigev_notify != SIGEV_NONE)) {
  81                 if (!(st = malloc(sizeof *st + cnt*sizeof *cbs))) {
  82                         errno = EAGAIN;
  83                         return -1;
  84                 }
  85                 st->cnt = cnt;
  86                 st->sev = sev;
  87                 memcpy(st->cbs, (void*) cbs, cnt*sizeof *cbs);
  88         }
  89
  90         for (i=0; i<cnt; i++) {
  91                 if (!cbs[i]) continue;
  92                 switch (cbs[i]->aio_lio_opcode) {
  93                 case LIO_READ:
  94                         ret = aio_read(cbs[i]);
  95                         break;
  96                 case LIO_WRITE:
  97                         ret = aio_write(cbs[i]);
  98                         break;
  99                 default:
 100                         continue;
 101                 }
 102                 if (ret) {
 103                         free(st);
 104                         errno = EAGAIN;
 105                         return -1;
 106                 }
 107         }
 108
 109         if (mode == LIO_WAIT) {
 110                 ret = lio_wait(st);
 111                 free(st);
 112                 return ret;
 113         }
 114
 115         if (st) {
 116                 pthread_attr_t a;
 117                 sigset_t set;
 118                 pthread_t td;
 119
 120                 if (sev->sigev_notify == SIGEV_THREAD) {
 121                         if (sev->sigev_notify_attributes)
 122                                 a = *sev->sigev_notify_attributes;
 123                         else
 124                                 pthread_attr_init(&a);
 125                 } else {
 126                         pthread_attr_init(&a);
 127                         pthread_attr_setstacksize(&a, PAGE_SIZE);
 128                         pthread_attr_setguardsize(&a, 0);
 129                 }
 130                 pthread_attr_setdetachstate(&a, PTHREAD_CREATE_DETACHED);
 131                 sigfillset(&set);
 132                 pthread_sigmask(SIG_BLOCK, &set, &set);
 133                 if (pthread_create(&td, &a, wait_thread, st)) {
 134                         free(st);
 135                         errno = EAGAIN;
 136                         return -1;
 137                 }
 138                 pthread_sigmask(SIG_SETMASK, &set, 0);
 139         }
 140
 141         return 0;
 142 }
 143
 144 LFS64(lio_listio);