mono/metadata/threadpool-ms-io-epoll.c

   1
   2 #if defined(HAVE_EPOLL)
   3
   4 #include <sys/epoll.h>
   5
   6 #if defined(HOST_WIN32)
   7 /* We assume that epoll is not available on windows */
   8 #error
   9 #endif
  10
  11 #define EPOLL_NEVENTS 128
  12
  13 static gint epoll_fd;
  14 static struct epoll_event *epoll_events;
  15
  16 static gboolean
  17 epoll_init (gint wakeup_pipe_fd)
  18 {
  19         struct epoll_event event;
  20
  21 #ifdef EPOOL_CLOEXEC
  22         epoll_fd = epoll_create1 (EPOLL_CLOEXEC);
  23 #else
  24         epoll_fd = epoll_create (256);
  25         fcntl (epoll_fd, F_SETFD, FD_CLOEXEC);
  26 #endif
  27
  28         if (epoll_fd == -1) {
  29 #ifdef EPOOL_CLOEXEC
  30                 g_error ("epoll_init: epoll (EPOLL_CLOEXEC) failed, error (%d) %s\n", errno, g_strerror (errno));
  31 #else
  32                 g_error ("epoll_init: epoll (256) failed, error (%d) %s\n", errno, g_strerror (errno));
  33 #endif
  34                 return FALSE;
  35         }
  36
  37         event.events = EPOLLIN;
  38         event.data.fd = wakeup_pipe_fd;
  39         if (epoll_ctl (epoll_fd, EPOLL_CTL_ADD, event.data.fd, &event) == -1) {
  40                 g_error ("epoll_init: epoll_ctl () failed, error (%d) %s", errno, g_strerror (errno));
  41                 close (epoll_fd);
  42                 return FALSE;
  43         }
  44
  45         epoll_events = g_new0 (struct epoll_event, EPOLL_NEVENTS);
  46
  47         return TRUE;
  48 }
  49
  50 static void
  51 epoll_register_fd (gint fd, gint events, gboolean is_new)
  52 {
  53         struct epoll_event event;
  54
  55 #ifndef EPOLLONESHOT
  56 /* it was only defined on android in May 2013 */
  57 #define EPOLLONESHOT 0x40000000
  58 #endif
  59
  60         event.data.fd = fd;
  61         event.events = EPOLLONESHOT;
  62         if ((events & EVENT_IN) != 0)
  63                 event.events |= EPOLLIN;
  64         if ((events & EVENT_OUT) != 0)
  65                 event.events |= EPOLLOUT;
  66
  67         if (epoll_ctl (epoll_fd, is_new ? EPOLL_CTL_ADD : EPOLL_CTL_MOD, event.data.fd, &event) == -1)
  68                 g_error ("epoll_register_fd: epoll_ctl(%s) failed, error (%d) %s", is_new ? "EPOLL_CTL_ADD" : "EPOLL_CTL_MOD", errno, g_strerror (errno));
  69 }
  70
  71 static void
  72 epoll_remove_fd (gint fd)
  73 {
  74         if (epoll_ctl (epoll_fd, EPOLL_CTL_DEL, fd, NULL) == -1)
  75                         g_error ("epoll_remove_fd: epoll_ctl (EPOLL_CTL_DEL) failed, error (%d) %s", errno, g_strerror (errno));
  76 }
  77
  78 static gint
  79 epoll_event_wait (void (*callback) (gint fd, gint events, gpointer user_data), gpointer user_data)
  80 {
  81         gint i, ready;
  82
  83         memset (epoll_events, 0, sizeof (struct epoll_event) * EPOLL_NEVENTS);
  84
  85         mono_gc_set_skip_thread (TRUE);
  86
  87         MONO_ENTER_GC_SAFE;
  88         ready = epoll_wait (epoll_fd, epoll_events, EPOLL_NEVENTS, -1);
  89         MONO_EXIT_GC_SAFE;
  90
  91         mono_gc_set_skip_thread (FALSE);
  92
  93         if (ready == -1) {
  94                 switch (errno) {
  95                 case EINTR:
  96                         mono_thread_internal_check_for_interruption_critical (mono_thread_internal_current ());
  97                         ready = 0;
  98                         break;
  99                 default:
 100                         g_error ("epoll_event_wait: epoll_wait () failed, error (%d) %s", errno, g_strerror (errno));
 101                         break;
 102                 }
 103         }
 104
 105         if (ready == -1)
 106                 return -1;
 107
 108         for (i = 0; i < ready; ++i) {
 109                 gint fd, events = 0;
 110
 111                 fd = epoll_events [i].data.fd;
 112                 if (epoll_events [i].events & (EPOLLIN | EPOLLERR | EPOLLHUP))
 113                         events |= EVENT_IN;
 114                 if (epoll_events [i].events & (EPOLLOUT | EPOLLERR | EPOLLHUP))
 115                         events |= EVENT_OUT;
 116
 117                 callback (fd, events, user_data);
 118         }
 119
 120         return 0;
 121 }
 122
 123 static ThreadPoolIOBackend backend_epoll = {
 124         .init = epoll_init,
 125         .register_fd = epoll_register_fd,
 126         .remove_fd = epoll_remove_fd,
 127         .event_wait = epoll_event_wait,
 128 };
 129
 130 #endif