libgo/runtime/go-close.c

   1 /* go-close.c -- the builtin close function.
   2
   3    Copyright 2009 The Go Authors. All rights reserved.
   4    Use of this source code is governed by a BSD-style
   5    license that can be found in the LICENSE file.  */
   6
   7 #include "go-assert.h"
   8 #include "go-panic.h"
   9 #include "channel.h"
  10
  11 /* Close a channel.  After a channel is closed, sends are no longer
  12    permitted.  Receives always return zero.  */
  13
  14 void
  15 __go_builtin_close (struct __go_channel *channel)
  16 {
  17   int i;
  18
  19   i = pthread_mutex_lock (&channel->lock);
  20   __go_assert (i == 0);
  21
  22   while (channel->selected_for_send)
  23     {
  24       i = pthread_cond_wait (&channel->cond, &channel->lock);
  25       __go_assert (i == 0);
  26     }
  27
  28   if (channel->is_closed)
  29     {
  30       i = pthread_mutex_unlock (&channel->lock);
  31       __go_assert (i == 0);
  32       __go_panic_msg ("close of closed channel");
  33     }
  34
  35   channel->is_closed = 1;
  36
  37   i = pthread_cond_broadcast (&channel->cond);
  38   __go_assert (i == 0);
  39
  40   __go_unlock_and_notify_selects (channel);
  41 }