libgo/runtime/go-rec-big.c

   1 /* go-rec-big.c -- receive something larger than 64 bits on a channel.
   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 <stdint.h>
   8
   9 #include "go-panic.h"
  10 #include "channel.h"
  11
  12 void
  13 __go_receive_big (struct __go_channel *channel, void *val, _Bool for_select)
  14 {
  15   size_t alloc_size;
  16   size_t offset;
  17
  18   if (channel == NULL)
  19     __go_panic_msg ("receive from nil channel");
  20
  21   alloc_size = ((channel->element_size + sizeof (uint64_t) - 1)
  22                 / sizeof (uint64_t));
  23
  24   if (!__go_receive_acquire (channel, for_select))
  25     {
  26       __builtin_memset (val, 0, channel->element_size);
  27       return;
  28     }
  29
  30   offset = channel->next_fetch * alloc_size;
  31   __builtin_memcpy (val, &channel->data[offset], channel->element_size);
  32
  33   __go_receive_release (channel);
  34 }