gcc/libgo/runtime/go-rec-nb-big.c

47 lines
1.1 KiB
C

/* go-rec-nb-big.c -- nonblocking receive of something big on a channel.
Copyright 2009 The Go Authors. All rights reserved.
Use of this source code is governed by a BSD-style
license that can be found in the LICENSE file. */
#include <stdint.h>
#include "channel.h"
/* Return true if a value was received, false if not. */
_Bool
__go_receive_nonblocking_big (struct __go_channel* channel, void *val,
_Bool *closed)
{
uintptr_t element_size;
size_t alloc_size;
size_t offset;
if (channel == NULL)
{
if (closed != NULL)
*closed = 0;
return 0;
}
element_size = channel->element_type->__size;
alloc_size = (element_size + sizeof (uint64_t) - 1) / sizeof (uint64_t);
int data = __go_receive_nonblocking_acquire (channel);
if (data != RECEIVE_NONBLOCKING_ACQUIRE_DATA)
{
__builtin_memset (val, 0, element_size);
if (closed != NULL)
*closed = data == RECEIVE_NONBLOCKING_ACQUIRE_CLOSED;
return 0;
}
offset = channel->next_fetch * alloc_size;
__builtin_memcpy (val, &channel->data[offset], element_size);
__go_receive_release (channel);
return 1;
}