gcc/libgo/runtime/go-new-channel.c
Ian Lance Taylor b39c10b813 Unify handling of runtime support functions.
This introduces the new approach, and rewrites the lowering
code which uses runtime functions.  The code which calls
runtime functions at GENERIC conversion time is not yet
rewritten.

From-SVN: r172396
2011-04-13 21:00:59 +00:00

58 lines
1.6 KiB
C

/* go-new-channel.c -- allocate a new 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 <stddef.h>
#include <stdint.h>
#include "go-alloc.h"
#include "go-assert.h"
#include "go-panic.h"
#include "channel.h"
struct __go_channel*
__go_new_channel (uintptr_t element_size, uintptr_t entries)
{
struct __go_channel* ret;
size_t alloc_size;
int i;
if ((uintptr_t) (int) entries != entries
|| entries > (uintptr_t) -1 / element_size)
__go_panic_msg ("chan size out of range");
alloc_size = (element_size + sizeof (uint64_t) - 1) / sizeof (uint64_t);
/* We use a circular buffer which means that when next_fetch ==
next_store we don't know whether the buffer is empty or full. So
we allocate an extra space, and always leave a space open.
FIXME. */
if (entries != 0)
++entries;
ret = (struct __go_channel*) __go_alloc (sizeof (struct __go_channel)
+ ((entries == 0 ? 1 : entries)
* alloc_size
* sizeof (uint64_t)));
i = pthread_mutex_init (&ret->lock, NULL);
__go_assert (i == 0);
i = pthread_cond_init (&ret->cond, NULL);
__go_assert (i == 0);
ret->element_size = element_size;
ret->waiting_to_send = 0;
ret->waiting_to_receive = 0;
ret->selected_for_send = 0;
ret->selected_for_receive = 0;
ret->is_closed = 0;
ret->select_send_queue = NULL;
ret->select_receive_queue = NULL;
ret->select_mutex = NULL;
ret->select_cond = NULL;
ret->num_entries = entries;
ret->next_store = 0;
ret->next_fetch = 0;
return ret;
}