gcc/libgo/runtime/thread.c
2011-12-01 23:50:48 +00:00

93 lines
1.8 KiB
C

// Copyright 2010 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 <errno.h>
#include <signal.h>
#include "runtime.h"
#include "go-assert.h"
/* For targets which don't have the required sync support. Really
these should be provided by gcc itself. FIXME. */
#if !defined (HAVE_SYNC_BOOL_COMPARE_AND_SWAP_4) || !defined (HAVE_SYNC_FETCH_AND_ADD_4)
static pthread_mutex_t sync_lock = PTHREAD_MUTEX_INITIALIZER;
#endif
#ifndef HAVE_SYNC_BOOL_COMPARE_AND_SWAP_4
_Bool
__sync_bool_compare_and_swap_4 (uint32*, uint32, uint32)
__attribute__ ((visibility ("hidden")));
_Bool
__sync_bool_compare_and_swap_4 (uint32* ptr, uint32 old, uint32 new)
{
int i;
_Bool ret;
i = pthread_mutex_lock (&sync_lock);
__go_assert (i == 0);
if (*ptr != old)
ret = 0;
else
{
*ptr = new;
ret = 1;
}
i = pthread_mutex_unlock (&sync_lock);
__go_assert (i == 0);
return ret;
}
#endif
#ifndef HAVE_SYNC_FETCH_AND_ADD_4
uint32
__sync_fetch_and_add_4 (uint32*, uint32)
__attribute__ ((visibility ("hidden")));
uint32
__sync_fetch_and_add_4 (uint32* ptr, uint32 add)
{
int i;
uint32 ret;
i = pthread_mutex_lock (&sync_lock);
__go_assert (i == 0);
ret = *ptr;
*ptr += add;
i = pthread_mutex_unlock (&sync_lock);
__go_assert (i == 0);
return ret;
}
#endif
// Called to initialize a new m (including the bootstrap m).
void
runtime_minit(void)
{
byte* stack;
size_t stacksize;
stack_t ss;
// Initialize signal handling.
runtime_m()->gsignal = runtime_malg(32*1024, &stack, &stacksize); // OS X wants >=8K, Linux >=2K
ss.ss_sp = stack;
ss.ss_flags = 0;
ss.ss_size = stacksize;
if(sigaltstack(&ss, nil) < 0)
*(int *)0xf1 = 0xf1;
}