blob: 2d5382a8f09b6916c3af1a52426a2a39227807f9 [file] [log] [blame]
// 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 "libcgo.h"
/* Stub for creating a new thread */
x_cgo_thread_start(ThreadStart *arg)
ThreadStart *ts;
/* Make our own copy that can persist after we return. */
ts = malloc(sizeof *ts);
if(ts == nil) {
fprintf(stderr, "runtime/cgo: out of memory in thread_start\n");
*ts = *arg;
_cgo_sys_thread_start(ts); /* OS-dependent half */
#ifndef CGO_TSAN
void(* const _cgo_yield)() = NULL;
#include <string.h>
Stub for allowing libc interceptors to execute.
_cgo_yield is set to NULL if we do not expect libc interceptors to exist.
static void
The libc function(s) we call here must form a no-op and include at least one
call that triggers TSAN to process pending asynchronous signals.
sleep(0) would be fine, but it's not portable C (so it would need more header
free(NULL) has a fast-path special case in TSAN, so it doesn't
trigger signal delivery.
free(malloc(0)) would work (triggering the interceptors in malloc), but
it also runs a bunch of user-supplied malloc hooks.
So we choose strncpy(_, _, 0): it requires an extra header,
but it's standard and should be very efficient.
char nothing = 0;
strncpy(&nothing, &nothing, 0);
void(* const _cgo_yield)() = &x_cgo_yield;
#endif /* GO_TSAN */