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Text file src/runtime/cgo/gcc_netbsd.c

Documentation: runtime/cgo

     1// Copyright 2009 The Go Authors. All rights reserved.
     2// Use of this source code is governed by a BSD-style
     3// license that can be found in the LICENSE file.
     4
     5//go:build netbsd && (386 || amd64 || arm || arm64)
     6
     7#include <sys/types.h>
     8#include <pthread.h>
     9#include <signal.h>
    10#include <string.h>
    11#include "libcgo.h"
    12#include "libcgo_unix.h"
    13
    14static void* threadentry(void*);
    15static void (*setg_gcc)(void*);
    16
    17void
    18x_cgo_init(G *g, void (*setg)(void*))
    19{
    20	setg_gcc = setg;
    21	_cgo_set_stacklo(g, NULL);
    22}
    23
    24
    25void
    26_cgo_sys_thread_start(ThreadStart *ts)
    27{
    28	pthread_attr_t attr;
    29	sigset_t ign, oset;
    30	pthread_t p;
    31	size_t size;
    32	int err;
    33
    34	sigfillset(&ign);
    35	pthread_sigmask(SIG_SETMASK, &ign, &oset);
    36
    37	pthread_attr_init(&attr);
    38	pthread_attr_getstacksize(&attr, &size);
    39	// Leave stacklo=0 and set stackhi=size; mstart will do the rest.
    40	ts->g->stackhi = size;
    41	err = _cgo_try_pthread_create(&p, &attr, threadentry, ts);
    42
    43	pthread_sigmask(SIG_SETMASK, &oset, nil);
    44
    45	if (err != 0) {
    46		fatalf("pthread_create failed: %s", strerror(err));
    47	}
    48}
    49
    50extern void crosscall1(void (*fn)(void), void (*setg_gcc)(void*), void *g);
    51static void*
    52threadentry(void *v)
    53{
    54	ThreadStart ts;
    55	stack_t ss;
    56
    57	ts = *(ThreadStart*)v;
    58	free(v);
    59
    60	// On NetBSD, a new thread inherits the signal stack of the
    61	// creating thread. That confuses minit, so we remove that
    62	// signal stack here before calling the regular mstart. It's
    63	// a bit baroque to remove a signal stack here only to add one
    64	// in minit, but it's a simple change that keeps NetBSD
    65	// working like other OS's. At this point all signals are
    66	// blocked, so there is no race.
    67	memset(&ss, 0, sizeof ss);
    68	ss.ss_flags = SS_DISABLE;
    69	sigaltstack(&ss, nil);
    70
    71	crosscall1(ts.fn, setg_gcc, ts.g);
    72	return nil;
    73}

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