github.com/ice-blockchain/go/src@v0.0.0-20240403114104-1564d284e521/runtime/cgo/gcc_netbsd.c (about)

     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  
    14  static void* threadentry(void*);
    15  static void (*setg_gcc)(void*);
    16  
    17  void
    18  x_cgo_init(G *g, void (*setg)(void*))
    19  {
    20  	setg_gcc = setg;
    21  	_cgo_set_stacklo(g, NULL);
    22  }
    23  
    24  
    25  void
    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  
    50  extern void crosscall1(void (*fn)(void), void (*setg_gcc)(void*), void *g);
    51  static void*
    52  threadentry(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  }