github.com/panjjo/go@v0.0.0-20161104043856-d62b31386338/src/runtime/cgo/gcc_netbsd_amd64.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  #include <sys/types.h>
     6  #include <pthread.h>
     7  #include <signal.h>
     8  #include <string.h>
     9  #include "libcgo.h"
    10  
    11  static void* threadentry(void*);
    12  static void (*setg_gcc)(void*);
    13  
    14  void
    15  x_cgo_init(G *g, void (*setg)(void*))
    16  {
    17  	pthread_attr_t attr;
    18  	size_t size;
    19  
    20  	setg_gcc = setg;
    21  	pthread_attr_init(&attr);
    22  	pthread_attr_getstacksize(&attr, &size);
    23  	g->stacklo = (uintptr)&attr - size + 4096;
    24  	pthread_attr_destroy(&attr);
    25  }
    26  
    27  
    28  void
    29  _cgo_sys_thread_start(ThreadStart *ts)
    30  {
    31  	pthread_attr_t attr;
    32  	sigset_t ign, oset;
    33  	pthread_t p;
    34  	size_t size;
    35  	int err;
    36  
    37  	sigfillset(&ign);
    38  	pthread_sigmask(SIG_SETMASK, &ign, &oset);
    39  
    40  	pthread_attr_init(&attr);
    41  	pthread_attr_getstacksize(&attr, &size);
    42  
    43  	// Leave stacklo=0 and set stackhi=size; mstack will do the rest.
    44  	ts->g->stackhi = size;
    45  	err = pthread_create(&p, &attr, threadentry, ts);
    46  
    47  	pthread_sigmask(SIG_SETMASK, &oset, nil);
    48  
    49  	if (err != 0) {
    50  		fprintf(stderr, "runtime/cgo: pthread_create failed: %s\n", strerror(err));
    51  		abort();
    52  	}
    53  }
    54  
    55  static void*
    56  threadentry(void *v)
    57  {
    58  	ThreadStart ts;
    59  	stack_t ss;
    60  
    61  	ts = *(ThreadStart*)v;
    62  	free(v);
    63  
    64  	/*
    65  	 * Set specific keys.
    66  	 */
    67  	setg_gcc((void*)ts.g);
    68  
    69  	// On NetBSD, a new thread inherits the signal stack of the
    70  	// creating thread. That confuses minit, so we remove that
    71  	// signal stack here before calling the regular mstart. It's
    72  	// a bit baroque to remove a signal stack here only to add one
    73  	// in minit, but it's a simple change that keeps NetBSD
    74  	// working like other OS's. At this point all signals are
    75  	// blocked, so there is no race.
    76  	memset(&ss, 0, sizeof ss);
    77  	ss.ss_flags = SS_DISABLE;
    78  	sigaltstack(&ss, nil);
    79  
    80  	crosscall_amd64(ts.fn);
    81  	return nil;
    82  }