github.com/ader1990/go@v0.0.0-20140630135419-8c24447fa791/src/pkg/runtime/cgo/gcc_linux_386.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 <pthread.h>
     6  #include <string.h>
     7  #include <signal.h>
     8  #include "libcgo.h"
     9  
    10  static void *threadentry(void*);
    11  static void (*setmg_gcc)(void*, void*);
    12  
    13  void
    14  x_cgo_init(G *g, void (*setmg)(void*, void*))
    15  {
    16  	pthread_attr_t attr;
    17  	size_t size;
    18  
    19  	setmg_gcc = setmg;
    20  	pthread_attr_init(&attr);
    21  	pthread_attr_getstacksize(&attr, &size);
    22  	g->stackguard = (uintptr)&attr - size + 4096;
    23  	pthread_attr_destroy(&attr);
    24  }
    25  
    26  
    27  void
    28  _cgo_sys_thread_start(ThreadStart *ts)
    29  {
    30  	pthread_attr_t attr;
    31  	sigset_t ign, oset;
    32  	pthread_t p;
    33  	size_t size;
    34  	int err;
    35  
    36  	sigfillset(&ign);
    37  	pthread_sigmask(SIG_SETMASK, &ign, &oset);
    38  
    39  	// Not sure why the memset is necessary here,
    40  	// but without it, we get a bogus stack size
    41  	// out of pthread_attr_getstacksize.  C'est la Linux.
    42  	memset(&attr, 0, sizeof attr);
    43  	pthread_attr_init(&attr);
    44  	size = 0;
    45  	pthread_attr_getstacksize(&attr, &size);
    46  	ts->g->stackguard = size;
    47  	err = pthread_create(&p, &attr, threadentry, ts);
    48  
    49  	pthread_sigmask(SIG_SETMASK, &oset, nil);
    50  
    51  	if (err != 0) {
    52  		fprintf(stderr, "runtime/cgo: pthread_create failed: %s\n", strerror(err));
    53  		abort();
    54  	}
    55  }
    56  
    57  static void*
    58  threadentry(void *v)
    59  {
    60  	ThreadStart ts;
    61  
    62  	ts = *(ThreadStart*)v;
    63  	free(v);
    64  
    65  	ts.g->stackbase = (uintptr)&ts;
    66  
    67  	/*
    68  	 * _cgo_sys_thread_start set stackguard to stack size;
    69  	 * change to actual guard pointer.
    70  	 */
    71  	ts.g->stackguard = (uintptr)&ts - ts.g->stackguard + 4096;
    72  
    73  	/*
    74  	 * Set specific keys.
    75  	 */
    76  	setmg_gcc((void*)ts.m, (void*)ts.g);
    77  
    78  	crosscall_386(ts.fn);
    79  	return nil;
    80  }