github.com/shijuvar/go@v0.0.0-20141209052335-e8f13700b70c/src/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 (*setg_gcc)(void*);
    12  
    13  void
    14  x_cgo_init(G *g, void (*setg)(void*))
    15  {
    16  	pthread_attr_t attr;
    17  	size_t size;
    18  
    19  	setg_gcc = setg;
    20  	pthread_attr_init(&attr);
    21  	pthread_attr_getstacksize(&attr, &size);
    22  	g->stacklo = (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  	// Leave stacklo=0 and set stackhi=size; mstack will do the rest.
    47  	ts->g->stackhi = size;
    48  	err = pthread_create(&p, &attr, threadentry, ts);
    49  
    50  	pthread_sigmask(SIG_SETMASK, &oset, nil);
    51  
    52  	if (err != 0) {
    53  		fatalf("pthread_create failed: %s", strerror(err));
    54  	}
    55  }
    56  
    57  static void*
    58  threadentry(void *v)
    59  {
    60  	ThreadStart ts;
    61  
    62  	ts = *(ThreadStart*)v;
    63  	free(v);
    64  
    65  	/*
    66  	 * Set specific keys.
    67  	 */
    68  	setg_gcc((void*)ts.g);
    69  
    70  	crosscall_386(ts.fn);
    71  	return nil;
    72  }