github.com/panjjo/go@v0.0.0-20161104043856-d62b31386338/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  // These will be set in gcc_android_386.c for android-specific customization.
    14  void (*x_cgo_inittls)(void);
    15  void* (*x_cgo_threadentry)(void*);
    16  
    17  void
    18  x_cgo_init(G *g, void (*setg)(void*))
    19  {
    20  	pthread_attr_t attr;
    21  	size_t size;
    22  
    23  	setg_gcc = setg;
    24  	pthread_attr_init(&attr);
    25  	pthread_attr_getstacksize(&attr, &size);
    26  	g->stacklo = (uintptr)&attr - size + 4096;
    27  	pthread_attr_destroy(&attr);
    28  
    29  	if (x_cgo_inittls) {
    30  		x_cgo_inittls();
    31  	}
    32  }
    33  
    34  
    35  void
    36  _cgo_sys_thread_start(ThreadStart *ts)
    37  {
    38  	pthread_attr_t attr;
    39  	sigset_t ign, oset;
    40  	pthread_t p;
    41  	size_t size;
    42  	int err;
    43  
    44  	sigfillset(&ign);
    45  	pthread_sigmask(SIG_SETMASK, &ign, &oset);
    46  
    47  	// Not sure why the memset is necessary here,
    48  	// but without it, we get a bogus stack size
    49  	// out of pthread_attr_getstacksize. C'est la Linux.
    50  	memset(&attr, 0, sizeof attr);
    51  	pthread_attr_init(&attr);
    52  	size = 0;
    53  	pthread_attr_getstacksize(&attr, &size);
    54  	// Leave stacklo=0 and set stackhi=size; mstack will do the rest.
    55  	ts->g->stackhi = size;
    56  	err = pthread_create(&p, &attr, threadentry, ts);
    57  
    58  	pthread_sigmask(SIG_SETMASK, &oset, nil);
    59  
    60  	if (err != 0) {
    61  		fatalf("pthread_create failed: %s", strerror(err));
    62  	}
    63  }
    64  
    65  static void*
    66  threadentry(void *v)
    67  {
    68  	if (x_cgo_threadentry) {
    69  		return x_cgo_threadentry(v);
    70  	}
    71  
    72  	ThreadStart ts;
    73  
    74  	ts = *(ThreadStart*)v;
    75  	free(v);
    76  
    77  	/*
    78  	 * Set specific keys.
    79  	 */
    80  	setg_gcc((void*)ts.g);
    81  
    82  	crosscall_386(ts.fn);
    83  	return nil;
    84  }