github.com/zebozhuang/go@v0.0.0-20200207033046-f8a98f6f5c5d/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  #include "libcgo_unix.h"
    10  
    11  static void *threadentry(void*);
    12  static void (*setg_gcc)(void*);
    13  
    14  // These will be set in gcc_android_386.c for android-specific customization.
    15  void (*x_cgo_inittls)(void);
    16  void* (*x_cgo_threadentry)(void*);
    17  
    18  void
    19  x_cgo_init(G *g, void (*setg)(void*))
    20  {
    21  	pthread_attr_t attr;
    22  	size_t size;
    23  
    24  	setg_gcc = setg;
    25  	pthread_attr_init(&attr);
    26  	pthread_attr_getstacksize(&attr, &size);
    27  	g->stacklo = (uintptr)&attr - size + 4096;
    28  	pthread_attr_destroy(&attr);
    29  
    30  	if (x_cgo_inittls) {
    31  		x_cgo_inittls();
    32  	}
    33  }
    34  
    35  
    36  void
    37  _cgo_sys_thread_start(ThreadStart *ts)
    38  {
    39  	pthread_attr_t attr;
    40  	sigset_t ign, oset;
    41  	pthread_t p;
    42  	size_t size;
    43  	int err;
    44  
    45  	sigfillset(&ign);
    46  	pthread_sigmask(SIG_SETMASK, &ign, &oset);
    47  
    48  	// Not sure why the memset is necessary here,
    49  	// but without it, we get a bogus stack size
    50  	// out of pthread_attr_getstacksize. C'est la Linux.
    51  	memset(&attr, 0, sizeof attr);
    52  	pthread_attr_init(&attr);
    53  	size = 0;
    54  	pthread_attr_getstacksize(&attr, &size);
    55  	// Leave stacklo=0 and set stackhi=size; mstart will do the rest.
    56  	ts->g->stackhi = size;
    57  	err = _cgo_try_pthread_create(&p, &attr, threadentry, ts);
    58  
    59  	pthread_sigmask(SIG_SETMASK, &oset, nil);
    60  
    61  	if (err != 0) {
    62  		fatalf("pthread_create failed: %s", strerror(err));
    63  	}
    64  }
    65  
    66  static void*
    67  threadentry(void *v)
    68  {
    69  	if (x_cgo_threadentry) {
    70  		return x_cgo_threadentry(v);
    71  	}
    72  
    73  	ThreadStart ts;
    74  
    75  	ts = *(ThreadStart*)v;
    76  	free(v);
    77  
    78  	/*
    79  	 * Set specific keys.
    80  	 */
    81  	setg_gcc((void*)ts.g);
    82  
    83  	crosscall_386(ts.fn);
    84  	return nil;
    85  }