github.com/geraldss/go/src@v0.0.0-20210511222824-ac7d0ebfc235/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  // This will be set in gcc_android.c for android-specific customization.
    15  void (*x_cgo_inittls)(void **tlsg, void **tlsbase) __attribute__((common));
    16  
    17  void
    18  x_cgo_init(G *g, void (*setg)(void*), void **tlsg, void **tlsbase)
    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(tlsg, tlsbase);
    31  	}
    32  }
    33  
    34  void
    35  _cgo_sys_thread_start(ThreadStart *ts)
    36  {
    37  	pthread_attr_t attr;
    38  	sigset_t ign, oset;
    39  	pthread_t p;
    40  	size_t size;
    41  	int err;
    42  
    43  	sigfillset(&ign);
    44  	pthread_sigmask(SIG_SETMASK, &ign, &oset);
    45  
    46  	// Not sure why the memset is necessary here,
    47  	// but without it, we get a bogus stack size
    48  	// out of pthread_attr_getstacksize. C'est la Linux.
    49  	memset(&attr, 0, sizeof attr);
    50  	pthread_attr_init(&attr);
    51  	size = 0;
    52  	pthread_attr_getstacksize(&attr, &size);
    53  	// Leave stacklo=0 and set stackhi=size; mstart will do the rest.
    54  	ts->g->stackhi = size;
    55  	err = _cgo_try_pthread_create(&p, &attr, threadentry, ts);
    56  
    57  	pthread_sigmask(SIG_SETMASK, &oset, nil);
    58  
    59  	if (err != 0) {
    60  		fatalf("pthread_create failed: %s", strerror(err));
    61  	}
    62  }
    63  
    64  static void*
    65  threadentry(void *v)
    66  {
    67  	ThreadStart ts;
    68  
    69  	ts = *(ThreadStart*)v;
    70  	free(v);
    71  
    72  	/*
    73  	 * Set specific keys.
    74  	 */
    75  	setg_gcc((void*)ts.g);
    76  
    77  	crosscall_386(ts.fn);
    78  	return nil;
    79  }