text: // Copyright 2016 The Go Authors. All rights reserved.
  // Use of this source code is governed by a BSD-style
  // license that can be found in the LICENSE file.
  
  #include <pthread.h>
  #include <string.h>
  #include <signal.h>
  #include "libcgo.h"
  #include "libcgo_unix.h"
  
  static void *threadentry(void*);
  
  void (*x_cgo_inittls)(void **tlsg, void **tlsbase);
  static void (*setg_gcc)(void*);
  
  void
  x_cgo_init(G *g, void (*setg)(void*), void **tlsbase)
  {
  	pthread_attr_t attr;
  	size_t size;
  
  	setg_gcc = setg;
  	pthread_attr_init(&attr);
  	pthread_attr_getstacksize(&attr, &size);
  	g->stacklo = (uintptr)&attr - size + 4096;
  	pthread_attr_destroy(&attr);
  }
  
  void
  _cgo_sys_thread_start(ThreadStart *ts)
  {
  	pthread_attr_t attr;
  	sigset_t ign, oset;
  	pthread_t p;
  	size_t size;
  	int err;
  
  	sigfillset(&ign);
  	pthread_sigmask(SIG_SETMASK, &ign, &oset);
  
  	pthread_attr_init(&attr);
  	pthread_attr_getstacksize(&attr, &size);
  	// Leave stacklo=0 and set stackhi=size; mstack will do the rest.
  	ts->g->stackhi = size;
  	err = _cgo_try_pthread_create(&p, &attr, threadentry, ts);
  
  	pthread_sigmask(SIG_SETMASK, &oset, nil);
  
  	if (err != 0) {
  		fatalf("pthread_create failed: %s", strerror(err));
  	}
  }
  
  extern void crosscall_s390x(void (*fn)(void), void *g);
  
  static void*
  threadentry(void *v)
  {
  	ThreadStart ts;
  
  	ts = *(ThreadStart*)v;
  	free(v);
  
  	// Save g for this thread in C TLS
  	setg_gcc((void*)ts.g);
  
  	crosscall_s390x(ts.fn, (void*)ts.g);
  	return nil;
  }
  