path: root/nptl/pthread_create.c

/* Copyright (C) 2002, 2003 Free Software Foundation, Inc.
   This file is part of the GNU C Library.
   Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, write to the Free
   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   02111-1307 USA.  */

#include <errno.h>
#include <stdbool.h>
#include <stdlib.h>
#include <string.h>
#include "pthreadP.h"
#include <hp-timing.h>
#include <ldsodefs.h>
#include <atomic.h>

#include <shlib-compat.h>


/* Local function to start thread and handle cleanup.  */
static int start_thread (void *arg);
/* Similar version used when debugging.  */
static int start_thread_debug (void *arg);


/* Nozero if debugging mode is enabled.  */
int __pthread_debug;

/* Globally enabled events.  */
static td_thr_events_t __nptl_threads_events;

/* Pointer to descriptor with the last event.  */
static struct pthread *__nptl_last_event;

/* Number of threads running.  */
unsigned int __nptl_nthreads = 1;


/* Code to allocate and deallocate a stack.  */
#define DEFINE_DEALLOC
#include "allocatestack.c"

/* Code to create the thread.  */
#include "createthread.c"


/* Table of the key information.  */
struct pthread_key_struct __pthread_keys[PTHREAD_KEYS_MAX]
  __attribute__ ((section (".bss")));
hidden_def (__pthread_keys)

/* This is for libthread_db only.  */
const int __pthread_pthread_sizeof_descr = sizeof (struct pthread);

struct pthread *
internal_function
__find_in_stack_list (pd)
     struct pthread *pd;
{
  list_t *entry;
  struct pthread *result = NULL;

  lll_lock (stack_cache_lock);

  list_for_each (entry, &stack_used)
    {
      struct pthread *curp;

      curp = list_entry (entry, struct pthread, header.data.list);
      if (curp == pd)
	{
	  result = curp;
	  break;
	}
    }

  if (result == NULL)
    list_for_each (entry, &__stack_user)
      {
	struct pthread *curp;

	curp = list_entry (entry, struct pthread, header.data.list);
	if (curp == pd)
	  {
	    result = curp;
	    break;
	  }
      }

  lll_unlock (stack_cache_lock);

  return result;
}


/* Deallocate POSIX thread-local-storage.  */
static void
internal_function
deallocate_tsd (struct pthread *pd)
{
  /* Maybe no data was ever allocated.  This happens often so we have
     a flag for this.  */
  if (pd->specific_used)
    {
      size_t round;
      bool found_nonzero;

      for (round = 0, found_nonzero = true;
	   found_nonzero && round < PTHREAD_DESTRUCTOR_ITERATIONS;
	   ++round)
	{
	  size_t cnt;
	  size_t idx;

	  for (cnt = idx = 0; cnt < PTHREAD_KEY_1STLEVEL_SIZE; ++cnt)
	    if (pd->specific[cnt] != NULL)
	      {
		size_t inner;

		for (inner = 0; inner < PTHREAD_KEY_2NDLEVEL_SIZE;
		     ++inner, ++idx)
		  {
		    void *data = pd->specific[cnt][inner].data;

		    if (data != NULL
			/* Make sure the data corresponds to a valid
			   key.  This test fails if the key was
			   deallocated and also if it was
			   re-allocated.  It is the user's
			   responsibility to free the memory in this
			   case.  */
			&& (pd->specific[cnt][inner].seq
			    == __pthread_keys[idx].seq)
			/* It is not necessary to register a destructor
			   function.  */
			&& __pthread_keys[idx].destr != NULL)
		      {
			pd->specific[cnt][inner].data = NULL;
			__pthread_keys[idx].destr (data);
			found_nonzero = true;
		      }
		  }

		if (cnt != 0)
		  {
		    /* The first block is allocated as part of the thread
		       descriptor.  */
		    free (pd->specific[cnt]);
		    pd->specific[cnt] = NULL;
		  }
		else
		  /* Clear the memory of the first block for reuse.  */
		  memset (pd->specific[0], '\0',
			  sizeof (struct pthread_key_data));
	      }
	    else
	      idx += PTHREAD_KEY_1STLEVEL_SIZE;
	}

      pd->specific_used = false;
    }
}


/* Deallocate a thread's stack after optionally making sure the thread
   descriptor is still valid.  */
void
internal_function
__free_tcb (struct pthread *pd)
{
  /* The thread is exiting now.  */
  if (__builtin_expect (atomic_bit_test_set (&pd->cancelhandling,
					     TERMINATED_BIT) == 0, 1))
    {