path: root/nptl/allocatestack.c

/* Copyright (C) 2002, 2003, 2004 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 <assert.h>
#include <errno.h>
#include <stdint.h>
#include <string.h>
#include <unistd.h>
#include <sys/mman.h>
#include <sys/param.h>
#include <dl-sysdep.h>
#include <tls.h>



#ifndef NEED_SEPARATE_REGISTER_STACK

/* Most architectures have exactly one stack pointer.  Some have more.  */
# define STACK_VARIABLES void *stackaddr

/* How to pass the values to the 'create_thread' function.  */
# define STACK_VARIABLES_ARGS stackaddr

/* How to declare function which gets there parameters.  */
# define STACK_VARIABLES_PARMS void *stackaddr

/* How to declare allocate_stack.  */
# define ALLOCATE_STACK_PARMS void **stack

/* This is how the function is called.  We do it this way to allow
   other variants of the function to have more parameters.  */
# define ALLOCATE_STACK(attr, pd) allocate_stack (attr, pd, &stackaddr)

#else

/* We need two stacks.  The kernel will place them but we have to tell
   the kernel about the size of the reserved address space.  */
# define STACK_VARIABLES void *stackaddr; size_t stacksize

/* How to pass the values to the 'create_thread' function.  */
# define STACK_VARIABLES_ARGS stackaddr, stacksize

/* How to declare function which gets there parameters.  */
# define STACK_VARIABLES_PARMS void *stackaddr, size_t stacksize

/* How to declare allocate_stack.  */
# define ALLOCATE_STACK_PARMS void **stack, size_t *stacksize

/* This is how the function is called.  We do it this way to allow
   other variants of the function to have more parameters.  */
# define ALLOCATE_STACK(attr, pd) \
  allocate_stack (attr, pd, &stackaddr, &stacksize)

#endif


/* Default alignment of stack.  */
#ifndef STACK_ALIGN
# define STACK_ALIGN __alignof__ (long double)
#endif

/* Default value for minimal stack size after allocating thread
   descriptor and guard.  */
#ifndef MINIMAL_REST_STACK
# define MINIMAL_REST_STACK	4096
#endif


/* Let the architecture add some flags to the mmap() call used to
   allocate stacks.  */
#ifndef ARCH_MAP_FLAGS
# define ARCH_MAP_FLAGS 0
#endif

/* This yields the pointer that TLS support code calls the thread pointer.  */
#if TLS_TCB_AT_TP
# define TLS_TPADJ(pd) (pd)
#elif TLS_DTV_AT_TP
# define TLS_TPADJ(pd) ((struct pthread *)((char *) (pd) + TLS_PRE_TCB_SIZE))
#endif

/* Cache handling for not-yet free stacks.  */

/* Maximum size in kB of cache.  */
static size_t stack_cache_maxsize = 40 * 1024 * 1024; /* 40MiBi by default.  */
static size_t stack_cache_actsize;

/* Mutex protecting this variable.  */
static lll_lock_t stack_cache_lock = LLL_LOCK_INITIALIZER;

/* List of queued stack frames.  */
static LIST_HEAD (stack_cache);

/* List of the stacks in use.  */
static LIST_HEAD (stack_used);

/* List of the threads with user provided stacks in use.  No need to
   initialize this, since it's done in __pthread_initialize_minimal.  */
list_t __stack_user __attribute__ ((nocommon));
hidden_data_def (__stack_user)

#if COLORING_INCREMENT != 0
/* Number of threads created.  */
static unsigned int nptl_ncreated;
#endif


/* Check whether the stack is still used or not.  */
#define FREE_P(descr) ((descr)->tid <= 0)


/* We create a double linked list of all cache entries.  Double link