text: /* Thread package specific definitions of stream lock type.  NPTL version.
     Copyright (C) 2000-2017 Free Software Foundation, Inc.
     This file is part of the GNU C Library.
  
     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, see
     <http://www.gnu.org/licenses/>.  */
  
  #ifndef _STDIO_LOCK_H
  #define _STDIO_LOCK_H 1
  
  #include <libc-lock.h>
  #include <lowlevellock.h>
  
  
  /* The locking here is very inexpensive, even for inlining.  */
  #define _IO_lock_inexpensive	1
  
  typedef struct { int lock; int cnt; void *owner; } _IO_lock_t;
  
  #define _IO_lock_initializer { LLL_LOCK_INITIALIZER, 0, NULL }
  
  #define _IO_lock_init(_name) \
    ((void) ((_name) = (_IO_lock_t) _IO_lock_initializer))
  
  #define _IO_lock_fini(_name) \
    ((void) 0)
  
  #define _IO_lock_lock(_name) \
    do {									      \
      void *__self = THREAD_SELF;						      \
      if ((_name).owner != __self)					      \
        {									      \
  	lll_lock ((_name).lock, LLL_PRIVATE);				      \
          (_name).owner = __self;						      \
        }									      \
      ++(_name).cnt;							      \
    } while (0)
  
  #define _IO_lock_trylock(_name) \
    ({									      \
      int __result = 0;							      \
      void *__self = THREAD_SELF;						      \
      if ((_name).owner != __self)					      \
        {									      \
          if (lll_trylock ((_name).lock) == 0)				      \
            {								      \
              (_name).owner = __self;					      \
              (_name).cnt = 1;						      \
            }								      \
          else								      \
            __result = EBUSY;						      \
        }									      \
      else								      \
        ++(_name).cnt;							      \
      __result;								      \
    })
  
  #define _IO_lock_unlock(_name) \
    do {									      \
      if (--(_name).cnt == 0)						      \
        {									      \
          (_name).owner = NULL;						      \
  	lll_unlock ((_name).lock, LLL_PRIVATE);				      \
        }									      \
    } while (0)
  
  
  
  #define _IO_cleanup_region_start(_fct, _fp) \
    __libc_cleanup_region_start (((_fp)->_flags & _IO_USER_LOCK) == 0, _fct, _fp)
  #define _IO_cleanup_region_start_noarg(_fct) \
    __libc_cleanup_region_start (1, _fct, NULL)
  #define _IO_cleanup_region_end(_doit) \
    __libc_cleanup_region_end (_doit)
  
  #if defined _LIBC && IS_IN (libc)
  
  # ifdef __EXCEPTIONS
  #  define _IO_acquire_lock(_fp) \
    do {									      \
      _IO_FILE *_IO_acquire_lock_file					      \
  	__attribute__((cleanup (_IO_acquire_lock_fct)))			      \
  	= (_fp);							      \
      _IO_flockfile (_IO_acquire_lock_file);
  #  define _IO_acquire_lock_clear_flags2(_fp) \
    do {									      \
      _IO_FILE *_IO_acquire_lock_file					      \
  	__attribute__((cleanup (_IO_acquire_lock_clear_flags2_fct)))	      \
  	= (_fp);							      \
      _IO_flockfile (_IO_acquire_lock_file);
  # else
  #  define _IO_acquire_lock(_fp) _IO_acquire_lock_needs_exceptions_enabled
  #  define _IO_acquire_lock_clear_flags2(_fp) _IO_acquire_lock (_fp)
  # endif
  # define _IO_release_lock(_fp) ; } while (0)
  
  #endif
  
  #endif /* stdio-lock.h */
  