gnulib/lib/glthread/lock.h

/* Locking in multithreaded situations.
   Copyright (C) 2005-2025 Free Software Foundation, Inc.

   This file 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.

   This file 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 this program.  If not, see <https://www.gnu.org/licenses/>.  */

/* Written by Bruno Haible <bruno@clisp.org>, 2005.
   Based on GCC's gthr-posix.h, gthr-posix95.h, gthr-win32.h.  */

/* This file contains locking primitives for use with a given thread library.
   It does not contain primitives for creating threads or for other
   synchronization primitives.

   Normal (non-recursive) locks:
     Type:                gl_lock_t
     Declaration:         gl_lock_define(extern, name)
     Initializer:         gl_lock_define_initialized(, name)
     Initialization:      gl_lock_init (name);
     Taking the lock:     gl_lock_lock (name);
     Releasing the lock:  gl_lock_unlock (name);
     De-initialization:   gl_lock_destroy (name);
   Equivalent functions with control of error handling:
     Initialization:      err = glthread_lock_init (&name);
     Taking the lock:     err = glthread_lock_lock (&name);
     Releasing the lock:  err = glthread_lock_unlock (&name);
     De-initialization:   err = glthread_lock_destroy (&name);

   Read-Write (non-recursive) locks:
     Type:                gl_rwlock_t
     Declaration:         gl_rwlock_define(extern, name)
     Initializer:         gl_rwlock_define_initialized(, name)
     Initialization:      gl_rwlock_init (name);
     Taking the lock:     gl_rwlock_rdlock (name);
                          gl_rwlock_wrlock (name);
     Releasing the lock:  gl_rwlock_unlock (name);
     De-initialization:   gl_rwlock_destroy (name);
   Equivalent functions with control of error handling:
     Initialization:      err = glthread_rwlock_init (&name);
     Taking the lock:     err = glthread_rwlock_rdlock (&name);
                          err = glthread_rwlock_wrlock (&name);
     Releasing the lock:  err = glthread_rwlock_unlock (&name);
     De-initialization:   err = glthread_rwlock_destroy (&name);

   Recursive locks:
     Type:                gl_recursive_lock_t
     Declaration:         gl_recursive_lock_define(extern, name)
     Initializer:         gl_recursive_lock_define_initialized(, name)
     Initialization:      gl_recursive_lock_init (name);
     Taking the lock:     gl_recursive_lock_lock (name);
     Releasing the lock:  gl_recursive_lock_unlock (name);
     De-initialization:   gl_recursive_lock_destroy (name);
   Equivalent functions with control of error handling:
     Initialization:      err = glthread_recursive_lock_init (&name);
     Taking the lock:     err = glthread_recursive_lock_lock (&name);
     Releasing the lock:  err = glthread_recursive_lock_unlock (&name);
     De-initialization:   err = glthread_recursive_lock_destroy (&name);
*/


#ifndef _LOCK_H
#define _LOCK_H

/* This file uses HAVE_THREADS_H, HAVE_PTHREAD_RWLOCK,
   HAVE_PTHREAD_RWLOCK_RDLOCK_PREFER_WRITER,
   PTHREAD_RWLOCK_WRITER_NONRECURSIVE_INITIALIZER_NP,
   HAVE_PTHREAD_MUTEX_RECURSIVE.  */
#if !_GL_CONFIG_H_INCLUDED
 #error "Please include config.h first."
#endif

#include <errno.h>
#include <stdlib.h>

#include "glthread/once.h"

/* c11_threads_in_use() is defined in glthread/once.h.  */

/* ========================================================================= */

#if USE_ISOC_THREADS || USE_ISOC_AND_POSIX_THREADS

/* Use the ISO C threads library.  */

# include <threads.h>

# ifdef __cplusplus
extern "C" {
# endif

/* -------------------------- gl_lock_t datatype -------------------------- */

typedef struct
        {
          int volatile init_needed;
          once_flag init_once;
          void (*init_func) (void);
          mtx_t mutex;
        }
        gl_lock_t;
# define gl_lock_define(STORAGECLASS, NAME) \
    STORAGECLASS gl_lock_t NAME;
# define gl_lock_define_initialized(STORAGECLASS, NAME) \
    static void _atomic_init_##NAME (void);       \
    STORAGECLASS gl_lock_t NAME =                 \
      { 1, ONCE_FLAG_INIT, _atomic_init_##NAME }; \
    static void _atomic_init_##NAME (void)        \
    {                                             \
      if (glthread_lock_init (&(NAME)))           \
        abort ();                                 \
    }
extern int glthread_lock_init (gl_lock_t *lock);
extern int glthread_lock_lock (gl_lock_t *lock);
extern int glthread_lock_unlock (gl_lock_t *lock);
extern int glthread_lock_destroy (gl_lock_t *lock);

/* ------------------------- gl_rwlock_t datatype ------------------------- */

typedef struct
        {
          int volatile init_needed;
          once_flag init_once;
          void (*init_func) (void);
          mtx_t lock; /* protects the remaining fields */
          cnd_t waiting_readers; /* waiting readers */
          cnd_t waiting_writers; /* waiting writers */
          unsigned int waiting_writers_count; /* number of waiting writers */
          int runcount; /* number of readers running, or -1 when a writer runs */
        }
        gl_rwlock_t;
# define gl_rwlock_define(STORAGECLASS, NAME) \
    STORAGECLASS gl_rwlock_t NAME;
# define gl_rwlock_define_initialized(STORAGECLASS, NAME) \
    static void _atomic_init_##NAME (void);       \
    STORAGECLASS gl_rwlock_t NAME =               \
      { 1, ONCE_FLAG_INIT, _atomic_init_##NAME }; \
    static void _atomic_init_##NAME (void)        \
    {                                             \
      if (glthread_rwlock_init (&(NAME)))         \
        abort ();                                 \
    }
extern int glthread_rwlock_init (gl_rwlock_t *lock);
extern int glthread_rwlock_rdlock (gl_rwlock_t *lock);
extern int glthread_rwlock_wrlock (gl_rwlock_t *lock);
extern int glthread_rwlock_unlock (gl_rwlock_t *lock);
extern int glthread_rwlock_destroy (gl_rwlock_t *lock);

/* --------------------- gl_recursive_lock_t datatype --------------------- */

typedef struct
        {
          int volatile init_needed;
          once_flag init_once;
          void (*init_func) (void);
          mtx_t mutex;
        }
        gl_recursive_lock_t;
# define gl_recursive_lock_define(STORAGECLASS, NAME) \
    STORAGECLASS gl_recursive_lock_t NAME;
# define gl_recursive_lock_define_initialized(STORAGECLASS, NAME) \
    static void _atomic_init_##NAME (void);       \
    STORAGECLASS gl_recursive_lock_t NAME =       \
      { 1, ONCE_FLAG_INIT, _atomic_init_##NAME }; \
    static void _atomic_init_##NAME (void)        \
    {                                             \
      if (glthread_recursive_lock_init (&(NAME))) \
        abort ();                                 \
    }
extern int glthread_recursive_lock_init (gl_recursive_lock_t *lock);
extern int glthread_recursive_lock_lock (gl_recursive_lock_t *lock);
extern int glthread_recursive_lock_unlock (gl_recursive_lock_t *lock);
extern int glthread_recursive_lock_destroy (gl_recursive_lock_t *lock);

# ifdef __cplusplus
}
# endif

#endif

/* ========================================================================= */

#if USE_POSIX_THREADS

/* Use the POSIX threads library.  */

# include <pthread.h>

# ifdef __cplusplus
extern "C" {
# endif

/* pthread_in_use() is defined in glthread/once.h.  */

/* -------------------------- gl_lock_t datatype -------------------------- */

typedef pthread_mutex_t gl_lock_t;
# define gl_lock_define(STORAGECLASS, NAME) \
    STORAGECLASS pthread_mutex_t NAME;
# define gl_lock_define_initialized(STORAGECLASS, NAME) \
    STORAGECLASS pthread_mutex_t NAME = gl_lock_initializer;
# define gl_lock_initializer \
    PTHREAD_MUTEX_INITIALIZER
# define glthread_lock_init(LOCK) \
    (pthread_in_use () ? pthread_mutex_init (LOCK, NULL) : 0)
# define glthread_lock_lock(LOCK) \
    (pthread_in_use () ? pthread_mutex_lock (LOCK) : 0)
# define glthread_lock_unlock(LOCK) \
    (pthread_in_use () ? pthread_mutex_unlock (LOCK) : 0)
# define glthread_lock_destroy(LOCK) \
    (pthread_in_use () ? pthread_mutex_destroy (LOCK) : 0)

/* ------------------------- gl_rwlock_t datatype ------------------------- */

# if HAVE_PTHREAD_RWLOCK && (HAVE_PTHREAD_RWLOCK_RDLOCK_PREFER_WRITER || (defined PTHREAD_RWLOCK_WRITER_NONRECURSIVE_INITIALIZER_NP && (__GNU_LIBRARY__ > 1)))

#  if defined PTHREAD_RWLOCK_INITIALIZER || defined PTHREAD_RWLOCK_INITIALIZER_NP

typedef pthread_rwlock_t gl_rwlock_t;
#   define gl_rwlock_define(STORAGECLASS, NAME) \
      STORAGECLASS pthread_rwlock_t NAME;
#   define gl_rwlock_define_initialized(STORAGECLASS, NAME) \
      STORAGECLASS pthread_rwlock_t NAME = gl_rwlock_initializer;
#   if HAVE_PTHREAD_RWLOCK_RDLOCK_PREFER_WRITER
#    if defined PTHREAD_RWLOCK_INITIALIZER
#     define gl_rwlock_initializer \
        PTHREAD_RWLOCK_INITIALIZER
#    else
#     define gl_rwlock_initializer \
        PTHREAD_RWLOCK_INITIALIZER_NP
#    endif
#    define glthread_rwlock_init(LOCK) \
       (pthread_in_use () ? pthread_rwlock_init (LOCK, NULL) : 0)
#   else /* glibc with bug https://sourceware.org/PR13701 */
#    define gl_rwlock_initializer \
       PTHREAD_RWLOCK_WRITER_NONRECURSIVE_INITIALIZER_NP
#    define glthread_rwlock_init(LOCK) \
       (pthread_in_use () ? glthread_rwlock_init_for_glibc (LOCK) : 0)
extern int glthread_rwlock_init_for_glibc (pthread_rwlock_t *lock);
#   endif
#   define glthread_rwlock_rdlock(LOCK) \
      (pthread_in_use () ? pthread_rwlock_rdlock (LOCK) : 0)
#   define glthread_rwlock_wrlock(LOCK) \
      (pthread_in_use () ? pthread_rwlock_wrlock (LOCK) : 0)
#   define glthread_rwlock_unlock(LOCK) \
      (pthread_in_use () ? pthread_rwlock_unlock (LOCK) : 0)
#   define glthread_rwlock_destroy(LOCK) \
      (pthread_in_use () ? pthread_rwlock_destroy (LOCK) : 0)

#  else

typedef struct
        {
          int initialized;
          pthread_mutex_t guard;   /* protects the initialization */
          pthread_rwlock_t rwlock; /* read-write lock */
        }
        gl_rwlock_t;
#   define gl_rwlock_define(STORAGECLASS, NAME) \
      STORAGECLASS gl_rwlock_t NAME;
#   define gl_rwlock_define_initialized(STORAGECLASS, NAME) \
      STORAGECLASS gl_rwlock_t NAME = gl_rwlock_initializer;
#   define gl_rwlock_initializer \
      { 0, PTHREAD_MUTEX_INITIALIZER }
#   define glthread_rwlock_init(LOCK) \
      (pthread_in_use () ? glthread_rwlock_init_multithreaded (LOCK) : 0)
#   define glthread_rwlock_rdlock(LOCK) \
      (pthread_in_use () ? glthread_rwlock_rdlock_multithreaded (LOCK) : 0)
#   define glthread_rwlock_wrlock(LOCK) \
      (pthread_in_use () ? glthread_rwlock_wrlock_multithreaded (LOCK) : 0)
#   define glthread_rwlock_unlock(LOCK) \
      (pthread_in_use () ? glthread_rwlock_unlock_multithreaded (LOCK) : 0)
#   define glthread_rwlock_destroy(LOCK) \
      (pthread_in_use () ? glthread_rwlock_destroy_multithreaded (LOCK) : 0)
extern int glthread_rwlock_init_multithreaded (gl_rwlock_t *lock);
extern int glthread_rwlock_rdlock_multithreaded (gl_rwlock_t *lock);
extern int glthread_rwlock_wrlock_multithreaded (gl_rwlock_t *lock);
extern int glthread_rwlock_unlock_multithreaded (gl_rwlock_t *lock);
extern int glthread_rwlock_destroy_multithreaded (gl_rwlock_t *lock);

#  endif

# else

typedef struct
        {
          pthread_mutex_t lock; /* protects the remaining fields */
          pthread_cond_t waiting_readers; /* waiting readers */
          pthread_cond_t waiting_writers; /* waiting writers */
          unsigned int waiting_writers_count; /* number of waiting writers */
          int runcount; /* number of readers running, or -1 when a writer runs */
        }
        gl_rwlock_t;
# define gl_rwlock_define(STORAGECLASS, NAME) \
    STORAGECLASS gl_rwlock_t NAME;
# define gl_rwlock_define_initialized(STORAGECLASS, NAME) \
    STORAGECLASS gl_rwlock_t NAME = gl_rwlock_initializer;
# define gl_rwlock_initializer \
    { PTHREAD_MUTEX_INITIALIZER, PTHREAD_COND_INITIALIZER, PTHREAD_COND_INITIALIZER, 0, 0 }
# define glthread_rwlock_init(LOCK) \
    (pthread_in_use () ? glthread_rwlock_init_multithreaded (LOCK) : 0)
# define glthread_rwlock_rdlock(LOCK) \
    (pthread_in_use () ? glthread_rwlock_rdlock_multithreaded (LOCK) : 0)
# define glthread_rwlock_wrlock(LOCK) \
    (pthread_in_use () ? glthread_rwlock_wrlock_multithreaded (LOCK) : 0)
# define glthread_rwlock_unlock(LOCK) \
    (pthread_in_use () ? glthread_rwlock_unlock_multithreaded (LOCK) : 0)
# define glthread_rwlock_destroy(LOCK) \
    (pthread_in_use () ? glthread_rwlock_destroy_multithreaded (LOCK) : 0)
extern int glthread_rwlock_init_multithreaded (gl_rwlock_t *lock);
extern int glthread_rwlock_rdlock_multithreaded (gl_rwlock_t *lock);
extern int glthread_rwlock_wrlock_multithreaded (gl_rwlock_t *lock);
extern int glthread_rwlock_unlock_multithreaded (gl_rwlock_t *lock);
extern int glthread_rwlock_destroy_multithreaded (gl_rwlock_t *lock);

# endif

/* --------------------- gl_recursive_lock_t datatype --------------------- */

# if HAVE_PTHREAD_MUTEX_RECURSIVE

#  if defined PTHREAD_RECURSIVE_MUTEX_INITIALIZER || defined PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP

typedef pthread_mutex_t gl_recursive_lock_t;
#   define gl_recursive_lock_define(STORAGECLASS, NAME) \
      STORAGECLASS pthread_mutex_t NAME;
#   define gl_recursive_lock_define_initialized(STORAGECLASS, NAME) \
      STORAGECLASS pthread_mutex_t NAME = gl_recursive_lock_initializer;
#   ifdef PTHREAD_RECURSIVE_MUTEX_INITIALIZER
#    define gl_recursive_lock_initializer \
       PTHREAD_RECURSIVE_MUTEX_INITIALIZER
#   else
#    define gl_recursive_lock_initializer \
       PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP
#   endif
#   define glthread_recursive_lock_init(LOCK) \
      (pthread_in_use () ? glthread_recursive_lock_init_multithreaded (LOCK) : 0)
#   define glthread_recursive_lock_lock(LOCK) \
      (pthread_in_use () ? pthread_mutex_lock (LOCK) : 0)
#   define glthread_recursive_lock_unlock(LOCK) \
      (pthread_in_use () ? pthread_mutex_unlock (LOCK) : 0)
#   define glthread_recursive_lock_destroy(LOCK) \
      (pthread_in_use () ? pthread_mutex_destroy (LOCK) : 0)
extern int glthread_recursive_lock_init_multithreaded (gl_recursive_lock_t *lock);

#  else

typedef struct
        {
          pthread_mutex_t recmutex; /* recursive mutex */
          pthread_mutex_t guard;    /* protects the initialization */
          int initialized;
        }
        gl_recursive_lock_t;
#   define gl_recursive_lock_define(STORAGECLASS, NAME) \
      STORAGECLASS gl_recursive_lock_t NAME;
#   define gl_recursive_lock_define_initialized(STORAGECLASS, NAME) \
      STORAGECLASS gl_recursive_lock_t NAME = gl_recursive_lock_initializer;
#   define gl_recursive_lock_initializer \
      { PTHREAD_MUTEX_INITIALIZER, PTHREAD_MUTEX_INITIALIZER, 0 }
#   define glthread_recursive_lock_init(LOCK) \
      (pthread_in_use () ? glthread_recursive_lock_init_multithreaded (LOCK) : 0)
#   define glthread_recursive_lock_lock(LOCK) \
      (pthread_in_use () ? glthread_recursive_lock_lock_multithreaded (LOCK) : 0)
#   define glthread_recursive_lock_unlock(LOCK) \
      (pthread_in_use () ? glthread_recursive_lock_unlock_multithreaded (LOCK) : 0)
#   define glthread_recursive_lock_destroy(LOCK) \
      (pthread_in_use () ? glthread_recursive_lock_destroy_multithreaded (LOCK) : 0)
extern int glthread_recursive_lock_init_multithreaded (gl_recursive_lock_t *lock);
extern int glthread_recursive_lock_lock_multithreaded (gl_recursive_lock_t *lock);
extern int glthread_recursive_lock_unlock_multithreaded (gl_recursive_lock_t *lock);
extern int glthread_recursive_lock_destroy_multithreaded (gl_recursive_lock_t *lock);

#  endif

# else

/* Old versions of POSIX threads on Solaris did not have recursive locks.
   We have to implement them ourselves.  */

typedef struct
        {
          pthread_mutex_t mutex;
          pthread_t owner;
          unsigned long depth;
        }
        gl_recursive_lock_t;
#  define gl_recursive_lock_define(STORAGECLASS, NAME) \
     STORAGECLASS gl_recursive_lock_t NAME;
#  define gl_recursive_lock_define_initialized(STORAGECLASS, NAME) \
     STORAGECLASS gl_recursive_lock_t NAME = gl_recursive_lock_initializer;
#  define gl_recursive_lock_initializer \
     { PTHREAD_MUTEX_INITIALIZER, (pthread_t) 0, 0 }
#  define glthread_recursive_lock_init(LOCK) \
     (pthread_in_use () ? glthread_recursive_lock_init_multithreaded (LOCK) : 0)
#  define glthread_recursive_lock_lock(LOCK) \
     (pthread_in_use () ? glthread_recursive_lock_lock_multithreaded (LOCK) : 0)
#  define glthread_recursive_lock_unlock(LOCK) \
     (pthread_in_use () ? glthread_recursive_lock_unlock_multithreaded (LOCK) : 0)
#  define glthread_recursive_lock_destroy(LOCK) \
     (pthread_in_use () ? glthread_recursive_lock_destroy_multithreaded (LOCK) : 0)
extern int glthread_recursive_lock_init_multithreaded (gl_recursive_lock_t *lock);
extern int glthread_recursive_lock_lock_multithreaded (gl_recursive_lock_t *lock);
extern int glthread_recursive_lock_unlock_multithreaded (gl_recursive_lock_t *lock);
extern int glthread_recursive_lock_destroy_multithreaded (gl_recursive_lock_t *lock);

# endif

# ifdef __cplusplus
}
# endif

#endif

/* ========================================================================= */

#if USE_WINDOWS_THREADS

# define WIN32_LEAN_AND_MEAN  /* avoid including junk */
# include <windows.h>

# include "windows-mutex.h"
# include "windows-rwlock.h"
# include "windows-recmutex.h"

# ifdef __cplusplus
extern "C" {
# endif

/* We can use CRITICAL_SECTION directly, rather than the native Windows Event,
   Mutex, Semaphore types, because
     - we need only to synchronize inside a single process (address space),
       not inter-process locking,
     - we don't need to support trylock operations.  (TryEnterCriticalSection
       does not work on Windows 95/98/ME.  Packages that need trylock usually
       define their own mutex type.)  */

/* There is no way to statically initialize a CRITICAL_SECTION.  It needs
   to be done lazily, once only.  For this we need spinlocks.  */

/* -------------------------- gl_lock_t datatype -------------------------- */

typedef glwthread_mutex_t gl_lock_t;
# define gl_lock_define(STORAGECLASS, NAME) \
    STORAGECLASS gl_lock_t NAME;
# define gl_lock_define_initialized(STORAGECLASS, NAME) \
    STORAGECLASS gl_lock_t NAME = gl_lock_initializer;
# define gl_lock_initializer \
    GLWTHREAD_MUTEX_INIT
# define glthread_lock_init(LOCK) \
    (glwthread_mutex_init (LOCK), 0)
# define glthread_lock_lock(LOCK) \
    glwthread_mutex_lock (LOCK)
# define glthread_lock_unlock(LOCK) \
    glwthread_mutex_unlock (LOCK)
# define glthread_lock_destroy(LOCK) \
    glwthread_mutex_destroy (LOCK)

/* ------------------------- gl_rwlock_t datatype ------------------------- */

typedef glwthread_rwlock_t gl_rwlock_t;
# define gl_rwlock_define(STORAGECLASS, NAME) \
    STORAGECLASS gl_rwlock_t NAME;
# define gl_rwlock_define_initialized(STORAGECLASS, NAME) \
    STORAGECLASS gl_rwlock_t NAME = gl_rwlock_initializer;
# define gl_rwlock_initializer \
    GLWTHREAD_RWLOCK_INIT
# define glthread_rwlock_init(LOCK) \
    (glwthread_rwlock_init (LOCK), 0)
# define glthread_rwlock_rdlock(LOCK) \
    glwthread_rwlock_rdlock (LOCK)
# define glthread_rwlock_wrlock(LOCK) \
    glwthread_rwlock_wrlock (LOCK)
# define glthread_rwlock_unlock(LOCK) \
    glwthread_rwlock_unlock (LOCK)
# define glthread_rwlock_destroy(LOCK) \
    glwthread_rwlock_destroy (LOCK)

/* --------------------- gl_recursive_lock_t datatype --------------------- */

typedef glwthread_recmutex_t gl_recursive_lock_t;
# define gl_recursive_lock_define(STORAGECLASS, NAME) \
    STORAGECLASS gl_recursive_lock_t NAME;
# define gl_recursive_lock_define_initialized(STORAGECLASS, NAME) \
    STORAGECLASS gl_recursive_lock_t NAME = gl_recursive_lock_initializer;
# define gl_recursive_lock_initializer \
    GLWTHREAD_RECMUTEX_INIT
# define glthread_recursive_lock_init(LOCK) \
    (glwthread_recmutex_init (LOCK), 0)
# define glthread_recursive_lock_lock(LOCK) \
    glwthread_recmutex_lock (LOCK)
# define glthread_recursive_lock_unlock(LOCK) \
    glwthread_recmutex_unlock (LOCK)
# define glthread_recursive_lock_destroy(LOCK) \
    glwthread_recmutex_destroy (LOCK)

# ifdef __cplusplus
}
# endif

#endif

/* ========================================================================= */

#if !(USE_ISOC_THREADS || USE_POSIX_THREADS || USE_ISOC_AND_POSIX_THREADS || USE_WINDOWS_THREADS)

/* Provide dummy implementation if threads are not supported.  */

/* -------------------------- gl_lock_t datatype -------------------------- */

typedef int gl_lock_t;
# define gl_lock_define(STORAGECLASS, NAME)
# define gl_lock_define_initialized(STORAGECLASS, NAME)
# define glthread_lock_init(NAME) 0
# define glthread_lock_lock(NAME) 0
# define glthread_lock_unlock(NAME) 0
# define glthread_lock_destroy(NAME) 0

/* ------------------------- gl_rwlock_t datatype ------------------------- */

typedef int gl_rwlock_t;
# define gl_rwlock_define(STORAGECLASS, NAME)
# define gl_rwlock_define_initialized(STORAGECLASS, NAME)
# define glthread_rwlock_init(NAME) 0
# define glthread_rwlock_rdlock(NAME) 0
# define glthread_rwlock_wrlock(NAME) 0
# define glthread_rwlock_unlock(NAME) 0
# define glthread_rwlock_destroy(NAME) 0

/* --------------------- gl_recursive_lock_t datatype --------------------- */

typedef int gl_recursive_lock_t;
# define gl_recursive_lock_define(STORAGECLASS, NAME)
# define gl_recursive_lock_define_initialized(STORAGECLASS, NAME)
# define glthread_recursive_lock_init(NAME) 0
# define glthread_recursive_lock_lock(NAME) 0
# define glthread_recursive_lock_unlock(NAME) 0
# define glthread_recursive_lock_destroy(NAME) 0

#endif

/* ========================================================================= */

/* Macros with built-in error handling.  */

/* -------------------------- gl_lock_t datatype -------------------------- */

#define gl_lock_init(NAME) \
   do                                  \
     {                                 \
       if (glthread_lock_init (&NAME)) \
         abort ();                     \
     }                                 \
   while (0)
#define gl_lock_lock(NAME) \
   do                                  \
     {                                 \
       if (glthread_lock_lock (&NAME)) \
         abort ();                     \
     }                                 \
   while (0)
#define gl_lock_unlock(NAME) \
   do                                    \
     {                                   \
       if (glthread_lock_unlock (&NAME)) \
         abort ();                       \
     }                                   \
   while (0)
#define gl_lock_destroy(NAME) \
   do                                     \
     {                                    \
       if (glthread_lock_destroy (&NAME)) \
         abort ();                        \
     }                                    \
   while (0)

/* ------------------------- gl_rwlock_t datatype ------------------------- */

#define gl_rwlock_init(NAME) \
   do                                    \
     {                                   \
       if (glthread_rwlock_init (&NAME)) \
         abort ();                       \
     }                                   \
   while (0)
#define gl_rwlock_rdlock(NAME) \
   do                                      \
     {                                     \
       if (glthread_rwlock_rdlock (&NAME)) \
         abort ();                         \
     }                                     \
   while (0)
#define gl_rwlock_wrlock(NAME) \
   do                                      \
     {                                     \
       if (glthread_rwlock_wrlock (&NAME)) \
         abort ();                         \
     }                                     \
   while (0)
#define gl_rwlock_unlock(NAME) \
   do                                      \
     {                                     \
       if (glthread_rwlock_unlock (&NAME)) \
         abort ();                         \
     }                                     \
   while (0)
#define gl_rwlock_destroy(NAME) \
   do                                       \
     {                                      \
       if (glthread_rwlock_destroy (&NAME)) \
         abort ();                          \
     }                                      \
   while (0)

/* --------------------- gl_recursive_lock_t datatype --------------------- */

#define gl_recursive_lock_init(NAME) \
   do                                            \
     {                                           \
       if (glthread_recursive_lock_init (&NAME)) \
         abort ();                               \
     }                                           \
   while (0)
#define gl_recursive_lock_lock(NAME) \
   do                                            \
     {                                           \
       if (glthread_recursive_lock_lock (&NAME)) \
         abort ();                               \
     }                                           \
   while (0)
#define gl_recursive_lock_unlock(NAME) \
   do                                              \
     {                                             \
       if (glthread_recursive_lock_unlock (&NAME)) \
         abort ();                                 \
     }                                             \
   while (0)
#define gl_recursive_lock_destroy(NAME) \
   do                                               \
     {                                              \
       if (glthread_recursive_lock_destroy (&NAME)) \
         abort ();                                  \
     }                                              \
   while (0)

/* ========================================================================= */

#endif /* _LOCK_H */