1: /* Copyright (C) 1994, 1996, 2007 Free Software Foundation, Inc.
    2:    This file is part of the GNU C Library.
    3: 
    4:    The GNU C Library is free software; you can redistribute it and/or
    5:    modify it under the terms of the GNU Lesser General Public
    6:    License as published by the Free Software Foundation; either
    7:    version 2.1 of the License, or (at your option) any later version.
    8: 
    9:    The GNU C Library is distributed in the hope that it will be useful,
   10:    but WITHOUT ANY WARRANTY; without even the implied warranty of
   11:    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   12:    Lesser General Public License for more details.
   13: 
   14:    You should have received a copy of the GNU Lesser General Public
   15:    License along with the GNU C Library; if not, write to the Free
   16:    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   17:    02111-1307 USA.  */
   18: 
   19: #ifndef _LOCK_INTERN_H
   20: #define _LOCK_INTERN_H
   21: 
   22: #include <sys/cdefs.h>
   23: #include <machine-lock.h>
   24: 
   25: #ifndef _EXTERN_INLINE
   26: #define _EXTERN_INLINE __extern_inline
   27: #endif
   28: 
   29: 
   30: /* Initialize LOCK.  */
   31: 
   32: _EXTERN_INLINE void
   33: __spin_lock_init (__spin_lock_t *__lock)
   34: {
   35:   *__lock = __SPIN_LOCK_INITIALIZER;
   36: }
   37: 
   38: 
   39: /* Lock LOCK, blocking if we can't get it.  */
   40: extern void __spin_lock_solid (__spin_lock_t *__lock);
   41: 
   42: /* Lock the spin lock LOCK.  */
   43: 
   44: _EXTERN_INLINE void
   45: __spin_lock (__spin_lock_t *__lock)
   46: {
   47:   if (! __spin_try_lock (__lock))
   48:     __spin_lock_solid (__lock);
   49: }
   50: ^L
   51: /* Name space-clean internal interface to mutex locks.
   52: 
   53:    Code internal to the C library uses these functions to lock and unlock
   54:    mutex locks.  These locks are of type `struct mutex', defined in
   55:    <cthreads.h>.  The functions here are name space-clean.  If the program
   56:    is linked with the cthreads library, `__mutex_lock_solid' and
   57:    `__mutex_unlock_solid' will invoke the corresponding cthreads functions
   58:    to implement real mutex locks.  If not, simple stub versions just use
   59:    spin locks.  */
   60: 
   61: 
   62: /* Initialize the newly allocated mutex lock LOCK for further use.  */
   63: extern void __mutex_init (void *__lock);
   64: 
   65: /* Lock LOCK, blocking if we can't get it.  */
   66: extern void __mutex_lock_solid (void *__lock);
   67: 
   68: /* Finish unlocking LOCK, after the spin lock LOCK->held has already been
   69:    unlocked.  This function will wake up any thread waiting on LOCK.  */
   70: extern void __mutex_unlock_solid (void *__lock);
   71: 
   72: /* Lock the mutex lock LOCK.  */
   73: 
   74: _EXTERN_INLINE void
   75: __mutex_lock (void *__lock)
   76: {
   77:   if (! __spin_try_lock ((__spin_lock_t *) __lock))
   78:     __mutex_lock_solid (__lock);
   79: }
   80: 
   81: /* Unlock the mutex lock LOCK.  */
   82: 
   83: _EXTERN_INLINE void
   84: __mutex_unlock (void *__lock)
   85: {
   86:   __spin_unlock ((__spin_lock_t *) __lock);
   87:   __mutex_unlock_solid (__lock);
   88: }
   89: 
   90: 
   91: _EXTERN_INLINE int
   92: __mutex_trylock (void *__lock)
   93: {
   94:   return __spin_try_lock ((__spin_lock_t *) __lock);
   95: }
   96: 
   97: #endif /* lock-intern.h */