iokit/Kernel/IOLocks.cpp

   1 /*
   2  * Copyright (c) 1998-2007 Apple Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28
  29 #include <IOKit/system.h>
  30
  31 #include <IOKit/IOReturn.h>
  32 #include <IOKit/IOLib.h>
  33 #include <IOKit/assert.h>
  34
  35 #include <IOKit/IOLocksPrivate.h>
  36
  37 extern "C" {
  38 #include <kern/locks.h>
  39
  40 void    IOLockInitWithState( IOLock * lock, IOLockState state)
  41 {
  42     if( state == kIOLockStateLocked)
  43         lck_mtx_lock( lock);
  44 }
  45
  46 IOLock * IOLockAlloc( void )
  47 {
  48     return( lck_mtx_alloc_init(IOLockGroup, LCK_ATTR_NULL) );
  49 }
  50
  51 void    IOLockFree( IOLock * lock)
  52 {
  53     lck_mtx_free( lock, IOLockGroup);
  54 }
  55
  56 lck_mtx_t * IOLockGetMachLock( IOLock * lock)
  57 {
  58     return( (lck_mtx_t *)lock);
  59 }
  60
  61 int     IOLockSleep( IOLock * lock, void *event, UInt32 interType)
  62 {
  63     return (int) lck_mtx_sleep(lock, LCK_SLEEP_DEFAULT, (event_t) event, (wait_interrupt_t) interType);
  64 }
  65
  66 int     IOLockSleepDeadline( IOLock * lock, void *event,
  67                                 AbsoluteTime deadline, UInt32 interType)
  68 {
  69     return (int) lck_mtx_sleep_deadline(lock, LCK_SLEEP_DEFAULT, (event_t) event,
  70                                         (wait_interrupt_t) interType, __OSAbsoluteTime(deadline));
  71 }
  72
  73 void    IOLockWakeup(IOLock * lock, void *event, bool oneThread)
  74 {
  75         thread_wakeup_prim((event_t) event, oneThread, THREAD_AWAKENED);
  76 }
  77
  78
  79 struct _IORecursiveLock {
  80         lck_mtx_t       *mutex;
  81         lck_grp_t       *group;
  82         thread_t        thread;
  83         UInt32          count;
  84 };
  85
  86 IORecursiveLock * IORecursiveLockAllocWithLockGroup( lck_grp_t * lockGroup )
  87 {
  88     _IORecursiveLock * lock;
  89
  90     if( lockGroup == 0 )
  91         return( 0 );
  92
  93     lock = IONew( _IORecursiveLock, 1 );
  94     if( !lock )
  95         return( 0 );
  96
  97     lock->mutex = lck_mtx_alloc_init( lockGroup, LCK_ATTR_NULL );
  98     if( lock->mutex ) {
  99                 lock->group = lockGroup;
 100         lock->thread = 0;
 101         lock->count  = 0;
 102     } else {
 103         IODelete( lock, _IORecursiveLock, 1 );
 104         lock = 0;
 105     }
 106
 107     return( (IORecursiveLock *) lock );
 108 }
 109
 110
 111 IORecursiveLock * IORecursiveLockAlloc( void )
 112 {
 113     return IORecursiveLockAllocWithLockGroup( IOLockGroup );
 114 }
 115
 116 void IORecursiveLockFree( IORecursiveLock * _lock )
 117 {
 118     _IORecursiveLock * lock = (_IORecursiveLock *)_lock;
 119
 120     lck_mtx_free( lock->mutex, lock->group );
 121     IODelete( lock, _IORecursiveLock, 1 );
 122 }
 123
 124 lck_mtx_t * IORecursiveLockGetMachLock( IORecursiveLock * lock )
 125 {
 126     return( lock->mutex );
 127 }
 128
 129 void IORecursiveLockLock( IORecursiveLock * _lock)
 130 {
 131     _IORecursiveLock * lock = (_IORecursiveLock *)_lock;
 132
 133     if( lock->thread == IOThreadSelf())
 134         lock->count++;
 135     else {
 136         lck_mtx_lock( lock->mutex );
 137         assert( lock->thread == 0 );
 138         assert( lock->count == 0 );
 139         lock->thread = IOThreadSelf();
 140         lock->count = 1;
 141     }
 142 }
 143
 144 boolean_t IORecursiveLockTryLock( IORecursiveLock * _lock)
 145 {
 146     _IORecursiveLock * lock = (_IORecursiveLock *)_lock;
 147
 148     if( lock->thread == IOThreadSelf()) {
 149         lock->count++;
 150         return( true );
 151     } else {
 152         if( lck_mtx_try_lock( lock->mutex )) {
 153             assert( lock->thread == 0 );
 154             assert( lock->count == 0 );
 155             lock->thread = IOThreadSelf();
 156             lock->count = 1;
 157             return( true );
 158         }
 159     }
 160     return( false );
 161 }
 162
 163 void IORecursiveLockUnlock( IORecursiveLock * _lock)
 164 {
 165     _IORecursiveLock * lock = (_IORecursiveLock *)_lock;
 166
 167     assert( lock->thread == IOThreadSelf() );
 168
 169     if( 0 == (--lock->count)) {
 170         lock->thread = 0;
 171         lck_mtx_unlock( lock->mutex );
 172     }
 173 }
 174
 175 boolean_t IORecursiveLockHaveLock( const IORecursiveLock * _lock)
 176 {
 177     _IORecursiveLock * lock = (_IORecursiveLock *)_lock;
 178
 179     return( lock->thread == IOThreadSelf());
 180 }
 181
 182 int IORecursiveLockSleep(IORecursiveLock *_lock, void *event, UInt32 interType)
 183 {
 184     _IORecursiveLock * lock = (_IORecursiveLock *)_lock;
 185     UInt32 count = lock->count;
 186     int res;
 187
 188     assert(lock->thread == IOThreadSelf());
 189
 190     lock->count = 0;
 191     lock->thread = 0;
 192     res = lck_mtx_sleep(lock->mutex, LCK_SLEEP_DEFAULT, (event_t) event, (wait_interrupt_t) interType);
 193
 194     // Must re-establish the recursive lock no matter why we woke up
 195     // otherwise we would potentially leave the return path corrupted.
 196     assert(lock->thread == 0);
 197     assert(lock->count == 0);
 198     lock->thread = IOThreadSelf();
 199     lock->count = count;
 200     return res;
 201 }
 202
 203 int     IORecursiveLockSleepDeadline( IORecursiveLock * _lock, void *event,
 204                                   AbsoluteTime deadline, UInt32 interType)
 205 {
 206     _IORecursiveLock * lock = (_IORecursiveLock *)_lock;
 207     UInt32 count = lock->count;
 208     int res;
 209
 210     assert(lock->thread == IOThreadSelf());
 211
 212     lock->count = 0;
 213     lock->thread = 0;
 214     res = lck_mtx_sleep_deadline(lock->mutex, LCK_SLEEP_DEFAULT, (event_t) event,
 215                                                                  (wait_interrupt_t) interType, __OSAbsoluteTime(deadline));
 216
 217     // Must re-establish the recursive lock no matter why we woke up
 218     // otherwise we would potentially leave the return path corrupted.
 219     assert(lock->thread == 0);
 220     assert(lock->count == 0);
 221     lock->thread = IOThreadSelf();
 222     lock->count = count;
 223     return res;
 224 }
 225
 226 void IORecursiveLockWakeup(IORecursiveLock *, void *event, bool oneThread)
 227 {
 228     thread_wakeup_prim((event_t) event, oneThread, THREAD_AWAKENED);
 229 }
 230
 231 /*
 232  * Complex (read/write) lock operations
 233  */
 234
 235 IORWLock * IORWLockAlloc( void )
 236 {
 237     return(  lck_rw_alloc_init(IOLockGroup, LCK_ATTR_NULL)  );
 238 }
 239
 240 void    IORWLockFree( IORWLock * lock)
 241 {
 242     lck_rw_free( lock, IOLockGroup);
 243 }
 244
 245 lck_rw_t * IORWLockGetMachLock( IORWLock * lock)
 246 {
 247     return( (lck_rw_t *)lock);
 248 }
 249
 250
 251 /*
 252  * Spin locks
 253  */
 254
 255 IOSimpleLock * IOSimpleLockAlloc( void )
 256 {
 257     return( lck_spin_alloc_init( IOLockGroup, LCK_ATTR_NULL) );
 258 }
 259
 260 void IOSimpleLockInit( IOSimpleLock * lock)
 261 {
 262     lck_spin_init( lock, IOLockGroup, LCK_ATTR_NULL);
 263 }
 264
 265 void IOSimpleLockFree( IOSimpleLock * lock )
 266 {
 267     lck_spin_free( lock, IOLockGroup);
 268 }
 269
 270 lck_spin_t * IOSimpleLockGetMachLock( IOSimpleLock * lock)
 271 {
 272     return( (lck_spin_t *)lock);
 273 }
 274
 275 } /* extern "C" */
 276
 277