iokit/Kernel/IOLocks.cpp

   1 /*
   2  * Copyright (c) 1998-2000 Apple Computer, 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  * Copyright (c) 1998 Apple Computer, Inc.  All rights reserved.
  30  *
  31  * HISTORY
  32  *
  33  */
  34
  35
  36 #define IOLOCKS_CPP     1
  37
  38 #include <IOKit/system.h>
  39
  40 #include <IOKit/IOReturn.h>
  41 #include <IOKit/IOLib.h>
  42 #include <IOKit/assert.h>
  43
  44 extern "C" {
  45 #include <kern/locks.h>
  46
  47 void    IOLockInitWithState( IOLock * lock, IOLockState state)
  48 {
  49     if( state == kIOLockStateLocked)
  50         lck_mtx_lock( lock);
  51 }
  52
  53 IOLock * IOLockAlloc( void )
  54 {
  55     return( lck_mtx_alloc_init(IOLockGroup, LCK_ATTR_NULL) );
  56 }
  57
  58 void    IOLockFree( IOLock * lock)
  59 {
  60     lck_mtx_free( lock, IOLockGroup);
  61 }
  62
  63 lck_mtx_t * IOLockGetMachLock( IOLock * lock)
  64 {
  65     return( (lck_mtx_t *)lock);
  66 }
  67
  68 int     IOLockSleep( IOLock * lock, void *event, UInt32 interType)
  69 {
  70     return (int) lck_mtx_sleep(lock, LCK_SLEEP_DEFAULT, (event_t) event, (wait_interrupt_t) interType);
  71 }
  72
  73 int     IOLockSleepDeadline( IOLock * lock, void *event,
  74                                 AbsoluteTime deadline, UInt32 interType)
  75 {
  76     return (int) lck_mtx_sleep_deadline(lock, LCK_SLEEP_DEFAULT, (event_t) event,
  77                                         (wait_interrupt_t) interType, __OSAbsoluteTime(deadline));
  78 }
  79
  80 void    IOLockWakeup(IOLock * lock, void *event, bool oneThread)
  81 {
  82         thread_wakeup_prim((event_t) event, oneThread, THREAD_AWAKENED);
  83 }
  84
  85
  86 struct _IORecursiveLock {
  87     lck_mtx_t   *mutex;
  88     thread_t    thread;
  89     UInt32      count;
  90 };
  91
  92 IORecursiveLock * IORecursiveLockAlloc( void )
  93 {
  94     _IORecursiveLock * lock;
  95
  96     lock = IONew( _IORecursiveLock, 1);
  97     if( !lock)
  98         return( 0 );
  99
 100     lock->mutex = lck_mtx_alloc_init(IOLockGroup, LCK_ATTR_NULL);
 101     if( lock->mutex) {
 102         lock->thread = 0;
 103         lock->count  = 0;
 104     } else {
 105         IODelete( lock, _IORecursiveLock, 1);
 106         lock = 0;
 107     }
 108
 109     return( (IORecursiveLock *) lock );
 110 }
 111
 112 void IORecursiveLockFree( IORecursiveLock * _lock )
 113 {
 114     _IORecursiveLock * lock = (_IORecursiveLock *)_lock;
 115
 116     lck_mtx_free( lock->mutex , IOLockGroup);
 117     IODelete( lock, _IORecursiveLock, 1);
 118 }
 119
 120 lck_mtx_t * IORecursiveLockGetMachLock( IORecursiveLock * lock)
 121 {
 122     return( lock->mutex);
 123 }
 124
 125 void IORecursiveLockLock( IORecursiveLock * _lock)
 126 {
 127     _IORecursiveLock * lock = (_IORecursiveLock *)_lock;
 128
 129     if( lock->thread == IOThreadSelf())
 130         lock->count++;
 131     else {
 132         lck_mtx_lock( lock->mutex );
 133         assert( lock->thread == 0 );
 134         assert( lock->count == 0 );
 135         lock->thread = IOThreadSelf();
 136         lock->count = 1;
 137     }
 138 }
 139
 140 boolean_t IORecursiveLockTryLock( IORecursiveLock * _lock)
 141 {
 142     _IORecursiveLock * lock = (_IORecursiveLock *)_lock;
 143
 144     if( lock->thread == IOThreadSelf()) {
 145         lock->count++;
 146         return( true );
 147     } else {
 148         if( lck_mtx_try_lock( lock->mutex )) {
 149             assert( lock->thread == 0 );
 150             assert( lock->count == 0 );
 151             lock->thread = IOThreadSelf();
 152             lock->count = 1;
 153             return( true );
 154         }
 155     }
 156     return( false );
 157 }
 158
 159 void IORecursiveLockUnlock( IORecursiveLock * _lock)
 160 {
 161     _IORecursiveLock * lock = (_IORecursiveLock *)_lock;
 162
 163     assert( lock->thread == IOThreadSelf() );
 164
 165     if( 0 == (--lock->count)) {
 166         lock->thread = 0;
 167         lck_mtx_unlock( lock->mutex );
 168     }
 169 }
 170
 171 boolean_t IORecursiveLockHaveLock( const IORecursiveLock * _lock)
 172 {
 173     _IORecursiveLock * lock = (_IORecursiveLock *)_lock;
 174
 175     return( lock->thread == IOThreadSelf());
 176 }
 177
 178 int IORecursiveLockSleep(IORecursiveLock *_lock, void *event, UInt32 interType)
 179 {
 180     _IORecursiveLock * lock = (_IORecursiveLock *)_lock;
 181     UInt32 count = lock->count;
 182     int res;
 183
 184     assert(lock->thread == IOThreadSelf());
 185     assert(lock->count == 1 || interType == THREAD_UNINT);
 186
 187     lock->count = 0;
 188     lock->thread = 0;
 189     res = lck_mtx_sleep(lock->mutex, LCK_SLEEP_DEFAULT, (event_t) event, (wait_interrupt_t) interType);
 190
 191     // Must re-establish the recursive lock no matter why we woke up
 192     // otherwise we would potentially leave the return path corrupted.
 193     assert(lock->thread == 0);
 194     assert(lock->count == 0);
 195     lock->thread = IOThreadSelf();
 196     lock->count = count;
 197     return res;
 198 }
 199
 200 void IORecursiveLockWakeup(IORecursiveLock *, void *event, bool oneThread)
 201 {
 202     thread_wakeup_prim((event_t) event, oneThread, THREAD_AWAKENED);
 203 }
 204
 205 /*
 206  * Complex (read/write) lock operations
 207  */
 208
 209 IORWLock * IORWLockAlloc( void )
 210 {
 211     return(  lck_rw_alloc_init(IOLockGroup, LCK_ATTR_NULL)  );
 212 }
 213
 214 void    IORWLockFree( IORWLock * lock)
 215 {
 216     lck_rw_free( lock, IOLockGroup);
 217 }
 218
 219 lck_rw_t * IORWLockGetMachLock( IORWLock * lock)
 220 {
 221     return( (lck_rw_t *)lock);
 222 }
 223
 224
 225 /*
 226  * Spin locks
 227  */
 228
 229 IOSimpleLock * IOSimpleLockAlloc( void )
 230 {
 231     return( lck_spin_alloc_init( IOLockGroup, LCK_ATTR_NULL) );
 232 }
 233
 234 void IOSimpleLockInit( IOSimpleLock * lock)
 235 {
 236     lck_spin_init( lock, IOLockGroup, LCK_ATTR_NULL);
 237 }
 238
 239 void IOSimpleLockFree( IOSimpleLock * lock )
 240 {
 241     lck_spin_free( lock, IOLockGroup);
 242 }
 243
 244 lck_spin_t * IOSimpleLockGetMachLock( IOSimpleLock * lock)
 245 {
 246     return( (lck_spin_t *)lock);
 247 }
 248
 249 } /* extern "C" */
 250
 251