MdePkg/Include/Library/SynchronizationLib.h

   1 /** @file
   2   Provides synchronization functions.
   3
   4 Copyright (c) 2006 - 2008, Intel Corporation<BR>
   5 All rights reserved. This program and the accompanying materials
   6 are licensed and made available under the terms and conditions of the BSD License
   7 which accompanies this distribution.  The full text of the license may be found at
   8 http://opensource.org/licenses/bsd-license.php
   9
  10 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  11 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  12
  13 **/
  14
  15 #ifndef __SYNCHRONIZATION_LIB__
  16 #define __SYNCHRONIZATION_LIB__
  17
  18 ///
  19 /// Definitions for SPIN_LOCK
  20 ///
  21 typedef volatile UINTN              SPIN_LOCK;
  22
  23
  24 /**
  25   Retrieves the architecture-specific spin lock alignment requirements for
  26   optimal spin lock performance.
  27
  28   This function retrieves the spin lock alignment requirements for optimal
  29   performance on a given CPU architecture. The spin lock alignment must be a
  30   power of two and is returned by this function. If there are no alignment
  31   requirements, then 1 must be returned. The spin lock synchronization
  32   functions must function correctly if the spin lock size and alignment values
  33   returned by this function are not used at all. These values are hints to the
  34   consumers of the spin lock synchronization functions to obtain optimal spin
  35   lock performance.
  36
  37   @return The architecture-specific spin lock alignment.
  38
  39 **/
  40 UINTN
  41 EFIAPI
  42 GetSpinLockProperties (
  43   VOID
  44   );
  45
  46
  47 /**
  48   Initializes a spin lock to the released state and returns the spin lock.
  49
  50   This function initializes the spin lock specified by SpinLock to the released
  51   state, and returns SpinLock. Optimal performance can be achieved by calling
  52   GetSpinLockProperties() to determine the size and alignment requirements for
  53   SpinLock.
  54
  55   If SpinLock is NULL, then ASSERT().
  56
  57   @param  SpinLock  A pointer to the spin lock to initialize to the released
  58                     state.
  59
  60   @return SpinLock in release state.
  61
  62 **/
  63 SPIN_LOCK *
  64 EFIAPI
  65 InitializeSpinLock (
  66   OUT      SPIN_LOCK                 *SpinLock
  67   );
  68
  69
  70 /**
  71   Waits until a spin lock can be placed in the acquired state.
  72
  73   This function checks the state of the spin lock specified by SpinLock. If
  74   SpinLock is in the released state, then this function places SpinLock in the
  75   acquired state and returns SpinLock. Otherwise, this function waits
  76   indefinitely for the spin lock to be released, and then places it in the
  77   acquired state and returns SpinLock. All state transitions of SpinLock must
  78   be performed using MP safe mechanisms.
  79
  80   If SpinLock is NULL, then ASSERT().
  81   If SpinLock was not initialized with InitializeSpinLock(), then ASSERT().
  82   If PcdSpinLockTimeout is not zero, and SpinLock is can not be acquired in
  83   PcdSpinLockTimeout microseconds, then ASSERT().
  84
  85   @param  SpinLock  A pointer to the spin lock to place in the acquired state.
  86
  87   @return SpinLock acquired lock.
  88
  89 **/
  90 SPIN_LOCK *
  91 EFIAPI
  92 AcquireSpinLock (
  93   IN OUT  SPIN_LOCK                 *SpinLock
  94   );
  95
  96
  97 /**
  98   Attempts to place a spin lock in the acquired state.
  99
 100   This function checks the state of the spin lock specified by SpinLock. If
 101   SpinLock is in the released state, then this function places SpinLock in the
 102   acquired state and returns TRUE. Otherwise, FALSE is returned. All state
 103   transitions of SpinLock must be performed using MP safe mechanisms.
 104
 105   If SpinLock is NULL, then ASSERT().
 106   If SpinLock was not initialized with InitializeSpinLock(), then ASSERT().
 107
 108   @param  SpinLock  A pointer to the spin lock to place in the acquired state.
 109
 110   @retval TRUE  SpinLock was placed in the acquired state.
 111   @retval FALSE SpinLock could not be acquired.
 112
 113 **/
 114 BOOLEAN
 115 EFIAPI
 116 AcquireSpinLockOrFail (
 117   IN OUT  SPIN_LOCK                 *SpinLock
 118   );
 119
 120
 121 /**
 122   Releases a spin lock.
 123
 124   This function places the spin lock specified by SpinLock in the release state
 125   and returns SpinLock.
 126
 127   If SpinLock is NULL, then ASSERT().
 128   If SpinLock was not initialized with InitializeSpinLock(), then ASSERT().
 129
 130   @param  SpinLock  A pointer to the spin lock to release.
 131
 132   @return SpinLock released lock.
 133
 134 **/
 135 SPIN_LOCK *
 136 EFIAPI
 137 ReleaseSpinLock (
 138   IN OUT  SPIN_LOCK                 *SpinLock
 139   );
 140
 141
 142 /**
 143   Performs an atomic increment of a 32-bit unsigned integer.
 144
 145   Performs an atomic increment of the 32-bit unsigned integer specified by
 146   Value and returns the incremented value. The increment operation must be
 147   performed using MP safe mechanisms. The state of the return value is not
 148   guaranteed to be MP safe.
 149
 150   If Value is NULL, then ASSERT().
 151
 152   @param  Value A pointer to the 32-bit value to increment.
 153
 154   @return The incremented value.
 155
 156 **/
 157 UINT32
 158 EFIAPI
 159 InterlockedIncrement (
 160   IN      UINT32                    *Value
 161   );
 162
 163
 164 /**
 165   Performs an atomic decrement of a 32-bit unsigned integer.
 166
 167   Performs an atomic decrement of the 32-bit unsigned integer specified by
 168   Value and returns the decremented value. The decrement operation must be
 169   performed using MP safe mechanisms. The state of the return value is not
 170   guaranteed to be MP safe.
 171
 172   If Value is NULL, then ASSERT().
 173
 174   @param  Value A pointer to the 32-bit value to decrement.
 175
 176   @return The decremented value.
 177
 178 **/
 179 UINT32
 180 EFIAPI
 181 InterlockedDecrement (
 182   IN      UINT32                    *Value
 183   );
 184
 185
 186 /**
 187   Performs an atomic compare exchange operation on a 32-bit unsigned integer.
 188
 189   Performs an atomic compare exchange operation on the 32-bit unsigned integer
 190   specified by Value.  If Value is equal to CompareValue, then Value is set to
 191   ExchangeValue and CompareValue is returned.  If Value is not equal to CompareValue,
 192   then Value is returned.  The compare exchange operation must be performed using
 193   MP safe mechanisms.
 194
 195   If Value is NULL, then ASSERT().
 196
 197   @param  Value         A pointer to the 32-bit value for the compare exchange
 198                         operation.
 199   @param  CompareValue  32-bit value used in compare operation.
 200   @param  ExchangeValue 32-bit value used in exchange operation.
 201
 202   @return The original *Value before exchange.
 203
 204 **/
 205 UINT32
 206 EFIAPI
 207 InterlockedCompareExchange32 (
 208   IN OUT  UINT32                    *Value,
 209   IN      UINT32                    CompareValue,
 210   IN      UINT32                    ExchangeValue
 211   );
 212
 213
 214 /**
 215   Performs an atomic compare exchange operation on a 64-bit unsigned integer.
 216
 217   Performs an atomic compare exchange operation on the 64-bit unsigned integer specified
 218   by Value.  If Value is equal to CompareValue, then Value is set to ExchangeValue and
 219   CompareValue is returned.  If Value is not equal to CompareValue, then Value is returned.
 220   The compare exchange operation must be performed using MP safe mechanisms.
 221
 222   If Value is NULL, then ASSERT().
 223
 224   @param  Value         A pointer to the 64-bit value for the compare exchange
 225                         operation.
 226   @param  CompareValue  64-bit value used in compare operation.
 227   @param  ExchangeValue 64-bit value used in exchange operation.
 228
 229   @return The original *Value before exchange.
 230
 231 **/
 232 UINT64
 233 EFIAPI
 234 InterlockedCompareExchange64 (
 235   IN OUT  UINT64                    *Value,
 236   IN      UINT64                    CompareValue,
 237   IN      UINT64                    ExchangeValue
 238   );
 239
 240
 241 /**
 242   Performs an atomic compare exchange operation on a pointer value.
 243
 244   Performs an atomic compare exchange operation on the pointer value specified
 245   by Value. If Value is equal to CompareValue, then Value is set to
 246   ExchangeValue and CompareValue is returned. If Value is not equal to
 247   CompareValue, then Value is returned. The compare exchange operation must be
 248   performed using MP safe mechanisms.
 249
 250   If Value is NULL, then ASSERT().
 251
 252   @param  Value         A pointer to the pointer value for the compare exchange
 253                         operation.
 254   @param  CompareValue  Pointer value used in compare operation.
 255   @param  ExchangeValue Pointer value used in exchange operation.
 256
 257   @return The original *Value before exchange.
 258 **/
 259 VOID *
 260 EFIAPI
 261 InterlockedCompareExchangePointer (
 262   IN OUT  VOID                      **Value,
 263   IN      VOID                      *CompareValue,
 264   IN      VOID                      *ExchangeValue
 265   );
 266
 267 #endif
 268
 269