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git.proxmox.com Git - mirror_edk2.git/blob - MdePkg/Library/BaseLib/SynchronizationMsc.c
2 Implementation of synchronization functions.
4 Copyright (c) 2006 - 2007, 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
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.
16 // Include common header file for this module.
20 #include "BaseLibInternals.h"
23 Microsoft Visual Studio 7.1 Function Prototypes for read write barrier Intrinsics.
25 void _ReadWriteBarrier (void);
26 #pragma intrinsic(_ReadWriteBarrier)
29 #define SPIN_LOCK_RELEASED ((UINTN) 1)
30 #define SPIN_LOCK_ACQUIRED ((UINTN) 2)
33 Retrieves the architecture specific spin lock alignment requirements for
34 optimal spin lock performance.
36 This function retrieves the spin lock alignment requirements for optimal
37 performance on a given CPU architecture. The spin lock alignment must be a
38 power of two and is returned by this function. If there are no alignment
39 requirements, then 1 must be returned. The spin lock synchronization
40 functions must function correctly if the spin lock size and alignment values
41 returned by this function are not used at all. These values are hints to the
42 consumers of the spin lock synchronization functions to obtain optimal spin
45 @return The architecture specific spin lock alignment.
50 GetSpinLockProperties (
58 Initializes a spin lock to the released state and returns the spin lock.
60 This function initializes the spin lock specified by SpinLock to the released
61 state, and returns SpinLock. Optimal performance can be achieved by calling
62 GetSpinLockProperties() to determine the size and alignment requirements for
65 If SpinLock is NULL, then ASSERT().
67 @param SpinLock A pointer to the spin lock to initialize to the released
70 @return SpinLock in released state.
76 OUT SPIN_LOCK
*SpinLock
79 ASSERT (SpinLock
!= NULL
);
82 *SpinLock
= SPIN_LOCK_RELEASED
;
89 Waits until a spin lock can be placed in the acquired state.
91 This function checks the state of the spin lock specified by SpinLock. If
92 SpinLock is in the released state, then this function places SpinLock in the
93 acquired state and returns SpinLock. Otherwise, this function waits
94 indefinitely for the spin lock to be released, and then places it in the
95 acquired state and returns SpinLock. All state transitions of SpinLock must
96 be performed using MP safe mechanisms.
98 If SpinLock is NULL, then ASSERT().
99 If SpinLock was not initialized with InitializeSpinLock(), then ASSERT().
100 If PcdSpinLockTimeout is not zero, and SpinLock is can not be acquired in
101 PcdSpinLockTimeout microseconds, then ASSERT().
103 @param SpinLock A pointer to the spin lock to place in the acquired state.
105 @return SpinLock aquiring lock.
111 IN OUT SPIN_LOCK
*SpinLock
123 if (PcdGet32 (PcdSpinLockTimeout
) > 0) {
125 // Get the current timer value
127 Current
= GetPerformanceCounter();
130 // Initialize local variables
137 // Retrieve the performance counter properties and compute the number of performance
138 // counter ticks required to reach the timeout
140 Timeout
= DivU64x32 (
142 GetPerformanceCounterProperties (&Start
, &End
),
143 PcdGet32 (PcdSpinLockTimeout
)
153 while (!AcquireSpinLockOrFail (SpinLock
)) {
156 Current
= GetPerformanceCounter();
157 Delta
= (INT64
) (Current
- Previous
);
165 ASSERT (Total
< Timeout
);
168 while (!AcquireSpinLockOrFail (SpinLock
)) {
176 Attempts to place a spin lock in the acquired state.
178 This function checks the state of the spin lock specified by SpinLock. If
179 SpinLock is in the released state, then this function places SpinLock in the
180 acquired state and returns TRUE. Otherwise, FALSE is returned. All state
181 transitions of SpinLock must be performed using MP safe mechanisms.
183 If SpinLock is NULL, then ASSERT().
184 If SpinLock was not initialized with InitializeSpinLock(), then ASSERT().
186 @param SpinLock A pointer to the spin lock to place in the acquired state.
188 @retval TRUE SpinLock was placed in the acquired state.
189 @retval FALSE SpinLock could not be acquired.
194 AcquireSpinLockOrFail (
195 IN OUT SPIN_LOCK
*SpinLock
201 ASSERT (SpinLock
!= NULL
);
203 LockValue
= *SpinLock
;
204 ASSERT (LockValue
== SPIN_LOCK_ACQUIRED
|| LockValue
== SPIN_LOCK_RELEASED
);
206 _ReadWriteBarrier ();
207 Result
= InterlockedCompareExchangePointer (
209 (VOID
*)SPIN_LOCK_RELEASED
,
210 (VOID
*)SPIN_LOCK_ACQUIRED
213 _ReadWriteBarrier ();
214 return (BOOLEAN
) (Result
== (VOID
*) SPIN_LOCK_RELEASED
);
218 Releases a spin lock.
220 This function places the spin lock specified by SpinLock in the release state
221 and returns SpinLock.
223 If SpinLock is NULL, then ASSERT().
224 If SpinLock was not initialized with InitializeSpinLock(), then ASSERT().
226 @param SpinLock A pointer to the spin lock to release.
228 @return SpinLock releasing lock.
234 IN OUT SPIN_LOCK
*SpinLock
239 ASSERT (SpinLock
!= NULL
);
241 LockValue
= *SpinLock
;
242 ASSERT (LockValue
== SPIN_LOCK_ACQUIRED
|| LockValue
== SPIN_LOCK_RELEASED
);
244 _ReadWriteBarrier ();
245 *SpinLock
= SPIN_LOCK_RELEASED
;
246 _ReadWriteBarrier ();
252 Performs an atomic increment of an 32-bit unsigned integer.
254 Performs an atomic increment of the 32-bit unsigned integer specified by
255 Value and returns the incremented value. The increment operation must be
256 performed using MP safe mechanisms. The state of the return value is not
257 guaranteed to be MP safe.
259 If Value is NULL, then ASSERT().
261 @param Value A pointer to the 32-bit value to increment.
263 @return The incremented value.
268 InterlockedIncrement (
272 ASSERT (Value
!= NULL
);
273 return InternalSyncIncrement (Value
);
277 Performs an atomic decrement of an 32-bit unsigned integer.
279 Performs an atomic decrement of the 32-bit unsigned integer specified by
280 Value and returns the decremented value. The decrement operation must be
281 performed using MP safe mechanisms. The state of the return value is not
282 guaranteed to be MP safe.
284 If Value is NULL, then ASSERT().
286 @param Value A pointer to the 32-bit value to decrement.
288 @return The decremented value.
293 InterlockedDecrement (
297 ASSERT (Value
!= NULL
);
298 return InternalSyncDecrement (Value
);
302 Performs an atomic compare exchange operation on a 32-bit unsigned integer.
304 Performs an atomic compare exchange operation on the 32-bit unsigned integer
305 specified by Value. If Value is equal to CompareValue, then Value is set to
306 ExchangeValue and CompareValue is returned. If Value is not equal to CompareValue,
307 then Value is returned. The compare exchange operation must be performed using
310 If Value is NULL, then ASSERT().
312 @param Value A pointer to the 32-bit value for the compare exchange
314 @param CompareValue 32-bit value used in compare operation.
315 @param ExchangeValue 32-bit value used in exchange operation.
317 @return The original *Value before exchange.
322 InterlockedCompareExchange32 (
323 IN OUT UINT32
*Value
,
324 IN UINT32 CompareValue
,
325 IN UINT32 ExchangeValue
328 ASSERT (Value
!= NULL
);
329 return InternalSyncCompareExchange32 (Value
, CompareValue
, ExchangeValue
);
333 Performs an atomic compare exchange operation on a 64-bit unsigned integer.
335 Performs an atomic compare exchange operation on the 64-bit unsigned integer specified
336 by Value. If Value is equal to CompareValue, then Value is set to ExchangeValue and
337 CompareValue is returned. If Value is not equal to CompareValue, then Value is returned.
338 The compare exchange operation must be performed using MP safe mechanisms.
340 If Value is NULL, then ASSERT().
342 @param Value A pointer to the 64-bit value for the compare exchange
344 @param CompareValue 64-bit value used in compare operation.
345 @param ExchangeValue 64-bit value used in exchange operation.
347 @return The original *Value before exchange.
352 InterlockedCompareExchange64 (
353 IN OUT UINT64
*Value
,
354 IN UINT64 CompareValue
,
355 IN UINT64 ExchangeValue
358 ASSERT (Value
!= NULL
);
359 return InternalSyncCompareExchange64 (Value
, CompareValue
, ExchangeValue
);
363 Performs an atomic compare exchange operation on a pointer value.
365 Performs an atomic compare exchange operation on the pointer value specified
366 by Value. If Value is equal to CompareValue, then Value is set to
367 ExchangeValue and CompareValue is returned. If Value is not equal to
368 CompareValue, then Value is returned. The compare exchange operation must be
369 performed using MP safe mechanisms.
371 If Value is NULL, then ASSERT().
373 @param Value A pointer to the pointer value for the compare exchange
375 @param CompareValue Pointer value used in compare operation.
376 @param ExchangeValue Pointer value used in exchange operation.
378 @return The original *Value before exchange.
383 InterlockedCompareExchangePointer (
385 IN VOID
*CompareValue
,
386 IN VOID
*ExchangeValue
391 SizeOfValue
= sizeof (*Value
);
393 switch (SizeOfValue
) {
394 case sizeof (UINT32
):
395 return (VOID
*)(UINTN
)InterlockedCompareExchange32 (
397 (UINT32
)(UINTN
)CompareValue
,
398 (UINT32
)(UINTN
)ExchangeValue
400 case sizeof (UINT64
):
401 return (VOID
*)(UINTN
)InterlockedCompareExchange64 (
403 (UINT64
)(UINTN
)CompareValue
,
404 (UINT64
)(UINTN
)ExchangeValue