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git.proxmox.com Git - mirror_edk2.git/blob - MdePkg/Library/BaseSynchronizationLib/SynchronizationMsc.c
2 Implementation of synchronization functions.
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
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.
15 #include "BaseSynchronizationLibInternals.h"
18 Microsoft Visual Studio 7.1 Function Prototypes for read write barrier Intrinsics.
21 void _ReadWriteBarrier (void);
22 #pragma intrinsic(_ReadWriteBarrier)
25 #define SPIN_LOCK_RELEASED ((UINTN) 1)
26 #define SPIN_LOCK_ACQUIRED ((UINTN) 2)
29 Retrieves the architecture specific spin lock alignment requirements for
30 optimal spin lock performance.
32 This function retrieves the spin lock alignment requirements for optimal
33 performance on a given CPU architecture. The spin lock alignment must be a
34 power of two and is returned by this function. If there are no alignment
35 requirements, then 1 must be returned. The spin lock synchronization
36 functions must function correctly if the spin lock size and alignment values
37 returned by this function are not used at all. These values are hints to the
38 consumers of the spin lock synchronization functions to obtain optimal spin
41 @return The architecture specific spin lock alignment.
46 GetSpinLockProperties (
54 Initializes a spin lock to the released state and returns the spin lock.
56 This function initializes the spin lock specified by SpinLock to the released
57 state, and returns SpinLock. Optimal performance can be achieved by calling
58 GetSpinLockProperties() to determine the size and alignment requirements for
61 If SpinLock is NULL, then ASSERT().
63 @param SpinLock A pointer to the spin lock to initialize to the released
66 @return SpinLock in release state.
72 OUT SPIN_LOCK
*SpinLock
75 ASSERT (SpinLock
!= NULL
);
78 *SpinLock
= SPIN_LOCK_RELEASED
;
85 Waits until a spin lock can be placed in the acquired state.
87 This function checks the state of the spin lock specified by SpinLock. If
88 SpinLock is in the released state, then this function places SpinLock in the
89 acquired state and returns SpinLock. Otherwise, this function waits
90 indefinitely for the spin lock to be released, and then places it in the
91 acquired state and returns SpinLock. All state transitions of SpinLock must
92 be performed using MP safe mechanisms.
94 If SpinLock is NULL, then ASSERT().
95 If SpinLock was not initialized with InitializeSpinLock(), then ASSERT().
96 If PcdSpinLockTimeout is not zero, and SpinLock is can not be acquired in
97 PcdSpinLockTimeout microseconds, then ASSERT().
99 @param SpinLock A pointer to the spin lock to place in the acquired state.
101 @return SpinLock acquired lock.
107 IN OUT SPIN_LOCK
*SpinLock
119 if (PcdGet32 (PcdSpinLockTimeout
) > 0) {
121 // Get the current timer value
123 Current
= GetPerformanceCounter();
126 // Initialize local variables
133 // Retrieve the performance counter properties and compute the number of performance
134 // counter ticks required to reach the timeout
136 Timeout
= DivU64x32 (
138 GetPerformanceCounterProperties (&Start
, &End
),
139 PcdGet32 (PcdSpinLockTimeout
)
149 while (!AcquireSpinLockOrFail (SpinLock
)) {
152 Current
= GetPerformanceCounter();
153 Delta
= (INT64
) (Current
- Previous
);
161 ASSERT (Total
< Timeout
);
164 while (!AcquireSpinLockOrFail (SpinLock
)) {
172 Attempts to place a spin lock in the acquired state.
174 This function checks the state of the spin lock specified by SpinLock. If
175 SpinLock is in the released state, then this function places SpinLock in the
176 acquired state and returns TRUE. Otherwise, FALSE is returned. All state
177 transitions of SpinLock must be performed using MP safe mechanisms.
179 If SpinLock is NULL, then ASSERT().
180 If SpinLock was not initialized with InitializeSpinLock(), then ASSERT().
182 @param SpinLock A pointer to the spin lock to place in the acquired state.
184 @retval TRUE SpinLock was placed in the acquired state.
185 @retval FALSE SpinLock could not be acquired.
190 AcquireSpinLockOrFail (
191 IN OUT SPIN_LOCK
*SpinLock
197 ASSERT (SpinLock
!= NULL
);
199 LockValue
= *SpinLock
;
200 ASSERT (LockValue
== SPIN_LOCK_ACQUIRED
|| LockValue
== SPIN_LOCK_RELEASED
);
202 _ReadWriteBarrier ();
203 Result
= InterlockedCompareExchangePointer (
205 (VOID
*)SPIN_LOCK_RELEASED
,
206 (VOID
*)SPIN_LOCK_ACQUIRED
209 _ReadWriteBarrier ();
210 return (BOOLEAN
) (Result
== (VOID
*) SPIN_LOCK_RELEASED
);
214 Releases a spin lock.
216 This function places the spin lock specified by SpinLock in the release state
217 and returns SpinLock.
219 If SpinLock is NULL, then ASSERT().
220 If SpinLock was not initialized with InitializeSpinLock(), then ASSERT().
222 @param SpinLock A pointer to the spin lock to release.
224 @return SpinLock released lock.
230 IN OUT SPIN_LOCK
*SpinLock
235 ASSERT (SpinLock
!= NULL
);
237 LockValue
= *SpinLock
;
238 ASSERT (LockValue
== SPIN_LOCK_ACQUIRED
|| LockValue
== SPIN_LOCK_RELEASED
);
240 _ReadWriteBarrier ();
241 *SpinLock
= SPIN_LOCK_RELEASED
;
242 _ReadWriteBarrier ();
248 Performs an atomic increment of an 32-bit unsigned integer.
250 Performs an atomic increment of the 32-bit unsigned integer specified by
251 Value and returns the incremented value. The increment operation must be
252 performed using MP safe mechanisms. The state of the return value is not
253 guaranteed to be MP safe.
255 If Value is NULL, then ASSERT().
257 @param Value A pointer to the 32-bit value to increment.
259 @return The incremented value.
264 InterlockedIncrement (
268 ASSERT (Value
!= NULL
);
269 return InternalSyncIncrement (Value
);
273 Performs an atomic decrement of an 32-bit unsigned integer.
275 Performs an atomic decrement of the 32-bit unsigned integer specified by
276 Value and returns the decremented value. The decrement operation must be
277 performed using MP safe mechanisms. The state of the return value is not
278 guaranteed to be MP safe.
280 If Value is NULL, then ASSERT().
282 @param Value A pointer to the 32-bit value to decrement.
284 @return The decremented value.
289 InterlockedDecrement (
293 ASSERT (Value
!= NULL
);
294 return InternalSyncDecrement (Value
);
298 Performs an atomic compare exchange operation on a 32-bit unsigned integer.
300 Performs an atomic compare exchange operation on the 32-bit unsigned integer
301 specified by Value. If Value is equal to CompareValue, then Value is set to
302 ExchangeValue and CompareValue is returned. If Value is not equal to CompareValue,
303 then Value is returned. The compare exchange operation must be performed using
306 If Value is NULL, then ASSERT().
308 @param Value A pointer to the 32-bit value for the compare exchange
310 @param CompareValue 32-bit value used in compare operation.
311 @param ExchangeValue 32-bit value used in exchange operation.
313 @return The original *Value before exchange.
318 InterlockedCompareExchange32 (
319 IN OUT UINT32
*Value
,
320 IN UINT32 CompareValue
,
321 IN UINT32 ExchangeValue
324 ASSERT (Value
!= NULL
);
325 return InternalSyncCompareExchange32 (Value
, CompareValue
, ExchangeValue
);
329 Performs an atomic compare exchange operation on a 64-bit unsigned integer.
331 Performs an atomic compare exchange operation on the 64-bit unsigned integer specified
332 by Value. If Value is equal to CompareValue, then Value is set to ExchangeValue and
333 CompareValue is returned. If Value is not equal to CompareValue, then Value is returned.
334 The compare exchange operation must be performed using MP safe mechanisms.
336 If Value is NULL, then ASSERT().
338 @param Value A pointer to the 64-bit value for the compare exchange
340 @param CompareValue 64-bit value used in compare operation.
341 @param ExchangeValue 64-bit value used in exchange operation.
343 @return The original *Value before exchange.
348 InterlockedCompareExchange64 (
349 IN OUT UINT64
*Value
,
350 IN UINT64 CompareValue
,
351 IN UINT64 ExchangeValue
354 ASSERT (Value
!= NULL
);
355 return InternalSyncCompareExchange64 (Value
, CompareValue
, ExchangeValue
);
359 Performs an atomic compare exchange operation on a pointer value.
361 Performs an atomic compare exchange operation on the pointer value specified
362 by Value. If Value is equal to CompareValue, then Value is set to
363 ExchangeValue and CompareValue is returned. If Value is not equal to
364 CompareValue, then Value is returned. The compare exchange operation must be
365 performed using MP safe mechanisms.
367 If Value is NULL, then ASSERT().
369 @param Value A pointer to the pointer value for the compare exchange
371 @param CompareValue Pointer value used in compare operation.
372 @param ExchangeValue Pointer value used in exchange operation.
374 @return The original *Value before exchange.
378 InterlockedCompareExchangePointer (
380 IN VOID
*CompareValue
,
381 IN VOID
*ExchangeValue
386 SizeOfValue
= sizeof (*Value
);
388 switch (SizeOfValue
) {
389 case sizeof (UINT32
):
390 return (VOID
*)(UINTN
)InterlockedCompareExchange32 (
392 (UINT32
)(UINTN
)CompareValue
,
393 (UINT32
)(UINTN
)ExchangeValue
395 case sizeof (UINT64
):
396 return (VOID
*)(UINTN
)InterlockedCompareExchange64 (
398 (UINT64
)(UINTN
)CompareValue
,
399 (UINT64
)(UINTN
)ExchangeValue