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git.proxmox.com Git - mirror_edk2.git/blob - OldMdePkg/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.
13 Module Name: SynchronizationMsc.c
17 #include "BaseLibInternals.h"
20 // Microsoft Visual Studio 7.1 Function Prototypes for read write barrier Intrinsics
22 void _ReadWriteBarrier (void);
23 #pragma intrinsic(_ReadWriteBarrier)
26 #define SPIN_LOCK_RELEASED ((UINTN) 1)
27 #define SPIN_LOCK_ACQUIRED ((UINTN) 2)
30 Retrieves the architecture specific spin lock alignment requirements for
31 optimal spin lock performance.
33 This function retrieves the spin lock alignment requirements for optimal
34 performance on a given CPU architecture. The spin lock alignment must be a
35 power of two and is returned by this function. If there are no alignment
36 requirements, then 1 must be returned. The spin lock synchronization
37 functions must function correctly if the spin lock size and alignment values
38 returned by this function are not used at all. These values are hints to the
39 consumers of the spin lock synchronization functions to obtain optimal spin
42 @return The architecture specific spin lock alignment.
47 GetSpinLockProperties (
51 // @bug May use a PCD entry to determine this alignment.
56 Initializes a spin lock to the released state and returns the spin lock.
58 This function initializes the spin lock specified by SpinLock to the released
59 state, and returns SpinLock. Optimal performance can be achieved by calling
60 GetSpinLockProperties() to determine the size and alignment requirements for
63 If SpinLock is NULL, then ASSERT().
65 @param SpinLock A pointer to the spin lock to initialize to the released
74 OUT SPIN_LOCK
*SpinLock
77 ASSERT (SpinLock
!= NULL
);
80 *SpinLock
= SPIN_LOCK_RELEASED
;
87 Waits until a spin lock can be placed in the acquired state.
89 This function checks the state of the spin lock specified by SpinLock. If
90 SpinLock is in the released state, then this function places SpinLock in the
91 acquired state and returns SpinLock. Otherwise, this function waits
92 indefinitely for the spin lock to be released, and then places it in the
93 acquired state and returns SpinLock. All state transitions of SpinLock must
94 be performed using MP safe mechanisms.
96 If SpinLock is NULL, then ASSERT().
97 If SpinLock was not initialized with InitializeSpinLock(), then ASSERT().
98 If PcdSpinLockTimeout is not zero, and SpinLock is can not be acquired in
99 PcdSpinLockTimeout microseconds, then ASSERT().
101 @param SpinLock A pointer to the spin lock to place in the acquired state.
109 IN OUT SPIN_LOCK
*SpinLock
119 if (PcdGet32 (PcdSpinLockTimeout
) > 0) {
120 Tick
= GetPerformanceCounter ();
121 Timeout
= DivU64x32 (
123 GetPerformanceCounterProperties (&Start
, &End
),
124 PcdGet32 (PcdSpinLockTimeout
)
135 while (!AcquireSpinLockOrFail (SpinLock
)) {
137 ASSERT ((Start
< End
) ^ (Tick
<= GetPerformanceCounter ()));
143 Attempts to place a spin lock in the acquired state.
145 This function checks the state of the spin lock specified by SpinLock. If
146 SpinLock is in the released state, then this function places SpinLock in the
147 acquired state and returns TRUE. Otherwise, FALSE is returned. All state
148 transitions of SpinLock must be performed using MP safe mechanisms.
150 If SpinLock is NULL, then ASSERT().
151 If SpinLock was not initialized with InitializeSpinLock(), then ASSERT().
153 @param SpinLock A pointer to the spin lock to place in the acquired state.
155 @retval TRUE SpinLock was placed in the acquired state.
156 @retval FALSE SpinLock could not be acquired.
161 AcquireSpinLockOrFail (
162 IN OUT SPIN_LOCK
*SpinLock
168 ASSERT (SpinLock
!= NULL
);
170 LockValue
= *SpinLock
;
171 ASSERT (LockValue
== SPIN_LOCK_ACQUIRED
|| LockValue
== SPIN_LOCK_RELEASED
);
173 _ReadWriteBarrier ();
174 Result
= InterlockedCompareExchangePointer (
176 (VOID
*)SPIN_LOCK_RELEASED
,
177 (VOID
*)SPIN_LOCK_ACQUIRED
180 _ReadWriteBarrier ();
181 return (BOOLEAN
) (Result
== (VOID
*) SPIN_LOCK_RELEASED
);
185 Releases a spin lock.
187 This function places the spin lock specified by SpinLock in the release state
188 and returns SpinLock.
190 If SpinLock is NULL, then ASSERT().
191 If SpinLock was not initialized with InitializeSpinLock(), then ASSERT().
193 @param SpinLock A pointer to the spin lock to release.
201 IN OUT SPIN_LOCK
*SpinLock
206 ASSERT (SpinLock
!= NULL
);
208 LockValue
= *SpinLock
;
209 ASSERT (LockValue
== SPIN_LOCK_ACQUIRED
|| LockValue
== SPIN_LOCK_RELEASED
);
211 _ReadWriteBarrier ();
212 *SpinLock
= SPIN_LOCK_RELEASED
;
213 _ReadWriteBarrier ();
219 Performs an atomic increment of an 32-bit unsigned integer.
221 Performs an atomic increment of the 32-bit unsigned integer specified by
222 Value and returns the incremented value. The increment operation must be
223 performed using MP safe mechanisms. The state of the return value is not
224 guaranteed to be MP safe.
226 If Value is NULL, then ASSERT().
228 @param Value A pointer to the 32-bit value to increment.
230 @return The incremented value.
235 InterlockedIncrement (
239 ASSERT (Value
!= NULL
);
240 return InternalSyncIncrement (Value
);
244 Performs an atomic decrement of an 32-bit unsigned integer.
246 Performs an atomic decrement of the 32-bit unsigned integer specified by
247 Value and returns the decremented value. The decrement operation must be
248 performed using MP safe mechanisms. The state of the return value is not
249 guaranteed to be MP safe.
251 If Value is NULL, then ASSERT().
253 @param Value A pointer to the 32-bit value to decrement.
255 @return The decremented value.
260 InterlockedDecrement (
264 ASSERT (Value
!= NULL
);
265 return InternalSyncDecrement (Value
);
269 Performs an atomic compare exchange operation on a 32-bit unsigned integer.
271 Performs an atomic compare exchange operation on the 32-bit unsigned integer
272 specified by Value. If Value is equal to CompareValue, then Value is set to
273 ExchangeValue and CompareValue is returned. If Value is not equal to CompareValue,
274 then Value is returned. The compare exchange operation must be performed using
277 If Value is NULL, then ASSERT().
279 @param Value A pointer to the 32-bit value for the compare exchange
281 @param CompareValue 32-bit value used in compare operation.
282 @param ExchangeValue 32-bit value used in exchange operation.
284 @return The original *Value before exchange.
289 InterlockedCompareExchange32 (
290 IN OUT UINT32
*Value
,
291 IN UINT32 CompareValue
,
292 IN UINT32 ExchangeValue
295 ASSERT (Value
!= NULL
);
296 return InternalSyncCompareExchange32 (Value
, CompareValue
, ExchangeValue
);
300 Performs an atomic compare exchange operation on a 64-bit unsigned integer.
302 Performs an atomic compare exchange operation on the 64-bit unsigned integer specified
303 by Value. If Value is equal to CompareValue, then Value is set to ExchangeValue and
304 CompareValue is returned. If Value is not equal to CompareValue, then Value is returned.
305 The compare exchange operation must be performed using MP safe mechanisms.
307 If Value is NULL, then ASSERT().
309 @param Value A pointer to the 64-bit value for the compare exchange
311 @param CompareValue 64-bit value used in compare operation.
312 @param ExchangeValue 64-bit value used in exchange operation.
314 @return The original *Value before exchange.
319 InterlockedCompareExchange64 (
320 IN OUT UINT64
*Value
,
321 IN UINT64 CompareValue
,
322 IN UINT64 ExchangeValue
325 ASSERT (Value
!= NULL
);
326 return InternalSyncCompareExchange64 (Value
, CompareValue
, ExchangeValue
);
330 Performs an atomic compare exchange operation on a pointer value.
332 Performs an atomic compare exchange operation on the pointer value specified
333 by Value. If Value is equal to CompareValue, then Value is set to
334 ExchangeValue and CompareValue is returned. If Value is not equal to
335 CompareValue, then Value is returned. The compare exchange operation must be
336 performed using MP safe mechanisms.
338 If Value is NULL, then ASSERT().
340 @param Value A pointer to the pointer value for the compare exchange
342 @param CompareValue Pointer value used in compare operation.
343 @param ExchangeValue Pointer value used in exchange operation.
348 InterlockedCompareExchangePointer (
350 IN VOID
*CompareValue
,
351 IN VOID
*ExchangeValue
356 SizeOfValue
= sizeof (*Value
);
358 switch (SizeOfValue
) {
359 case sizeof (UINT32
):
360 return (VOID
*)(UINTN
)InterlockedCompareExchange32 (
362 (UINT32
)(UINTN
)CompareValue
,
363 (UINT32
)(UINTN
)ExchangeValue
365 case sizeof (UINT64
):
366 return (VOID
*)(UINTN
)InterlockedCompareExchange64 (
368 (UINT64
)(UINTN
)CompareValue
,
369 (UINT64
)(UINTN
)ExchangeValue