82 lines
1.8 KiB
C
82 lines
1.8 KiB
C
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/*++
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Copyright (c) 1995-2000 Microsoft Corporation
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Module Name:
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locking.h
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Abstract:
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Private header file for locking/synchronization functions
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within SPUTILS
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Author:
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Ted Miller (tedm) 31-Mar-1995
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Revision History:
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Jamie Hunter (JamieHun) Jun-27-2000
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Moved out of SetupAPI
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--*/
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//
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// Locking functions. These functions are used to make various parts of
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// the DLL multithread-safe. The basic idea is to have a mutex and an event.
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// The mutex is used to synchronize access to the structure being guarded.
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// The event is only signalled when the structure being guarded is destroyed.
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// To gain access to the guarded structure, a routine waits on both the mutex
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// and the event. If the event gets signalled, then the structure was destroyed.
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// If the mutex gets signalled, then the thread has access to the structure.
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//
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typedef struct _MYLOCK {
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HANDLE Handles[2];
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} MYLOCK, *PMYLOCK;
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//
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// Indices into Locks array in string table structure.
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//
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#define TABLE_DESTROYED_EVENT 0
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#define TABLE_ACCESS_MUTEX 1
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BOOL
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__inline
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BeginSynchronizedAccess(
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IN PMYLOCK Lock
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)
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{
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DWORD d = WaitForMultipleObjects(2,Lock->Handles,FALSE,INFINITE);
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//
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// Success if the mutex object satisfied the wait;
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// Failure if the table destroyed event satisified the wait, or
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// the mutex was abandoned, etc.
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//
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return((d - WAIT_OBJECT_0) == TABLE_ACCESS_MUTEX);
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}
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VOID
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__inline
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EndSynchronizedAccess(
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IN PMYLOCK Lock
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)
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{
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ReleaseMutex(Lock->Handles[TABLE_ACCESS_MUTEX]);
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}
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BOOL
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_pSpUtilsInitializeSynchronizedAccess(
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OUT PMYLOCK Lock
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);
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VOID
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_pSpUtilsDestroySynchronizedAccess(
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IN OUT PMYLOCK Lock
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);
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#define InitializeSynchronizedAccess _pSpUtilsInitializeSynchronizedAccess
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#define DestroySynchronizedAccess _pSpUtilsDestroySynchronizedAccess
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