163 lines
6.4 KiB
C
163 lines
6.4 KiB
C
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//================================================================================
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// Microsoft Confidential
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// Copyright (C) Microsoft 1997
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//
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// Author: RameshV
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//================================================================================
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//================================================================================
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// Required Headers
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//================================================================================
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#include <adt.h>
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//================================================================================
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// Definitions of the functions.
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//================================================================================
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DWORD // Win32 Errors
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InitializeProducerConsumer( // Initialize the pointer
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OUT PPRODCONS Synch, // The memory must be pre-allocated
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IN DWORD MaxProducers, // Total # of simultaneous producers
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IN DWORD MaxConsumers // Totat # of consumers
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) {
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Synch->ProducerSemaphore = Synch->ConsumerSemaphore = NULL;
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Synch->ProducerSemaphore = CreateSemaphore(
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(LPSECURITY_ATTRIBUTES)NULL, // No security here
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MaxProducers, // Initial allowed # of producers
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MaxProducers, // Max allowed at any time
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NULL // Unnamed
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);
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if( NULL == Synch->ProducerSemaphore ) return GetLastError();
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Synch->ConsumerSemaphore = CreateSemaphore(
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(LPSECURITY_ATTRIBUTES)NULL, // No security here
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0, // Initial allowed # of consumers
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MaxConsumers, // Max allowed at any time
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NULL // Unnamed
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);
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if( NULL == Synch->ConsumerSemaphore ) return GetLastError();
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Synch->MaxProducers = MaxProducers;
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Synch->MaxConsumers = MaxConsumers;
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return ERROR_SUCCESS;
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}
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VOID
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DestroyProducerConsumer( // Destroy and free up resources
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IN PPRODCONS Synch // The producer consumer object
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) {
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if(Synch->ProducerSemaphore) CloseHandle(Synch->ProducerSemaphore);
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if(Synch->ConsumerSemaphore) CloseHandle(Synch->ConsumerSemaphore);
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}
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//================================================================================
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// StartProducerEx is expected to be called before trying to "produce" an
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// element. If a timeout is specified, then the timeout will act like the
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// same as in WaitForSingleObjectEx. Also, if the Alertable flag is on, the
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// wait is altertable. The same thing with StartConsumerEx.
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//================================================================================
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DWORD static _inline // Win32 errors
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StartProdConsExInternal( // Gen. fn to enter prod/cons code (internal)
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IN PPRODCONS Synch, // Synchronization object
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IN DWORD TimeOutMilliSec,// Timeout in milliseconds; 0 ==> polling
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IN BOOL Alertable, // Is the wait alertable?
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IN BOOL Producer // Is this call from a producer or consumer?
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) {
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DWORD Status;
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Status = WaitForSingleObjectEx(
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Producer? Synch->ProducerSemaphore : Synch->ConsumerSemaphore,
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TimeOutMilliSec,
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Alertable
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);
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return Status;
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}
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DWORD static _inline // Win32 errors
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EndProdConsExInternal( // Gen. fn to leave prod/cons code(internal)
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IN PPRODCONS Synch, // Synchronization object
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IN BOOL Producer // Is this call from a producer or consumer?
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) {
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BOOL Status;
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Status = ReleaseSemaphore(
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Producer? Synch->ConsumerSemaphore : Synch->ProducerSemaphore,
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1, // Release one producer/consumer
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NULL // Dont care about how many are still out there
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);
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if( FALSE == Status ) return GetLastError();
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return ERROR_SUCCESS;
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}
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//================================================================================
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// The exported versions are below. The Ex functions allow specification of
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// TimeOut and if the wait is alertable. The non-Ex functions have the timeout
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// as INFINITE and Alertable as FALSE by default.
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//================================================================================
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DWORD // Win32 errors
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StartProducerEx( // See StartProdConsExInternal
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IN PPRODCONS Synch, // Syncho. object
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IN DWORD TimeOutMilliSec,// Timeout for wait in milliseconds
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IN BOOL Alertable // Is the wait alertable?
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) {
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return StartProdConsExInternal(Synch,TimeOutMilliSec,Alertable,TRUE);
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}
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DWORD // Win32 errors
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StartConsumerEx( // See StartProdConsExInternal
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IN PPRODCONS Synch, // Syncho. object
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IN DWORD TimeOutMilliSec,// Timeout for wait in milliseconds
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IN BOOL Alertable // Is the wait alertable?
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) {
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return StartProdConsExInternal(Synch,TimeOutMilliSec,Alertable,FALSE);
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}
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// These are usual versions. Return value is success if we entered.
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// Alertable wait by default, timeout = infinite. So, can return
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// WAIT_IO_COMPLETION on success.
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DWORD // Win32 errors
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StartProducer( // Wait until a producer can start
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IN PPRODCONS Synch // The synch object
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) {
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DWORD Status = StartProducerEx(Synch, INFINITE, FALSE);
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if( WAIT_OBJECT_0 == Status ) return ERROR_SUCCESS;
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return Status;
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}
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DWORD // Win32 errors
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StartConsumer( // Wait until a consumer can start
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IN PPRODCONS Synch // The synch object
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) {
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DWORD Status = StartConsumerEx(Synch, INFINITE, FALSE);
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if( WAIT_OBJECT_0 == Status ) return ERROR_SUCCESS;
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return Status;
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}
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DWORD // Win32 Errors
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EndProducer( // See EndProdConsExInternal
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IN PPRODCONS Synch // Synch object
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) {
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return EndProdConsExInternal(Synch, TRUE);
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}
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DWORD // Win32 errors
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EndConsumer( // See EndProdConsExInternal
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IN PPRODCONS Synch // Synch object
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) {
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return EndProdConsExInternal(Synch, TRUE);
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}
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//================================================================================
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// End of file
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//================================================================================
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