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tony |
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{Used by ISQLMonitor and implements System V IPC}
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const
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IPCFileName: string = 'FB.SQL.MONITOR1_0';
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cNumberOfSemaphores = 10;
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cMutexSemaphore = 0;
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cMonitorCounter = 1;
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cReadReadyEventSemaphore = 2;
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cReadFinishedEventSemaphore = 4;
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cDataAvailableEventSemaphore = 6;
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cWriterBusyEventSemaphore = 8;
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cDefaultTimeout = 1; { 1 seconds }
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{
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The call to semctl in ipc is broken in FPC release 2.4.2 and earlier. Hence
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need to replace with a working libc call. semtimedop is not present in 2.4.2 and earlier.
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}
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{$IF FPC_FULLVERSION <= 20402 }
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Function real_semctl(semid:cint; semnum:cint; cmd:cint): cint; cdecl; varargs; external clib name 'semctl';
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Function semctl(semid:cint; semnum:cint; cmd:cint; var arg: tsemun): cint;
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begin
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semctl := real_semctl(semid,semnum,cmd,pointer(arg));
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end;
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{$IFDEF HAS_SEMTIMEDOP}
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Function semtimedop(semid:cint; sops: psembuf; nsops: cuint; timeOut: ptimespec): cint; cdecl; external clib name 'semtimedop';
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{$ENDIF}
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Function semget(key:Tkey; nsems:cint; semflg:cint): cint; cdecl; external clib name 'semget';
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Function semop(semid:cint; sops: psembuf; nsops: cuint): cint; cdecl; external clib name 'semop';
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function GetLastErrno: cint;
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begin
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Result := fpgetCerrno
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end;
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{$ELSE}
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function GetLastErrno: cint;
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begin
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Result := fpgetErrno
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end;
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{$ENDIF}
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type
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TGlobalInterface = class;
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{Interprocess Communication Objects. All platform dependent IPC is abstracted
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into this set of objects }
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{ TIpcCommon }
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TIpcCommon = class
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private
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function GetSa: PSecurityAttributes;
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protected
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FInitialiser: boolean; static;
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FSemaphoreSetID: cint; static;
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FSharedMemoryID: cint; static;
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function sem_op(SemNum, op: integer; flags: cshort = 0): cint;
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function sem_timedop(SemNum, op: integer; timeout_secs: integer; flags: cshort = 0): cint;
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function GetSemValue(SemNum: integer): cint;
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procedure SemInit(SemNum, AValue: cint);
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public
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property Sa : PSecurityAttributes read GetSa;
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end;
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{ TSharedMemory }
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{
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The shared memory segment is used for interprocess communication and
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holds both a message buffer and a number of shared variables. Shared
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memory is allocated to each shared variable using the Allocate function.
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An underlying assumption is that each process using the shared memory
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calls "Allocate" in the same order and for the same memory sizes.
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Linux:
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The Linux implementation uses Linux shared memory. IPC_PRIVATE is used
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to allocate the memory and the resulting memory id is written to a
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well known file. By default this is in the current user's home directory,
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but this can be over-ridden to specify a globally unique filename.
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Access to the shared memory is restricted to the current user/group.
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Note that the Linux semaphore set is also created with the shared memory.
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}
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TSharedMemory = class(TIpcCommon)
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private
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FBuffer: PChar;
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FLastAllocationSize: integer;
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FUnused: integer;
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FBufptr: PChar;
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procedure DropSharedMemory;
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procedure GetSharedMemory(MemSize: integer);
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public
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constructor Create(MemSize: integer);
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destructor Destroy; override;
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function Allocate(Size: integer): PChar;
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property LastAllocationSize: integer read FLastAllocationSize;
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end;
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{TMutex}
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TMutex = class(TIpcCommon)
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private
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FMutexSemaphore: cint;
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FLockCount: integer;
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public
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constructor Create(SemNumber: cint);
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procedure Lock;
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procedure Unlock;
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end;
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{ TSingleLockGate }
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{
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A single lock gate is either open or closed. When open, any thread can pass
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through it while, when closed, all threads are blocked as they try to pass
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through the gate. When the gate is opened, all blocked threads are resumed.
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There is an implementation assumption that only one writer thread at
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a time (i.e. the thread which locks or unlocks the gate) can have access to
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it at any one time. I.e. an external Mutex prevents race conditions.
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Linux:
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In the Linux implementation, the gate is implemented by a semaphore
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and a share memory integer used as a bi-state variable. When the gate
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is open, the bi-state variable is non-zero. It is set to zero when closed.
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Another shared memory integer is used to count the number of waiting
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threads, and a second semaphore is used to protect access to this.
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The event semaphore is initialised to zero. When a thread passes through the gate
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it checks the state. If open, the thread continues. If closed then it
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increments the count of waiting threads and then decrements the semaphore
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and hence enters an indefinite wait state.
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When the gate is locked, the state is set to zero. When unlocked, the state
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is set to one and the semaphore incremented by the number of waiting threads,
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which itself is then zeroed.
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Always initialised to the Unlocked state
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}
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TSingleLockGate = class(TIpcCommon)
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private
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FOwner: TGlobalInterface;
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FSemaphore: cint;
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FMutex: cint;
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FSignalledState: PInteger;
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FWaitingThreads: PInteger;
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function GetWaitingThreads: integer;
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public
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constructor Create(SemNum: cint; AOwner: TGlobalInterface);
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property WaitingThreads: integer read GetWaitingThreads;
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public
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procedure PassthroughGate;
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procedure Unlock;
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procedure Lock;
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end;
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{ TMultilockGate }
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{ This type of Gate is used where several reader threads must pass
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through the gate before it can be opened for a writer thread.
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The reader threads register their interest by each locking the gate.
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The writer thread then waits on the locked gate until all the reader
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threads have separately unlocked the gate.
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There is an underlying assumption of a single writer. A Mutex must
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be used to control access to the gate from the writer side if this
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assumption is invalid.
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Linux:
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The Linux implementation uses a single semaphore to implement the gate,
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which is initialised to 1 (unlocked), and a count of the number of
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threads that have locked the gate (LockCount). A mutex semaphore
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protects access to the LockCount. When the gate is locked, the lockcount
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is incremented and, if the LockCount was originally zero, the semaphore is
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set to zero (Gate Closed).
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Unlocking the gate, is the reverse. The LockCount is decremented and, if it
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reaches zero, the semaphore is set to one (Gate Opened).
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When a writer passes through the gate, it checks the LockCount, if zero it
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proceeds to pass through the gate. Otherwise it decrements and waits on the
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semaphore. When the writer resumes, it increments the semaphore in order
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to return it to its unlocked state. The wait is a timed wait, as there is
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a risk that a reader thread may terminate while the gate is locked. If the
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LockCount is non-zero, it is decremented and the writer returns to wait on
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the gate.
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Always initialised to the Unlocked state
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}
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TMultilockGate = class(TIpcCommon)
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private
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FOnGateTimeout: TNotifyEvent;
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FOwner: TGlobalInterface;
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FSemaphore: cint;
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FMutex: cint;
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FLockCount: PInteger;
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function GetLockCount: integer;
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public
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constructor Create(SemNum: cint; AOwner: TGlobalInterface);
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procedure Lock;
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procedure Unlock;
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procedure PassthroughGate;
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property LockCount: integer read GetLockCount;
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property OnGateTimeout: TNotifyEvent read FOnGateTimeout write FOnGateTimeout;
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end;
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{ TGlobalInterface }
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TGlobalInterface = class(TIpcCommon)
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private
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FMaxBufferSize: integer;
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FSharedMemory: TSharedMemory;
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FWriteLock: TMutex;
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FBuffer: PChar;
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FTraceDataType,
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FBufferSize: PInteger;
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FTimeStamp: PDateTime;
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FReadReadyEvent: TMultiLockGate;
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FReadFinishedEvent: TMultiLockGate;
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FDataAvailableEvent: TSingleLockGate;
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FWriterBusyEvent: TSingleLockGate;
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function GetMonitorCount: integer;
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public
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constructor Create;
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destructor Destroy; override;
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procedure IncMonitorCount;
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procedure DecMonitorCount;
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procedure SendTrace(TraceObject: TTraceObject);
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procedure ReceiveTrace(TraceObject: TTraceObject);
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property DataAvailableEvent: TSingleLockGate read FDataAvailableEvent;
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property WriterBusyEvent: TSingleLockGate read FWriterBusyEvent;
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property ReadReadyEvent: TMultiLockGate read FReadReadyEvent;
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property ReadFinishedEvent: TMultiLockGate read FReadFinishedEvent;
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property WriteLock: TMutex read FWriteLock;
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property MonitorCount: integer read GetMonitorCount;
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property SharedMemory: TSharedMemory read FSharedMemory;
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property MaxBufferSize: integer read FMaxBufferSize;
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end;
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{ TSharedMemory }
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procedure TSharedMemory.GetSharedMemory(MemSize: integer);
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var F: cint;
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begin
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{Get the Shared Memory and Semaphore IDs from the Global File if it exists
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or create them and the file otherwise }
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repeat
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F := fpOpen(IPCFileName, O_WrOnly or O_Creat or O_Excl);
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if F < 0 then
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begin
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if fpgetErrno = 17 {EEXIST} then
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begin
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{ looks like it already exists}
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Sleep(100);
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F := fpOpen(IPCFileName,O_RdOnly);
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if (F < 0) and (fpgetErrno = 2 {ENOENT}) then
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{probably just got deleted }
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else
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if F < 0 then
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IBError(ibxeCannotCreateSharedResource,['Error accessing IPC File - ' +
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StrError(fpgetErrno)]);
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end
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else
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IBError(ibxeCannotCreateSharedResource,['Error creating IPC File - ' +
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StrError(fpgetErrno)]);
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end
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else
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FInitialiser := true
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until F >= 0;
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if FInitialiser then
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begin
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FSharedMemoryID := shmget(IPC_PRIVATE,MemSize, IPC_CREAT or
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S_IRUSR or S_IWUSR or S_IRGRP or S_IWGRP);
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if FSharedMemoryID < 0 then
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IBError(ibxeCannotCreateSharedResource,['Cannot create shared memory segment - ' +
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StrError(fpgetErrno)]);
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FSemaphoreSetID := semget(IPC_PRIVATE, cNumberOfSemaphores,IPC_CREAT or
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S_IRUSR or S_IWUSR or S_IRGRP or S_IWGRP);
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if FSemaphoreSetID < 0 then
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IBError(ibxeCannotCreateSharedResource,['Cannot create shared semaphore set - ' +
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StrError(fpgetErrno)]);
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fpWrite(F,FSharedMemoryID,sizeof(FSharedMemoryID));
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fpWrite(F,FSemaphoreSetID,sizeof(FSemaphoreSetID));
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end
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else
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begin
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fpRead(F,FSharedMemoryID,sizeof(FSharedMemoryID));
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fpRead(F,FSemaphoreSetID,sizeof(FSemaphoreSetID));
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if GetSemValue(cMonitorCounter) = 0 then
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begin
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FInitialiser := true;
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//writeln('Opened file and is initialiser');
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end
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end;
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fpClose(F);
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end;
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procedure TSharedMemory.DropSharedMemory;
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var ds: TShmid_ds;
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arg: tsemun;
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begin
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if shmctl(FSharedMemoryID,IPC_STAT,@ds) < 0 then
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IBError(ibxeSV5APIError,['Error getting shared memory info' + strError(fpgetErrno)]);
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if ds.shm_nattch = 0 then { we are the last one out - so, turn off the lights }
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begin
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shmctl(FSharedMemoryID,IPC_RMID,nil);
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semctl(FSemaphoreSetID,0,IPC_RMID,arg);
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DeleteFile(IPCFileName);
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end;
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end;
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constructor TSharedMemory.Create(MemSize: integer);
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begin
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inherited Create;
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FInitialiser := false;
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GetSharedMemory(MemSize);
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FBuffer := shmat(FSharedMemoryID,nil,0);
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if PtrInt(FBuffer) = -1 then
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IBError(ibxeCannotCreateSharedResource,[StrError(Errno)]);
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FBufPtr := FBuffer;
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FUnused := MemSize
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end;
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destructor TSharedMemory.Destroy;
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begin
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shmdt(FBuffer);
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DropSharedMemory;
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inherited Destroy;
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end;
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342 |
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function TSharedMemory.Allocate(Size: integer): PChar;
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343 |
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begin
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344 |
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if Size > FUnused then
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345 |
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IBError(ibxeCannotCreateSharedResource, ['Not enough shared memory']);
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Result := FBufPtr;
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347 |
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|
348 |
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if Size = 0 then
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349 |
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begin
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350 |
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FLastAllocationSize := FUnused;
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FUnused := 0
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end
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353 |
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else
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354 |
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begin
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355 |
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FLastAllocationSize := Size;
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356 |
|
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Dec(FUnused,Size);
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|
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end;
|
358 |
|
|
Inc(FBufPtr,Size)
|
359 |
|
|
end;
|
360 |
|
|
|
361 |
|
|
{ TIpcCommon }
|
362 |
|
|
|
363 |
|
|
function TIpcCommon.GetSa: PSecurityAttributes;
|
364 |
|
|
begin
|
365 |
|
|
Result := nil
|
366 |
|
|
end;
|
367 |
|
|
|
368 |
|
|
function TIpcCommon.sem_op(SemNum, op: integer; flags: cshort): cint;
|
369 |
|
|
var sembuf: TSEMbuf;
|
370 |
|
|
begin
|
371 |
|
|
sembuf.sem_num := SemNum;
|
372 |
|
|
sembuf.sem_op:= op;
|
373 |
|
|
sembuf.sem_flg := flags or SEM_UNDO;
|
374 |
|
|
Result := semop(FSemaphoreSetID,@sembuf,1);
|
375 |
|
|
end;
|
376 |
|
|
|
377 |
|
|
function TIpcCommon.sem_timedop(SemNum, op: integer; timeout_secs: integer;
|
378 |
|
|
flags: cshort): cint;
|
379 |
|
|
var sembuf: TSEMbuf;
|
380 |
|
|
timeout: TimeSpec;
|
381 |
|
|
begin
|
382 |
|
|
sembuf.sem_num := SemNum;
|
383 |
|
|
sembuf.sem_op:= op;
|
384 |
|
|
sembuf.sem_flg := flags or SEM_UNDO;
|
385 |
|
|
timeout.tv_sec := timeout_secs;
|
386 |
|
|
timeout.tv_nsec := 0;
|
387 |
|
|
{$IFDEF HAS_SEMTIMEDOP}
|
388 |
|
|
Result := semtimedop(FSemaphoreSetID,@sembuf,1,@timeout);
|
389 |
|
|
{$ELSE}
|
390 |
|
|
Result := semop(FSemaphoreSetID,@sembuf,1); {May hang on race condition}
|
391 |
|
|
{$ENDIF}
|
392 |
|
|
end;
|
393 |
|
|
|
394 |
|
|
function TIpcCommon.GetSemValue(SemNum: integer): cint;
|
395 |
|
|
var args :TSEMun;
|
396 |
|
|
begin
|
397 |
|
|
Result := semctl(FSemaphoreSetID,SemNum,SEM_GETVAL,args);
|
398 |
|
|
if Result < 0 then
|
399 |
|
|
IBError(ibxeSV5APIError,['GetSemValue: '+strError(GetLastErrno)]);
|
400 |
|
|
end;
|
401 |
|
|
|
402 |
|
|
procedure TIpcCommon.SemInit(SemNum, AValue: cint);
|
403 |
|
|
var args :TSEMun;
|
404 |
|
|
begin
|
405 |
|
|
//writeln('Initialising ',SemNum,' to ',AValue);
|
406 |
|
|
args.val := AValue;
|
407 |
|
|
if semctl(FSemaphoreSetID,SemNum,SEM_SETVAL,args) < 0 then
|
408 |
|
|
IBError(ibxeCannotCreateSharedResource,['Unable to initialise Semaphone ' +
|
409 |
|
|
IntToStr(SemNum) + '- ' + StrError(GetLastErrno)]);
|
410 |
|
|
|
411 |
|
|
end;
|
412 |
|
|
|
413 |
|
|
{ TMutex }
|
414 |
|
|
|
415 |
|
|
constructor TMutex.Create(SemNumber: cint);
|
416 |
|
|
begin
|
417 |
|
|
inherited Create;
|
418 |
|
|
FMutexSemaphore := SemNumber;
|
419 |
|
|
if FInitialiser then
|
420 |
|
|
SemInit(FMutexSemaphore,1)
|
421 |
|
|
end;
|
422 |
|
|
|
423 |
|
|
{ Obtain ownership of the Mutex and prevent other threads from accessing protected resource }
|
424 |
|
|
|
425 |
|
|
procedure TMutex.Lock;
|
426 |
|
|
begin
|
427 |
|
|
//writeln('Lock: Entering Mutex ',FMutexSemaphore,' LockCount=',FLockCount,' State = ',GetSemValue(FMutexSemaphore));
|
428 |
|
|
if FLockCount = 0 then
|
429 |
|
|
sem_op(FMutexSemaphore,-1);
|
430 |
|
|
Inc(FLockCount);
|
431 |
|
|
//writeln('Lock: Mutex Exit');
|
432 |
|
|
end;
|
433 |
|
|
|
434 |
|
|
{Give up ownership of the Mutex and allow other threads access }
|
435 |
|
|
|
436 |
|
|
procedure TMutex.Unlock;
|
437 |
|
|
begin
|
438 |
|
|
//writeln('UnLock: Entering Mutex, LockCount=',FLockCount);
|
439 |
|
|
if FLockCount = 0 then Exit;
|
440 |
|
|
Dec(FLockCount);
|
441 |
|
|
if FLockCount = 0 then
|
442 |
|
|
sem_op(FMutexSemaphore,1);
|
443 |
|
|
//writeln('UnLock: Mutex Exit',' State = ',GetSemValue(FMutexSemaphore));
|
444 |
|
|
end;
|
445 |
|
|
|
446 |
|
|
{ TSingleLockGate }
|
447 |
|
|
|
448 |
|
|
function TSingleLockGate.GetWaitingThreads: integer;
|
449 |
|
|
begin
|
450 |
|
|
Result := FWaitingThreads^
|
451 |
|
|
end;
|
452 |
|
|
|
453 |
|
|
constructor TSingleLockGate.Create(SemNum: cint; AOwner: TGlobalInterface);
|
454 |
|
|
begin
|
455 |
|
|
inherited Create;
|
456 |
|
|
FOwner := AOwner;
|
457 |
|
|
FSignalledState := PInteger(FOwner.SharedMemory.Allocate(sizeof(FSignalledState)));
|
458 |
|
|
FWaitingThreads := PInteger(FOwner.SharedMemory.Allocate(sizeof(FWaitingThreads)));
|
459 |
|
|
FSemaphore := SemNum;
|
460 |
|
|
FMutex := SemNum + 1;
|
461 |
|
|
if FInitialiser then
|
462 |
|
|
begin
|
463 |
|
|
FSignalledState^ := 1;
|
464 |
|
|
FWaitingThreads^ := 0;
|
465 |
|
|
SemInit(FSemaphore,0);
|
466 |
|
|
SemInit(FMutex,1);
|
467 |
|
|
end;
|
468 |
|
|
end;
|
469 |
|
|
|
470 |
|
|
procedure TSingleLockGate.PassthroughGate;
|
471 |
|
|
begin
|
472 |
|
|
if FSignalledState^ = 0 then
|
473 |
|
|
begin
|
474 |
|
|
sem_op(FMutex,-1,0); //Acquire Mutex
|
475 |
|
|
Inc(FWaitingThreads^);
|
476 |
|
|
sem_op(FMutex,1,0); //Release Mutex
|
477 |
|
|
//writeln(ClassName + ': Wait State Entered ',FSemaphore,' = ',GetSemValue(FSemaphore));
|
478 |
|
|
sem_op(FSemaphore,-1,0); //Enter Wait
|
479 |
|
|
//writeln(ClassName + ': Wait State Ends ',FSemaphore);
|
480 |
|
|
end;
|
481 |
|
|
end;
|
482 |
|
|
|
483 |
|
|
procedure TSingleLockGate.Unlock;
|
484 |
|
|
begin
|
485 |
|
|
if FSignalledState^ = 0 then
|
486 |
|
|
begin
|
487 |
|
|
FSignalledState^ := 1;
|
488 |
|
|
sem_op(FMutex,-1,0); //Acquire Mutex
|
489 |
|
|
//writeln(ClassName + ': Unlocking' ,FSemaphore);
|
490 |
|
|
sem_op(FSemaphore,FWaitingThreads^,0);
|
491 |
|
|
FWaitingThreads^ := 0;
|
492 |
|
|
sem_op(FMutex,1,0); //Release Mutex
|
493 |
|
|
end;
|
494 |
|
|
end;
|
495 |
|
|
|
496 |
|
|
procedure TSingleLockGate.Lock;
|
497 |
|
|
begin
|
498 |
|
|
if FSignalledState^ = 1 then
|
499 |
|
|
begin
|
500 |
|
|
//writeln(ClassName + ': Locking Gate ',FSemaphore);
|
501 |
|
|
SemInit(FSemaphore,0);
|
502 |
|
|
FSignalledState^ := 0;
|
503 |
|
|
end;
|
504 |
|
|
end;
|
505 |
|
|
|
506 |
|
|
{ TMultilockGate }
|
507 |
|
|
|
508 |
|
|
constructor TMultilockGate.Create(SemNum: cint; AOwner: TGlobalInterface);
|
509 |
|
|
begin
|
510 |
|
|
inherited Create;
|
511 |
|
|
FOwner := AOwner;
|
512 |
|
|
FSemaphore := SemNum;
|
513 |
|
|
FMutex := SemNum + 1;
|
514 |
|
|
FLockCount := PInteger(FOwner.SharedMemory.Allocate(sizeof(FLockCount)));
|
515 |
|
|
if FInitialiser then
|
516 |
|
|
begin
|
517 |
|
|
FLockCount^ := 0;
|
518 |
|
|
SemInit(FSemaphore,1);
|
519 |
|
|
SemInit(FMutex,1);
|
520 |
|
|
end;
|
521 |
|
|
end;
|
522 |
|
|
|
523 |
|
|
function TMultilockGate.GetLockCount: integer;
|
524 |
|
|
begin
|
525 |
|
|
Result := FLockCount^
|
526 |
|
|
end;
|
527 |
|
|
|
528 |
|
|
procedure TMultilockGate.Lock;
|
529 |
|
|
begin
|
530 |
|
|
sem_op(FMutex,-1,0); //Acquire Mutex
|
531 |
|
|
if FLockCount^ = 0 then
|
532 |
|
|
begin
|
533 |
|
|
//writeln(ClassName,': Locking ',FSemaphore);
|
534 |
|
|
SemInit(FSemaphore,0);
|
535 |
|
|
end;
|
536 |
|
|
Inc(FLockCount^);
|
537 |
|
|
sem_op(FMutex,1,0); //Release Mutex
|
538 |
|
|
end;
|
539 |
|
|
|
540 |
|
|
procedure TMultilockGate.Unlock;
|
541 |
|
|
begin
|
542 |
|
|
sem_op(FMutex,-1,0); //Acquire Mutex
|
543 |
|
|
Dec(FLockCount^);
|
544 |
|
|
if FLockCount^ <= 0 then
|
545 |
|
|
begin
|
546 |
|
|
//writeln(ClassName,': UnLocking ',FSemaphore);
|
547 |
|
|
SemInit(FSemaphore,1);
|
548 |
|
|
FLockCount^ := 0
|
549 |
|
|
end;
|
550 |
|
|
sem_op(FMutex,1,0); //Release Mutex
|
551 |
|
|
end;
|
552 |
|
|
|
553 |
|
|
procedure TMultilockGate.PassthroughGate;
|
554 |
|
|
begin
|
555 |
|
|
if FLockCount^ = 0 then
|
556 |
|
|
Exit;
|
557 |
|
|
//writeln(ClassName,': Waiting on ',FSemaphore);
|
558 |
|
|
while sem_timedop(FSemaphore,-1,cDefaultTimeout) < 0 do
|
559 |
|
|
{looks like we lost a reader}
|
560 |
|
|
begin
|
561 |
|
|
if FLockCount^ > 0 then
|
562 |
|
|
begin
|
563 |
|
|
UnLock;
|
564 |
|
|
if assigned(FOnGateTimeout) then
|
565 |
|
|
OnGateTimeout(self)
|
566 |
|
|
end
|
567 |
|
|
end;
|
568 |
|
|
sem_op(FSemaphore,1);
|
569 |
|
|
//writeln(ClassName,': Wait done on ',FSemaphore);
|
570 |
|
|
end;
|
571 |
|
|
|
572 |
|
|
|
573 |
|
|
{ TGlobalInterface }
|
574 |
|
|
|
575 |
|
|
function TGlobalInterface.GetMonitorCount: integer;
|
576 |
|
|
begin
|
577 |
|
|
Result := GetSemValue(cMonitorCounter)
|
578 |
|
|
end;
|
579 |
|
|
|
580 |
|
|
constructor TGlobalInterface.Create;
|
581 |
|
|
begin
|
582 |
|
|
inherited Create;
|
583 |
|
|
FSharedMemory := TSharedMemory.Create(cMonitorHookSize);
|
584 |
|
|
|
585 |
|
|
FWriteLock := TMutex.Create(cMutexSemaphore);
|
586 |
|
|
|
587 |
|
|
FDataAvailableEvent := TSingleLockGate.Create(cDataAvailableEventSemaphore,self);
|
588 |
|
|
FWriterBusyEvent := TSingleLockGate.Create(cWriterBusyEventSemaphore,self);
|
589 |
|
|
FReadReadyEvent := TMultiLockGate.Create(cReadReadyEventSemaphore,self);
|
590 |
|
|
FReadFinishedEvent := TMultiLockGate.Create(cReadFinishedEventSemaphore,self);
|
591 |
|
|
|
592 |
|
|
if FInitialiser then
|
593 |
|
|
SemInit(cMonitorCounter,0);
|
594 |
|
|
FTraceDataType := PInteger(FSharedMemory.Allocate(sizeof(Integer)));
|
595 |
|
|
FTimeStamp := PDateTime(FSharedMemory.Allocate(sizeof(TDateTime)));
|
596 |
|
|
FBufferSize := PInteger(FSharedMemory.Allocate(sizeof(Integer)));
|
597 |
|
|
FBuffer := FSharedMemory.Allocate(0); //All remaining
|
598 |
|
|
FMaxBufferSize := FSharedMemory.LastAllocationSize;
|
599 |
|
|
|
600 |
|
|
if FInitialiser then
|
601 |
|
|
begin
|
602 |
|
|
FBufferSize^ := 0;
|
603 |
|
|
FDataAvailableEvent.Lock
|
604 |
|
|
end;
|
605 |
|
|
end;
|
606 |
|
|
|
607 |
|
|
destructor TGlobalInterface.Destroy;
|
608 |
|
|
begin
|
609 |
|
|
if assigned(FWriteLock) then FWriteLock.Free;
|
610 |
|
|
if assigned(FDataAvailableEvent) then FDataAvailableEvent.Free;
|
611 |
|
|
if assigned(FWriterBusyEvent) then FWriterBusyEvent.Free;
|
612 |
|
|
if assigned(FReadReadyEvent) then FReadReadyEvent.Free;
|
613 |
|
|
if assigned(FReadFinishedEvent) then FReadFinishedEvent.Free;
|
614 |
|
|
if assigned(FSharedMemory) then FSharedMemory.Free;
|
615 |
|
|
inherited Destroy;
|
616 |
|
|
end;
|
617 |
|
|
|
618 |
|
|
procedure TGlobalInterface.IncMonitorCount;
|
619 |
|
|
begin
|
620 |
|
|
sem_op(cMonitorCounter,1);
|
621 |
|
|
end;
|
622 |
|
|
|
623 |
|
|
procedure TGlobalInterface.DecMonitorCount;
|
624 |
|
|
begin
|
625 |
|
|
sem_op(cMonitorCounter,-1,IPC_NOWAIT);
|
626 |
|
|
end;
|
627 |
|
|
|
628 |
|
|
procedure TGlobalInterface.SendTrace(TraceObject: TTraceObject);
|
629 |
|
|
begin
|
630 |
|
|
FTraceDataType^ := Integer(TraceObject.FDataType);
|
631 |
|
|
FTimeStamp^ := TraceObject.FTimeStamp;
|
632 |
|
|
FBufferSize^ := Min(Length(TraceObject.FMsg), MaxBufferSize);
|
633 |
|
|
Move(TraceObject.FMsg[1], FBuffer^, FBufferSize^);
|
634 |
|
|
end;
|
635 |
|
|
|
636 |
|
|
procedure TGlobalInterface.ReceiveTrace(TraceObject: TTraceObject);
|
637 |
|
|
begin
|
638 |
|
|
SetString(TraceObject.FMsg, FBuffer, FBufferSize^);
|
639 |
|
|
TraceObject.FDataType := TTraceFlag(FTraceDataType^);
|
640 |
|
|
TraceObject.FTimeStamp := TDateTime(FTimeStamp^);
|
641 |
|
|
end;
|
642 |
|
|
|
643 |
|
|
|
644 |
|
|
|