TThread

[Properties (by Name)][Methods (by Name)][Events (by Name)]

Abstract Thread class.

Declaration

Source position: classesh.inc line 1860

Type
  TThread = class
  private
    PThreadQueueEntry = ^TThreadQueueEntry;
    TThreadQueueEntry = record
      Method : TThreadMethod;
      Thread : TThread;
      ThreadID : TThreadID;
      Exception : TObject;
      SyncEvent : PRTLEvent;
      Next : PThreadQueueEntry;
    end
    ;
  public
    TSystemTimes = record
      IdleTime : QWord;
      UserTime : QWord;
      KernelTime : QWord;
      NiceTime : QWord;
    end
    ;
  private
    FProcessorCount : LongWord;
    FHandle : TThreadID;
    FTerminated : Boolean;
    FFreeOnTerminate : Boolean;
    FFinished : Boolean;
    FSuspended : LongBool;
    FReturnValue : Integer;
    FOnTerminate : TNotifyEvent;
    FFatalException : TObject;
    FExternalThread : Boolean;
    FSynchronizeEntry : PThreadQueueEntry;
    class function GetCurrentThread : TThread;  Static;
    class function GetIsSingleProcessor : Boolean;  Static;
    class procedure InternalQueue(aThread: TThread; aMethod: TThreadMethod; 
                                 aQueueIfMain: Boolean);  Static;
    procedure CallOnTerminate;
    function GetPriority : TThreadPriority;
    procedure SetPriority(Value: TThreadPriority);
    procedure SetSuspended(Value: Boolean);
    function GetSuspended : Boolean;
    procedure InitSynchronizeEvent;
    procedure DoneSynchronizeEvent;
    procedure SysCreate(CreateSuspended: Boolean; const StackSize: SizeUInt);
    procedure SysDestroy;
  protected
    FThreadID : TThreadID;
    procedure DoTerminate;  Virtual;
    procedure TerminatedSet;  Virtual;
    procedure Execute;  Virtual;  Abstract;
    procedure Synchronize(AMethod: TThreadMethod);
    class procedure Synchronize(AThread: TThread; AMethod: TThreadMethod);
    procedure Queue(aMethod: TThreadMethod);
    class procedure Queue(aThread: TThread; aMethod: TThreadMethod);  Static;
    procedure ForceQueue(aMethod: TThreadMethod);
    class procedure ForceQueue(aThread: TThread; aMethod: TThreadMethod)
                              ;  Static;
    ReturnValue : Integer;
    Terminated : Boolean;
  private
    FSuspendEvent : PRTLEvent;
    FInitialSuspended : Boolean;
    FSuspendedInternal : longbool;
    FThreadReaped : Boolean;
  public
    constructor Create(CreateSuspended: Boolean; const StackSize: SizeUInt);
    destructor Destroy;  Override;
    class function CreateAnonymousThread(aProc: TProcedure) : TThread
                                        ;  Static;
    class procedure NameThreadForDebugging(aThreadName: UnicodeString; 
                                          aThreadID: TThreadID);  Static;
    class procedure NameThreadForDebugging(aThreadName: AnsiString; 
                                          aThreadID: TThreadID);  Static;
    class procedure SetReturnValue(aValue: Integer);  Static;
    class function CheckTerminated : Boolean;  Static;
    class procedure RemoveQueuedEvents(aThread: TThread; 
                                      aMethod: TThreadMethod);  Static;
    class procedure RemoveQueuedEvents(aMethod: TThreadMethod);  Static;
    class procedure RemoveQueuedEvents(aThread: TThread);  Static;
    class procedure SpinWait(aIterations: LongWord);  Static;
    class procedure Sleep(aMilliseconds: Cardinal);  Static;
    class procedure Yield;  Static;
    class procedure GetSystemTimes(out aSystemTimes: TSystemTimes);  Static;
    class function GetTickCount : LongWord;  Static;
    class function GetTickCount64 : QWord;  Static;
    class function ExecuteInThread(AMethod: TThreadExecuteHandler; 
                                  AOnTerminate: TNotifyEvent) : TThread
                                  ;  Overload;  Static;
    class function ExecuteInThread(AMethod: TThreadExecuteStatusHandler; 
                                  AOnStatus: TThreadStatusNotifyEvent; 
                                  AOnTerminate: TNotifyEvent) : TThread
                                  ;  Overload;  Static;
    class function ExecuteInThread(AMethod: TThreadExecuteCallBack; 
                                  AData: Pointer; 
                                  AOnTerminate: TNotifyCallBack) : TThread
                                  ;  Overload;  Static;
    class function ExecuteInThread(AMethod: TThreadExecuteStatusCallBack; 
                                  AOnStatus: TThreadStatusNotifyCallBack; 
                                  AData: Pointer; 
                                  AOnTerminate: TNotifyCallBack) : TThread
                                  ;  Overload;  Static;
    procedure AfterConstruction;  Override;
    procedure Start;
    procedure Resume;
    procedure Suspend;
    procedure Terminate;
    function WaitFor : Integer;
    CurrentThread : TThread;
    ProcessorCount : LongWord;
    IsSingleProcessor : Boolean;
    FreeOnTerminate : Boolean;
    Handle : TThreadID;
    ExternalThread : Boolean;
    Priority : TThreadPriority;
    Suspended : Boolean;
    Finished : Boolean;
    ThreadID : TThreadID;
    OnTerminate : TNotifyEvent;
    FatalException : TObject;
  end
  ;

Description

The TThread class encapsulates the native thread support of the operating system. To create a thread, declare a descendant of the TThread object and override the Execute method. In this method, the tthread's code should be executed. To run a thread, create an instance of the tthread descendant, and call it's execute method.

It is also possible to simply execute a method or static procedure in a thread using the TThread.ExecuteInThread class method.

Members

Member	Type	Visibility	Description
AfterConstruction	Method	public	Code to be executed after construction but before execute.
CallOnTerminate	Method	private
CheckTerminated	Method	public	Check if the current thread has finished executing.
Create	Method	public	Creates a new thread.
CreateAnonymousThread	Method	public	Execute code in an anonymous thread
CurrentThread	Property	public	Return current thread instance
Destroy	Method	public	Destroys the thread object.
DoneSynchronizeEvent	Method	private
DoTerminate	Method	protected	Terminates the thread.
Execute	Method	protected	Execute method. Must be overridden in a descendant thread.
ExecuteInThread	Method	public	Execute a method or static procedure in a thread
ExternalThread	Property	public	Is the thread instance an external thread ?
FatalException	Property	public	Exception that occurred during thread execution
FExternalThread	Field	private
FFatalException	Field	private
FFinished	Field	private
FFreeOnTerminate	Field	private
FHandle	Field	private
Finished	Property	public	Has the thread finished executing
FInitialSuspended	Field	private
FOnTerminate	Field	private
ForceQueue	Method	protected
FProcessorCount	Field	private
FreeOnTerminate	Property	public	Indicates whether the thread should free itself when it stops executing.
FReturnValue	Field	private
FSuspended	Field	private
FSuspendedInternal	Field	private
FSuspendEvent	Field	private
FSynchronizeEntry	Field	private
FTerminated	Field	private
FThreadID	Field	protected
FThreadReaped	Field	private
GetCurrentThread	Method	private
GetIsSingleProcessor	Method	private
GetPriority	Method	private
GetSuspended	Method	private
GetSystemTimes	Method	public	Return CPU stats
GetTickCount	Method	public	Return tick count (32-bit)
GetTickCount64	Method	public	Return tick count (64-bit)
Handle	Property	public	Returns the thread handle.
InitSynchronizeEvent	Method	private
InternalQueue	Method	private
IsSingleProcessor	Property	public	Is the current system single processor or not
NameThreadForDebugging	Method	public	Set a thread name
OnTerminate	Property	public	Event called when the thread terminates.
Priority	Property	public	Returns the thread priority.
ProcessorCount	Property	public	Return the processor count for this system
PThreadQueueEntry	Type	private
Queue	Method	protected	Queue a method for execution in the main thread
RemoveQueuedEvents	Method	public	Remove methods scheduled for execution from queue
Resume	Method	public	Resumes the thread's execution. Deprecated, see TThread.Start
ReturnValue	Property	protected	Return value of the thread when it stops executing.
SetPriority	Method	private
SetReturnValue	Method	public	Set return value of a thread
SetSuspended	Method	private
Sleep	Method	public	Prevent thread execution
SpinWait	Method	public	Prevent thread execution in a spin-wait loop
Start	Method	public	Starts a thread that was created in a suspended state.
Suspend	Method	public	Suspends the thread's execution.
Suspended	Property	public	Indicates whether the thread is suspended.
Synchronize	Method	protected	Synchronizes the thread by executing the method in the main thread.
SysCreate	Method	private
SysDestroy	Method	private
Terminate	Method	public	Signals the thread it should terminate.
Terminated	Property	protected	Indicates whether the Terminate method was called by the user.
TerminatedSet	Method	protected
ThreadID	Property	public	Returns the thread ID.
TSystemTimes	Type	public	Record for returning processor usage
TThreadQueueEntry	Type	private
WaitFor	Method	public	Waits for the thread to terminate and returns the exit status.
Yield	Method	public	Yield execution to other threads

Inheritance

Class	Description
TThread	Abstract Thread class.

Name	Description
EThread	Thread error exception.
Integer	A signed 16-bits integer
Integer	A signed 16-bits integer
LongWord	An unsigned 32-bits integer
LongWord	An unsigned 32-bits integer
PRTLEvent	Pointer to RTLEvent, which is an opaque type.
TNotifyEvent	Standard event handler type.
TNotifyEvent	Standard event handler type.
TObject	Base class of all classes.
TObject	Base class of all classes.
TThread	Abstract Thread class.
TThread.Execute	Execute method. Must be overridden in a descendant thread.
TThread.ExecuteInThread	Execute a method or static procedure in a thread
TThreadID	Type for Thread-IDs
TThreadID	Type for Thread-IDs
TThreadID	Type for Thread-IDs
TThreadID	Type for Thread-IDs
TThreadPriority	Enumeration specifying the priority at which a thread runs.

TThread

Declaration

Description

Members

Inheritance

See also