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AsyncCalls.pas
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AsyncCalls.pas
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{**************************************************************************************************}
{ }
{ Asynchronous function calls utilizing multiple threads. }
{ }
{ The contents of this file are subject to the Mozilla Public License Version 1.1 (the "License"); }
{ you may not use this file except in compliance with the License. You may obtain a copy of the }
{ License at http://www.mozilla.org/MPL/ }
{ }
{ Software distributed under the License is distributed on an "AS IS" basis, WITHOUT WARRANTY OF }
{ ANY KIND, either express or implied. See the License for the specific language governing rights }
{ and limitations under the License. }
{ }
{ The Original Code is AsyncCalls.pas. }
{ }
{ The Initial Developer of the Original Code is Andreas Hausladen. }
{ Portions created by Andreas Hausladen are Copyright (C) 2006-2011 Andreas Hausladen. }
{ All Rights Reserved. }
{ }
{ Contributor(s): }
{ }
{**************************************************************************************************}
{ }
{ Version: 2.99 (2011-12-14) }
{ Added: IAsyncCall.CancelInvocation method }
{ Added: IAsyncCall.Forget method }
{ }
{ Version: 2.98 (2011-10-22) }
{ Added: Support for Delphi XE2 64bit }
{ }
{ Version: 2.97 (2011-05-21) }
{ Fixed: The thread priority wasn't reset to Normal for new AsyncCall tasks. }
{ Fixed: Replaced Suspend/Resume code to prevent a race condition where all threads are }
{ suspended but their FSuspended flag is false. }
{ Fixed: Exception handling in TAsyncCall.InternExecuteSyncCall. Quit() wasn't called after an }
{ exception was raised. }
{ }
{ Version: 2.96 (2010-09-12) }
{ Fixed: CoInitialize call was missing }
{ }
{ Version: 2.95 (2010-09-12) }
{ Added: Support for RAD Studio XE }
{ Added: Support for UnicodeString }
{ }
{ Version: 2.92 (2009-08-30) }
{ Added: Support for RAD Studio 2010 }
{ Restored: Delphi 2009 Update 1 fixed the compiler bug. All generic methods are now available. }
{ }
{ Version: 2.91 (2008-09-29) }
{ Fixed: All generic methods are now disabled due to an internal compiler error in Delphi 2009 }
{ }
{ Version: 2.9 (2008-09-27) }
{ Fixed: Window message handling }
{ Added: Delphi 2009 support with generics and anonymous methods }
{ Added: AsyncCall(Runnable: IAsyncRunnable) }
{ }
{ Version: 2.21 (2008-05-14) }
{ Fixed: Fixed bug in AsyncMultiSync }
{ }
{ Version: 2.2 (2008-05-12) }
{ Fixed: Bugs in main thread AsyncMultiSync implementation }
{ Added: Delphi 5 support }
{ }
{ Version: 2.1 (2008-05-06) }
{ Added: Delphi 6 support }
{ Added: Support for "Exit;" in the MainThread block }
{ Fixed: Exception handling for Delphi 6, 7 and 2005 }
{ Fixed: EBX, ESI and EDI weren't copied into the synchronized block (e.g. used for Self-Pointer)}
{ }
{ Version: 2.0 (2008-05-04) }
{ Added: EnterMainThread/LeaveMainThread }
{ Added: LocalVclCall, LocalAsyncVclCall, MsgAsyncMultiSync }
{ Added: LocalAsyncExec, AsyncExec }
{ Added: IAsyncCall.ForceDifferentThread }
{ Fixed: Exception handling }
{ Removed: Delphi 5 and 6 support }
{ }
{ Version: 1.2 (2008-02-10) }
{ Added: CoInitialize }
{ Added: LocalAsynCall() function }
{ }
{ Version: 1.1 (2007-08-14) }
{ Fixed: Workaround for TThread.Resume bug }
{ }
{ Version: 1.0 (2006-12-23) }
{ Initial release }
{**************************************************************************************************}
{$A+,B-,C-,D-,E-,F-,G+,H+,I+,J-,K-,L+,M-,N+,O+,P+,Q-,R-,S-,T-,U-,V+,W+,X+,Y+,Z1}
unit AsyncCalls;
{.$DEFINE DEBUG_ASYNCCALLS}
{.$DEFINE DEBUG_ASYNCCALLS_ODS}
{.$DEFINE DEBUG_THREADSTATS}
{$IFDEF MSWINDOWS}
{$IFNDEF CPUX64}
{$DEFINE SUPPORT_LOCAL_FUNCTIONS}
{$ENDIF ~CPUX64}
{$ENDIF MSWINDOWS}
interface
{$IFNDEF CONDITIONALEXPRESSIONS}
{$IFDEF VER130}
{$DEFINE DELPHI5}
{$ELSE}
'Your compiler version is not supported'
{$ENDIF}
{$ELSE}
{$IFDEF VER140}
{$DEFINE DELPHI6}
{.$MESSAGE ERROR 'Your compiler version is not supported'}
{$ELSE}
{$DEFINE DELPHI7_UP}
{$ENDIF}
{$WARN SYMBOL_PLATFORM OFF}
{$WARN UNIT_PLATFORM OFF}
{$IF CompilerVersion >= 15.0}
{$WARN UNSAFE_TYPE OFF}
{$WARN UNSAFE_CODE OFF}
{$WARN UNSAFE_CAST OFF}
{$IFEND}
{$IF CompilerVersion >= 18.0}
{$DEFINE SUPPORTS_INLINE}
{$IFEND}
{$IF CompilerVersion >= 20.0}
{$DEFINE DELPHI2009_UP}
{$IFEND}
{$IF CompilerVersion >= 21.0}
{$DEFINE DELPHI2010_UP}
{$IFEND}
{$ENDIF}
{$IFDEF DEBUG_ASYNCCALLS}
{$D+,C+}
{$ENDIF DEBUG_ASYNCCALLS}
uses
Windows, Messages, SysUtils, Classes, Contnrs, ActiveX, SyncObjs;
type
{$IFNDEF CONDITIONALEXPRESSIONS}
INT_PTR = Integer;
IInterface = IUnknown;
{$ELSE}
{$IF not declared(INT_PTR)}
INT_PTR = Integer;
{$IFEND}
{$ENDIF}
TAsyncIdleMsgMethod = procedure of object;
{$IFDEF SUPPORT_LOCAL_FUNCTIONS}
TCdeclFunc = Pointer; // function(Arg1: Type1; Arg2: Type2; ...); cdecl;
TCdeclMethod = TMethod; // function(Arg1: Type1; Arg2: Type2; ...) of object; cdecl;
TLocalAsyncProc = function: Integer;
TLocalVclProc = function(Param: INT_PTR): INT_PTR;
TLocalAsyncProcEx = function(Param: INT_PTR): INT_PTR;
//TLocalAsyncForLoopProc = function(Index: Integer; SyncLock: TCriticalSection): Boolean;
{$ENDIF SUPPORT_LOCAL_FUNCTIONS}
TAsyncCallArgObjectProc = function(Arg: TObject): Integer;
TAsyncCallArgIntegerProc = function(Arg: Integer): Integer;
TAsyncCallArgStringProc = function(const Arg: string): Integer;
TAsyncCallArgWideStringProc = function(const Arg: WideString): Integer;
TAsyncCallArgInterfaceProc = function(const Arg: IInterface): Integer;
TAsyncCallArgExtendedProc = function(const Arg: Extended): Integer;
TAsyncCallArgVariantProc = function(const Arg: Variant): Integer;
TAsyncCallArgObjectMethod = function(Arg: TObject): Integer of object;
TAsyncCallArgIntegerMethod = function(Arg: Integer): Integer of object;
TAsyncCallArgStringMethod = function(const Arg: string): Integer of object;
TAsyncCallArgWideStringMethod = function(const Arg: WideString): Integer of object;
TAsyncCallArgInterfaceMethod = function(const Arg: IInterface): Integer of object;
TAsyncCallArgExtendedMethod = function(const Arg: Extended): Integer of object;
TAsyncCallArgVariantMethod = function(const Arg: Variant): Integer of object;
TAsyncCallArgObjectEvent = procedure(Arg: TObject) of object;
TAsyncCallArgIntegerEvent = procedure(Arg: Integer) of object;
TAsyncCallArgStringEvent = procedure(const Arg: string) of object;
TAsyncCallArgWideStringEvent = procedure(const Arg: WideString) of object;
TAsyncCallArgInterfaceEvent = procedure(const Arg: IInterface) of object;
TAsyncCallArgExtendedEvent = procedure(const Arg: Extended) of object;
TAsyncCallArgVariantEvent = procedure(const Arg: Variant) of object;
TAsyncCallArgRecordProc = function(var Arg{: TRecordType}): Integer;
TAsyncCallArgRecordMethod = function(var Arg{: TRecordType}): Integer of object;
TAsyncCallArgRecordEvent = procedure(var Arg{: TRecordType}) of object;
EAsyncCallError = class(Exception);
IAsyncCall = interface
{ Sync() waits until the asynchronous call has finished and returns the
result value of the called function if that exists. }
function Sync: Integer;
{ Finished() returns True if the asynchronous call has finished. }
function Finished: Boolean;
{ ReturnValue() returns the result of the asynchronous call. It raises an
exception if called before the function has finished. It returns 0 if the
AsyncCall invocation was canceled. }
function ReturnValue: Integer;
{ Canceled() returns True if the AsyncCall was canceled by CancelInvocation(). }
function Canceled: Boolean;
{ ForceDifferentThread() tells AsyncCalls that the assigned function must
not be executed in the current thread. }
procedure ForceDifferentThread;
{ CancelInvocation() stopps the AsyncCall from being invoked. If the AsyncCall is already
processed, a call to CancelInvocation() has no effect and the Canceled() function will
return False as the AsyncCall wasn't canceled. }
procedure CancelInvocation;
{ Forget() unlinks the IAsyncCall interface from the internal AsyncCall. This means that
if the last reference to the IAsyncCall interface is gone, the asynchronous call will
be still executed. The interface's methods will throw an exception if called after calling
Forget(). The async function must not call into the main thread because it could be executed
after the TThread.Synchronize/Queue mechanism was shut down by the RTL what can cause a
dead lock. }
procedure Forget;
end;
{ *** Internal interface. Do not use it *** }
IAsyncCallEx = interface
['{A31D8EE4-17B6-4FC7-AC94-77887201EE56}']
function GetEvent: THandle;
function SyncInThisThreadIfPossible: Boolean;
end;
IAsyncRunnable = interface
['{1A313BBD-0F89-43AD-8B57-BBA3205F4888}']
procedure AsyncRun;
end;
{ SetMaxAsyncCallThreads() controls how many threads can be used by the
async call thread pool. The thread pool creates threads when they are needed.
Allocated threads are not destroyed until the application has terminated, but
they are suspended if not used. }
procedure SetMaxAsyncCallThreads(MaxThreads: Integer);
{ GetMaxAsyncCallThreads() returns the maximum number of threads that can
exist in the thread pool. }
function GetMaxAsyncCallThreads: Integer;
{ AsyncCall() executes the given function/procedure in a separate thread. The
result value of the asynchronous function is returned by IAsyncCall.Sync() and
IAsyncCall.ReturnValue().
The AsyncExec() function calls the IdleMsgMethod in a loop, while the async.
method is executed.
Example:
function FileAgeAsync(const Filename: string): Integer;
begin
Result := FileAge(Filename);
end;
var
a: IAsyncCall;
begin
a := AsyncCall(FileAgeAsync, 'C:\Windows\notepad.exe');
// do something
Age := a.Sync;
end;
}
function AsyncCall(Proc: TAsyncCallArgObjectProc; Arg: TObject): IAsyncCall; overload;
function AsyncCall(Proc: TAsyncCallArgIntegerProc; Arg: Integer): IAsyncCall; overload;
function AsyncCall(Proc: TAsyncCallArgStringProc; const Arg: string): IAsyncCall; overload;
function AsyncCall(Proc: TAsyncCallArgWideStringProc; const Arg: WideString): IAsyncCall; overload;
function AsyncCall(Proc: TAsyncCallArgInterfaceProc; const Arg: IInterface): IAsyncCall; overload;
function AsyncCall(Proc: TAsyncCallArgExtendedProc; const Arg: Extended): IAsyncCall; overload;
function AsyncCallVar(Proc: TAsyncCallArgVariantProc; const Arg: Variant): IAsyncCall; overload;
function AsyncCall(Method: TAsyncCallArgObjectMethod; Arg: TObject): IAsyncCall; overload;
function AsyncCall(Method: TAsyncCallArgIntegerMethod; Arg: Integer): IAsyncCall; overload;
function AsyncCall(Method: TAsyncCallArgStringMethod; const Arg: string): IAsyncCall; overload;
function AsyncCall(Method: TAsyncCallArgWideStringMethod; const Arg: WideString): IAsyncCall; overload;
function AsyncCall(Method: TAsyncCallArgInterfaceMethod; const Arg: IInterface): IAsyncCall; overload;
function AsyncCall(Method: TAsyncCallArgExtendedMethod; const Arg: Extended): IAsyncCall; overload;
function AsyncCallVar(Method: TAsyncCallArgVariantMethod; const Arg: Variant): IAsyncCall; overload;
function AsyncCall(Method: TAsyncCallArgObjectEvent; Arg: TObject): IAsyncCall; overload;
function AsyncCall(Method: TAsyncCallArgIntegerEvent; Arg: Integer): IAsyncCall; overload;
function AsyncCall(Method: TAsyncCallArgStringEvent; const Arg: string): IAsyncCall; overload;
function AsyncCall(Method: TAsyncCallArgWideStringEvent; const Arg: WideString): IAsyncCall; overload;
function AsyncCall(Method: TAsyncCallArgInterfaceEvent; const Arg: IInterface): IAsyncCall; overload;
function AsyncCall(Method: TAsyncCallArgExtendedEvent; const Arg: Extended): IAsyncCall; overload;
function AsyncCallVar(Method: TAsyncCallArgVariantEvent; const Arg: Variant): IAsyncCall; overload;
function AsyncCall(Runnable: IAsyncRunnable): IAsyncCall; overload;
procedure AsyncExec(Method: TNotifyEvent; Arg: TObject; IdleMsgMethod: TAsyncIdleMsgMethod);
{$IFDEF SUPPORT_LOCAL_FUNCTIONS}
{ LocalAsyncCall() executes the given local function/procedure in a separate thread.
The result value of the asynchronous function is returned by IAsyncCall.Sync() and
IAsyncCall.ReturnValue().
The LocalAsyncExec() function calls the IdleMsgMethod while the local procedure is
executed.
Example:
procedure MainProc(const S: string);
var
Value: Integer;
a: IAsyncCall;
function DoSomething: Integer;
begin
if S = 'Abc' then
Value := 1;
Result := 0;
end;
begin
a := LocalAsyncCall(@DoSomething);
// do something
a.Sync;
LocalAsyncExec(@DoSomething, Application.ProcessMessages);
end;
}
function LocalAsyncCall(LocalProc: TLocalAsyncProc): IAsyncCall;
function LocalAsyncCallEx(LocalProc: TLocalAsyncProcEx; Param: INT_PTR): IAsyncCall;
procedure LocalAsyncExec(Proc: TLocalAsyncProc; IdleMsgMethod: TAsyncIdleMsgMethod);
{ LocalVclCall() executes the given local function/procedure in the main thread. It
uses the TThread.Synchronize function which blocks the current thread.
LocalAsyncVclCall() execute the given local function/procedure in the main thread.
It does not wait for the main thread to execute the function unless the current
thread is the main thread. In that case it executes and waits for the specified
function in the current thread like LocalVclCall().
The result value of the asynchronous function is returned by IAsyncCall.Sync() and
IAsyncCall.ReturnValue().
Example:
procedure TForm1.MainProc;
procedure DoSomething;
procedure UpdateProgressBar(Percentage: Integer);
begin
ProgressBar.Position := Percentage;
Sleep(20); // This delay does not affect the time for the 0..100 loop
// because UpdateProgressBar is non-blocking.
end;
procedure Finished;
begin
ShowMessage('Finished');
end;
var
I: Integer;
begin
for I := 0 to 100 do
begin
// Do some time consuming stuff
Sleep(30);
LocalAsyncVclCall(@UpdateProgressBar, I); // non-blocking
end;
LocalVclCall(@Finished); // blocking
end;
var
a: IAsyncCall;
begin
a := LocalAsyncCall(@DoSomething);
a.ForceDifferentThread; // Do not execute in the main thread because this will
// change LocalAyncVclCall into a blocking LocalVclCall
// do something
//a.Sync; The Compiler will call this for us in the Interface._Release method
end;
}
procedure LocalVclCall(LocalProc: TLocalVclProc; Param: INT_PTR = 0);
function LocalAsyncVclCall(LocalProc: TLocalVclProc; Param: INT_PTR = 0): IAsyncCall;
{$ENDIF SUPPORT_LOCAL_FUNCTIONS}
{ AsyncCallEx() executes the given function/procedure in a separate thread. The
Arg parameter can be a record type. The fields of the record can be modified
in the asynchon function.
Example:
type
TData = record
Value: Integer;
end;
procedure TestRec(var Data: TData);
begin
Data.Value := 70;
end;
a := AsyncCallEx(@TestRec, MyData);
a.Sync; // MyData.Value is now 70
}
function AsyncCallEx(Proc: TAsyncCallArgRecordProc; var Arg{: TRecordType}): IAsyncCall; overload;
function AsyncCallEx(Method: TAsyncCallArgRecordMethod; var Arg{: TRecordType}): IAsyncCall; overload;
function AsyncCallEx(Method: TAsyncCallArgRecordEvent; var Arg{: TRecordType}): IAsyncCall; overload;
{$IFDEF SUPPORT_LOCAL_FUNCTIONS}
{ The following AsyncCall() functions support variable parameters. All reference
counted types are protected by an AddRef and later Release. The ShortString,
Extended, Currency and Int64 types are internally copied to a temporary location.
Supported types:
Integer : Arg: Integer
Boolean : Arg: Boolean
Char : Arg: AnsiChar
WideChar : Arg: WideChar
Int64 : [const] Arg: Int64
Extended : [const] Arg: Extended
Currency : [const] Arg: Currency
String : [const] Arg: ShortString
Pointer : [const] Arg: Pointer
PChar : [const] Arg: PChar
Object : [const] Arg: TObject
Class : [const] Arg: TClass
AnsiString : [const] Arg: AnsiString
UnicodeString: [const] Arg: UnicodeString
PWideChar : [const] Arg: PWideChar
WideString : [const] Arg: WideString
Interface : [const] Arg: IInterface
Variant : const Arg: Variant
Example:
procedure Test(const S: string; I: Integer; E: Extended; Obj: TObject); cdecl;
begin
end;
AsyncCall(@Test, ['Hallo', 10, 3.5, MyObject]);
}
function AsyncCall(Proc: TCdeclFunc; const Args: array of const): IAsyncCall; overload;
function AsyncCall(Proc: TCdeclMethod; const Args: array of const): IAsyncCall; overload;
{$ENDIF SUPPORT_LOCAL_FUNCTIONS}
{ AsyncMultiSync() waits for the async calls and other handles to finish.
MsgAsyncMultiSync() waits for the async calls, other handles and the message queue.
Arguments:
List : An array of IAsyncCall interfaces for which the function
should wait.
Handles : An array of THandle for which the function should wait.
WaitAll = True : The function returns when all listed async calls have
finished. If Milliseconds is INFINITE the async calls
meight be executed in the current thread.
The return value is zero when all async calls have finished.
Otherwise it is -1.
WaitAll = False : The function returns when at least one of the async calls
has finished. The return value is the list index of the
first finished async call. If there was a timeout, the
return value is -1.
Milliseconds : Specifies the number of milliseconds to wait until a
timeout happens. The value INFINITE lets the function wait
until all async calls have finished.
dwWakeMask : see Windows.MsgWaitForMultipleObjects()
Limitations:
Length(List)+Length(Handles) must not exceed MAXIMUM_ASYNC_WAIT_OBJECTS.
Return value:
WAIT_TIMEOUT
The function timed out
WAIT_OBJECT_0+index
The first finished async call
WAIT_OBJECT_0+Length(List)+index
The first signaled handle
WAIT_OBJECT_0+Length(List)+Length(Handles)
A message was signaled
WAIT_ABANDONED_0+index
The abandoned async call
WAIT_ABANDONED_0+Length(List)+index
The abandoned handle
WAIT_FAILED
The function failed
}
const
MAXIMUM_ASYNC_WAIT_OBJECTS = MAXIMUM_WAIT_OBJECTS - 3;
function AsyncMultiSync(const List: array of IAsyncCall; WaitAll: Boolean = True;
Milliseconds: Cardinal = INFINITE): Cardinal;
function AsyncMultiSyncEx(const List: array of IAsyncCall; const Handles: array of THandle;
WaitAll: Boolean = True; Milliseconds: Cardinal = INFINITE): Cardinal;
function MsgAsyncMultiSync(const List: array of IAsyncCall; WaitAll: Boolean;
Milliseconds: Cardinal; dwWakeMask: DWORD): Cardinal;
function MsgAsyncMultiSyncEx(const List: array of IAsyncCall; const Handles: array of THandle;
WaitAll: Boolean; Milliseconds: Cardinal; dwWakeMask: DWORD): Cardinal;
{$IFDEF SUPPORT_LOCAL_FUNCTIONS}
{
EnterMainThread/LeaveMainThread can be used to temporary switch to the
main thread. The code that should be synchonized (blocking) has to be put
into a try/finally block and the LeaveMainThread() function must be called
from the finally block. A missing try/finally will lead to an access violation.
* All local variables can be used. (EBP points to the thread's stack while
ESP points the the main thread's stack)
* Unhandled exceptions are passed to the surrounding thread.
* The integrated Debugger is not able to follow the execution flow. You have
to use break points instead of "Step over/in".
* Nested calls to EnterMainThread/LeaveMainThread are ignored. But they must
strictly follow the try/finally structure.
Example:
procedure MyThreadProc;
var
S: string;
begin
Assert(GetCurrentThreadId <> MainThreadId);
S := 'Hallo, I''m executed in the main thread';
EnterMainThread;
try
Assert(GetCurrentThreadId = MainThreadId);
ShowMessage(S);
finally
LeaveMainThread;
end;
Assert(GetCurrentThreadId <> MainThreadId);
end;
}
procedure EnterMainThread;
procedure LeaveMainThread;
{$ENDIF SUPPORT_LOCAL_FUNCTIONS}
type
TAsyncCall = class;
{ *** Internal class. Do not use it *** }
{ TAsyncCall is the base class for all parameter based async call types }
TInternalAsyncCall = class(TObject)
private
FNext: TInternalAsyncCall;
FEvent: THandle;
FReturnValue: Integer;
FFinished: Boolean;
FFatalException: Exception;
FFatalErrorAddr: Pointer;
FForceDifferentThread: Boolean;
FCancelInvocation: Boolean;
FCanceled: Boolean;
FExecuted: Boolean;
FAutoDelete: Boolean;
procedure InternExecuteAsyncCall;
procedure InternExecuteSyncCall;
procedure Quit(AReturnValue: Integer);
protected
{ Decendants must implement this method. It is called when the async call
should be executed. }
function ExecuteAsyncCall: Integer; virtual; abstract;
private
constructor Create;
function ExecuteAsync: TAsyncCall;
function GetEvent: THandle;
function SyncInThisThreadIfPossible: Boolean;
function Sync: Integer;
function Finished: Boolean;
function ReturnValue: Integer;
function Canceled: Boolean;
procedure ForceDifferentThread;
procedure CancelInvocation;
procedure Forget;
public
destructor Destroy; override;
end;
{ *** Internal class. Do not use it *** }
TAsyncCall = class(TInterfacedObject, IAsyncCall, IAsyncCallEx)
private
FCall: TInternalAsyncCall;
procedure CheckForget;
{ IAsyncCallEx }
function GetEvent: THandle;
function SyncInThisThreadIfPossible: Boolean;
private
constructor Create(ACall: TInternalAsyncCall);
{ IAsyncCall }
function Sync: Integer;
function Finished: Boolean;
function ReturnValue: Integer;
function Canceled: Boolean;
procedure ForceDifferentThread;
procedure CancelInvocation;
procedure Forget;
public
destructor Destroy; override;
end;
{ *** Internal class. Do not use it *** }
{ TSyncCall is a fake IAsyncCall implementor. The async call was already
executed when the interface is returned. }
TSyncCall = class(TInterfacedObject, IAsyncCall)
private
FReturnValue: Integer;
private
constructor Create(AReturnValue: Integer);
function Sync: Integer;
function Finished: Boolean;
function ReturnValue: Integer;
function Canceled: Boolean;
procedure ForceDifferentThread;
procedure CancelInvocation;
procedure Forget;
end;
{$IFDEF DELPHI2009_UP}
type
{ *** Helper class *** }
TMultiArgProcCall<TProc, T1> = class(TInternalAsyncCall)
private
FProc: TProc;
FArg1: T1;
public
constructor Create(AProc: TProc; const AArg1: T1);
end;
TMultiArgProcCall<TProc, T1, T2> = class(TMultiArgProcCall<TProc, T1>)
private
FArg2: T2;
public
constructor Create(AProc: TProc; const AArg1: T1; const AArg2: T2);
end;
TMultiArgProcCall<TProc, T1, T2, T3> = class(TMultiArgProcCall<TProc, T1, T2>)
private
FArg3: T3;
public
constructor Create(AProc: TProc; const AArg1: T1; const AArg2: T2; const AArg3: T3);
end;
TMultiArgProcCall<TProc, T1, T2, T3, T4> = class(TMultiArgProcCall<TProc, T1, T2, T3>)
private
FArg4: T4;
public
constructor Create(AProc: TProc; const AArg1: T1; const AArg2: T2; const AArg3: T3; const AArg4: T4);
end;
TAsyncCalls = class(TObject)
private
type
TAsyncCallArgGenericProc<T> = function(Arg: T): Integer;
TAsyncCallArgGenericProc<T1, T2> = function(Arg1: T1; Arg2: T2): Integer;
TAsyncCallArgGenericProc<T1, T2, T3> = function(Arg1: T1; Arg2: T2; Arg3: T3): Integer;
TAsyncCallArgGenericProc<T1, T2, T3, T4> = function(Arg1: T1; Arg2: T2; Arg3: T3; Arg4: T4): Integer;
TAsyncCallArgGenericMethod<T> = function(Arg: T): Integer of object;
TAsyncCallArgGenericMethod<T1, T2> = function(Arg1: T1; Arg2: T2): Integer of object;
TAsyncCallArgGenericMethod<T1, T2, T3> = function(Arg1: T1; Arg2: T2; Arg3: T3): Integer of object;
TAsyncCallArgGenericMethod<T1, T2, T3, T4> = function(Arg1: T1; Arg2: T2; Arg3: T3; Arg4: T4): Integer of object;
TIntFunc = reference to function: Integer;
TAsyncCallArg<T> = class(TMultiArgProcCall<TAsyncCallArgGenericProc<T>, T>)
protected
function ExecuteAsyncCall: Integer; override;
end;
TAsyncCallArg<T1, T2> = class(TMultiArgProcCall<TAsyncCallArgGenericProc<T1, T2>, T1, T2>)
protected
function ExecuteAsyncCall: Integer; override;
end;
TAsyncCallArg<T1, T2, T3> = class(TMultiArgProcCall<TAsyncCallArgGenericProc<T1, T2, T3>, T1, T2, T3>)
protected
function ExecuteAsyncCall: Integer; override;
end;
TAsyncCallArg<T1, T2, T3, T4> = class(TMultiArgProcCall<TAsyncCallArgGenericProc<T1, T2, T3, T4>, T1, T2, T3, T4>)
protected
function ExecuteAsyncCall: Integer; override;
end;
TAsyncCallArgMethod<T> = class(TMultiArgProcCall<TAsyncCallArgGenericMethod<T>, T>)
protected
function ExecuteAsyncCall: Integer; override;
end;
TAsyncCallArgMethod<T1, T2> = class(TMultiArgProcCall<TAsyncCallArgGenericMethod<T1, T2>, T1, T2>)
protected
function ExecuteAsyncCall: Integer; override;
end;
TAsyncCallArgMethod<T1, T2, T3> = class(TMultiArgProcCall<TAsyncCallArgGenericMethod<T1, T2, T3>, T1, T2, T3>)
protected
function ExecuteAsyncCall: Integer; override;
end;
TAsyncCallArgMethod<T1, T2, T3, T4> = class(TMultiArgProcCall<TAsyncCallArgGenericMethod<T1, T2, T3, T4>, T1, T2, T3, T4>)
protected
function ExecuteAsyncCall: Integer; override;
end;
TAsyncCallAnonymProc = class(TInternalAsyncCall)
private
FProc: TProc;
protected
function ExecuteAsyncCall: Integer; override;
public
constructor Create(AProc: TProc);
end;
TAsyncCallAnonymFunc = class(TInternalAsyncCall)
private
FProc: TIntFunc;
protected
function ExecuteAsyncCall: Integer; override;
public
constructor Create(AProc: TIntFunc);
end;
TAsyncVclCallAnonymProc = class(TInternalAsyncCall)
private
FProc: TProc;
protected
function ExecuteAsyncCall: Integer; override;
public
constructor Create(AProc: TProc);
end;
public
{ Invoke an asynchronous function call }
class function Invoke<T>(Proc: TAsyncCallArgGenericProc<T>; const Arg: T): IAsyncCall; overload; static;
class function Invoke<T>(Event: TAsyncCallArgGenericMethod<T>; const Arg: T): IAsyncCall; overload; static;
class function Invoke<T1, T2>(Proc: TAsyncCallArgGenericProc<T1, T2>; const Arg1: T1; const Arg2: T2): IAsyncCall; overload; static;
class function Invoke<T1, T2>(Event: TAsyncCallArgGenericMethod<T1, T2>; const Arg1: T1; const Arg2: T2): IAsyncCall; overload; static;
class function Invoke<T1, T2, T3>(Proc: TAsyncCallArgGenericProc<T1, T2, T3>; const Arg1: T1; const Arg2: T2; const Arg3: T3): IAsyncCall; overload; static;
class function Invoke<T1, T2, T3>(Event: TAsyncCallArgGenericMethod<T1, T2, T3>; const Arg1: T1; const Arg2: T2; const Arg3: T3): IAsyncCall; overload; static;
class function Invoke<T1, T2, T3, T4>(Proc: TAsyncCallArgGenericProc<T1, T2, T3, T4>; const Arg1: T1; const Arg2: T2; const Arg3: T3; const Arg4: T4): IAsyncCall; overload; static;
class function Invoke<T1, T2, T3, T4>(Event: TAsyncCallArgGenericMethod<T1, T2, T3, T4>; const Arg1: T1; const Arg2: T2; const Arg3: T3; const Arg4: T4): IAsyncCall; overload; static;
{ Invoke an asynchronous anonymous method call }
class function Invoke(Func: TIntFunc): IAsyncCall; overload; static;
class function Invoke(Proc: TProc): IAsyncCall; overload; static;
{ MsgExec waits for the @AsyncCall to finish. If there are any messages in
the message queue and the function was called from the main thread, it will
call @IdleMsgMethod. "Application.ProcessMessages" can be specified for
@IdleMsgMethod. }
class procedure MsgExec(AsyncCall: IAsyncCall; IdleMsgMethod: TAsyncIdleMsgMethod); static;
{ Synchronize with the VCL }
{ VCLSync returns when the anonymous method was called in the main thread }
class procedure VCLSync(Proc: TProc); static;
{ VCLInvoke returns immediately. The anonymous method will be executed in
the main thread. }
class function VCLInvoke(Proc: TProc): IAsyncCall; static;
end;
{$ENDIF DELPHI2009_UP}
implementation
{$IFDEF DELPHI5}
uses
Forms; // AllocateHWnd
{$ENDIF DELPHI5}
resourcestring
RsAsyncCallNotFinished = 'The asynchronous call is not finished yet';
RsAsyncCallUnknownVarRecType = 'Unknown TVarRec type %d';
RsLeaveMainThreadNestedError = 'Unpaired call to AsyncCalls.LeaveMainThread()';
RsLeaveMainThreadThreadError = 'AsyncCalls.LeaveMainThread() was called outside of the main thread';
RsForgetWasCalled = 'IAsyncCall.Forget was called. The interface isn''t connected to the asynchronous call anymore';
RsNoVclSyncPossible = 'Cannot synchronize with the main thread anymore. Don''t call IAsyncCall.Forget for functions that access the VCL';
const
WM_VCLSYNC = WM_USER + 12;
{$IFNDEF DELPHI7_UP}
var
SyncEvent: THandle;
type
TThread = class(Classes.TThread)
{$IFDEF DELPHI6}
private
class procedure WakeMainThread(Sender: TObject);
{$ENDIF DELPHI6}
public
class procedure StaticSynchronize(AThread: TThread; AMethod: TThreadMethod);
end;
class procedure TThread.StaticSynchronize(AThread: TThread; AMethod: TThreadMethod);
var
Obj: TThread;
begin
if GetCurrentThreadId = MainThreadId then
AMethod
else if AThread <> nil then
AThread.Synchronize(AMethod)
else
begin
{$WARNINGS OFF} // suppress abstract class warning
Obj := TThread.Create(True);
{$WARNINGS ON}
try
Obj.Synchronize(AMethod);
finally
Obj.Free;
end;
end;
end;
{$ENDIF ~DELPHI7_UP}
procedure StaticSynchronize(AMethod: TThreadMethod);
begin
{$IFDEF DELPHI2010_UP}
TThread.Synchronize(nil, AMethod);
{$ELSE}
TThread.StaticSynchronize(nil, AMethod);
{$ENDIF DELPHI2010_UP}
end;
{$IFDEF DELPHI5}
function CheckSynchronize(Timeout: Integer = 0): Boolean;
begin
Result := False;
end;
function AcquireExceptionObject: Pointer;
type
PRaiseFrame = ^TRaiseFrame;
TRaiseFrame = record
NextRaise: PRaiseFrame;
ExceptAddr: Pointer;
ExceptObject: TObject;
ExceptionRecord: PExceptionRecord;
end;
begin
if RaiseList <> nil then
begin
Result := PRaiseFrame(RaiseList)^.ExceptObject;
PRaiseFrame(RaiseList)^.ExceptObject := nil;
end
else
Result := nil;
end;
{$ENDIF DELPHI5}
{$IFDEF DELPHI6}
var
OrgWakeMainThread: TNotifyEvent;
class procedure TThread.WakeMainThread(Sender: TObject);
begin
if Assigned(OrgWakeMainThread) then
OrgWakeMainThread(Sender);
SetEvent(SyncEvent);
end;
procedure HookWakeMainThread;
begin
OrgWakeMainThread := Classes.WakeMainThread;
Classes.WakeMainThread := TThread.WakeMainThread;
end;
procedure UnhookWakeMainThread;
begin
Classes.WakeMainThread := OrgWakeMainThread;
end;
{$ENDIF DELPHI6}
{$IFNDEF DELPHI2009_UP}
// Needed for older Delphi versions
function InterlockedCompareExchange(var Destination: Integer; Exchange: Integer; Comparand: Integer): Integer;
asm
XCHG EAX, ECX
LOCK CMPXCHG [ECX], EDX
end;
{$ENDIF ~DELPHI2009_UP}
type
{ TAsyncCallThread is a pooled thread. It looks itself for work. }
TAsyncCallThread = class(TThread)
{$IFDEF DEBUG_THREADSTATS}
private
FTaskCount: Integer;
FTaskTime: Int64;
{$ENDIF DEBUG_THREADSTATS}
protected
procedure Execute; override;
public
constructor Create(ACreateSuspended: Boolean);
end;
{ TThreadPool contains a pool of threads that are either suspended or busy. }
TThreadPool = class(TObject)
private
FWakeUpEvent: THandle;
FThreadTerminateEvent: THandle;
FSleepingThreadCount: Integer;
FMaxThreads: Integer;
FDestroying: Boolean;
FThreadCount: Integer;
FThreads: array[0..255] of TAsyncCallThread;
FAsyncCallsCritSect: TRTLCriticalSection;
FAsyncCallHead, FAsyncCallTail: TInternalAsyncCall;
FAutoDeleteAsyncCalls: TInternalAsyncCall;
FNumberOfProcessors: Cardinal;
{$IFDEF DEBUG_THREADSTATS}
FSyncExecutedCount, FAsyncExecutedCount: Integer;
{$ENDIF DEBUG_THREADSTATS}
FMainThreadSyncEvent: THandle;
FMainThreadVclHandle: HWND;
procedure MainThreadWndProc(var Msg: TMessage);
procedure ProcessMainThreadSync;
procedure AllocThread;
function GetNextAsyncCall: TInternalAsyncCall; // called from the threads
procedure WakeUpThread;
procedure Sleep;
procedure ReleaseAutoDeleteAsyncCalls;
procedure CheckAutoDelete(Call: TInternalAsyncCall);
public
constructor Create;
destructor Destroy; override;
procedure CheckDestroying;
procedure SendVclSync(Call: TInternalAsyncCall);
procedure AddAsyncCall(Call: TInternalAsyncCall);
function RemoveAsyncCall(Call: TInternalAsyncCall): Boolean;
procedure ForgetAsyncCall(Call: TInternalAsyncCall);
property MaxThreads: Integer read FMaxThreads;
property NumberOfProcessors: Cardinal read FNumberOfProcessors;
property MainThreadSyncEvent: THandle read FMainThreadSyncEvent;
end;
{ ---------------------------------------------------------------------------- }
TAsyncCallArgObject = class(TInternalAsyncCall)
private
FProc: TAsyncCallArgObjectProc;
FArg: TObject;
protected
function ExecuteAsyncCall: Integer; override;
public
constructor Create(AProc: TAsyncCallArgObjectProc; AArg: TObject);
end;
TAsyncCallArgString = class(TInternalAsyncCall)
private
FProc: TAsyncCallArgStringProc;
FArg: string;
protected
function ExecuteAsyncCall: Integer; override;
public
constructor Create(AProc: TAsyncCallArgStringProc; const AArg: string);
end;
TAsyncCallArgWideString = class(TInternalAsyncCall)
private
FProc: TAsyncCallArgWideStringProc;
FArg: WideString;
protected
function ExecuteAsyncCall: Integer; override;
public
constructor Create(AProc: TAsyncCallArgWideStringProc; const AArg: WideString);
end;
TAsyncCallArgInterface = class(TInternalAsyncCall)
private
FProc: TAsyncCallArgInterfaceProc;
FArg: IInterface;
protected
function ExecuteAsyncCall: Integer; override;