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{
$Id: libasync.inc,v 1.6 2005/02/14 17:13:19 peter Exp $
libasync: Asynchronous event management
Copyright (C) 2001-2002 by
Areca Systems GmbH / Sebastian Guenther, sg@freepascal.org
Common implementation
See the file COPYING.FPC, included in this distribution,
for details about the copyright.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
}
type
PTimerData = ^TTimerData;
TTimerData = record
Next: PTimerData;
MSec: LongInt;
NextTick: Int64;
Callback: TAsyncCallback;
UserData: Pointer;
Periodic: Boolean;
end;
TCallbackTypes = set of (cbRead, cbWrite);
{ An implementation unit has to implement the following fordward procedures,
and additionally asyncGetTicks }
procedure InternalInit(Handle: TAsyncHandle); forward;
procedure InternalFree(Handle: TAsyncHandle); forward;
procedure InternalRun(Handle: TAsyncHandle; TimeOut: Int64); forward;
procedure InternalInitIOCallback(Handle: TAsyncHandle; Data: PIOCallbackData;
InitData: Boolean; CallbackTypes: TCallbackTypes); forward;
procedure InternalClearIOCallback(Handle: TAsyncHandle; IOHandle: LongInt;
CallbackTypes: TCallbackTypes); forward;
function InitIOCallback(Handle: TAsyncHandle; IOHandle: LongInt;
ARead: Boolean; ReadCallback: TAsyncCallback; ReadUserData: Pointer;
AWrite: Boolean; WriteCallback: TAsyncCallback; WriteUserData: Pointer):
TAsyncResult;
var
Data: PIOCallbackData;
NeedData: Boolean;
CallbackTypes: TCallbackTypes;
begin
if (IOHandle < 0) or (IOHandle > MaxHandle) then
begin
Result := asyncInvalidFileHandle;
exit;
end;
NeedData := True;
Data := Handle^.Data.FirstIOCallback;
while Assigned(Data) do
begin
if Data^.IOHandle = IOHandle then
begin
if ARead then
begin
if Assigned(Data^.ReadCallback) then
begin
Result := asyncHandlerAlreadySet;
exit;
end;
Data^.ReadCallback := ReadCallback;
Data^.ReadUserData := ReadUserData;
end;
if AWrite then
begin
if Assigned(Data^.WriteCallback) then
begin
Result := asyncHandlerAlreadySet;
exit;
end;
Data^.WriteCallback := WriteCallback;
Data^.WriteUserData := WriteUserData;
end;
NeedData := False;
break;
end;
Data := Data^.Next;
end;
if NeedData then
begin
New(Data);
Data^.Next := Handle^.Data.FirstIOCallback;
Handle^.Data.FirstIOCallback := Data;
Data^.IOHandle := IOHandle;
if ARead then
begin
Data^.ReadCallback := ReadCallback;
Data^.ReadUserData := ReadUserData;
end else
Data^.ReadCallback := nil;
if AWrite then
begin
Data^.WriteCallback := WriteCallback;
Data^.WriteUserData := WriteUserData;
end else
Data^.WriteCallback := nil;
end;
CallbackTypes := [];
if ARead then
CallbackTypes := [cbRead];
if AWrite then
CallbackTypes := CallbackTypes + [cbWrite];
InternalInitIOCallback(Handle, Data, NeedData, CallbackTypes);
Handle^.Data.HasCallbacks := True;
Result := asyncOK;
end;
procedure CheckForCallbacks(Handle: TAsyncHandle);
begin
if (Handle^.Data.HasCallbacks) and
(not Assigned(Handle^.Data.FirstIOCallback)) and
(not Assigned(Handle^.Data.FirstTimer)) then
Handle^.Data.HasCallbacks := False;
end;
procedure asyncInit(Handle: TAsyncHandle); cdecl;
begin
InternalInit(Handle);
end;
procedure asyncFree(Handle: TAsyncHandle); cdecl;
var
Timer, NextTimer: PTimerData;
IOCallback, NextIOCallback: PIOCallbackData;
begin
InternalFree(Handle);
Timer := PTimerData(Handle^.Data.FirstTimer);
while Assigned(Timer) do
begin
NextTimer := Timer^.Next;
Dispose(Timer);
Timer := NextTimer;
end;
IOCallback := PIOCallbackData(Handle^.Data.FirstIOCallback);
while Assigned(IOCallback) do
begin
NextIOCallback := IOCallback^.Next;
Dispose(IOCallback);
IOCallback := NextIOCallback;
end;
Handle^.Data.NextIOCallback := nil;
end;
procedure asyncRun(Handle: TAsyncHandle); cdecl;
var
Timer, NextTimer: PTimerData;
TimeOut, CurTime, NextTick: Int64;
begin
if Handle^.Data.IsRunning then
exit;
Handle^.Data.DoBreak := False;
Handle^.Data.IsRunning := True;
// Prepare timers
if Assigned(Handle^.Data.FirstTimer) then
begin
CurTime := asyncGetTicks;
Timer := Handle^.Data.FirstTimer;
while Assigned(Timer) do
begin
Timer^.NextTick := CurTime + Timer^.MSec;
Timer := Timer^.Next;
end;
end;
while (not Handle^.Data.DoBreak) and Handle^.Data.HasCallbacks do
begin
Timer := Handle^.Data.FirstTimer;
if Assigned(Handle^.Data.FirstTimer) then
begin
// Determine when the next timer tick will happen
CurTime := asyncGetTicks;
NextTick := High(Int64);
Timer := Handle^.Data.FirstTimer;
while Assigned(Timer) do
begin
if Timer^.NextTick < NextTick then
NextTick := Timer^.NextTick;
Timer := Timer^.Next;
end;
TimeOut := NextTick - CurTime;
if TimeOut < 0 then
TimeOut := 0;
end else
TimeOut := -1;
InternalRun(Handle, TimeOut);
{if Handle^.Data.HighestHandle >= 0 then
begin
CurReadFDSet := PFDSet(Handle^.Data.FDData)[0];
CurWriteFDSet := PFDSet(Handle^.Data.FDData)[1];
AsyncResult := Select(Handle^.Data.HighestHandle + 1,
@CurReadFDSet, @CurWriteFDSet, nil, TimeOut);
end else
AsyncResult := Select(0, nil, nil, nil, TimeOut);
if (AsyncResult > 0) and not Handle^.Data.DoBreak then
begin
// Check for I/O events
Handle^.Data.CurIOCallback := Handle^.Data.FirstIOCallback;
while Assigned(Handle^.Data.CurIOCallback) do
begin
CurIOCallback := PIOCallbackData(Handle^.Data.CurIOCallback);
Handle^.Data.NextIOCallback := CurIOCallback^.Next;
if FD_IsSet(CurIOCallback^.IOHandle, CurReadFDSet) and
FD_IsSet(CurIOCallback^.IOHandle, PFDSet(Handle^.Data.FDData)[0]) and
Assigned(CurIOCallback^.ReadCallback) then
begin
CurIOCallback^.ReadCallback(CurIOCallback^.ReadUserData);
if Handle^.Data.DoBreak then
break;
end;
CurIOCallback := PIOCallbackData(Handle^.Data.CurIOCallback);
if Assigned(CurIOCallback) and
FD_IsSet(CurIOCallback^.IOHandle, CurWriteFDSet) and
FD_IsSet(CurIOCallback^.IOHandle, PFDSet(Handle^.Data.FDData)[1]) and
Assigned(CurIOCallback^.WriteCallback) then
begin
CurIOCallback^.WriteCallback(CurIOCallback^.WriteUserData);
if Handle^.Data.DoBreak then
break;
end;
Handle^.Data.CurIOCallback := Handle^.Data.NextIOCallback;
end;
end;}
if Assigned(Handle^.Data.FirstTimer) then
begin
// Check for triggered timers
CurTime := asyncGetTicks;
Timer := Handle^.Data.FirstTimer;
while Assigned(Timer) do
begin
if Timer^.NextTick <= CurTime then
begin
Timer^.Callback(Timer^.UserData);
NextTimer := Timer^.Next;
if Timer^.Periodic then
Inc(Timer^.NextTick, Timer^.MSec)
else
asyncRemoveTimer(Handle, Timer);
if Handle^.Data.DoBreak then
break;
Timer := NextTimer;
end else
Timer := Timer^.Next;
end;
end;
end;
Handle^.Data.CurIOCallback := nil;
Handle^.Data.NextIOCallback := nil;
Handle^.Data.IsRunning := False;
end;
procedure asyncBreak(Handle: TAsyncHandle); cdecl;
begin
Handle^.Data.DoBreak := True;
end;
function asyncIsRunning(Handle: TAsyncHandle): Boolean; cdecl;
begin
Result := Handle^.Data.IsRunning;
end;
function asyncAddTimer(
Handle: TAsyncHandle;
MSec: LongInt;
Periodic: Boolean;
Callback: TAsyncCallback;
UserData: Pointer
): TAsyncTimer; cdecl;
var
Data: PTimerData;
begin
if not Assigned(Callback) then
exit;
New(Data);
Result := Data;
Data^.Next := Handle^.Data.FirstTimer;
Handle^.Data.FirstTimer := Data;
Data^.MSec := MSec;
Data^.Periodic := Periodic;
Data^.Callback := Callback;
Data^.UserData := UserData;
if Handle^.Data.IsRunning then
Data^.NextTick := asyncGetTicks + MSec;
Handle^.Data.HasCallbacks := True;
end;
procedure asyncRemoveTimer(
Handle: TAsyncHandle;
Timer: TASyncTimer); cdecl;
var
Data, CurData, PrevData, NextData: PTimerData;
begin
Data := PTimerData(Timer);
CurData := Handle^.Data.FirstTimer;
PrevData := nil;
while Assigned(CurData) do
begin
NextData := CurData^.Next;
if CurData = Data then
begin
if Assigned(PrevData) then
PrevData^.Next := NextData
else
Handle^.Data.FirstTimer := NextData;
break;
end;
PrevData := CurData;
CurData := NextData;
end;
Dispose(Data);
CheckForCallbacks(Handle);
end;
function asyncSetIOCallback(
Handle: TAsyncHandle;
IOHandle: LongInt;
Callback: TAsyncCallback;
UserData: Pointer): TAsyncResult; cdecl;
begin
Result := InitIOCallback(Handle, IOHandle, True, Callback, UserData,
True, Callback, UserData);
end;
procedure asyncClearIOCallback(Handle: TAsyncHandle;
IOHandle: LongInt); cdecl;
var
CurData, PrevData, NextData: PIOCallbackData;
begin
CurData := Handle^.Data.FirstIOCallback;
PrevData := nil;
while Assigned(CurData) do
begin
NextData := CurData^.Next;
if CurData^.IOHandle = IOHandle then
begin
if Handle^.Data.CurIOCallback = CurData then
Handle^.Data.CurIOCallback := nil;
if Handle^.Data.NextIOCallback = CurData then
Handle^.Data.NextIOCallback := NextData;
InternalClearIOCallback(Handle, IOHandle, [cbRead, cbWrite]);
if Assigned(PrevData) then
PrevData^.Next := NextData
else
Handle^.Data.FirstIOCallback := NextData;
Dispose(CurData);
break;
end;
PrevData := CurData;
CurData := NextData;
end;
CheckForCallbacks(Handle);
end;
function asyncSetDataAvailableCallback(
Handle: TAsyncHandle;
IOHandle: LongInt;
Callback: TAsyncCallback;
UserData: Pointer): TAsyncResult; cdecl;
begin
Result := InitIOCallback(Handle, IOHandle, True, Callback, UserData, False,
nil, nil);
end;
procedure asyncClearDataAvailableCallback(Handle: TAsyncHandle;
IOHandle: LongInt); cdecl;
var
CurData, PrevData, NextData: PIOCallbackData;
begin
CurData := Handle^.Data.FirstIOCallback;
PrevData := nil;
while Assigned(CurData) do
begin
NextData := CurData^.Next;
if CurData^.IOHandle = IOHandle then
begin
if Handle^.Data.CurIOCallback = CurData then
Handle^.Data.CurIOCallback := nil;
if Handle^.Data.NextIOCallback = CurData then
Handle^.Data.NextIOCallback := NextData;
InternalClearIOCallback(Handle, IOHandle, [cbRead]);
if Assigned(CurData^.WriteCallback) then
CurData^.ReadCallback := nil
else
begin
if Assigned(PrevData) then
PrevData^.Next := NextData
else
Handle^.Data.FirstIOCallback := NextData;
Dispose(CurData);
end;
break;
end;
PrevData := CurData;
CurData := NextData;
end;
CheckForCallbacks(Handle);
end;
function asyncSetCanWriteCallback(
Handle: TAsyncHandle;
IOHandle: LongInt;
Callback: TAsyncCallback;
UserData: Pointer): TAsyncResult; cdecl;
begin
Result := InitIOCallback(Handle, IOHandle, False, nil, nil, True,
Callback, UserData);
end;
procedure asyncClearCanWriteCallback(Handle: TAsyncHandle;
IOHandle: LongInt); cdecl;
var
CurData, PrevData, NextData: PIOCallbackData;
begin
CurData := Handle^.Data.FirstIOCallback;
PrevData := nil;
while Assigned(CurData) do
begin
NextData := CurData^.Next;
if CurData^.IOHandle = IOHandle then
begin
if Handle^.Data.CurIOCallback = CurData then
Handle^.Data.CurIOCallback := nil;
if Handle^.Data.NextIOCallback = CurData then
Handle^.Data.NextIOCallback := NextData;
InternalClearIOCallback(Handle, IOHandle, [cbWrite]);
if Assigned(CurData^.ReadCallback) then
CurData^.WriteCallback := nil
else
begin
if Assigned(PrevData) then
PrevData^.Next := NextData
else
Handle^.Data.FirstIOCallback := NextData;
Dispose(CurData);
end;
break;
end;
PrevData := CurData;
CurData := NextData;
end;
CheckForCallbacks(Handle);
end;
{
$Log: libasync.inc,v $
Revision 1.6 2005/02/14 17:13:19 peter
* truncate log
}
|
