function GetDosOutput(CommandLine: string; Work: string = 'C:\'): string;
var
SA: TSecurityAttributes;
SI: TStartupInfo;
PI: TProcessInformation;
StdOutPipeRead, StdOutPipeWrite: THandle;
WasOK: Boolean;
Buffer: array[0..255] of AnsiChar;
BytesRead: Cardinal;
WorkDir: string;
Handle: Boolean;
begin
Result := '';
with SA do begin
nLength := SizeOf(SA);
bInheritHandle := True;
lpSecurityDescriptor := nil;
end;
CreatePipe(StdOutPipeRead, StdOutPipeWrite, @SA, 0);
try
with SI do
begin
FillChar(SI, SizeOf(SI), 0);
cb := SizeOf(SI);
dwFlags := STARTF_USESHOWWINDOW or STARTF_USESTDHANDLES;
wShowWindow := SW_HIDE;
hStdInput := GetStdHandle(STD_INPUT_HANDLE); // don't redirect stdin
hStdOutput := StdOutPipeWrite;
hStdError := StdOutPipeWrite;
end;
WorkDir := Work;
Handle := CreateProcess(nil, PChar('cmd.exe /C ' + CommandLine),
nil, nil, True, 0, nil,
PChar(WorkDir), SI, PI);
CloseHandle(StdOutPipeWrite);
if Handle then
try
repeat
WasOK := ReadFile(StdOutPipeRead, Buffer, 255, BytesRead, nil);
if BytesRead > 0 then
begin
Buffer[BytesRead] := #0;
Result := Result + Buffer;
end;
until not WasOK or (BytesRead = 0);
WaitForSingleObject(PI.hProcess, INFINITE);
finally
CloseHandle(PI.hThread);
CloseHandle(PI.hProcess);
end;
finally
CloseHandle(StdOutPipeRead);
end;
end;
I have copied updated method GetDosOutput from the below link and calling that in service's execute method. This method triggered for every 3 seconds.
Getting output from a shell/dos app into a Delphi app
procedure TMyFVODService.ServiceExecute(Sender: TService);
const SecBetweenRuns = 3;
var Count, WaitTimeMil: Integer;
begin
while not Terminated do
begin
Inc(Count);
if Count >= SecBetweenRuns then
begin
Count:=0;
GetDosOutput('d:\usr\local\myApp -<SysName> STO','D:\');
end;
Sleep(1000);
ServiceThread.ProcessRequests(False);
end;
end;
Apart from these two methods, I don't have any code snippet in my service project.
Problem: When I start my service, memory consumption is increasing and after 7-10 days, system is going to not responding mode. Especially, private bytes of one of the instances of svcHost i.e. LocalServiceNetworkRestricted is increasing. There is no increase in private bytes of my service when observe in Resource Monitor. When I stop that service, there is no increase in the memory consumption.
NOTE: But, when I run same command "d:\usr\local\myApp - STO" for every 3 seconds using Task Scheduler, there is no increase in the memory consumption.
Query 1: Is there any memory leak in the copied code or I missed any. If yes, please suggest your solution.
Query 2: Why svcHost is taking memory, when I am running my service. Is there any relation between them.
Query 3: As a workaround, I thought to restart my service. But, its not releasing that memory. When I start it again, the memory consumption resumes from that point and finally system gets frozen.
