CODEWITHSUNDEEP
c++multithreadingdelphithread-safetyc++builder
IceCold
IceCold

Reputation: 21154

How to use Synchronize()?

The manual says that Synchronize is a member of TThread. However it shows that you can call Synchronize directly. Other sources tell the same.

//Synchronize() performs actions contained in a routine as if they were executed from the main VCL thread    

void __fastcall TCriticalThread::Execute()
{
   ...
   Synchronize(UpdateCaption);
   ...
}

But if I do this, my compiler tells me "E2268 Call to undefined function 'Synchronize'". Of course I included the library:

#include <System.Classes.hpp>

On the other hand, TThread::Synchronize is found by the compiler, but it does not accept MainThreadID as parameter:

TThread::Synchronize(MainThreadID, MainForm->UpdateCaption );

PS: I am new to C++ Builder.

Upvotes: 2

Views: 2484

Answers (1)

Remy Lebeau
Remy Lebeau

Reputation: 596352

Synchronize() is a method of the RTL's TThread class. In all versions of C++Builder, TThread has a non-static version of Synchronize(), which is the version the code you showed is trying to call. That requires TCriticalThread to be derived for TThread, eg:

class TCriticalThread : public TThread
{
...
protected:
    virtual void __fastcall Execute();
...
};

void __fastcall TCriticalThread::Execute()
{
   ...
   Synchronize(UpdateCaption);
   ...
}

If that is not the case in your situation, TThread also has a static version of Synchronize() that can be used with threads that are not derived from TThread, eg:

void __fastcall TCriticalThread::Execute()
{
   ...
   TThread::Synchronize(NULL, UpdateCaption);
   ...
}

Upvotes: 6

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