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copied!<p>COM should be initialized only once per thread, but the <code>OnExecute</code> event is triggered multiple times during a client's lifetime.</p> <p>If you are not using thread pooling with <code>TIdTCPServer</code> (by attaching a <code>TIdSchedulerOfThreadPool</code> component to the <code>TIdTCPServer::Scheduler</code> property), then you can use the <code>TIdTCPServer::OnConnect</code> and <code>TIdTCPServer::OnDisconnect</code> events to initialize/finalize your ADO objects and then use them in the <code>TIdTCPServer::OnExecute</code> event as needed, eg:</p> <pre><code>class TMyContextData { public: TADOConnection *sql_conn; TADOQuery *pos_q; TMyContextData(); ~TMyContextData(); }; TMyContextData::TMyContextData() { sql_conn = new TADOConnection(NULL); pos_q = new TADOQuery(NULL); } TMyContextData::~TMyContextData() { delete pos_q; delete sql_conn; } void __fastcall TMyForm::tcp_serverConnect(TIdContext *AContext) { ::CoInitialize(NULL); AContext->Data = new TMyContextData; } void __fastcall TMyForm::tcp_serverDisconnect(TIdContext *AContext) { delete static_cast<TMyContextData*>(AContext->Data); AContext->Data = NULL; ::CoUninitialize(); } void __fastcall TMyForm::tcp_serverExecute(TIdContext *AContext) { TMyContextData *pData = static_cast<TMyContextData*>(AContext->Data); // use pData->sql_conn and pData->pos_q as needed... } </code></pre> <p>Or, derive a new class from <code>TIdServerContext</code> instead:</p> <pre><code>class TMyContext : public TIdServerContext { public: TADOConnection *sql_conn; TADOQuery *pos_q; __fastcall TMyContext(TIdTCPConnection *AConnection, TIdYarn *AYarn, TIdContextThreadList *AList = NULL); __fastcall ~TMyContext(); }; __fastcall TMyContext::TMyContext(TIdTCPConnection *AConnection, TIdYarn *AYarn, TIdContextThreadList *AList) : TIdServerContext(AConnection, AYarn, AList) { ::CoInitialize(NULL); sql_conn = new TADOConnection(NULL); pos_q = new TADOQuery(NULL); } __fastcall TMyContext::~TMyContext() { delete pos_q; delete sql_conn; ::CoUninitialize(); } __fastcall TMyForm::TMyForm(TComponent *Owner) : TForm(Owner) { // do this before activating TIdTCPServer tcp_server->ContextClass = __classid(TMyContext); } void __fastcall TMyForm::tcp_serverExecute(TIdContext *AContext) { TMyContext *pContext = static_cast<TMyContext*>(AContext); // use pContext->sql_conn and pContext->pos_q as needed... } </code></pre> <p>However, if you are using thread pooling, then multiple clients can be serviced by the same physical thread, so you should move your COM initialization into the actual thread object that manages <code>TIdContext</code> objects (you should also move your ADO objects into the thread so you can reuse them for multiple clients), eg:</p> <pre><code>class TMyADOThread : public TIdThreadWithTask { protected: virtual void __fastcall AfterExecute(); virtual void __fastcall BeforeExecute(); public: TADOConnection *sql_conn; TADOQuery *pos_q; __fastcall TMyADOThread(TIdTask *ATask = NULL, const String AName = ""); }; __fastcall TMyADOThread::TMyADOThread(TIdTask *ATask, const String AName) : TIdThreadWithTask(ATask, AName) { } void __fastcall TMyADOThread::BeforeExecute() { TIdThreadWithTask::BeforeExecute(); ::CoInitialize(NULL); sql_conn = new TADOConnection(NULL); pos_q = new TADOQuery(NULL); } void __fastcall TMyADOThread::AfterExecute() { delete pos_q; delete sql_conn; ::CoUninitialize(); TIdThreadWithTask::AfterExecute(); } __fastcall TMyForm::TMyForm(TComponent *Owner) : TForm(Owner) { // do this before activating TIdTCPServer IdSchedulerOfThreadPool1->ThreadClass = __classid(TMyADOThread); } void __fastcall TMyForm::tcp_serverExecute(TIdContext *AContext) { TMyADOThread *pThread = static_cast<TMyADOThread*>(static_cast<TIdYarnOfThread*>(AContext->Yarn)->Thread); // use pThread->sql_conn and pThread->pos_q as needed... } </code></pre>

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