CJob: Add a way to do stuff on the main thread

This just moves the pipe from the socket code to the thread pool. However, now
all CJobs can use this and there is a single place for them to get deleted.

Signed-off-by: Uli Schlachter <psychon@znc.in>

include/znc/Socket.h

@@ -102,11 +102,9 @@ public:
 private:
 	void FinishConnect(const CString& sHostname, u_short iPort, const CString& sSockName, int iTimeout, bool bSSL, const CString& sBindHost, CZNCSock *pcSock);
 
-#ifdef HAVE_THREADED_DNS
-	int              m_iTDNSpipe[2];
-
 	class CTDNSMonitorFD;
 	friend class CTDNSMonitorFD;
+#ifdef HAVE_THREADED_DNS
 	struct TDNSTask {
 		CString   sHostname;
 		u_short   iPort;
@@ -123,19 +121,19 @@ private:
 	};
 	class CDNSJob : public CJob {
 	public:
-		CString          sHostname;
-		TDNSTask*        task;
-		int              fd;
-		bool             bBind;
+		CString       sHostname;
+		TDNSTask*     task;
+		CSockManager* pManager;
+		bool          bBind;
 
-		int              iRes;
-		addrinfo*        aiResult;
+		int           iRes;
+		addrinfo*     aiResult;
 
-		void run();
+		void runThread();
+		void runMain();
 	};
 	void StartTDNSThread(TDNSTask* task, bool bBind);
 	void SetTDNSThreadFinished(TDNSTask* task, bool bBind, addrinfo* aiResult);
-	void RetrieveTDNSResult();
 	static void* TDNSThread(void* argument);
 #endif
 protected:

include/znc/Threads.h

@@ -182,14 +182,13 @@ public:
 class CJob {
 public:
 	virtual ~CJob() {}
-	virtual void run() = 0;
+	virtual void runThread() = 0;
+	virtual void runMain() = 0;
 };
 
 class CThreadPool {
 private:
-	CThreadPool() : m_done(false), m_num_threads(0), m_num_idle(0) {
-	}
-
+	CThreadPool();
 	~CThreadPool();
 
 public:
@@ -197,7 +196,15 @@ public:
 
 	void addJob(CJob *job);
 
+	int getReadFD() const {
+		return m_iJobPipe[0];
+	}
+
+	void handlePipeReadable() const;
+
 private:
+	void jobDone(const CJob* pJob) const;
+
 	// Check if the calling thread is still needed, must be called with m_mutex held
 	bool threadNeeded() const;
 
@@ -223,6 +230,10 @@ private:
 	// number of idle threads waiting on the condition variable
 	size_t m_num_idle;
 
+	// pipe for waking up the main thread
+	int m_iJobPipe[2];
+
+	// list of pending jobs
 	std::list<CJob *> m_jobs;
 };