the begginning

exemgr/femsghandler.cpp

@@ -0,0 +1,130 @@
+/* Copyright (C) 2014 InfiniDB, Inc.
+
+   This program is free software; you can redistribute it and/or
+   modify it under the terms of the GNU General Public License
+   as published by the Free Software Foundation; version 2 of
+   the License.
+
+   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.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+   MA 02110-1301, USA. */
+
+#include "messagequeue.h"
+#include "iosocket.h"
+
+#include "femsghandler.h"
+
+using namespace std;
+using namespace joblist;
+using namespace messageqcpp;
+
+namespace {
+
+class Runner
+{
+public:
+	Runner(FEMsgHandler *f) : target(f) { }
+	void operator()() { target->threadFcn(); }
+	FEMsgHandler *target;
+};
+
+}
+
+FEMsgHandler::FEMsgHandler() : die(false), running(false), sawData(false), sock(NULL)
+{
+}
+
+FEMsgHandler::FEMsgHandler(boost::shared_ptr<JobList> j, IOSocket *s) :
+	die(false), running(false), sawData(false), jl(j)
+{
+	sock = s;
+	assert(sock);
+}
+
+FEMsgHandler::~FEMsgHandler()
+{
+	stop();
+	thr.join();
+}
+
+void FEMsgHandler::start()
+{
+	if (!running) {
+		running = true;
+		thr = boost::thread(Runner(this));
+	}
+}
+
+void FEMsgHandler::stop()
+{
+	die = true;
+	jl.reset();
+}
+
+void FEMsgHandler::setJobList(boost::shared_ptr<JobList> j)
+{
+	jl = j;
+}
+
+void FEMsgHandler::setSocket(IOSocket *i)
+{
+	sock = i;
+	assert(sock);
+}
+
+/* Note, the next two fcns strongly depend on ExeMgr's current implementation.  There's a
+ * good chance that if ExeMgr's table send loop is changed, these will need to be
+ * updated to match.
+ */
+
+/* This is currently only called if InetStreamSocket::write() throws, implying
+ * a connection error.  It might not make sense in other contexts.
+ */
+bool FEMsgHandler::aborted()
+{
+	if (sawData)
+		return true;
+
+	boost::mutex::scoped_lock sl(mutex);
+	int err;
+	int connectionNum = sock->getConnectionNum();
+
+	err = InetStreamSocket::pollConnection(connectionNum, 1000);
+	if (err == 1) {
+		sawData = true;
+		return true;
+	}
+	return false;
+}
+
+void FEMsgHandler::threadFcn()
+{
+	int err = 0;
+	int connectionNum = sock->getConnectionNum();
+
+	/* This waits for the next readable event on sock.  An abort is signaled
+	 * by sending something (anything at the moment), then dropping the connection.
+	 * This fcn exits on all other events.
+	 */
+	while (!die && err == 0) {
+		boost::mutex::scoped_lock sl(mutex);
+		err = InetStreamSocket::pollConnection(connectionNum, 1000);
+	}
+
+	if (err == 1)
+		sawData = true;   // there's data to read, must be the abort signal
+	if (!die && (err == 2 || err == 1)) {
+		die = true;
+		jl->abort();
+		jl.reset();
+	}
+
+	running = false;
+}
+