Added missing implementation of AgentReference.

Fixed race condition detected by helgrind in ArchiveMount.

objectstore/AgentReference.cpp

+/*
+ * The CERN Tape Archive (CTA) project
+ * Copyright (C) 2015  CERN
+ *
+ * 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, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * 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, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "AgentReference.hpp"
+#include "common/exception/Errnum.hpp"
+
+#include <sstream>
+#include <unistd.h>
+#include <sys/syscall.h>
+#include <iomanip>
+
+namespace cta { namespace objectstore {
+
+AgentReference::AgentReference(const std::string & clientType) {
+  m_nextId=0;
+  std::stringstream aid;
+  // Get time
+  time_t now = time(0);
+  struct tm localNow;
+  localtime_r(&now, &localNow);
+  // Get hostname
+  char host[200];
+  cta::exception::Errnum::throwOnMinusOne(::gethostname(host, sizeof(host)),
+    "In AgentId::AgentId:  failed to gethostname");
+  // gettid is a safe system call (never fails)
+  aid << clientType << "-" << host << "-" << syscall(SYS_gettid) << "-"
+    << 1900 + localNow.tm_year
+    << std::setfill('0') << std::setw(2) 
+    << 1 + localNow.tm_mon
+    << std::setw(2) << localNow.tm_mday << "-"
+    << std::setw(2) << localNow.tm_hour << ":"
+    << std::setw(2) << localNow.tm_min << ":"
+    << std::setw(2) << localNow.tm_sec;
+  m_agentAddress = aid.str();
+}
+
+std::string AgentReference::getAgentAddress() {
+  return m_agentAddress;
+}
+
+std::string AgentReference::nextId(const std::string& childType) {
+  std::stringstream id;
+  id << childType << "-" << m_agentAddress << "-" << m_nextId++;
+  return id.str();
+}
+
+}}
\ No newline at end of file

objectstore/AgentReference.hpp

+/*
+ * The CERN Tape Archive (CTA) project
+ * Copyright (C) 2015  CERN
+ *
+ * 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, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * 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, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+#include "common/threading/Mutex.hpp"
+#include <atomic>
+#include <string>
+
+namespace cta { namespace objectstore {
+
+/**
+ * A class allowing the passing of the address of an Agent object, plus a thread safe
+ * object name generator, that will allow unique name generation by several threads.
+ * This object should be created once and for all per session (as the corresponding
+ * Agent object in the object store).
+ * A process 
+ */
+class AgentReference {
+public:
+  /**
+   * Constructor will implicitly generate the address of the Agent object.
+   * @param clientType is an indicative string used to generate the agent object's name.
+   */
+  AgentReference(const std::string &clientType);
+  
+  /**
+   * Generates a unique address for a newly created child object. This function is thread
+   * safe.
+   * @param childType the name of the child object type.
+   * @return a unique address for the child object, derived from the agent's address.
+   */
+  std::string nextId(const std::string & childType);
+  
+  /**
+   * Gets the address of the Agent object generated on construction.
+   * @return the agent object address.
+   */
+  std::string getAgentAddress();
+private:
+  std::atomic<uint64_t> m_nextId;
+  std::string m_agentAddress;
+};
+
+}} 

scheduler/ArchiveMount.hpp

@@ -25,6 +25,7 @@
 #include "catalogue/Catalogue.hpp"
 
 #include <memory>
+#include <atomic>
 
 namespace cta {
   /**
@@ -143,7 +144,7 @@ namespace cta {
     /**
      * Internal tracking of the session completion
      */
-    bool m_sessionRunning;
+    std::atomic<bool> m_sessionRunning;
     
   }; // class ArchiveMount