MCOL-5555 Add support for startreadonly command.

This patch adds support for `startreadonly` command which waits
until all active cpimport jobs are done and then puts controller node to readonly
mode.

versioning/BRM/sessionmanagerserver.h

@@ -27,8 +27,9 @@
 #pragma once
 
 #include <map>
+#include <condition_variable>
 
-
+#include <unordered_set>
 #include <boost/thread/mutex.hpp>
 #include <boost/thread/condition_variable.hpp>
 
@@ -39,7 +40,6 @@
 
 #define EXPORT
 
-
 namespace BRM
 {
 /** @brief Issues transaction IDs and keeps track of the current system-wide version ID.
@@ -146,6 +146,15 @@ class SessionManagerServer
    */
   EXPORT const TxnID newTxnID(const SID session, bool block = true, bool isDDL = false);
 
+  // Adds a new job into `active` cpimport job list and return id of that job.
+  EXPORT uint32_t newCpimportJob();
+
+  // Removes the given `jobId` from `active` cpimort job list.
+  EXPORT void finishCpimortJob(uint32_t jobId);
+
+  // Clears all active cpimport jobs.
+  EXPORT void clearAllCpimportJobs();
+
   /** @brief Record that a transaction has been committed
    *
    * Record that a transaction has been committed.
@@ -253,6 +262,9 @@ class SessionManagerServer
    */
   EXPORT uint32_t getTxnCount();
 
+
+  EXPORT uint32_t getCpimportJobsCount();
+
  private:
   SessionManagerServer(const SessionManagerServer&);
   SessionManagerServer& operator=(const SessionManagerServer&);
@@ -277,9 +289,12 @@ class SessionManagerServer
   boost::mutex mutex;
   boost::condition_variable condvar;  // used to synthesize a semaphore
   uint32_t semValue;
+
+  std::unordered_set<uint32_t> activeCpimportJobs;
+  uint32_t cpimportJobId{0};
+  std::mutex cpimportMutex;
 };
 
 }  // namespace BRM
 
-
 #undef EXPORT