Disable option to allow multiple async rpc workers.

src/init.cpp

@@ -424,7 +424,9 @@ std::string HelpMessage(HelpMessageMode mode)
     strUsage += HelpMessageOpt("-rpcallowip=<ip>", _("Allow JSON-RPC connections from specified source. Valid for <ip> are a single IP (e.g. 1.2.3.4), a network/netmask (e.g. 1.2.3.4/255.255.255.0) or a network/CIDR (e.g. 1.2.3.4/24). This option can be specified multiple times"));
     strUsage += HelpMessageOpt("-rpcthreads=<n>", strprintf(_("Set the number of threads to service RPC calls (default: %d)"), 4));
     strUsage += HelpMessageOpt("-rpckeepalive", strprintf(_("RPC support for HTTP persistent connections (default: %d)"), 1));
-    strUsage += HelpMessageOpt("-rpcasyncthreads=<n>", strprintf(_("Set the number of threads to service Async RPC calls (default: %d)"), 1));
+
+    // Disabled until we can lock notes and also tune performance of libsnark which by default uses multiple threads
+    //strUsage += HelpMessageOpt("-rpcasyncthreads=<n>", strprintf(_("Set the number of threads to service Async RPC calls (default: %d)"), 1));
 
     strUsage += HelpMessageGroup(_("RPC SSL options: (see the Bitcoin Wiki for SSL setup instructions)"));
     strUsage += HelpMessageOpt("-rpcssl", _("Use OpenSSL (https) for JSON-RPC connections"));

src/rpcserver.cpp

@@ -746,8 +746,10 @@ void StartRPCThreads()
     fRPCRunning = true;
     g_rpcSignals.Started();
 
-    // Launch at least one async rpc worker
+    // Launch one async rpc worker.  The ability to launch multiple workers is not recommended at present and thus the option is disabled.
     async_rpc_queue = std::make_shared<AsyncRPCQueue>();
+    async_rpc_queue->addWorker();
+/*   
     int n = GetArg("-rpcasyncthreads", 1);
     if (n<1) {
         LogPrintf("ERROR: Invalid value %d for -rpcasyncthreads.  Must be at least 1.\n", n);
@@ -758,7 +760,7 @@ void StartRPCThreads()
     }
     for (int i = 0; i < n; i++)
         async_rpc_queue->addWorker();
-
+*/
 }
 
 void StartDummyRPCThread()