Add ability to change debug category on the fly from console

NOTE: Before switching to another debug catgory you'd need to turn debugging off via "debug 0"
      and wait a bit (each thread (de)activates debug mode on its own)

src/rpcmisc.cpp

@@ -24,6 +24,7 @@
 #include <stdint.h>
 
 #include <boost/assign/list_of.hpp>
+#include <boost/algorithm/string.hpp>
 
 #include <univalue.h>
 
@@ -113,6 +114,30 @@ UniValue getinfo(const UniValue& params, bool fHelp)
     return obj;
 }
 
+UniValue debug(const UniValue& params, bool fHelp)
+{
+    if (fHelp || params.size() != 1)
+        throw runtime_error(
+            "debug ( 0|1|addrman|alert|bench|coindb|db|lock|rand|rpc|selectcoins|mempool"
+            "|mempoolrej|net|proxy|prune|http|libevent|tor|zmq|"
+            "dash|darksend|instantx|masternode|keepass|mnpayments|mnbudget )\n"
+            "Change debug category on the fly. Specify single category or use comma to specify many.\n"
+            "\nExamples:\n"
+            + HelpExampleCli("debug", "dash")
+            + HelpExampleRpc("debug", "dash,net")
+        );
+
+    std::string strMode = params[0].get_str();
+
+    mapMultiArgs["-debug"].clear();
+    boost::split(mapMultiArgs["-debug"], strMode, boost::is_any_of(","));
+    mapArgs["-debug"] = mapMultiArgs["-debug"][mapMultiArgs["-debug"].size() - 1];
+
+    fDebug = mapArgs["-debug"] != "0";
+
+    return "Debug mode: " + (fDebug ? strMode : "off");
+}
+
 UniValue mnsync(const UniValue& params, bool fHelp)
 {
     if (fHelp || params.size() != 1)

src/rpcserver.cpp

@@ -258,6 +258,7 @@ static const CRPCCommand vRPCCommands[] =
   //  --------------------- ------------------------  -----------------------  ----------
     /* Overall control/query calls */
     { "control",            "getinfo",                &getinfo,                true  }, /* uses wallet if enabled */
+    { "control",            "debug",                  &debug,                  true  },
     { "control",            "help",                   &help,                   true  },
     { "control",            "stop",                   &stop,                   true  },
 

src/rpcserver.h

@@ -232,6 +232,7 @@ extern UniValue walletlock(const UniValue& params, bool fHelp);
 extern UniValue encryptwallet(const UniValue& params, bool fHelp);
 extern UniValue validateaddress(const UniValue& params, bool fHelp);
 extern UniValue getinfo(const UniValue& params, bool fHelp);
+extern UniValue debug(const UniValue& params, bool fHelp);
 extern UniValue getwalletinfo(const UniValue& params, bool fHelp);
 extern UniValue getblockchaininfo(const UniValue& params, bool fHelp);
 extern UniValue getnetworkinfo(const UniValue& params, bool fHelp);

src/util.cpp

@@ -253,16 +253,26 @@ bool LogAcceptCategory(const char* category)
 {
     if (category != NULL)
     {
-        if (!fDebug)
-            return false;
-
         // Give each thread quick access to -debug settings.
         // This helps prevent issues debugging global destructors,
         // where mapMultiArgs might be deleted before another
         // global destructor calls LogPrint()
         static boost::thread_specific_ptr<set<string> > ptrCategory;
+
+        if (!fDebug) {
+            if (ptrCategory.get() != NULL) {
+                LogPrintf("debug turned off: thread %s\n", GetThreadName());
+                ptrCategory.release();
+            }
+            return false;
+        }
+
         if (ptrCategory.get() == NULL)
         {
+            std::string strThreadName = GetThreadName();
+            LogPrintf("debug turned on:\n");
+            for (int i = 0; i < (int)mapMultiArgs["-debug"].size(); ++i)
+                LogPrintf("  thread %s category %s\n", strThreadName, mapMultiArgs["-debug"][i]);
             const vector<string>& categories = mapMultiArgs["-debug"];
             ptrCategory.reset(new set<string>(categories.begin(), categories.end()));
             // thread_specific_ptr automatically deletes the set when the thread ends.