Merge bitcoin#15622: Remove global symbols: Avoid using the global na…

…mespace if possible

fb43415 Remove global symbols: Avoid using the global namespace if possible (practicalswift)

Pull request description:

  Remove global symbols: Avoid using the global namespace if possible.

  Partially resolves bitcoin#15612 ("Reduce the number of global symbols used").

  Change in global symbols as reported by `nm bitcoind` before vs after:

  ```
  $ diff -u <(nm src/bitcoind-before | c++filt | grep -E '^[0-9a-f]+ [A-Z] ' | cut -f3- -d' ' | sort -u) \
            <(nm src/bitcoind-after  | c++filt | grep -E '^[0-9a-f]+ [A-Z] ' | cut -f3- -d' ' | sort -u) \
            | grep -E '^[+-][^+-]'
  -boundSockets
  -cs_warnings
  -eventHTTP
  -fFeeEstimatesInitialized
  -fLargeWorkForkFound
  -fLargeWorkInvalidChainFound
  -pathHandlers
  -strMiscWarning[abi:cxx11]
  -threadHTTP
  ```

ACKs for commit fb4341:

Tree-SHA512: d2f78f6188a992b0e0de8d107e2c494cfa0faa2de4fda634a1d3606d6515633bec86289cf2a2e78ffe467b17b795e2243cc459fb44e0dfe2fc69899506ff61c9

src/httpserver.cpp

@@ -144,15 +144,15 @@ struct HTTPPathHandler
 //! libevent event loop
 static struct event_base* eventBase = nullptr;
 //! HTTP server
-struct evhttp* eventHTTP = nullptr;
+static struct evhttp* eventHTTP = nullptr;
 //! List of subnets to allow RPC connections from
 static std::vector<CSubNet> rpc_allow_subnets;
 //! Work queue for handling longer requests off the event loop thread
 static WorkQueue<HTTPClosure>* workQueue = nullptr;
 //! Handlers for (sub)paths
-std::vector<HTTPPathHandler> pathHandlers;
+static std::vector<HTTPPathHandler> pathHandlers;
 //! Bound listening sockets
-std::vector<evhttp_bound_socket *> boundSockets;
+static std::vector<evhttp_bound_socket *> boundSockets;
 
 /** Check if a network address is allowed to access the HTTP server */
 static bool ClientAllowed(const CNetAddr& netaddr)
@@ -433,7 +433,7 @@ bool UpdateHTTPServerLogging(bool enable) {
 #endif
 }
 
-std::thread threadHTTP;
+static std::thread threadHTTP;
 static std::vector<std::thread> g_thread_http_workers;
 
 bool StartHTTPServer()

src/init.cpp

@@ -93,7 +93,7 @@
 #include <zmq/zmqrpc.h>
 #endif
 
-bool fFeeEstimatesInitialized = false;
+static bool fFeeEstimatesInitialized = false;
 static const bool DEFAULT_PROXYRANDOMIZE = true;
 static const bool DEFAULT_REST_ENABLE = false;
 static const bool DEFAULT_STOPAFTERBLOCKIMPORT = false;

src/warnings.cpp

@@ -9,10 +9,10 @@
 #include <warnings.h>
 #include <hash.h>
 
-CCriticalSection cs_warnings;
-std::string strMiscWarning GUARDED_BY(cs_warnings);
-bool fLargeWorkForkFound GUARDED_BY(cs_warnings) = false;
-bool fLargeWorkInvalidChainFound GUARDED_BY(cs_warnings) = false;
+static RecursiveMutex cs_warnings;
+static std::string strMiscWarning GUARDED_BY(cs_warnings);
+static bool fLargeWorkForkFound GUARDED_BY(cs_warnings) = false;
+static bool fLargeWorkInvalidChainFound GUARDED_BY(cs_warnings) = false;
 
 void SetMiscWarning(const std::string& strWarning)
 {