Do the sometimes rather big "pong" in a background worker thread.

controller/EmbeddedNetworkController.cpp

@@ -467,26 +467,14 @@ void EmbeddedNetworkController::request(
 {
 	if (((!_signingId)||(!_signingId.hasPrivate()))||(_signingId.address().toInt() != (nwid >> 24))||(!_sender))
 		return;
-
-	{
-		Mutex::Lock _l(_threads_m);
-		if (_threads.size() == 0) {
-			long hwc = (long)(std::thread::hardware_concurrency() / 2);
-			if (hwc < 1)
-				hwc = 1;
-			else if (hwc > 16)
-				hwc = 16;
-			for(long i=0;i<hwc;++i)
-				_threads.push_back(Thread::start(this));
-		}
-	}
-
+	_startThreads();
 	_RQEntry *qe = new _RQEntry;
 	qe->nwid = nwid;
 	qe->requestPacketId = requestPacketId;
 	qe->fromAddr = fromAddr;
 	qe->identity = identity;
 	qe->metaData = metaData;
+	qe->type = _RQEntry::RQENTRY_TYPE_REQUEST;
 	_queue.post(qe);
 }
 
@@ -1051,33 +1039,14 @@ unsigned int EmbeddedNetworkController::handleControlPlaneHttpPOST(
 
 	} else if (path[0] == "ping") {
 
-		const uint64_t now = OSUtils::now();
-		bool first = true;
-		std::string pong("{\"memberStatus\":{");
-		{
-			Mutex::Lock _l(_memberStatus_m);
-			pong.reserve(64 * _memberStatus.size());
-			_db.eachId([this,&pong,&now,&first](uint64_t networkId,uint64_t nodeId) {
-				char tmp[64];
-				uint64_t lrt = 0ULL;
-				auto ms = this->_memberStatus.find(_MemberStatusKey(networkId,nodeId));
-				if (ms != _memberStatus.end())
-					lrt = ms->second.lastRequestTime;
-				Utils::snprintf(tmp,sizeof(tmp),"%s\"%.16llx-%.10llx\":%llu",
-					(first) ? "" : ",",
-					(unsigned long long)networkId,
-					(unsigned long long)nodeId,
-					(unsigned long long)lrt);
-				pong.append(tmp);
-				first = false;
-			});
-		}
-		char tmp2[256];
-		Utils::snprintf(tmp2,sizeof(tmp2),"},\"clock\":%llu,\"startTime\":%llu}",(unsigned long long)now,(unsigned long long)_startTime);
-		pong.append(tmp2);
-		_db.writeRaw("pong",pong);
+		_startThreads();
+		_RQEntry *qe = new _RQEntry;
+		qe->type = _RQEntry::RQENTRY_TYPE_PING;
+		_queue.post(qe);
 
-		responseBody = "{}";
+		char tmp[64];
+		Utils::snprintf(tmp,sizeof(tmp),"{\"clock\":%llu}",(unsigned long long)now);
+		responseBody = tmp;
 		responseContentType = "application/json";
 
 		return 200;
@@ -1150,7 +1119,35 @@ void EmbeddedNetworkController::threadMain()
 	_RQEntry *qe = (_RQEntry *)0;
 	while ((_running)&&((qe = _queue.get()))) {
 		try {
-			_request(qe->nwid,qe->fromAddr,qe->requestPacketId,qe->identity,qe->metaData);
+			if (qe->type == _RQEntry::RQENTRY_TYPE_REQUEST) {
+				_request(qe->nwid,qe->fromAddr,qe->requestPacketId,qe->identity,qe->metaData);
+			} else if (qe->type == _RQEntry::RQENTRY_TYPE_PING) {
+				const uint64_t now = OSUtils::now();
+				bool first = true;
+				std::string pong("{\"memberStatus\":{");
+				{
+					Mutex::Lock _l(_memberStatus_m);
+					pong.reserve(64 * _memberStatus.size());
+					_db.eachId([this,&pong,&now,&first](uint64_t networkId,uint64_t nodeId) {
+						char tmp[64];
+						uint64_t lrt = 0ULL;
+						auto ms = this->_memberStatus.find(_MemberStatusKey(networkId,nodeId));
+						if (ms != _memberStatus.end())
+							lrt = ms->second.lastRequestTime;
+						Utils::snprintf(tmp,sizeof(tmp),"%s\"%.16llx-%.10llx\":%llu",
+							(first) ? "" : ",",
+							(unsigned long long)networkId,
+							(unsigned long long)nodeId,
+							(unsigned long long)lrt);
+						pong.append(tmp);
+						first = false;
+					});
+				}
+				char tmp2[256];
+				Utils::snprintf(tmp2,sizeof(tmp2),"},\"clock\":%llu,\"startTime\":%llu}",(unsigned long long)now,(unsigned long long)_startTime);
+				pong.append(tmp2);
+				_db.writeRaw("pong",pong);
+			}
 		} catch ( ... ) {}
 		delete qe;
 

controller/EmbeddedNetworkController.hpp

@@ -26,6 +26,7 @@
 #include <vector>
 #include <set>
 #include <list>
+#include <thread>
 
 #include "../node/Constants.hpp"
 
@@ -103,11 +104,29 @@ private:
 		InetAddress fromAddr;
 		Identity identity;
 		Dictionary<ZT_NETWORKCONFIG_METADATA_DICT_CAPACITY> metaData;
+		enum {
+			RQENTRY_TYPE_REQUEST = 0,
+			RQENTRY_TYPE_PING = 1
+		} type;
 	};
 
 	static void _circuitTestCallback(ZT_Node *node,ZT_CircuitTest *test,const ZT_CircuitTestReport *report);
 	void _request(uint64_t nwid,const InetAddress &fromAddr,uint64_t requestPacketId,const Identity &identity,const Dictionary<ZT_NETWORKCONFIG_METADATA_DICT_CAPACITY> &metaData);
 
+	inline void _startThreads()
+	{
+		Mutex::Lock _l(_threads_m);
+		if (_threads.size() == 0) {
+			long hwc = (long)std::thread::hardware_concurrency();
+			if (hwc < 1)
+				hwc = 1;
+			else if (hwc > 16)
+				hwc = 16;
+			for(long i=0;i<hwc;++i)
+				_threads.push_back(Thread::start(this));
+		}
+	}
+
 	// These init objects with default and static/informational fields
 	inline void _initMember(nlohmann::json &member)
 	{