GH-773: Make EventMgr an IOSource so that events interrupt kevent waits

src/Event.cc

@@ -9,6 +9,9 @@
 #include "Trigger.h"
 #include "Val.h"
 #include "plugin/Manager.h"
+#include "iosource/Manager.h"
+#include "iosource/PktSrc.h"
+#include "Net.h"
 
 EventMgr mgr;
 
@@ -124,7 +127,10 @@ void EventMgr::QueueEvent(Event* event)
 		return;
 
 	if ( ! head )
+		{
 		head = tail = event;
+		queue_flare.Fire();
+		}
 	else
 		{
 		tail->SetNext(event);
@@ -204,3 +210,29 @@ void EventMgr::Describe(ODesc* d) const
 		d->NL();
 		}
 	}
+
+void EventMgr::Process()
+	{
+	// If we don't have a source, or the source is closed, or we're
+	// reading live (which includes pseudo-realtime), advance the time
+	// here to the current time since otherwise it won't move forward.
+	iosource::PktSrc* pkt_src = iosource_mgr->GetPktSrc();
+	if ( ! pkt_src || ! pkt_src->IsOpen() || reading_live )
+		net_update_time(current_time());
+
+	queue_flare.Extinguish();
+
+	// While it semes like the most logical thing to do, we dont want
+	// to call Drain() as part of this method. It will get called at
+	// the end of net_run after all of the sources have been processed
+	// and had the opportunity to spawn new events. We could use
+	// iosource_mgr->Wakeup() instead of making EventMgr an IOSource,
+	// but then we couldn't update the time above and nothing would
+	// drive it forward.
+	}
+
+void EventMgr::InitPostScript()
+	{
+	iosource_mgr->Register(this, true, false);
+	iosource_mgr->RegisterFd(queue_flare.FD(), this);
+	}

src/Event.h

@@ -4,6 +4,8 @@
 
 #include "BroList.h"
 #include "analyzer/Analyzer.h"
+#include "iosource/IOSource.h"
+#include "Flare.h"
 
 class EventMgr;
 
@@ -49,7 +51,7 @@ protected:
 extern uint64_t num_events_queued;
 extern uint64_t num_events_dispatched;
 
-class EventMgr : public BroObj {
+class EventMgr : public BroObj, public iosource::IOSource {
 public:
 	EventMgr();
 	~EventMgr() override;
@@ -113,6 +115,11 @@ public:
 
 	void Describe(ODesc* d) const override;
 
+	double GetNextTimeout() override { return -1; }
+	void Process() override;
+	const char* Tag() override { return "EventManager"; }
+	void InitPostScript();
+
 protected:
 	void QueueEvent(Event* event);
 
@@ -123,6 +130,7 @@ protected:
 	TimerMgr* current_mgr;
 	RecordVal* src_val;
 	bool draining;
+	bro::Flare queue_flare;
 };
 
 extern EventMgr mgr;

src/iosource/Manager.cc

@@ -58,9 +58,13 @@ Manager::~Manager()
 
 	for ( SourceList::iterator i = sources.begin(); i != sources.end(); ++i )
 		{
-		(*i)->src->Done();
+		auto src = *i;
-		delete (*i)->src;
+		src->src->Done();
-		delete *i;
+
+		if ( src->manage_lifetime )
+			delete src->src;
+
+		delete src;
 		}
 
 	sources.clear();
@@ -152,6 +156,9 @@ void Manager::FindReadySources(std::vector<IOSource*>* ready)
 			}
 		}
 
+	DBG_LOG(DBG_MAINLOOP, "timeout: %f   ready size: %ld   time_to_poll: %d\n",
+		timeout, ready->size(), time_to_poll);
+
 	// If we didn't find any IOSources with zero timeouts or it's time to
 	// force a poll, do that and return. Otherwise return the set of ready
 	// sources that we have.
@@ -253,7 +260,7 @@ bool Manager::UnregisterFd(int fd, IOSource* src)
 		}
 	}
 
-void Manager::Register(IOSource* src, bool dont_count)
+void Manager::Register(IOSource* src, bool dont_count, bool manage_lifetime)
 	{
 	// First see if we already have registered that source. If so, just
 	// adjust dont_count.
@@ -273,6 +280,7 @@ void Manager::Register(IOSource* src, bool dont_count)
 	Source* s = new Source;
 	s->src = src;
 	s->dont_count = dont_count;
+	s->manage_lifetime = manage_lifetime;
 	if ( dont_count )
 		++dont_counts;
 

src/iosource/Manager.h

@@ -53,7 +53,7 @@ public:
 	 * sources except for the non-counting ones have gone dry, processing
 	 * will shut down.
 	 */
-	void Register(IOSource* src, bool dont_count = false);
+	void Register(IOSource* src, bool dont_count = false, bool manage_lifetime = true);
 
 	/**
 	 * Returns the number of registered and still active sources,
@@ -182,8 +182,9 @@ private:
 		};
 
 	struct Source {
-		IOSource* src;
+		IOSource* src = nullptr;
-		bool dont_count;
+		bool dont_count = false;
+		bool manage_lifetime = false;
 	};
 
 	using SourceList = std::vector<Source*>;

src/main.cc

@@ -673,6 +673,7 @@ int main(int argc, char** argv)
 	zeekygen_mgr->InitPostScript();
 	broker_mgr->InitPostScript();
 	timer_mgr->InitPostScript();
+	mgr.InitPostScript();
 
 	if ( zeek::supervisor_mgr )
 		zeek::supervisor_mgr->InitPostScript();

testing/btest/Baseline/core.recursive-event/output

@@ -1 +1 @@
-9
+10