Remove timeouts from remote communication loop.

The select() now blocks until there's work to do instead of relying on a
small timeout value which can cause unproductive use of cpu cycles.

src/ChunkedIO.h

@@ -6,8 +6,9 @@
 #include "config.h"
 #include "List.h"
 #include "util.h"
-
+#include "Flare.h"
 #include <list>
+#include <vector>
 
 #ifdef NEED_KRB5_H
 # include <krb5.h>
@@ -95,6 +96,11 @@ public:
 	// Returns underlying fd if available, -1 otherwise.
 	virtual int Fd()	{ return -1; }
 
+	// Returns supplementary file descriptors that become read-ready in order
+	// to signal that there is some work that can be performed.
+	virtual std::vector<int> FdSupplements() const
+		{ return std::vector<int>(); }
+
 	// Makes sure that no additional protocol data is written into
 	// the output stream.  If this is activated, the output cannot
 	// be read again by any of these classes!
@@ -177,6 +183,7 @@ public:
 	virtual void Clear();
 	virtual bool Eof()	{ return eof; }
 	virtual int Fd()	{ return fd; }
+	virtual std::vector<int> FdSupplements() const;
 	virtual void Stats(char* buffer, int length);
 
 private:
@@ -240,6 +247,8 @@ private:
 	ChunkQueue* pending_tail;
 
 	pid_t pid;
+	bro::Flare write_flare;
+	bro::Flare read_flare;
 };
 
 // Chunked I/O using an SSL connection.
@@ -262,6 +271,7 @@ public:
 	virtual void Clear();
 	virtual bool Eof()	{ return eof; }
 	virtual int Fd()	{ return socket; }
+	virtual std::vector<int> FdSupplements() const;
 	virtual void Stats(char* buffer, int length);
 
 private:
@@ -303,6 +313,8 @@ private:
 
 	// One SSL for all connections.
 	static SSL_CTX* ctx;
+
+	bro::Flare write_flare;
 };
 
 #include <zlib.h>
@@ -328,6 +340,8 @@ public:
 
 	virtual bool Eof()	{ return io->Eof(); }
 	virtual int Fd()	{ return io->Fd(); }
+	virtual std::vector<int> FdSupplements() const
+		{ return io->FdSupplements(); }
 	virtual void Stats(char* buffer, int length);
 
 	void EnableCompression(int level)