Split Linux tap receive into two threads: one reader, one processor.

osdep/BlockingQueue.hpp

@@ -18,8 +18,8 @@
 #include <mutex>
 #include <condition_variable>
 #include <chrono>
-
-#include "Thread.hpp"
+#include <atomic>
+#include <vector>
 
 namespace ZeroTier {
 
@@ -67,7 +67,8 @@ public:
 	inline bool get(T &value)
 	{
 		std::unique_lock<std::mutex> lock(m);
-		if (!r) return false;
+		if (!r)
+			return false;
 		while (q.empty()) {
 			c.wait(lock);
 			if (!r) {
@@ -81,6 +82,16 @@ public:
 		return true;
 	}
 
+	inline std::vector<T> drain()
+	{
+		std::vector<T> v;
+		while (!q.empty()) {
+			v.push_back(q.front());
+			q.pop();
+		}
+		return v;
+	}
+
 	enum TimedWaitResult
 	{
 		OK,
@@ -92,7 +103,8 @@ public:
 	{
 		const std::chrono::milliseconds ms2{ms};
 		std::unique_lock<std::mutex> lock(m);
-		if (!r) return STOP;
+		if (!r)
+			return STOP;
 		while (q.empty()) {
 			if (c.wait_for(lock,ms2) == std::cv_status::timeout)
 				return ((r) ? TIMED_OUT : STOP);
@@ -105,10 +117,10 @@ public:
 	}
 
 private:
-	volatile bool r;
 	std::queue<T> q;
 	mutable std::mutex m;
 	mutable std::condition_variable c,gc;
+	std::atomic_bool r;
 };
 
 } // namespace ZeroTier