X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=spsc-bugfix%2Feventcount-relacy.h;fp=spsc-bugfix%2Feventcount-relacy.h;h=9eadcf3ab57f78414a7862099c82aea89b3e8975;hb=991d0fdc0fb17f85d485c97dc2c5d8d57a98dad9;hp=0000000000000000000000000000000000000000;hpb=91db0c118d7135f69846bcedfb8a26c0afb44045;p=model-checker-benchmarks.git

diff --git a/spsc-bugfix/eventcount-relacy.h b/spsc-bugfix/eventcount-relacy.h
new file mode 100644
index 0000000..9eadcf3
--- /dev/null
+++ b/spsc-bugfix/eventcount-relacy.h
@@ -0,0 +1,64 @@
+class eventcount
+{
+public:
+	eventcount() : waiters(0)
+	{
+		count($) = 0;
+	}
+
+	void signal_relaxed()
+	{
+		unsigned cmp = count.load(std::memory_order_relaxed);
+		signal_impl(cmp);
+	}
+
+	void signal()
+	{
+		unsigned cmp = count.fetch_add(0, std::memory_order_seq_cst);
+		signal_impl(cmp);
+	}
+
+	unsigned get()
+	{
+		unsigned cmp = count.fetch_or(0x80000000,
+std::memory_order_seq_cst);
+		return cmp & 0x7FFFFFFF;
+	}
+
+	void wait(unsigned cmp)
+	{
+		unsigned ec = count.load(std::memory_order_seq_cst);
+		if (cmp == (ec & 0x7FFFFFFF))
+		{
+			guard.lock($);
+			ec = count.load(std::memory_order_seq_cst);
+			if (cmp == (ec & 0x7FFFFFFF))
+			{
+				waiters($) += 1;
+				cv.wait(guard, $);
+			}
+			guard.unlock($);
+		}
+	}
+
+private:
+	std::atomic<unsigned> count;
+	rl::var<unsigned> waiters;
+	std::mutex guard;
+	std::condition_variable cv;
+
+	void signal_impl(unsigned cmp)
+	{
+		if (cmp & 0x80000000)
+		{
+			guard.lock($);
+			while (false == count.compare_exchange_weak(cmp,
+				(cmp + 1) & 0x7FFFFFFF, std::memory_order_relaxed));
+			unsigned w = waiters($);
+			waiters($) = 0;
+			guard.unlock($);
+			if (w)
+				cv.notify_all($);
+		}
+	}
+};