Add Counting Semaphore class

Fix threading in Network

bayesnet/network/CountingSemaphore.h

@@ -0,0 +1,33 @@
+#ifndef COUNTING_SEMAPHORE_H
+#define COUNTING_SEMAPHORE_H
+#include <mutex>
+#include <condition_variable>
+class CountingSemaphore {
+public:
+    explicit CountingSemaphore(size_t max_count) : max_count_(max_count), count_(max_count) {}
+
+    // Acquires a permit, blocking if necessary until one becomes available
+    void acquire()
+    {
+        std::unique_lock<std::mutex> lock(mtx_);
+        cv_.wait(lock, [this]() { return count_ > 0; });
+        --count_;
+    }
+
+    // Releases a permit, potentially waking up a blocked acquirer
+    void release()
+    {
+        std::lock_guard<std::mutex> lock(mtx_);
+        ++count_;
+        if (count_ <= max_count_) {
+            cv_.notify_one();
+        }
+    }
+
+private:
+    std::mutex mtx_;
+    std::condition_variable cv_;
+    size_t max_count_;
+    size_t count_;
+};
+#endif