add original source

source/listing_3.7.cpp

@@ -0,0 +1,64 @@
+#include <mutex>
+
+class hierarchical_mutex
+{
+public:
+    explicit hierarchical_mutex(unsigned level)
+    {}
+    
+    void lock()
+    {}
+    void unlock()
+    {}
+};
+
+
+hierarchical_mutex high_level_mutex(10000);
+hierarchical_mutex low_level_mutex(5000);
+
+int do_low_level_stuff()
+{
+    return 42;
+}
+
+
+int low_level_func()
+{
+    std::lock_guard<hierarchical_mutex> lk(low_level_mutex);
+    return do_low_level_stuff();
+}
+
+void high_level_stuff(int some_param)
+{}
+
+
+void high_level_func()
+{
+    std::lock_guard<hierarchical_mutex> lk(high_level_mutex);
+    high_level_stuff(low_level_func());
+}
+
+void thread_a()
+{
+    high_level_func();
+}
+
+hierarchical_mutex other_mutex(100);
+void do_other_stuff()
+{}
+
+
+void other_stuff()
+{
+    high_level_func();
+    do_other_stuff();
+}
+
+void thread_b()
+{
+    std::lock_guard<hierarchical_mutex> lk(other_mutex);
+    other_stuff();
+}
+
+int main()
+{}