Initial community commit

Src/Wasabi/bfc/critsec.h

@@ -0,0 +1,96 @@
+#ifndef _CRITSEC_H
+#define _CRITSEC_H
+
+#ifdef _WIN32
+#include <windows.h>
+#elif defined(__APPLE__)
+#include <CoreServices/CoreServices.h>
+#endif
+
+#include <bfc/common.h>
+#include <bfc/bfc_assert.h>
+
+/**
+  CriticalSection is a portable object that implements a critical section,
+  which is to say, it ensures that no two threads can be in that same
+  section of code at the same time. Usually you make them a global object
+  or allocate them with new and pass them to both threads.
+
+  @short Critical section class.
+  @author Nullsoft
+  @ver 1.0
+  @see Thread
+  @see InCriticalSection
+*/
+
+class CriticalSection {
+public:
+  CriticalSection();
+  virtual ~CriticalSection();
+
+/**
+  Enters the critical section. If another thread is already in the critical
+  section, the calling thread will be blocked until the other thread calls
+  leave().
+  @see leave()
+*/
+  void enter();
+/**
+  Leaves the critical section. If another thread is currently blocked on
+  this critical section, it will be unblocked. If multiple threads are blocking
+  only one will be unblocked.
+  @see enter()
+*/
+  void leave();
+
+/**
+  Calls enter() and leave() in quick succession. Useful to make sure that no
+  other thread is in the critical section (although another thread could
+  immediately re-enter)
+  @see enter()
+  @see leave()
+*/
+  void inout();
+
+private:
+#ifdef ASSERTS_ENABLED
+  int within;
+#endif
+#ifdef _WIN32
+  CRITICAL_SECTION cs;
+#elif defined(__APPLE__)
+  MPCriticalRegionID cr;
+#endif
+  
+};
+
+/**
+  This is a little helper class to ease the use of class CriticalSection.
+  When it is instantiated, it enters a given critical section. When it is
+  destroyed, it leaves the given critical section.
+    CriticalSection a_cs;
+    void blah() {
+      InCriticalSection cs(a_cs); // critical section protection begins
+      if (test) {
+        return 0; // critical section protection ends
+      }
+      // critical section protection still active!
+      doSomething();
+      return 1; // critical section protection ends
+    }
+  
+  @author Nullsoft
+  @see CriticalSection
+*/
+class InCriticalSection {
+public:
+  InCriticalSection(CriticalSection *cs) : m_cs(cs) { m_cs->enter(); }
+  InCriticalSection(CriticalSection &cs) : m_cs(&cs) { m_cs->enter(); }
+  ~InCriticalSection() { m_cs->leave(); }
+private:
+  CriticalSection *m_cs;
+};
+
+#define _INCRITICALSECTION(id, x) InCriticalSection __I_C_S__##id(x)
+#define INCRITICALSECTION(x) _INCRITICALSECTION(__LINE__, x)
+#endif