Grant independence to SkBaseMutex on Windows.
Under POSIX, class SkMutex inherits from struct SkBaseMutex.
Since we can't have a POD mutex on Windows, we used to just
typedef SkMutex SkBaseMutex there. However, that makes it
impossible to forward-declare SkBaseMutex consistently across
platforms. With this CL we declare an empty struct SkBaseMutex
on Windows, which should have 0 cost but make the compiler happy.
R=bungeman@google.com, mtklein@google.com, tomhudson@google.com, bungeman, mtklein
BUG=skia:
Author: tomhudson@chromium.org
Review URL: https://codereview.chromium.org/364473002
diff --git a/src/ports/SkMutex_win.h b/src/ports/SkMutex_win.h
index d12fd03..d84b0e4 100644
--- a/src/ports/SkMutex_win.h
+++ b/src/ports/SkMutex_win.h
@@ -31,15 +31,17 @@
#endif
// On Windows, SkBaseMutex and SkMutex are the same thing,
-// we can't easily get rid of static initializers.
-class SkMutex {
+// we can't easily get rid of static initializers. However,
+// we preserve the same inheritance pattern as other platforms
+// so that we can forward-declare cleanly.
+struct SkBaseMutex {
public:
- SkMutex() {
+ SkBaseMutex() {
InitializeCriticalSection(&fStorage);
SkDEBUGCODE(fOwner = 0;)
}
- ~SkMutex() {
+ ~SkBaseMutex() {
SkASSERT(0 == fOwner);
DeleteCriticalSection(&fStorage);
}
@@ -59,15 +61,16 @@
SkASSERT(GetCurrentThreadId() == fOwner);
}
-private:
- SkMutex(const SkMutex&);
- SkMutex& operator=(const SkMutex&);
-
+protected:
CRITICAL_SECTION fStorage;
SkDEBUGCODE(DWORD fOwner;)
+
+private:
+ SkBaseMutex(const SkBaseMutex&);
+ SkBaseMutex& operator=(const SkBaseMutex&);
};
-typedef SkMutex SkBaseMutex;
+class SkMutex : public SkBaseMutex { };
// Windows currently provides no documented means of POD initializing a CRITICAL_SECTION.
#define SK_DECLARE_STATIC_MUTEX(name) static SkBaseMutex name
