Fix race on creating the default typeface.
BUG=skia:1906
R=mtklein@google.com, reed@google.com
Review URL: https://codereview.chromium.org/113543005
git-svn-id: http://skia.googlecode.com/svn/trunk@12993 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/include/core/SkTypeface.h b/include/core/SkTypeface.h
index d873e69..04838da 100644
--- a/include/core/SkTypeface.h
+++ b/include/core/SkTypeface.h
@@ -334,6 +334,8 @@
size_t length, void* data) const = 0;
private:
+ static void create_default_typeface(Style style);
+
SkFontID fUniqueID;
Style fStyle;
bool fIsFixedPitch;
diff --git a/src/core/SkTypeface.cpp b/src/core/SkTypeface.cpp
index 09a6432..d15caeb 100644
--- a/src/core/SkTypeface.cpp
+++ b/src/core/SkTypeface.cpp
@@ -8,6 +8,7 @@
#include "SkAdvancedTypefaceMetrics.h"
#include "SkFontDescriptor.h"
#include "SkFontHost.h"
+#include "SkOnce.h"
#include "SkStream.h"
#include "SkTypeface.h"
@@ -69,24 +70,32 @@
}
};
-SkTypeface* SkTypeface::GetDefaultTypeface(Style style) {
- // we keep a reference to this guy for all time, since if we return its
- // fontID, the font cache may later on ask to resolve that back into a
- // typeface object.
- static const uint32_t FONT_STYLE_COUNT = 4;
- static SkTypeface* gDefaultTypefaces[FONT_STYLE_COUNT];
- SkASSERT((unsigned)style < FONT_STYLE_COUNT);
+static SkTypeface* gDefaultTypefaces[] = { NULL, NULL, NULL, NULL };
+static const size_t FONT_STYLE_COUNT = SK_ARRAY_COUNT(gDefaultTypefaces);
+static SkOnceFlag gDefaultTypefaceOnce[FONT_STYLE_COUNT] = {
+ SK_ONCE_INIT, SK_ONCE_INIT, SK_ONCE_INIT, SK_ONCE_INIT
+};
+template <uintmax_t N> struct SkTIsPow2 {
+ static const bool value = (N & (N - 1)) == 0;
+};
+SK_COMPILE_ASSERT(SkTIsPow2<FONT_STYLE_COUNT>::value, FONT_STYLE_COUNT_not_power_of_2);
- // mask off any other bits to avoid a crash in SK_RELEASE
- style = (Style)(style & 0x03);
-
+void SkTypeface::create_default_typeface(Style style) {
if (NULL == gDefaultTypefaces[style]) {
gDefaultTypefaces[style] = SkFontHost::CreateTypeface(NULL, NULL, style);
}
if (NULL == gDefaultTypefaces[style]) {
gDefaultTypefaces[style] = SkNEW(SkEmptyTypeface);
}
+}
+SkTypeface* SkTypeface::GetDefaultTypeface(Style style) {
+ SkASSERT((size_t)style < FONT_STYLE_COUNT);
+
+ // mask off any other bits to avoid a crash in SK_RELEASE
+ style = (Style)(style & (FONT_STYLE_COUNT - 1));
+
+ SkOnce(&gDefaultTypefaceOnce[style], SkTypeface::create_default_typeface, style);
return gDefaultTypefaces[style];
}