diff options
| -rw-r--r-- | src/ports/SkFontMgr_fontconfig.cpp | 24 |
1 files changed, 19 insertions, 5 deletions
diff --git a/src/ports/SkFontMgr_fontconfig.cpp b/src/ports/SkFontMgr_fontconfig.cpp index be4b17dd12..95c963d69f 100644 --- a/src/ports/SkFontMgr_fontconfig.cpp +++ b/src/ports/SkFontMgr_fontconfig.cpp @@ -73,10 +73,9 @@ void DeleteThreadFcLocked(void* v) { delete static_cast<bool*>(v); } static_cast<bool*>(SkTLS::Get(CreateThreadFcLocked, DeleteThreadFcLocked)) #endif -struct FCLocker { +class FCLocker { // Assume FcGetVersion() has always been thread safe. - - FCLocker() { + static void lock() { if (FcGetVersion() < 21091) { gFCMutex.acquire(); } else { @@ -85,8 +84,7 @@ struct FCLocker { SkDEBUGCODE(*threadLocked = true); } } - - ~FCLocker() { + static void unlock() { AssertHeld(); if (FcGetVersion() < 21091) { gFCMutex.release(); @@ -95,6 +93,20 @@ struct FCLocker { } } +public: + FCLocker() { lock(); } + ~FCLocker() { unlock(); } + + /** If acquire and release were free, FCLocker would be used around each call into FontConfig. + * Instead a much more granular approach is taken, but this means there are times when the + * mutex is held when it should not be. A Suspend will drop the lock until it is destroyed. + * While a Suspend exists, FontConfig should not be used without re-taking the lock. + */ + struct Suspend { + Suspend() { unlock(); } + ~Suspend() { lock(); } + }; + static void AssertHeld() { SkDEBUGCODE( if (FcGetVersion() < 21091) { gFCMutex.assertHeld(); @@ -652,6 +664,8 @@ class SkFontMgr_fontconfig : public SkFontMgr { FcPatternReference(pattern); face = SkTypeface_fontconfig::Create(pattern); if (face) { + // Cannot hold the lock when calling add; an evicted typeface may need to lock. + FCLocker::Suspend suspend; fTFCache.add(face); } } |