Title: [152816] trunk/Source/WTF
- Revision
- 152816
- Author
- benja...@webkit.org
- Date
- 2013-07-17 16:37:54 -0700 (Wed, 17 Jul 2013)
Log Message
Add a thread safety assertion when creating an AtomicString from a StringImpl
https://bugs.webkit.org/show_bug.cgi?id=118637
Reviewed by Sam Weinig.
The goal is to prevent this kind of use:
-Someone create a String from a StringImpl.
-At some point, the string becomes atomic.
-Later, when the string only has one ref, its ownership is 'passed' to an other thread
without checking String::isSafeToSendToAnotherThread().
-In the thread B, an AtomicString is created from the String.
->The AtomicString's StringImpl returned is not in the current thread string table.
* wtf/text/AtomicString.cpp:
(WTF::AtomicString::isInAtomicStringTable):
* wtf/text/AtomicString.h:
(WTF::AtomicString::add):
Modified Paths
Diff
Modified: trunk/Source/WTF/ChangeLog (152815 => 152816)
--- trunk/Source/WTF/ChangeLog 2013-07-17 23:34:13 UTC (rev 152815)
+++ trunk/Source/WTF/ChangeLog 2013-07-17 23:37:54 UTC (rev 152816)
@@ -1,5 +1,25 @@
2013-07-17 Benjamin Poulain <benja...@webkit.org>
+ Add a thread safety assertion when creating an AtomicString from a StringImpl
+ https://bugs.webkit.org/show_bug.cgi?id=118637
+
+ Reviewed by Sam Weinig.
+
+ The goal is to prevent this kind of use:
+ -Someone create a String from a StringImpl.
+ -At some point, the string becomes atomic.
+ -Later, when the string only has one ref, its ownership is 'passed' to an other thread
+ without checking String::isSafeToSendToAnotherThread().
+ -In the thread B, an AtomicString is created from the String.
+ ->The AtomicString's StringImpl returned is not in the current thread string table.
+
+ * wtf/text/AtomicString.cpp:
+ (WTF::AtomicString::isInAtomicStringTable):
+ * wtf/text/AtomicString.h:
+ (WTF::AtomicString::add):
+
+2013-07-17 Benjamin Poulain <benja...@webkit.org>
+
Simplify AtomicString::lower()
https://bugs.webkit.org/show_bug.cgi?id=118719
<rdar://problem/14452883>
Modified: trunk/Source/WTF/wtf/text/AtomicString.cpp (152815 => 152816)
--- trunk/Source/WTF/wtf/text/AtomicString.cpp 2013-07-17 23:34:13 UTC (rev 152815)
+++ trunk/Source/WTF/wtf/text/AtomicString.cpp 2013-07-17 23:37:54 UTC (rev 152816)
@@ -461,6 +461,14 @@
return atomicString;
}
+#if !ASSERT_DISABLED
+bool AtomicString::isInAtomicStringTable(StringImpl* string)
+{
+ AtomicStringTableLocker locker;
+ return stringTable().contains(string);
+}
+#endif
+
#ifndef NDEBUG
void AtomicString::show() const
{
Modified: trunk/Source/WTF/wtf/text/AtomicString.h (152815 => 152816)
--- trunk/Source/WTF/wtf/text/AtomicString.h 2013-07-17 23:34:13 UTC (rev 152815)
+++ trunk/Source/WTF/wtf/text/AtomicString.h 2013-07-17 23:37:54 UTC (rev 152816)
@@ -182,11 +182,13 @@
WTF_EXPORT_STRING_API static PassRefPtr<StringImpl> add(const UChar*, unsigned length, unsigned existingHash);
WTF_EXPORT_STRING_API static PassRefPtr<StringImpl> add(const UChar*);
WTF_EXPORT_STRING_API static PassRefPtr<StringImpl> add(StringImpl*, unsigned offset, unsigned length);
- ALWAYS_INLINE static PassRefPtr<StringImpl> add(StringImpl* r)
+ ALWAYS_INLINE static PassRefPtr<StringImpl> add(StringImpl* string)
{
- if (!r || r->isAtomic())
- return r;
- return addSlowCase(r);
+ if (!string || string->isAtomic()) {
+ ASSERT_WITH_MESSAGE(!string || isInAtomicStringTable(string), "The atomic string comes from an other thread!");
+ return string;
+ }
+ return addSlowCase(string);
}
WTF_EXPORT_STRING_API static PassRefPtr<StringImpl> addFromLiteralData(const char* characters, unsigned length);
WTF_EXPORT_STRING_API static PassRefPtr<StringImpl> addSlowCase(StringImpl*);
@@ -195,6 +197,10 @@
#endif
WTF_EXPORT_STRING_API static AtomicString fromUTF8Internal(const char*, const char*);
+
+#if !ASSERT_DISABLED
+ WTF_EXPORT_STRING_API static bool isInAtomicStringTable(StringImpl*);
+#endif
};
inline bool operator==(const AtomicString& a, const AtomicString& b) { return a.impl() == b.impl(); }
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