Imported WebKit commit 2ea9d364d0f6efa8fa64acf19f451504c59be0e4 (http://svn.webkit.org/repository/webkit/trunk@104285)

1 files changed, 281 insertions, 0 deletions

diff --git a/Source/JavaScriptCore/wtf/FastMalloc.h b/Source/JavaScriptCore/wtf/FastMalloc.h
new file mode 100644
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+++ b/Source/JavaScriptCore/wtf/FastMalloc.h
@@ -0,0 +1,281 @@
+/*
+ *  Copyright (C) 2005, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
+ *
+ *  This library is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU Library General Public
+ *  License as published by the Free Software Foundation; either
+ *  version 2 of the License, or (at your option) any later version.
+ *
+ *  This library is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *  Library General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Library General Public License
+ *  along with this library; see the file COPYING.LIB.  If not, write to
+ *  the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ *  Boston, MA 02110-1301, USA.
+ *
+ */
+
+#ifndef WTF_FastMalloc_h
+#define WTF_FastMalloc_h
+
+#include "Platform.h"
+#include "PossiblyNull.h"
+#include <stdlib.h>
+#include <new>
+
+namespace WTF {
+
+    // These functions call CRASH() if an allocation fails.
+    void* fastMalloc(size_t);
+    void* fastZeroedMalloc(size_t);
+    void* fastCalloc(size_t numElements, size_t elementSize);
+    void* fastRealloc(void*, size_t);
+    char* fastStrDup(const char*);
+    size_t fastMallocSize(const void*);
+
+    struct TryMallocReturnValue {
+        TryMallocReturnValue(void* data)
+            : m_data(data)
+        {
+        }
+        TryMallocReturnValue(const TryMallocReturnValue& source)
+            : m_data(source.m_data)
+        {
+            source.m_data = 0;
+        }
+        ~TryMallocReturnValue() { ASSERT(!m_data); }
+        template <typename T> bool getValue(T& data) WARN_UNUSED_RETURN;
+        template <typename T> operator PossiblyNull<T>()
+        { 
+            T value; 
+            getValue(value); 
+            return PossiblyNull<T>(value);
+        } 
+    private:
+        mutable void* m_data;
+    };
+    
+    template <typename T> bool TryMallocReturnValue::getValue(T& data)
+    {
+        union u { void* data; T target; } res;
+        res.data = m_data;
+        data = res.target;
+        bool returnValue = !!m_data;
+        m_data = 0;
+        return returnValue;
+    }
+
+    TryMallocReturnValue tryFastMalloc(size_t n);
+    TryMallocReturnValue tryFastZeroedMalloc(size_t n);
+    TryMallocReturnValue tryFastCalloc(size_t n_elements, size_t element_size);
+    TryMallocReturnValue tryFastRealloc(void* p, size_t n);
+
+    void fastFree(void*);
+
+#ifndef NDEBUG    
+    void fastMallocForbid();
+    void fastMallocAllow();
+#endif
+
+    void releaseFastMallocFreeMemory();
+    
+    struct FastMallocStatistics {
+        size_t reservedVMBytes;
+        size_t committedVMBytes;
+        size_t freeListBytes;
+    };
+    FastMallocStatistics fastMallocStatistics();
+
+    // This defines a type which holds an unsigned integer and is the same
+    // size as the minimally aligned memory allocation.
+    typedef unsigned long long AllocAlignmentInteger;
+
+    namespace Internal {
+        enum AllocType {                    // Start with an unusual number instead of zero, because zero is common.
+            AllocTypeMalloc = 0x375d6750,   // Encompasses fastMalloc, fastZeroedMalloc, fastCalloc, fastRealloc.
+            AllocTypeClassNew,              // Encompasses class operator new from FastAllocBase.
+            AllocTypeClassNewArray,         // Encompasses class operator new[] from FastAllocBase.
+            AllocTypeFastNew,               // Encompasses fastNew.
+            AllocTypeFastNewArray,          // Encompasses fastNewArray.
+            AllocTypeNew,                   // Encompasses global operator new.
+            AllocTypeNewArray               // Encompasses global operator new[].
+        };
+
+        enum {
+            ValidationPrefix = 0xf00df00d,
+            ValidationSuffix = 0x0badf00d
+        };
+
+        typedef unsigned ValidationTag;
+
+        struct ValidationHeader {
+            AllocType m_type;
+            unsigned m_size;
+            ValidationTag m_prefix;
+            unsigned m_alignment;
+        };
+
+        static const int ValidationBufferSize = sizeof(ValidationHeader) + sizeof(ValidationTag);
+    }
+
+#if ENABLE(WTF_MALLOC_VALIDATION)
+
+    // Malloc validation is a scheme whereby a tag is attached to an
+    // allocation which identifies how it was originally allocated.
+    // This allows us to verify that the freeing operation matches the
+    // allocation operation. If memory is allocated with operator new[]
+    // but freed with free or delete, this system would detect that.
+    // In the implementation here, the tag is an integer prepended to
+    // the allocation memory which is assigned one of the AllocType
+    // enumeration values. An alternative implementation of this
+    // scheme could store the tag somewhere else or ignore it.
+    // Users of FastMalloc don't need to know or care how this tagging
+    // is implemented.
+
+    namespace Internal {
+    
+        // Handle a detected alloc/free mismatch. By default this calls CRASH().
+        void fastMallocMatchFailed(void* p);
+
+        inline ValidationHeader* fastMallocValidationHeader(void* p)
+        {
+            return reinterpret_cast<ValidationHeader*>(static_cast<char*>(p) - sizeof(ValidationHeader));
+        }
+
+        inline ValidationTag* fastMallocValidationSuffix(void* p)
+        {
+            ValidationHeader* header = fastMallocValidationHeader(p);
+            if (header->m_prefix != static_cast<unsigned>(ValidationPrefix))
+                fastMallocMatchFailed(p);
+            
+            return reinterpret_cast<ValidationTag*>(static_cast<char*>(p) + header->m_size);
+        }
+
+        // Return the AllocType tag associated with the allocated block p.
+        inline AllocType fastMallocMatchValidationType(void* p)
+        {
+            return fastMallocValidationHeader(p)->m_type;
+        }
+
+        // Set the AllocType tag to be associaged with the allocated block p.
+        inline void setFastMallocMatchValidationType(void* p, AllocType allocType)
+        {
+            fastMallocValidationHeader(p)->m_type = allocType;
+        }
+
+    } // namespace Internal
+
+    // This is a higher level function which is used by FastMalloc-using code.
+    inline void fastMallocMatchValidateMalloc(void* p, Internal::AllocType allocType)
+    {
+        if (!p)
+            return;
+
+        Internal::setFastMallocMatchValidationType(p, allocType);
+    }
+
+    // This is a higher level function which is used by FastMalloc-using code.
+    inline void fastMallocMatchValidateFree(void* p, Internal::AllocType)
+    {
+        if (!p)
+            return;
+    
+        Internal::ValidationHeader* header = Internal::fastMallocValidationHeader(p);
+        if (header->m_prefix != static_cast<unsigned>(Internal::ValidationPrefix))
+            Internal::fastMallocMatchFailed(p);
+
+        if (*Internal::fastMallocValidationSuffix(p) != Internal::ValidationSuffix)
+            Internal::fastMallocMatchFailed(p);
+
+        Internal::setFastMallocMatchValidationType(p, Internal::AllocTypeMalloc);  // Set it to this so that fastFree thinks it's OK.
+    }
+
+    inline void fastMallocValidate(void* p)
+    {
+        if (!p)
+            return;
+        
+        Internal::ValidationHeader* header = Internal::fastMallocValidationHeader(p);
+        if (header->m_prefix != static_cast<unsigned>(Internal::ValidationPrefix))
+            Internal::fastMallocMatchFailed(p);
+        
+        if (*Internal::fastMallocValidationSuffix(p) != Internal::ValidationSuffix)
+            Internal::fastMallocMatchFailed(p);
+    }
+
+#else
+
+    inline void fastMallocMatchValidateMalloc(void*, Internal::AllocType)
+    {
+    }
+
+    inline void fastMallocMatchValidateFree(void*, Internal::AllocType)
+    {
+    }
+
+#endif
+
+} // namespace WTF
+
+using WTF::fastCalloc;
+using WTF::fastFree;
+using WTF::fastMalloc;
+using WTF::fastMallocSize;
+using WTF::fastRealloc;
+using WTF::fastStrDup;
+using WTF::fastZeroedMalloc;
+using WTF::tryFastCalloc;
+using WTF::tryFastMalloc;
+using WTF::tryFastRealloc;
+using WTF::tryFastZeroedMalloc;
+
+#ifndef NDEBUG    
+using WTF::fastMallocForbid;
+using WTF::fastMallocAllow;
+#endif
+
+#if COMPILER(GCC) && OS(DARWIN)
+#define WTF_PRIVATE_INLINE __private_extern__ inline __attribute__((always_inline))
+#elif COMPILER(GCC)
+#define WTF_PRIVATE_INLINE inline __attribute__((always_inline))
+#elif COMPILER(MSVC) || COMPILER(RVCT)
+#define WTF_PRIVATE_INLINE __forceinline
+#else
+#define WTF_PRIVATE_INLINE inline
+#endif
+
+#if !defined(_CRTDBG_MAP_ALLOC) && !(defined(USE_SYSTEM_MALLOC) && USE_SYSTEM_MALLOC)
+
+// The nothrow functions here are actually not all that helpful, because fastMalloc will
+// call CRASH() rather than returning 0, and returning 0 is what nothrow is all about.
+// But since WebKit code never uses exceptions or nothrow at all, this is probably OK.
+// Long term we will adopt FastAllocBase.h everywhere, and and replace this with
+// debug-only code to make sure we don't use the system malloc via the default operator
+// new by accident.
+
+#if ENABLE(GLOBAL_FASTMALLOC_NEW)
+
+#if COMPILER(MSVC)
+#pragma warning(push)
+#pragma warning(disable: 4290) // Disable the C++ exception specification ignored warning.
+#endif
+WTF_PRIVATE_INLINE void* operator new(size_t size) throw (std::bad_alloc) { return fastMalloc(size); }
+WTF_PRIVATE_INLINE void* operator new(size_t size, const std::nothrow_t&) throw() { return fastMalloc(size); }
+WTF_PRIVATE_INLINE void operator delete(void* p) throw() { fastFree(p); }
+WTF_PRIVATE_INLINE void operator delete(void* p, const std::nothrow_t&) throw() { fastFree(p); }
+WTF_PRIVATE_INLINE void* operator new[](size_t size) throw (std::bad_alloc) { return fastMalloc(size); }
+WTF_PRIVATE_INLINE void* operator new[](size_t size, const std::nothrow_t&) throw() { return fastMalloc(size); }
+WTF_PRIVATE_INLINE void operator delete[](void* p) throw() { fastFree(p); }
+WTF_PRIVATE_INLINE void operator delete[](void* p, const std::nothrow_t&) throw() { fastFree(p); }
+#if COMPILER(MSVC)
+#pragma warning(pop)
+#endif
+
+#endif
+
+#endif
+
+#endif /* WTF_FastMalloc_h */