--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/JavaScriptCore/jit/ExecutableAllocator.h Fri Sep 17 09:02:29 2010 +0300
@@ -0,0 +1,328 @@
+/*
+ * Copyright (C) 2008 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef ExecutableAllocator_h
+#define ExecutableAllocator_h
+#include <stddef.h> // for ptrdiff_t
+#include <limits>
+#include <wtf/Assertions.h>
+#include <wtf/PassRefPtr.h>
+#include <wtf/RefCounted.h>
+#include <wtf/UnusedParam.h>
+#include <wtf/Vector.h>
+
+#if OS(IPHONE_OS)
+#include <libkern/OSCacheControl.h>
+#include <sys/mman.h>
+#endif
+
+#if OS(SYMBIAN)
+#include <e32std.h>
+#endif
+
+#if CPU(MIPS) && OS(LINUX)
+#include <sys/cachectl.h>
+#endif
+
+#if OS(WINCE)
+// From pkfuncs.h (private header file from the Platform Builder)
+#define CACHE_SYNC_ALL 0x07F
+extern "C" __declspec(dllimport) void CacheRangeFlush(LPVOID pAddr, DWORD dwLength, DWORD dwFlags);
+#endif
+
+#define JIT_ALLOCATOR_PAGE_SIZE (ExecutableAllocator::pageSize)
+#define JIT_ALLOCATOR_LARGE_ALLOC_SIZE (ExecutableAllocator::pageSize * 4)
+
+#if ENABLE(ASSEMBLER_WX_EXCLUSIVE)
+#define PROTECTION_FLAGS_RW (PROT_READ | PROT_WRITE)
+#define PROTECTION_FLAGS_RX (PROT_READ | PROT_EXEC)
+#define INITIAL_PROTECTION_FLAGS PROTECTION_FLAGS_RX
+#else
+#define INITIAL_PROTECTION_FLAGS (PROT_READ | PROT_WRITE | PROT_EXEC)
+#endif
+
+namespace JSC {
+
+inline size_t roundUpAllocationSize(size_t request, size_t granularity)
+{
+ if ((std::numeric_limits<size_t>::max() - granularity) <= request)
+ CRASH(); // Allocation is too large
+
+ // Round up to next page boundary
+ size_t size = request + (granularity - 1);
+ size = size & ~(granularity - 1);
+ ASSERT(size >= request);
+ return size;
+}
+
+}
+
+#if ENABLE(JIT) && ENABLE(ASSEMBLER)
+
+namespace JSC {
+
+class ExecutablePool : public RefCounted<ExecutablePool> {
+private:
+ struct Allocation {
+ char* pages;
+ size_t size;
+#if OS(SYMBIAN)
+ RChunk* chunk;
+#endif
+ };
+ typedef Vector<Allocation, 2> AllocationList;
+
+public:
+ static PassRefPtr<ExecutablePool> create(size_t n)
+ {
+ return adoptRef(new ExecutablePool(n));
+ }
+
+ void* alloc(size_t n)
+ {
+ ASSERT(m_freePtr <= m_end);
+
+ // Round 'n' up to a multiple of word size; if all allocations are of
+ // word sized quantities, then all subsequent allocations will be aligned.
+ n = roundUpAllocationSize(n, sizeof(void*));
+
+ if (static_cast<ptrdiff_t>(n) < (m_end - m_freePtr)) {
+ void* result = m_freePtr;
+ m_freePtr += n;
+ return result;
+ }
+
+ // Insufficient space to allocate in the existing pool
+ // so we need allocate into a new pool
+ return poolAllocate(n);
+ }
+
+ ~ExecutablePool()
+ {
+ AllocationList::const_iterator end = m_pools.end();
+ for (AllocationList::const_iterator ptr = m_pools.begin(); ptr != end; ++ptr)
+ ExecutablePool::systemRelease(*ptr);
+ }
+
+ size_t available() const { return (m_pools.size() > 1) ? 0 : m_end - m_freePtr; }
+
+private:
+ static Allocation systemAlloc(size_t n);
+ static void systemRelease(const Allocation& alloc);
+
+ ExecutablePool(size_t n);
+
+ void* poolAllocate(size_t n);
+
+ char* m_freePtr;
+ char* m_end;
+ AllocationList m_pools;
+};
+
+class ExecutableAllocator {
+ enum ProtectionSeting { Writable, Executable };
+
+public:
+ static size_t pageSize;
+ ExecutableAllocator()
+ {
+ if (!pageSize)
+ intializePageSize();
+ if (isValid())
+ m_smallAllocationPool = ExecutablePool::create(JIT_ALLOCATOR_LARGE_ALLOC_SIZE);
+#if !ENABLE(INTERPRETER)
+ else
+ CRASH();
+#endif
+ }
+
+ bool isValid() const;
+
+ PassRefPtr<ExecutablePool> poolForSize(size_t n)
+ {
+ // Try to fit in the existing small allocator
+ ASSERT(m_smallAllocationPool);
+ if (n < m_smallAllocationPool->available())
+ return m_smallAllocationPool;
+
+ // If the request is large, we just provide a unshared allocator
+ if (n > JIT_ALLOCATOR_LARGE_ALLOC_SIZE)
+ return ExecutablePool::create(n);
+
+ // Create a new allocator
+ RefPtr<ExecutablePool> pool = ExecutablePool::create(JIT_ALLOCATOR_LARGE_ALLOC_SIZE);
+
+ // If the new allocator will result in more free space than in
+ // the current small allocator, then we will use it instead
+ if ((pool->available() - n) > m_smallAllocationPool->available())
+ m_smallAllocationPool = pool;
+ return pool.release();
+ }
+
+#if ENABLE(ASSEMBLER_WX_EXCLUSIVE)
+ static void makeWritable(void* start, size_t size)
+ {
+ reprotectRegion(start, size, Writable);
+ }
+
+ static void makeExecutable(void* start, size_t size)
+ {
+ reprotectRegion(start, size, Executable);
+ }
+#else
+ static void makeWritable(void*, size_t) {}
+ static void makeExecutable(void*, size_t) {}
+#endif
+
+
+#if CPU(X86) || CPU(X86_64)
+ static void cacheFlush(void*, size_t)
+ {
+ }
+#elif CPU(MIPS)
+ static void cacheFlush(void* code, size_t size)
+ {
+#if COMPILER(GCC) && (GCC_VERSION >= 40300)
+#if WTF_MIPS_ISA_REV(2) && (GCC_VERSION < 40403)
+ int lineSize;
+ asm("rdhwr %0, $1" : "=r" (lineSize));
+ //
+ // Modify "start" and "end" to avoid GCC 4.3.0-4.4.2 bug in
+ // mips_expand_synci_loop that may execute synci one more time.
+ // "start" points to the fisrt byte of the cache line.
+ // "end" points to the last byte of the line before the last cache line.
+ // Because size is always a multiple of 4, this is safe to set
+ // "end" to the last byte.
+ //
+ intptr_t start = reinterpret_cast<intptr_t>(code) & (-lineSize);
+ intptr_t end = ((reinterpret_cast<intptr_t>(code) + size - 1) & (-lineSize)) - 1;
+ __builtin___clear_cache(reinterpret_cast<char*>(start), reinterpret_cast<char*>(end));
+#else
+ intptr_t end = reinterpret_cast<intptr_t>(code) + size;
+ __builtin___clear_cache(reinterpret_cast<char*>(code), reinterpret_cast<char*>(end));
+#endif
+#else
+ _flush_cache(reinterpret_cast<char*>(code), size, BCACHE);
+#endif
+ }
+#elif CPU(ARM_THUMB2) && OS(IPHONE_OS)
+ static void cacheFlush(void* code, size_t size)
+ {
+ sys_dcache_flush(code, size);
+ sys_icache_invalidate(code, size);
+ }
+#elif CPU(ARM_THUMB2) && OS(LINUX)
+ static void cacheFlush(void* code, size_t size)
+ {
+ asm volatile (
+ "push {r7}\n"
+ "mov r0, %0\n"
+ "mov r1, %1\n"
+ "movw r7, #0x2\n"
+ "movt r7, #0xf\n"
+ "movs r2, #0x0\n"
+ "svc 0x0\n"
+ "pop {r7}\n"
+ :
+ : "r" (code), "r" (reinterpret_cast<char*>(code) + size)
+ : "r0", "r1", "r2");
+ }
+#elif OS(SYMBIAN)
+ static void cacheFlush(void* code, size_t size)
+ {
+ User::IMB_Range(code, static_cast<char*>(code) + size);
+ }
+#elif CPU(ARM_TRADITIONAL) && OS(LINUX) && COMPILER(RVCT)
+ static __asm void cacheFlush(void* code, size_t size);
+#elif CPU(ARM_TRADITIONAL) && OS(LINUX) && COMPILER(GCC)
+ static void cacheFlush(void* code, size_t size)
+ {
+ asm volatile (
+ "push {r7}\n"
+ "mov r0, %0\n"
+ "mov r1, %1\n"
+ "mov r7, #0xf0000\n"
+ "add r7, r7, #0x2\n"
+ "mov r2, #0x0\n"
+ "svc 0x0\n"
+ "pop {r7}\n"
+ :
+ : "r" (code), "r" (reinterpret_cast<char*>(code) + size)
+ : "r0", "r1", "r2");
+ }
+#elif OS(WINCE)
+ static void cacheFlush(void* code, size_t size)
+ {
+ CacheRangeFlush(code, size, CACHE_SYNC_ALL);
+ }
+#else
+ #error "The cacheFlush support is missing on this platform."
+#endif
+
+private:
+
+#if ENABLE(ASSEMBLER_WX_EXCLUSIVE)
+ static void reprotectRegion(void*, size_t, ProtectionSeting);
+#endif
+
+ RefPtr<ExecutablePool> m_smallAllocationPool;
+ static void intializePageSize();
+};
+
+inline ExecutablePool::ExecutablePool(size_t n)
+{
+ size_t allocSize = roundUpAllocationSize(n, JIT_ALLOCATOR_PAGE_SIZE);
+ Allocation mem = systemAlloc(allocSize);
+ m_pools.append(mem);
+ m_freePtr = mem.pages;
+ if (!m_freePtr)
+ CRASH(); // Failed to allocate
+ m_end = m_freePtr + allocSize;
+}
+
+inline void* ExecutablePool::poolAllocate(size_t n)
+{
+ size_t allocSize = roundUpAllocationSize(n, JIT_ALLOCATOR_PAGE_SIZE);
+
+ Allocation result = systemAlloc(allocSize);
+ if (!result.pages)
+ CRASH(); // Failed to allocate
+
+ ASSERT(m_end >= m_freePtr);
+ if ((allocSize - n) > static_cast<size_t>(m_end - m_freePtr)) {
+ // Replace allocation pool
+ m_freePtr = result.pages + n;
+ m_end = result.pages + allocSize;
+ }
+
+ m_pools.append(result);
+ return result.pages;
+}
+
+}
+
+#endif // ENABLE(JIT) && ENABLE(ASSEMBLER)
+
+#endif // !defined(ExecutableAllocator)