*/
#include "config.h"
-
#include "ExecutableAllocator.h"
+#include "JSCInlines.h"
+
+#if ENABLE(EXECUTABLE_ALLOCATOR_DEMAND)
+#include "CodeProfiling.h"
+#include <wtf/HashSet.h>
+#include <wtf/MetaAllocator.h>
+#include <wtf/NeverDestroyed.h>
+#include <wtf/PageReservation.h>
+#if ENABLE(ASSEMBLER_WX_EXCLUSIVE)
+#include <wtf/PassOwnPtr.h>
+#endif
+#include <wtf/ThreadingPrimitives.h>
+#include <wtf/VMTags.h>
+#endif
+
+// Uncomment to create an artificial executable memory usage limit. This limit
+// is imperfect and is primarily useful for testing the VM's ability to handle
+// out-of-executable-memory situations.
+// #define EXECUTABLE_MEMORY_LIMIT 1000000
+
#if ENABLE(ASSEMBLER)
+using namespace WTF;
+
namespace JSC {
-size_t ExecutableAllocator::pageSize = 0;
+#if ENABLE(EXECUTABLE_ALLOCATOR_DEMAND)
+
+class DemandExecutableAllocator : public MetaAllocator {
+public:
+ DemandExecutableAllocator()
+ : MetaAllocator(jitAllocationGranule)
+ {
+ std::lock_guard<std::mutex> lock(allocatorsMutex());
+ allocators().add(this);
+ // Don't preallocate any memory here.
+ }
+
+ virtual ~DemandExecutableAllocator()
+ {
+ {
+ std::lock_guard<std::mutex> lock(allocatorsMutex());
+ allocators().remove(this);
+ }
+ for (unsigned i = 0; i < reservations.size(); ++i)
+ reservations.at(i).deallocate();
+ }
+
+ static size_t bytesAllocatedByAllAllocators()
+ {
+ size_t total = 0;
+ std::lock_guard<std::mutex> lock(allocatorsMutex());
+ for (HashSet<DemandExecutableAllocator*>::const_iterator allocator = allocators().begin(); allocator != allocators().end(); ++allocator)
+ total += (*allocator)->bytesAllocated();
+ return total;
+ }
+
+ static size_t bytesCommittedByAllocactors()
+ {
+ size_t total = 0;
+ std::lock_guard<std::mutex> lock(allocatorsMutex());
+ for (HashSet<DemandExecutableAllocator*>::const_iterator allocator = allocators().begin(); allocator != allocators().end(); ++allocator)
+ total += (*allocator)->bytesCommitted();
+ return total;
+ }
+
+#if ENABLE(META_ALLOCATOR_PROFILE)
+ static void dumpProfileFromAllAllocators()
+ {
+ std::lock_guard<std::mutex> lock(allocatorsMutex());
+ for (HashSet<DemandExecutableAllocator*>::const_iterator allocator = allocators().begin(); allocator != allocators().end(); ++allocator)
+ (*allocator)->dumpProfile();
+ }
+#endif
+
+protected:
+ virtual void* allocateNewSpace(size_t& numPages)
+ {
+ size_t newNumPages = (((numPages * pageSize() + JIT_ALLOCATOR_LARGE_ALLOC_SIZE - 1) / JIT_ALLOCATOR_LARGE_ALLOC_SIZE * JIT_ALLOCATOR_LARGE_ALLOC_SIZE) + pageSize() - 1) / pageSize();
+
+ ASSERT(newNumPages >= numPages);
+
+ numPages = newNumPages;
+
+#ifdef EXECUTABLE_MEMORY_LIMIT
+ if (bytesAllocatedByAllAllocators() >= EXECUTABLE_MEMORY_LIMIT)
+ return 0;
+#endif
+
+ PageReservation reservation = PageReservation::reserve(numPages * pageSize(), OSAllocator::JSJITCodePages, EXECUTABLE_POOL_WRITABLE, true);
+ RELEASE_ASSERT(reservation);
+
+ reservations.append(reservation);
+
+ return reservation.base();
+ }
+
+ virtual void notifyNeedPage(void* page)
+ {
+ OSAllocator::commit(page, pageSize(), EXECUTABLE_POOL_WRITABLE, true);
+ }
+
+ virtual void notifyPageIsFree(void* page)
+ {
+ OSAllocator::decommit(page, pageSize());
+ }
+
+private:
+ Vector<PageReservation, 16> reservations;
+ static HashSet<DemandExecutableAllocator*>& allocators()
+ {
+ DEPRECATED_DEFINE_STATIC_LOCAL(HashSet<DemandExecutableAllocator*>, sAllocators, ());
+ return sAllocators;
+ }
+
+ static std::mutex& allocatorsMutex()
+ {
+ static NeverDestroyed<std::mutex> mutex;
+
+ return mutex;
+ }
+};
+
+#if ENABLE(ASSEMBLER_WX_EXCLUSIVE)
+void ExecutableAllocator::initializeAllocator()
+{
+}
+#else
+static DemandExecutableAllocator* gAllocator;
+
+namespace {
+static inline DemandExecutableAllocator* allocator()
+{
+ return gAllocator;
+}
+}
+
+void ExecutableAllocator::initializeAllocator()
+{
+ ASSERT(!gAllocator);
+ gAllocator = new DemandExecutableAllocator();
+ CodeProfiling::notifyAllocator(gAllocator);
+}
+#endif
+
+ExecutableAllocator::ExecutableAllocator(VM&)
+#if ENABLE(ASSEMBLER_WX_EXCLUSIVE)
+ : m_allocator(adoptPtr(new DemandExecutableAllocator()))
+#endif
+{
+ ASSERT(allocator());
+}
+
+ExecutableAllocator::~ExecutableAllocator()
+{
+}
+
+bool ExecutableAllocator::isValid() const
+{
+ return true;
+}
+
+bool ExecutableAllocator::underMemoryPressure()
+{
+#ifdef EXECUTABLE_MEMORY_LIMIT
+ return DemandExecutableAllocator::bytesAllocatedByAllAllocators() > EXECUTABLE_MEMORY_LIMIT / 2;
+#else
+ return false;
+#endif
+}
+
+double ExecutableAllocator::memoryPressureMultiplier(size_t addedMemoryUsage)
+{
+ double result;
+#ifdef EXECUTABLE_MEMORY_LIMIT
+ size_t bytesAllocated = DemandExecutableAllocator::bytesAllocatedByAllAllocators() + addedMemoryUsage;
+ if (bytesAllocated >= EXECUTABLE_MEMORY_LIMIT)
+ bytesAllocated = EXECUTABLE_MEMORY_LIMIT;
+ result = static_cast<double>(EXECUTABLE_MEMORY_LIMIT) /
+ (EXECUTABLE_MEMORY_LIMIT - bytesAllocated);
+#else
+ UNUSED_PARAM(addedMemoryUsage);
+ result = 1.0;
+#endif
+ if (result < 1.0)
+ result = 1.0;
+ return result;
+
+}
+
+PassRefPtr<ExecutableMemoryHandle> ExecutableAllocator::allocate(VM&, size_t sizeInBytes, void* ownerUID, JITCompilationEffort effort)
+{
+ RefPtr<ExecutableMemoryHandle> result = allocator()->allocate(sizeInBytes, ownerUID);
+ RELEASE_ASSERT(result || effort != JITCompilationMustSucceed);
+ return result.release();
+}
+
+size_t ExecutableAllocator::committedByteCount()
+{
+ return DemandExecutableAllocator::bytesCommittedByAllocactors();
+}
+
+#if ENABLE(META_ALLOCATOR_PROFILE)
+void ExecutableAllocator::dumpProfile()
+{
+ DemandExecutableAllocator::dumpProfileFromAllAllocators();
+}
+#endif
+
+#endif // ENABLE(EXECUTABLE_ALLOCATOR_DEMAND)
+
+#if ENABLE(ASSEMBLER_WX_EXCLUSIVE)
+
+#if OS(WINDOWS)
+#error "ASSEMBLER_WX_EXCLUSIVE not yet suported on this platform."
+#endif
+
+void ExecutableAllocator::reprotectRegion(void* start, size_t size, ProtectionSetting setting)
+{
+ size_t pageSize = WTF::pageSize();
+
+ // Calculate the start of the page containing this region,
+ // and account for this extra memory within size.
+ intptr_t startPtr = reinterpret_cast<intptr_t>(start);
+ intptr_t pageStartPtr = startPtr & ~(pageSize - 1);
+ void* pageStart = reinterpret_cast<void*>(pageStartPtr);
+ size += (startPtr - pageStartPtr);
+
+ // Round size up
+ size += (pageSize - 1);
+ size &= ~(pageSize - 1);
+
+ mprotect(pageStart, size, (setting == Writable) ? PROTECTION_FLAGS_RW : PROTECTION_FLAGS_RX);
+}
+
+#endif
}
projects / apple / javascriptcore.git / blobdiff