Vyacheslav Egorov
9ff0a654ca
This reverts commit6da340bf76. Reason for revert: almost all benchmarks are now failing on Golem linux-x64 target. Flutter Golem build is broken Original change's description: > Reland "[VM runtime] Dual mapping of executable pages." > > This is a reland of44186dfdcd> > Original change's description: > > [VM runtime] Dual mapping of executable pages. > > > > Change-Id: Iaad78d324e25462ce951f4df26974a6a368c50b7 > > Reviewed-on: https://dart-review.googlesource.com/c/93377 > > Commit-Queue: Régis Crelier <regis@google.com> > > Reviewed-by: Ryan Macnak <rmacnak@google.com> > > Change-Id: I7a0caa078950637d9fe831732577fd2467061099 > Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/95263 > Reviewed-by: Ryan Macnak <rmacnak@google.com> TBR=rmacnak@google.com,regis@google.com Change-Id: I3342de2584537269ffe9a53946bef27cb25a69fc No-Presubmit: true No-Tree-Checks: true No-Try: true Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/96161 Reviewed-by: Vyacheslav Egorov <vegorov@google.com> Commit-Queue: Vyacheslav Egorov <vegorov@google.com>
96 lines
3.1 KiB
C++
96 lines
3.1 KiB
C++
// Copyright (c) 2012, the Dart project authors. Please see the AUTHORS file
|
|
// for details. All rights reserved. Use of this source code is governed by a
|
|
// BSD-style license that can be found in the LICENSE file.
|
|
|
|
#ifndef RUNTIME_VM_VIRTUAL_MEMORY_H_
|
|
#define RUNTIME_VM_VIRTUAL_MEMORY_H_
|
|
|
|
#include "platform/utils.h"
|
|
#include "vm/globals.h"
|
|
#include "vm/memory_region.h"
|
|
|
|
namespace dart {
|
|
|
|
class VirtualMemory {
|
|
public:
|
|
enum Protection {
|
|
kNoAccess,
|
|
kReadOnly,
|
|
kReadWrite,
|
|
kReadExecute,
|
|
kReadWriteExecute
|
|
};
|
|
|
|
// The reserved memory is unmapped on destruction.
|
|
~VirtualMemory();
|
|
|
|
uword start() const { return region_.start(); }
|
|
uword end() const { return region_.end(); }
|
|
void* address() const { return region_.pointer(); }
|
|
intptr_t size() const { return region_.size(); }
|
|
|
|
static void Init();
|
|
|
|
bool Contains(uword addr) const { return region_.Contains(addr); }
|
|
|
|
// Changes the protection of the virtual memory area.
|
|
static void Protect(void* address, intptr_t size, Protection mode);
|
|
void Protect(Protection mode) { return Protect(address(), size(), mode); }
|
|
|
|
// Reserves and commits a virtual memory segment with size. If a segment of
|
|
// the requested size cannot be allocated, NULL is returned.
|
|
static VirtualMemory* Allocate(intptr_t size,
|
|
bool is_executable,
|
|
const char* name) {
|
|
return AllocateAligned(size, PageSize(), is_executable, name);
|
|
}
|
|
static VirtualMemory* AllocateAligned(intptr_t size,
|
|
intptr_t alignment,
|
|
bool is_executable,
|
|
const char* name);
|
|
|
|
static intptr_t PageSize() {
|
|
ASSERT(page_size_ != 0);
|
|
ASSERT(Utils::IsPowerOfTwo(page_size_));
|
|
return page_size_;
|
|
}
|
|
|
|
static bool InSamePage(uword address0, uword address1);
|
|
|
|
// Truncate this virtual memory segment.
|
|
void Truncate(intptr_t new_size);
|
|
|
|
// False for a part of a snapshot added directly to the Dart heap, which
|
|
// belongs to the embedder and must not be deallocated or have its
|
|
// protection status changed by the VM.
|
|
bool vm_owns_region() const { return reserved_.pointer() != NULL; }
|
|
|
|
static VirtualMemory* ForImagePage(void* pointer, uword size);
|
|
|
|
private:
|
|
// Free a sub segment. On operating systems that support it this
|
|
// can give back the virtual memory to the system. Returns true on success.
|
|
static void FreeSubSegment(void* address, intptr_t size);
|
|
|
|
// This constructor is only used internally when reserving new virtual spaces.
|
|
// It does not reserve any virtual address space on its own.
|
|
VirtualMemory(const MemoryRegion& region,
|
|
const MemoryRegion& reserved)
|
|
: region_(region), reserved_(reserved) {}
|
|
|
|
MemoryRegion region_;
|
|
|
|
// The underlying reservation not yet given back to the OS.
|
|
// Its address might disagree with region_ due to aligned allocations.
|
|
// Its size might disagree with region_ due to Truncate.
|
|
MemoryRegion reserved_;
|
|
|
|
static uword page_size_;
|
|
|
|
DISALLOW_IMPLICIT_CONSTRUCTORS(VirtualMemory);
|
|
};
|
|
|
|
} // namespace dart
|
|
|
|
#endif // RUNTIME_VM_VIRTUAL_MEMORY_H_
|