Matthew Dempsky
9308cac681
Callers always want to try to unmap the trailing pages, and the OS-specific FreeSubSegment helper routine can never fail. Simplify code accordingly. Change-Id: I32e4bc72f626e15032d73326bee76a4a2ef71025 Reviewed-on: https://dart-review.googlesource.com/c/91146 Auto-Submit: Matthew Dempsky <mdempsky@google.com> Reviewed-by: Zach Anderson <zra@google.com> Reviewed-by: Ryan Macnak <rmacnak@google.com> Commit-Queue: Ryan Macnak <rmacnak@google.com>
40 lines
1.4 KiB
C++
40 lines
1.4 KiB
C++
// Copyright (c) 2012, the Dart project authors. Please see the AUTHORS file
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// for details. All rights reserved. Use of this source code is governed by a
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// BSD-style license that can be found in the LICENSE file.
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#include "vm/virtual_memory.h"
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#include "platform/assert.h"
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#include "platform/utils.h"
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namespace dart {
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bool VirtualMemory::InSamePage(uword address0, uword address1) {
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return (Utils::RoundDown(address0, PageSize()) ==
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Utils::RoundDown(address1, PageSize()));
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}
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void VirtualMemory::Truncate(intptr_t new_size) {
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ASSERT(Utils::IsAligned(new_size, PageSize()));
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ASSERT(new_size <= size());
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if (reserved_.size() == region_.size()) { // Don't create holes in reservation.
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FreeSubSegment(reinterpret_cast<void*>(start() + new_size),
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size() - new_size);
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reserved_.set_size(new_size);
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}
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region_.Subregion(region_, 0, new_size);
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}
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VirtualMemory* VirtualMemory::ForImagePage(void* pointer, uword size) {
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// Memory for precompilated instructions was allocated by the embedder, so
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// create a VirtualMemory without allocating.
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MemoryRegion region(pointer, size);
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MemoryRegion reserved(0, 0); // NULL reservation indicates VM should not
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// attempt to free this memory.
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VirtualMemory* memory = new VirtualMemory(region, reserved);
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ASSERT(!memory->vm_owns_region());
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return memory;
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}
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} // namespace dart
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