1 | /* |
2 | * Copyright (C) 2010 Apple Inc. All rights reserved. |
3 | * |
4 | * Redistribution and use in source and binary forms, with or without |
5 | * modification, are permitted provided that the following conditions |
6 | * are met: |
7 | * 1. Redistributions of source code must retain the above copyright |
8 | * notice, this list of conditions and the following disclaimer. |
9 | * 2. Redistributions in binary form must reproduce the above copyright |
10 | * notice, this list of conditions and the following disclaimer in the |
11 | * documentation and/or other materials provided with the distribution. |
12 | * |
13 | * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' |
14 | * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, |
15 | * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
16 | * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS |
17 | * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
18 | * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
19 | * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
20 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
21 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
22 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF |
23 | * THE POSSIBILITY OF SUCH DAMAGE. |
24 | */ |
25 | |
26 | #include "config.h" |
27 | #include "PageAllocationAligned.h" |
28 | |
29 | namespace WTF { |
30 | |
31 | PageAllocationAligned PageAllocationAligned::allocate(size_t size, size_t alignment, OSAllocator::Usage usage, bool writable) |
32 | { |
33 | ASSERT(isPageAligned(size)); |
34 | ASSERT(isPageAligned(alignment)); |
35 | ASSERT(isPowerOfTwo(alignment)); |
36 | ASSERT(size >= alignment); |
37 | size_t alignmentMask = alignment - 1; |
38 | |
39 | #if OS(DARWIN) |
40 | int flags = VM_FLAGS_ANYWHERE; |
41 | if (usage != OSAllocator::UnknownUsage) |
42 | flags |= usage; |
43 | int protection = PROT_READ; |
44 | if (writable) |
45 | protection |= PROT_WRITE; |
46 | |
47 | vm_address_t address = 0; |
48 | vm_map(current_task(), &address, size, alignmentMask, flags, MEMORY_OBJECT_NULL, 0, FALSE, protection, PROT_READ | PROT_WRITE, VM_INHERIT_DEFAULT); |
49 | return PageAllocationAligned(reinterpret_cast<void*>(address), size); |
50 | #else |
51 | size_t alignmentDelta = alignment - pageSize(); |
52 | |
53 | // Resererve with suffcient additional VM to correctly align. |
54 | size_t reservationSize = size + alignmentDelta; |
55 | void* reservationBase = OSAllocator::reserveUncommitted(reservationSize, usage, writable); |
56 | |
57 | // Select an aligned region within the reservation and commit. |
58 | void* alignedBase = reinterpret_cast<uintptr_t>(reservationBase) & alignmentMask |
59 | ? reinterpret_cast<void*>((reinterpret_cast<uintptr_t>(reservationBase) & ~alignmentMask) + alignment) |
60 | : reservationBase; |
61 | OSAllocator::commit(alignedBase, size, writable, executable: false); |
62 | |
63 | return PageAllocationAligned(alignedBase, size, reservationBase, reservationSize); |
64 | #endif |
65 | } |
66 | |
67 | void PageAllocationAligned::deallocate() |
68 | { |
69 | // Clear base & size before calling release; if this is *inside* allocation |
70 | // then we won't be able to clear then after deallocating the memory. |
71 | PageAllocationAligned tmp; |
72 | std::swap(a&: tmp, b&: *this); |
73 | |
74 | ASSERT(tmp); |
75 | ASSERT(!*this); |
76 | |
77 | #if OS(DARWIN) |
78 | vm_deallocate(current_task(), reinterpret_cast<vm_address_t>(tmp.realBase()), tmp.realSize()); |
79 | #else |
80 | ASSERT(tmp.m_reservation.contains(tmp.realBase(), tmp.realSize())); |
81 | OSAllocator::decommitAndRelease(releaseBase: tmp.m_reservation.realBase(), releaseSize: tmp.m_reservation.realSize(), |
82 | decommitBase: tmp.realBase(), decommitSize: tmp.realSize()); |
83 | #endif |
84 | } |
85 | |
86 | } // namespace WTF |
87 | |