1 // Copyright 2020 the V8 project authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4
5 #include "v8config.h" // NOLINT(build/include_directory)
6
7 #if !defined(CPPGC_CAGED_HEAP)
8 #error "Must be compiled with caged heap enabled"
9 #endif
10
11 #include "src/heap/cppgc/caged-heap.h"
12
13 #include "include/cppgc/internal/caged-heap-local-data.h"
14 #include "include/cppgc/platform.h"
15 #include "src/base/bounded-page-allocator.h"
16 #include "src/base/logging.h"
17 #include "src/base/platform/platform.h"
18 #include "src/heap/cppgc/globals.h"
19
20 namespace cppgc {
21 namespace internal {
22
23 STATIC_ASSERT(api_constants::kCagedHeapReservationSize ==
24 kCagedHeapReservationSize);
25 STATIC_ASSERT(api_constants::kCagedHeapReservationAlignment ==
26 kCagedHeapReservationAlignment);
27
28 namespace {
29
ReserveCagedHeap(PageAllocator & platform_allocator)30 VirtualMemory ReserveCagedHeap(PageAllocator& platform_allocator) {
31 DCHECK_EQ(0u,
32 kCagedHeapReservationSize % platform_allocator.AllocatePageSize());
33
34 static constexpr size_t kAllocationTries = 4;
35 for (size_t i = 0; i < kAllocationTries; ++i) {
36 void* hint = reinterpret_cast<void*>(RoundDown(
37 reinterpret_cast<uintptr_t>(platform_allocator.GetRandomMmapAddr()),
38 kCagedHeapReservationAlignment));
39
40 VirtualMemory memory(&platform_allocator, kCagedHeapReservationSize,
41 kCagedHeapReservationAlignment, hint);
42 if (memory.IsReserved()) return memory;
43 }
44
45 FATAL("Fatal process out of memory: Failed to reserve memory for caged heap");
46 UNREACHABLE();
47 }
48
49 } // namespace
50
CagedHeap(HeapBase & heap_base,PageAllocator & platform_allocator)51 CagedHeap::CagedHeap(HeapBase& heap_base, PageAllocator& platform_allocator)
52 : reserved_area_(ReserveCagedHeap(platform_allocator)) {
53 using CagedAddress = CagedHeap::AllocatorType::Address;
54
55 const bool is_not_oom = platform_allocator.SetPermissions(
56 reserved_area_.address(),
57 RoundUp(sizeof(CagedHeapLocalData), platform_allocator.CommitPageSize()),
58 PageAllocator::kReadWrite);
59 // Failing to commit the reservation means that we are out of memory.
60 CHECK(is_not_oom);
61
62 new (reserved_area_.address())
63 CagedHeapLocalData(heap_base, platform_allocator);
64
65 const CagedAddress caged_heap_start =
66 RoundUp(reinterpret_cast<CagedAddress>(reserved_area_.address()) +
67 sizeof(CagedHeapLocalData),
68 kPageSize);
69 const size_t local_data_size_with_padding =
70 caged_heap_start -
71 reinterpret_cast<CagedAddress>(reserved_area_.address());
72
73 bounded_allocator_ = std::make_unique<v8::base::BoundedPageAllocator>(
74 &platform_allocator, caged_heap_start,
75 reserved_area_.size() - local_data_size_with_padding, kPageSize,
76 v8::base::PageInitializationMode::kAllocatedPagesMustBeZeroInitialized);
77 }
78
79 } // namespace internal
80 } // namespace cppgc
81