Skip to content

Navigation Menu

Sign in
Appearance settings

Search code, repositories, users, issues, pull requests...

Provide feedback

We read every piece of feedback, and take your input very seriously.

Saved searches

Use saved searches to filter your results more quickly
Appearance settings

Commit 44f64f1

Browse filesBrowse files
joyeecheungRafaelGSS
joyeecheung
authored and
RafaelGSS
committed
deps: V8: backport bef0d9c1bc90
Original commit message: [api] Add V8::GetWasmMemoryReservationSizeInBytes() When the system does not have enough virtual memory for the wasm cage, installing the trap handler would cause any code allocating wasm memory to throw. Therefore it's useful for the embedder to know when the system doesn't have enough virtual address space to allocate enough wasm cages and in that case, skip the trap handler installation so that wasm code can at least work (even not at the maximal performance). Node.js previously has a command line option --disable-wasm-trap-handler to fully disable trap-based bound checks, this new API would allow it to adapt automatically while keeping the optimization in the happy path, since it's not always possible for end users to opt-into disabling trap-based bound checks (for example, when a VS Code Server is loaded in a remote server for debugging). Refs: #62132 Refs: microsoft/vscode#251777 Change-Id: I345c076af2b2b47700e5716b49c3133fdf8a0981 Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/7638233 Reviewed-by: Jakob Kummerow <jkummerow@chromium.org> Reviewed-by: Michael Lippautz <mlippautz@chromium.org> Commit-Queue: Joyee Cheung <joyee@igalia.com> Reviewed-by: Clemens Backes <clemensb@chromium.org> Cr-Commit-Position: refs/heads/main@{#105702} Refs: v8/v8@bef0d9c Co-authored-by: Joyee Cheung <joyeec9h3@gmail.com> Refs: microsoft/vscode#251777 Refs: https://chromium-review.googlesource.com/c/v8/v8/+/7638233 PR-URL: #61898 Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com> Reviewed-By: Filip Skokan <panva.ip@gmail.com> Reviewed-By: Rafael Gonzaga <rafael.nunu@hotmail.com> Reviewed-By: Chengzhong Wu <legendecas@gmail.com> (cherry picked from commit 13fb819)
1 parent 1f8f288 commit 44f64f1
Copy full SHA for 44f64f1

6 files changed

+94-21Lines changed: 94 additions & 21 deletions

File tree

Expand file treeCollapse file tree
Open diff view settings
Filter options
Expand file treeCollapse file tree
Open diff view settings
Collapse file

‎common.gypi‎

Copy file name to clipboardExpand all lines: common.gypi
+1-1Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -38,7 +38,7 @@
3838

3939
# Reset this number to 0 on major V8 upgrades.
4040
# Increment by one for each non-official patch applied to deps/v8.
41-
'v8_embedder_string': '-node.12',
41+
'v8_embedder_string': '-node.13',
4242

4343
##### V8 defaults for Node.js #####
4444

Collapse file

‎deps/v8/include/v8-initialization.h‎

Copy file name to clipboardExpand all lines: deps/v8/include/v8-initialization.h
+29Lines changed: 29 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -253,6 +253,35 @@ class V8_EXPORT V8 {
253253
static size_t GetSandboxReservationSizeInBytes();
254254
#endif // V8_ENABLE_SANDBOX
255255

256+
enum class WasmMemoryType {
257+
kMemory32,
258+
kMemory64,
259+
};
260+
261+
/**
262+
* Returns the virtual address space reservation size (in bytes) needed
263+
* for one WebAssembly memory instance of the given capacity.
264+
*
265+
* \param type Whether this is a memory32 or memory64 instance.
266+
* \param byte_capacity The maximum size, in bytes, of the WebAssembly
267+
* memory. Values exceeding the engine's maximum allocatable memory
268+
* size for the given type (determined by max_mem32_pages or
269+
* max_mem64_pages) are clamped.
270+
*
271+
* When trap-based bounds checking is enabled by
272+
* EnableWebAssemblyTrapHandler(), the amount of virtual address space
273+
* that V8 needs to reserve for each WebAssembly memory instance can
274+
* be much bigger than the requested size. If the process does
275+
* not have enough virtual memory available, WebAssembly memory allocation
276+
* would fail. During the initialization of V8, embedders can use this method
277+
* to estimate whether the process has enough virtual memory for their
278+
* usage of WebAssembly, and decide whether to enable the trap handler
279+
* via EnableWebAssemblyTrapHandler(), or to skip it and reduce the amount of
280+
* virtual memory required to keep the application running.
281+
*/
282+
static size_t GetWasmMemoryReservationSizeInBytes(WasmMemoryType type,
283+
size_t byte_capacity);
284+
256285
/**
257286
* Activate trap-based bounds checking for WebAssembly.
258287
*
Collapse file

‎deps/v8/src/api/api.cc‎

Copy file name to clipboardExpand all lines: deps/v8/src/api/api.cc
+21Lines changed: 21 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -152,6 +152,7 @@
152152
#include "src/wasm/value-type.h"
153153
#include "src/wasm/wasm-engine.h"
154154
#include "src/wasm/wasm-js.h"
155+
#include "src/wasm/wasm-limits.h"
155156
#include "src/wasm/wasm-objects-inl.h"
156157
#include "src/wasm/wasm-result.h"
157158
#include "src/wasm/wasm-serialization.h"
@@ -6358,6 +6359,26 @@ bool TryHandleWebAssemblyTrapWindows(EXCEPTION_POINTERS* exception) {
63586359
}
63596360
#endif
63606361

6362+
size_t V8::GetWasmMemoryReservationSizeInBytes(WasmMemoryType type,
6363+
size_t byte_capacity) {
6364+
#if V8_ENABLE_WEBASSEMBLY
6365+
bool is_memory64 = type == WasmMemoryType::kMemory64;
6366+
uint64_t max_byte_capacity =
6367+
is_memory64 ? i::wasm::max_mem64_bytes() : i::wasm::max_mem32_bytes();
6368+
if (byte_capacity > max_byte_capacity) {
6369+
byte_capacity = static_cast<size_t>(max_byte_capacity);
6370+
}
6371+
#if V8_TRAP_HANDLER_SUPPORTED
6372+
if (!is_memory64 || i::v8_flags.wasm_memory64_trap_handling) {
6373+
return i::BackingStore::GetWasmReservationSize(
6374+
/* has_guard_regions */ true, byte_capacity,
6375+
/* is_wasm_memory64 */ is_memory64);
6376+
}
6377+
#endif // V8_TRAP_HANDLER_SUPPORTED
6378+
#endif // V8_ENABLE_WEBASSEMBLY
6379+
return byte_capacity;
6380+
}
6381+
63616382
bool V8::EnableWebAssemblyTrapHandler(bool use_v8_signal_handler) {
63626383
#if V8_ENABLE_WEBASSEMBLY
63636384
return i::trap_handler::EnableTrapHandler(use_v8_signal_handler);
Collapse file

‎deps/v8/src/objects/backing-store.cc‎

Copy file name to clipboardExpand all lines: deps/v8/src/objects/backing-store.cc
+22-20Lines changed: 22 additions & 20 deletions
Original file line numberDiff line numberDiff line change
@@ -51,8 +51,25 @@ enum class AllocationStatus {
5151
kOtherFailure // Failed for an unknown reason
5252
};
5353

54-
size_t GetReservationSize(bool has_guard_regions, size_t byte_capacity,
55-
bool is_wasm_memory64) {
54+
base::AddressRegion GetReservedRegion(bool has_guard_regions,
55+
bool is_wasm_memory64, void* buffer_start,
56+
size_t byte_capacity) {
57+
return base::AddressRegion(
58+
reinterpret_cast<Address>(buffer_start),
59+
BackingStore::GetWasmReservationSize(has_guard_regions, byte_capacity,
60+
is_wasm_memory64));
61+
}
62+
63+
void RecordStatus(Isolate* isolate, AllocationStatus status) {
64+
isolate->counters()->wasm_memory_allocation_result()->AddSample(
65+
static_cast<int>(status));
66+
}
67+
68+
} // namespace
69+
70+
size_t BackingStore::GetWasmReservationSize(bool has_guard_regions,
71+
size_t byte_capacity,
72+
bool is_wasm_memory64) {
5673
#if V8_TARGET_ARCH_64_BIT && V8_ENABLE_WEBASSEMBLY
5774
DCHECK_IMPLIES(is_wasm_memory64 && has_guard_regions,
5875
v8_flags.wasm_memory64_trap_handling);
@@ -73,21 +90,6 @@ size_t GetReservationSize(bool has_guard_regions, size_t byte_capacity,
7390
return byte_capacity;
7491
}
7592

76-
base::AddressRegion GetReservedRegion(bool has_guard_regions,
77-
bool is_wasm_memory64, void* buffer_start,
78-
size_t byte_capacity) {
79-
return base::AddressRegion(
80-
reinterpret_cast<Address>(buffer_start),
81-
GetReservationSize(has_guard_regions, byte_capacity, is_wasm_memory64));
82-
}
83-
84-
void RecordStatus(Isolate* isolate, AllocationStatus status) {
85-
isolate->counters()->wasm_memory_allocation_result()->AddSample(
86-
static_cast<int>(status));
87-
}
88-
89-
} // namespace
90-
9193
// The backing store for a Wasm shared memory remembers all the isolates
9294
// with which it has been shared.
9395
struct SharedWasmMemoryData {
@@ -169,7 +171,7 @@ BackingStore::~BackingStore() {
169171

170172
#if V8_ENABLE_WEBASSEMBLY
171173
if (is_wasm_memory()) {
172-
size_t reservation_size = GetReservationSize(
174+
size_t reservation_size = GetWasmReservationSize(
173175
has_guard_regions(), byte_capacity_, is_wasm_memory64());
174176
TRACE_BS(
175177
"BSw:free bs=%p mem=%p (length=%zu, capacity=%zu, reservation=%zu)\n",
@@ -319,8 +321,8 @@ std::unique_ptr<BackingStore> BackingStore::TryAllocateAndPartiallyCommitMemory(
319321
};
320322

321323
size_t byte_capacity = maximum_pages * page_size;
322-
size_t reservation_size =
323-
GetReservationSize(has_guard_regions, byte_capacity, is_wasm_memory64);
324+
size_t reservation_size = GetWasmReservationSize(
325+
has_guard_regions, byte_capacity, is_wasm_memory64);
324326

325327
//--------------------------------------------------------------------------
326328
// Allocate pages (inaccessible by default).
Collapse file

‎deps/v8/src/objects/backing-store.h‎

Copy file name to clipboardExpand all lines: deps/v8/src/objects/backing-store.h
+5Lines changed: 5 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -202,6 +202,11 @@ class V8_EXPORT_PRIVATE BackingStore : public BackingStoreBase {
202202

203203
uint32_t id() const { return id_; }
204204

205+
// Return the size of the reservation needed for a wasm backing store.
206+
static size_t GetWasmReservationSize(bool has_guard_regions,
207+
size_t byte_capacity,
208+
bool is_wasm_memory64);
209+
205210
private:
206211
friend class GlobalBackingStoreRegistry;
207212

Collapse file

‎deps/v8/test/unittests/api/api-wasm-unittest.cc‎

Copy file name to clipboardExpand all lines: deps/v8/test/unittests/api/api-wasm-unittest.cc
+16Lines changed: 16 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -124,6 +124,22 @@ void WasmStreamingMoreFunctionsCanBeSerializedCallback(
124124
streaming->SetMoreFunctionsCanBeSerializedCallback([](CompiledWasmModule) {});
125125
}
126126

127+
TEST_F(ApiWasmTest, GetWasmMemoryReservationSizeInBytes) {
128+
constexpr size_t kCapacity = 64 * 1024; // 64 KiB
129+
size_t reservation = V8::GetWasmMemoryReservationSizeInBytes(
130+
V8::WasmMemoryType::kMemory32, kCapacity);
131+
size_t reservation64 = V8::GetWasmMemoryReservationSizeInBytes(
132+
V8::WasmMemoryType::kMemory64, kCapacity);
133+
134+
#if V8_TRAP_HANDLER_SUPPORTED
135+
EXPECT_GE(reservation, kCapacity);
136+
EXPECT_GE(reservation64, kCapacity);
137+
#else
138+
EXPECT_EQ(reservation, kCapacity);
139+
EXPECT_EQ(reservation64, kCapacity);
140+
#endif // V8_TRAP_HANDLER_SUPPORTED
141+
}
142+
127143
TEST_F(ApiWasmTest, WasmStreamingCallback) {
128144
TestWasmStreaming(WasmStreamingCallbackTestCallbackIsCalled,
129145
Promise::kPending);

0 commit comments

Comments
0 (0)
Morty Proxy This is a proxified and sanitized view of the page, visit original site.