languages/dart-sdk
languages/dart-sdk
1
0
Fork 0
mirror of https://github.com/dart-lang/sdk synced 2024-10-02 23:59:16 +00:00
Code Issues Packages Projects Releases Wiki Activity

Update to the latest package:ffi

Browse source 
Remove SDK copies of `arena.dart` which is now in `package:ffi`.

Change-Id: Ic4808c473043be7d34cd1334406897a935c19263
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/204020
Auto-Submit: Nate Bosch <nbosch@google.com>
Commit-Queue: Daco Harkes <dacoharkes@google.com>
Reviewed-by: Daco Harkes <dacoharkes@google.com>
This commit is contained in:
Nate Bosch 2021-06-18 07:24:51 +00:00 committed by commit-bot@chromium.org
parent b3b2abb9eb
commit 8b2cacf9ca
13 changed files with 7 additions and 911 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

2
DEPS
View file

@ -109,7 +109,7 @@ vars = {
"dartdoc_rev" : "b733d4952dbd25374d55e28476a5f44bd60ed63f",
"devtools_rev" : "b3bf672474a2bff82f33e1176aa803539baa0d60+1",
"jsshell_tag": "version:88.0",
"ffi_rev": "f3346299c55669cc0db48afae85b8110088bf8da",
"ffi_rev": "4dd32429880a57b64edaf54c9d5af8a9fa9a4ffb",
"fixnum_rev": "16d3890c6dc82ca629659da1934e412292508bba",
"file_rev": "0e09370f581ab6388d46fda4cdab66638c0171a1",
"glob_rev": "a62acf590598f458d3198d9f2930c1c9dd4b1379",

182
samples/ffi/resource_management/arena.dart
View file

@ -1,182 +0,0 @@
// Copyright (c) 2019, 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.
//
// Explicit arena used for managing resources.
import 'dart:async';
import 'dart:ffi';
import 'package:ffi/ffi.dart';
/// An [Allocator] which frees all allocations at the same time.
///
/// The arena allows you to allocate heap memory, but ignores calls to [free].
/// Instead you call [releaseAll] to release all the allocations at the same
/// time.
///
/// Also allows other resources to be associated with the arena, through the
/// [using] method, to have a release function called for them when the arena is
/// released.
///
/// An [Allocator] can be provided to do the actual allocation and freeing.
/// Defaults to using [calloc].
class Arena implements Allocator {
/// The [Allocator] used for allocation and freeing.
final Allocator _wrappedAllocator;
/// Native memory under management by this [Arena].
final List<Pointer<NativeType>> _managedMemoryPointers = [];
/// Callbacks for releasing native resources under management by this [Arena].
final List<void Function()> _managedResourceReleaseCallbacks = [];
bool _inUse = true;
/// Creates a arena of allocations.
///
/// The [allocator] is used to do the actual allocation and freeing of
/// memory. It defaults to using [calloc].
Arena([Allocator allocator = calloc]) : _wrappedAllocator = allocator;
/// Allocates memory and includes it in the arena.
///
/// Uses the allocator provided to the [Arena] constructor to do the
/// allocation.
///
/// Throws an [ArgumentError] if the number of bytes or alignment cannot be
/// satisfied.
@override
Pointer<T> allocate<T extends NativeType>(int byteCount, {int? alignment}) {
_ensureInUse();
final p = _wrappedAllocator.allocate<T>(byteCount, alignment: alignment);
_managedMemoryPointers.add(p);
return p;
}
/// Registers [resource] in this arena.
///
/// Executes [releaseCallback] on [releaseAll].
///
/// Returns [resource] again, to allow for easily inserting
/// `arena.using(resource, ...)` where the resource is allocated.
T using<T>(T resource, void Function(T) releaseCallback) {
_ensureInUse();
releaseCallback = Zone.current.bindUnaryCallback(releaseCallback);
_managedResourceReleaseCallbacks.add(() => releaseCallback(resource));
return resource;
}
/// Registers [releaseResourceCallback] to be executed on [releaseAll].
void onReleaseAll(void Function() releaseResourceCallback) {
_managedResourceReleaseCallbacks.add(releaseResourceCallback);
}
/// Releases all resources that this [Arena] manages.
///
/// If [reuse] is `true`, the arena can be used again after resources
/// have been released. If not, the default, then the [allocate]
/// and [using] methods must not be called after a call to `releaseAll`.
///
/// If any of the callbacks throw, [releaseAll] is interrupted, and should
/// be started again.
void releaseAll({bool reuse = false}) {
if (!reuse) {
_inUse = false;
}
// The code below is deliberately wirtten to allow allocations to happen
// during `releaseAll(reuse:true)`. The arena will still be guaranteed
// empty when the `releaseAll` call returns.
while (_managedResourceReleaseCallbacks.isNotEmpty) {
_managedResourceReleaseCallbacks.removeLast()();
}
for (final p in _managedMemoryPointers) {
_wrappedAllocator.free(p);
}
_managedMemoryPointers.clear();
}
/// Does nothing, invoke [releaseAll] instead.
@override
void free(Pointer<NativeType> pointer) {}
void _ensureInUse() {
if (!_inUse) {
throw StateError(
'Arena no longer in use, `releaseAll(reuse: false)` was called.');
}
}
}
/// Runs [computation] with a new [Arena], and releases all allocations at the
/// end.
///
/// If the return value of [computation] is a [Future], all allocations are
/// released when the future completes.
///
/// If the isolate is shut down, through `Isolate.kill()`, resources are _not_
/// cleaned up.
R using<R>(R Function(Arena) computation,
[Allocator wrappedAllocator = calloc]) {
final arena = Arena(wrappedAllocator);
bool isAsync = false;
try {
final result = computation(arena);
if (result is Future) {
isAsync = true;
return (result.whenComplete(arena.releaseAll) as R);
}
return result;
} finally {
if (!isAsync) {
arena.releaseAll();
}
}
}
/// Creates a zoned [Arena] to manage native resources.
///
/// The arena is availabe through [zoneArena].
///
/// If the isolate is shut down, through `Isolate.kill()`, resources are _not_ cleaned up.
R withZoneArena<R>(R Function() computation,
[Allocator wrappedAllocator = calloc]) {
final arena = Arena(wrappedAllocator);
var arenaHolder = [arena];
bool isAsync = false;
try {
return runZoned(() {
final result = computation();
if (result is Future) {
isAsync = true;
result.whenComplete(arena.releaseAll);
}
return result;
}, zoneValues: {#_arena: arenaHolder});
} finally {
if (!isAsync) {
arena.releaseAll();
arenaHolder.clear();
}
}
}
/// A zone-specific [Arena].
///
/// Asynchronous computations can share a [Arena]. Use [withZoneArena] to create
/// a new zone with a fresh [Arena], and that arena will then be released
/// automatically when the function passed to [withZoneArena] completes.
/// All code inside that zone can use `zoneArena` to access the arena.
///
/// The current arena must not be accessed by code which is not running inside
/// a zone created by [withZoneArena].
Arena get zoneArena {
final List<Arena>? arenaHolder = Zone.current[#_arena];
if (arenaHolder == null) {
throw StateError('Not inside a zone created by `useArena`');
}
if (arenaHolder.isNotEmpty) {
return arenaHolder.single;
}
throw StateError('Arena has already been cleared with releaseAll.');
}

2
samples/ffi/resource_management/arena_isolate_shutdown_sample.dart
View file

@ -9,8 +9,8 @@ import "dart:isolate";
import 'dart:ffi';
import 'package:expect/expect.dart';
import 'package:ffi/ffi.dart';
import 'arena.dart';
import '../dylib_utils.dart';
void main() {

2
samples/ffi/resource_management/arena_sample.dart
View file

@ -8,8 +8,8 @@ import 'dart:async';
import 'dart:ffi';
import 'package:expect/expect.dart';
import 'package:ffi/ffi.dart';
import 'arena.dart';
import 'utf8_helpers.dart';
import '../dylib_utils.dart';

208
samples/ffi/resource_management/arena_test.dart
View file

@ -1,208 +0,0 @@
// Copyright (c) 2021, 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.
import 'dart:async';
import 'dart:ffi';
import 'package:ffi/ffi.dart';
import 'package:test/test.dart';
// TODO(dacoharkes): After merging into `package:ffi`, roll package in DEPS
// and remove arena.dart.
import 'arena.dart';
void main() async {
test('sync', () async {
List<int> freed = [];
void freeInt(int i) {
freed.add(i);
}
using((Arena arena) {
arena.using(1234, freeInt);
expect(freed.isEmpty, true);
});
expect(freed, [1234]);
});
test('async', () async {
/// Calling [using] waits with releasing its resources until after
/// [Future]s complete.
List<int> freed = [];
void freeInt(int i) {
freed.add(i);
}
Future<int> myFutureInt = using((Arena arena) {
return Future.microtask(() {
arena.using(1234, freeInt);
return 1;
});
});
expect(freed.isEmpty, true);
await myFutureInt;
expect(freed, [1234]);
});
test('throw', () {
/// [using] waits with releasing its resources until after [Future]s
/// complete.
List<int> freed = [];
void freeInt(int i) {
freed.add(i);
}
// Resources are freed also when abnormal control flow occurs.
var didThrow = false;
try {
using((Arena arena) {
arena.using(1234, freeInt);
expect(freed.isEmpty, true);
throw Exception('Exception 1');
});
} on Exception {
expect(freed.single, 1234);
didThrow = true;
}
expect(didThrow, true);
});
test(
'allocate',
() {
final countingAllocator = CountingAllocator();
// To ensure resources are freed, wrap them in a [using] call.
using((Arena arena) {
final p = arena<Int64>(2);
p[1] = p[0];
}, countingAllocator);
expect(countingAllocator.freeCount, 1);
},
);
test('allocate throw', () {
// Resources are freed also when abnormal control flow occurs.
bool didThrow = false;
final countingAllocator = CountingAllocator();
try {
using((Arena arena) {
final p = arena<Int64>(2);
p[0] = 25;
throw Exception('Exception 2');
}, countingAllocator);
} on Exception {
expect(countingAllocator.freeCount, 1);
didThrow = true;
}
expect(didThrow, true);
});
test('toNativeUtf8', () {
final countingAllocator = CountingAllocator();
using((Arena arena) {
final p = 'Hello world!'.toNativeUtf8(allocator: arena);
expect(p.toDartString(), 'Hello world!');
}, countingAllocator);
expect(countingAllocator.freeCount, 1);
});
test('zone', () async {
List<int> freed = [];
void freeInt(int i) {
freed.add(i);
}
withZoneArena(() {
zoneArena.using(1234, freeInt);
expect(freed.isEmpty, true);
});
expect(freed.length, 1);
expect(freed.single, 1234);
});
test('zone async', () async {
/// [using] waits with releasing its resources until after [Future]s
/// complete.
List<int> freed = [];
void freeInt(int i) {
freed.add(i);
}
Future<int> myFutureInt = withZoneArena(() {
return Future.microtask(() {
zoneArena.using(1234, freeInt);
return 1;
});
});
expect(freed.isEmpty, true);
await myFutureInt;
expect(freed.length, 1);
expect(freed.single, 1234);
});
test('zone throw', () {
/// [using] waits with releasing its resources until after [Future]s
/// complete.
List<int> freed = [];
void freeInt(int i) {
freed.add(i);
}
// Resources are freed also when abnormal control flow occurs.
bool didThrow = false;
try {
withZoneArena(() {
zoneArena.using(1234, freeInt);
expect(freed.isEmpty, true);
throw Exception('Exception 3');
});
} on Exception {
expect(freed.single, 1234);
didThrow = true;
}
expect(didThrow, true);
expect(freed.single, 1234);
});
test('allocate during releaseAll', () {
final countingAllocator = CountingAllocator();
final arena = Arena(countingAllocator);
arena.using(arena<Uint8>(), (Pointer discard) {
arena<Uint8>();
});
expect(countingAllocator.allocationCount, 1);
expect(countingAllocator.freeCount, 0);
arena.releaseAll(reuse: true);
expect(countingAllocator.allocationCount, 2);
expect(countingAllocator.freeCount, 2);
});
}
/// Keeps track of the number of allocates and frees for testing purposes.
class CountingAllocator implements Allocator {
final Allocator wrappedAllocator;
int allocationCount = 0;
int freeCount = 0;
CountingAllocator([this.wrappedAllocator = calloc]);
@override
Pointer<T> allocate<T extends NativeType>(int byteCount, {int? alignment}) {
allocationCount++;
return wrappedAllocator.allocate(byteCount, alignment: alignment);
}
@override
void free(Pointer<NativeType> pointer) {
freeCount++;
return wrappedAllocator.free(pointer);
}
}

2
samples/ffi/resource_management/arena_zoned_sample.dart
View file

@ -7,8 +7,8 @@
import 'dart:ffi';
import 'package:expect/expect.dart';
import 'package:ffi/ffi.dart';
import 'arena.dart';
import 'utf8_helpers.dart';
import '../dylib_utils.dart';

59
samples/ffi/sqlite/lib/src/ffi/arena.dart
View file

@ -1,59 +0,0 @@
// Copyright (c) 2019, 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.
import "dart:async";
import "dart:ffi";
import 'package:ffi/ffi.dart';
/// [Arena] manages allocated C memory.
///
/// Arenas are zoned.
class Arena {
Arena();
List<Pointer<Void>> _allocations = [];
/// Bound the lifetime of [ptr] to this [Arena].
T scoped<T extends Pointer>(T ptr) {
_allocations.add(ptr.cast());
return ptr;
}
/// Frees all memory pointed to by [Pointer]s in this arena.
void finalize() {
for (final ptr in _allocations) {
calloc.free(ptr);
}
}
/// The last [Arena] in the zone.
factory Arena.current() {
return Zone.current[#_currentArena];
}
}
/// Bound the lifetime of [ptr] to the current [Arena].
T scoped<T extends Pointer>(T ptr) => Arena.current().scoped(ptr);
class RethrownError {
dynamic original;
StackTrace originalStackTrace;
RethrownError(this.original, this.originalStackTrace);
toString() => """RethrownError(${original})
${originalStackTrace}""";
}
/// Runs the [body] in an [Arena] freeing all memory which is [scoped] during
/// execution of [body] at the end of the execution.
R runArena<R>(R Function(Arena) body) {
Arena arena = Arena();
try {
return runZoned(() => body(arena),
zoneValues: {#_currentArena: arena},
onError: (error, st) => throw RethrownError(error, st));
} finally {
arena.finalize();
}
}

184
samples_2/ffi/resource_management/arena.dart
View file

@ -1,184 +0,0 @@
// Copyright (c) 2019, 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.
//
// Explicit arena used for managing resources.
// @dart = 2.9
import 'dart:async';
import 'dart:ffi';
import 'package:ffi/ffi.dart';
/// An [Allocator] which frees all allocations at the same time.
///
/// The arena allows you to allocate heap memory, but ignores calls to [free].
/// Instead you call [releaseAll] to release all the allocations at the same
/// time.
///
/// Also allows other resources to be associated with the arena, through the
/// [using] method, to have a release function called for them when the arena is
/// released.
///
/// An [Allocator] can be provided to do the actual allocation and freeing.
/// Defaults to using [calloc].
class Arena implements Allocator {
/// The [Allocator] used for allocation and freeing.
final Allocator _wrappedAllocator;
/// Native memory under management by this [Arena].
final List<Pointer<NativeType>> _managedMemoryPointers = [];
/// Callbacks for releasing native resources under management by this [Arena].
final List<void Function()> _managedResourceReleaseCallbacks = [];
bool _inUse = true;
/// Creates a arena of allocations.
///
/// The [allocator] is used to do the actual allocation and freeing of
/// memory. It defaults to using [calloc].
Arena([Allocator allocator = calloc]) : _wrappedAllocator = allocator;
/// Allocates memory and includes it in the arena.
///
/// Uses the allocator provided to the [Arena] constructor to do the
/// allocation.
///
/// Throws an [ArgumentError] if the number of bytes or alignment cannot be
/// satisfied.
@override
Pointer<T> allocate<T extends NativeType>(int byteCount, {int alignment}) {
_ensureInUse();
final p = _wrappedAllocator.allocate<T>(byteCount, alignment: alignment);
_managedMemoryPointers.add(p);
return p;
}
/// Registers [resource] in this arena.
///
/// Executes [releaseCallback] on [releaseAll].
///
/// Returns [resource] again, to allow for easily inserting
/// `arena.using(resource, ...)` where the resource is allocated.
T using<T>(T resource, void Function(T) releaseCallback) {
_ensureInUse();
releaseCallback = Zone.current.bindUnaryCallback(releaseCallback);
_managedResourceReleaseCallbacks.add(() => releaseCallback(resource));
return resource;
}
/// Registers [releaseResourceCallback] to be executed on [releaseAll].
void onReleaseAll(void Function() releaseResourceCallback) {
_managedResourceReleaseCallbacks.add(releaseResourceCallback);
}
/// Releases all resources that this [Arena] manages.
///
/// If [reuse] is `true`, the arena can be used again after resources
/// have been released. If not, the default, then the [allocate]
/// and [using] methods must not be called after a call to `releaseAll`.
///
/// If any of the callbacks throw, [releaseAll] is interrupted, and should
/// be started again.
void releaseAll({bool reuse = false}) {
if (!reuse) {
_inUse = false;
}
// The code below is deliberately wirtten to allow allocations to happen
// during `releaseAll(reuse:true)`. The arena will still be guaranteed
// empty when the `releaseAll` call returns.
while (_managedResourceReleaseCallbacks.isNotEmpty) {
_managedResourceReleaseCallbacks.removeLast()();
}
for (final p in _managedMemoryPointers) {
_wrappedAllocator.free(p);
}
_managedMemoryPointers.clear();
}
/// Does nothing, invoke [releaseAll] instead.
@override
void free(Pointer<NativeType> pointer) {}
void _ensureInUse() {
if (!_inUse) {
throw StateError(
'Arena no longer in use, `releaseAll(reuse: false)` was called.');
}
}
}
/// Runs [computation] with a new [Arena], and releases all allocations at the
/// end.
///
/// If the return value of [computation] is a [Future], all allocations are
/// released when the future completes.
///
/// If the isolate is shut down, through `Isolate.kill()`, resources are _not_
/// cleaned up.
R using<R>(R Function(Arena) computation,
[Allocator wrappedAllocator = calloc]) {
final arena = Arena(wrappedAllocator);
bool isAsync = false;
try {
final result = computation(arena);
if (result is Future) {
isAsync = true;
return (result.whenComplete(arena.releaseAll) as R);
}
return result;
} finally {
if (!isAsync) {
arena.releaseAll();
}
}
}
/// Creates a zoned [Arena] to manage native resources.
///
/// The arena is availabe through [zoneArena].
///
/// If the isolate is shut down, through `Isolate.kill()`, resources are _not_ cleaned up.
R withZoneArena<R>(R Function() computation,
[Allocator wrappedAllocator = calloc]) {
final arena = Arena(wrappedAllocator);
var arenaHolder = [arena];
bool isAsync = false;
try {
return runZoned(() {
final result = computation();
if (result is Future) {
isAsync = true;
result.whenComplete(arena.releaseAll);
}
return result;
}, zoneValues: {#_arena: arenaHolder});
} finally {
if (!isAsync) {
arena.releaseAll();
arenaHolder.clear();
}
}
}
/// A zone-specific [Arena].
///
/// Asynchronous computations can share a [Arena]. Use [withZoneArena] to create
/// a new zone with a fresh [Arena], and that arena will then be released
/// automatically when the function passed to [withZoneArena] completes.
/// All code inside that zone can use `zoneArena` to access the arena.
///
/// The current arena must not be accessed by code which is not running inside
/// a zone created by [withZoneArena].
Arena get zoneArena {
final List<Arena> arenaHolder = Zone.current[#_arena];
if (arenaHolder == null) {
throw StateError('Not inside a zone created by `useArena`');
}
if (arenaHolder.isNotEmpty) {
return arenaHolder.single;
}
throw StateError('Arena has already been cleared with releaseAll.');
}

2
samples_2/ffi/resource_management/arena_isolate_shutdown_sample.dart
View file

@ -11,8 +11,8 @@ import "dart:isolate";
import 'dart:ffi';
import 'package:expect/expect.dart';
import 'package:ffi/ffi.dart';
import 'arena.dart';
import '../dylib_utils.dart';
void main() {

2
samples_2/ffi/resource_management/arena_sample.dart
View file

@ -9,8 +9,8 @@
import 'dart:ffi';
import 'package:expect/expect.dart';
import 'package:ffi/ffi.dart';
import 'arena.dart';
import 'utf8_helpers.dart';
import '../dylib_utils.dart';

210
samples_2/ffi/resource_management/arena_test.dart
View file

@ -1,210 +0,0 @@
// Copyright (c) 2021, 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.
//
// @dart = 2.9
import 'dart:async';
import 'dart:ffi';
import 'package:ffi/ffi.dart';
import 'package:test/test.dart';
// TODO(dacoharkes): After merging into `package:ffi`, roll package in DEPS
// and remove arena.dart.
import 'arena.dart';
void main() async {
test('sync', () async {
List<int> freed = [];
void freeInt(int i) {
freed.add(i);
}
using((Arena arena) {
arena.using(1234, freeInt);
expect(freed.isEmpty, true);
});
expect(freed, [1234]);
});
test('async', () async {
/// Calling [using] waits with releasing its resources until after
/// [Future]s complete.
List<int> freed = [];
void freeInt(int i) {
freed.add(i);
}
Future<int> myFutureInt = using((Arena arena) {
return Future.microtask(() {
arena.using(1234, freeInt);
return 1;
});
});
expect(freed.isEmpty, true);
await myFutureInt;
expect(freed, [1234]);
});
test('throw', () {
/// [using] waits with releasing its resources until after [Future]s
/// complete.
List<int> freed = [];
void freeInt(int i) {
freed.add(i);
}
// Resources are freed also when abnormal control flow occurs.
var didThrow = false;
try {
using((Arena arena) {
arena.using(1234, freeInt);
expect(freed.isEmpty, true);
throw Exception('Exception 1');
});
} on Exception {
expect(freed.single, 1234);
didThrow = true;
}
expect(didThrow, true);
});
test(
'allocate',
() {
final countingAllocator = CountingAllocator();
// To ensure resources are freed, wrap them in a [using] call.
using((Arena arena) {
final p = arena<Int64>(2);
p[1] = p[0];
}, countingAllocator);
expect(countingAllocator.freeCount, 1);
},
);
test('allocate throw', () {
// Resources are freed also when abnormal control flow occurs.
bool didThrow = false;
final countingAllocator = CountingAllocator();
try {
using((Arena arena) {
final p = arena<Int64>(2);
p[0] = 25;
throw Exception('Exception 2');
}, countingAllocator);
} on Exception {
expect(countingAllocator.freeCount, 1);
didThrow = true;
}
expect(didThrow, true);
});
test('toNativeUtf8', () {
final countingAllocator = CountingAllocator();
using((Arena arena) {
final p = 'Hello world!'.toNativeUtf8(allocator: arena);
expect(p.toDartString(), 'Hello world!');
}, countingAllocator);
expect(countingAllocator.freeCount, 1);
});
test('zone', () async {
List<int> freed = [];
void freeInt(int i) {
freed.add(i);
}
withZoneArena(() {
zoneArena.using(1234, freeInt);
expect(freed.isEmpty, true);
});
expect(freed.length, 1);
expect(freed.single, 1234);
});
test('zone async', () async {
/// [using] waits with releasing its resources until after [Future]s
/// complete.
List<int> freed = [];
void freeInt(int i) {
freed.add(i);
}
Future<int> myFutureInt = withZoneArena(() {
return Future.microtask(() {
zoneArena.using(1234, freeInt);
return 1;
});
});
expect(freed.isEmpty, true);
await myFutureInt;
expect(freed.length, 1);
expect(freed.single, 1234);
});
test('zone throw', () {
/// [using] waits with releasing its resources until after [Future]s
/// complete.
List<int> freed = [];
void freeInt(int i) {
freed.add(i);
}
// Resources are freed also when abnormal control flow occurs.
bool didThrow = false;
try {
withZoneArena(() {
zoneArena.using(1234, freeInt);
expect(freed.isEmpty, true);
throw Exception('Exception 3');
});
} on Exception {
expect(freed.single, 1234);
didThrow = true;
}
expect(didThrow, true);
expect(freed.single, 1234);
});
test('allocate during releaseAll', () {
final countingAllocator = CountingAllocator();
final arena = Arena(countingAllocator);
arena.using(arena<Uint8>(), (Pointer discard) {
arena<Uint8>();
});
expect(countingAllocator.allocationCount, 1);
expect(countingAllocator.freeCount, 0);
arena.releaseAll(reuse: true);
expect(countingAllocator.allocationCount, 2);
expect(countingAllocator.freeCount, 2);
});
}
/// Keeps track of the number of allocates and frees for testing purposes.
class CountingAllocator implements Allocator {
final Allocator wrappedAllocator;
int allocationCount = 0;
int freeCount = 0;
CountingAllocator([this.wrappedAllocator = calloc]);
@override
Pointer<T> allocate<T extends NativeType>(int byteCount, {int alignment}) {
allocationCount++;
return wrappedAllocator.allocate(byteCount, alignment: alignment);
}
@override
void free(Pointer<NativeType> pointer) {
freeCount++;
return wrappedAllocator.free(pointer);
}
}

2
samples_2/ffi/resource_management/arena_zoned_sample.dart
View file

@ -9,8 +9,8 @@
import 'dart:ffi';
import 'package:expect/expect.dart';
import 'package:ffi/ffi.dart';
import 'arena.dart';
import 'utf8_helpers.dart';
import '../dylib_utils.dart';

61
samples_2/ffi/sqlite/lib/src/ffi/arena.dart
View file

@ -1,61 +0,0 @@
// Copyright (c) 2019, 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.
// @dart = 2.9
import "dart:async";
import "dart:ffi";
import 'package:ffi/ffi.dart';
/// [Arena] manages allocated C memory.
///
/// Arenas are zoned.
class Arena {
Arena();
List<Pointer<Void>> _allocations = [];
/// Bound the lifetime of [ptr] to this [Arena].
T scoped<T extends Pointer>(T ptr) {
_allocations.add(ptr.cast());
return ptr;
}
/// Frees all memory pointed to by [Pointer]s in this arena.
void finalize() {
for (final ptr in _allocations) {
calloc.free(ptr);
}
}
/// The last [Arena] in the zone.
factory Arena.current() {
return Zone.current[#_currentArena];
}
}
/// Bound the lifetime of [ptr] to the current [Arena].
T scoped<T extends Pointer>(T ptr) => Arena.current().scoped(ptr);
class RethrownError {
dynamic original;
StackTrace originalStackTrace;
RethrownError(this.original, this.originalStackTrace);
toString() => """RethrownError(${original})
${originalStackTrace}""";
}
/// Runs the [body] in an [Arena] freeing all memory which is [scoped] during
/// execution of [body] at the end of the execution.
R runArena<R>(R Function(Arena) body) {
Arena arena = Arena();
try {
return runZoned(() => body(arena),
zoneValues: {#_currentArena: arena},
onError: (error, st) => throw RethrownError(error, st));
} finally {
arena.finalize();
}
}