76 lines
2.6 KiB
C++
76 lines
2.6 KiB
C++
// Copyright 2010 the V8 project authors. All rights reserved.
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// Use of this source code is governed by a BSD-style license that can be
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// found in the LICENSE file.
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#ifndef V8_EXTENSIONS_GC_EXTENSION_H_
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#define V8_EXTENSIONS_GC_EXTENSION_H_
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#include "include/v8-extension.h"
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#include "include/v8-local-handle.h"
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#include "src/base/strings.h"
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namespace v8 {
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template <typename T>
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class FunctionCallbackInfo;
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namespace internal {
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// Provides garbage collection on invoking |fun_name|(options), where
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// - options is a dictionary like object. See supported properties below.
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// - no parameter defaults to options:
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// {type: 'major', execution: 'sync'}.
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// - truthy parameter that is not setting any options:
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// {type: 'minor', execution: 'sync'}.
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//
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// Exceptions that occur during parsing the options bag are preserved and result
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// in skipping the GC call.
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//
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// Supported options:
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// - type:
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// - 'major': Full GC.
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// - 'minor': Young generation GC.
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// - 'major-snapshot': Full GC with taking a heap snapshot at the same time.
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// - execution: 'sync' or 'async' for synchronous and asynchronous
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// execution, respectively.
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// - flavor:
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// - 'regular': A regular GC.
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// - 'last-resort': A last resort GC.
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// - filename: Filename for the snapshot in case the type was
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// 'major-snapshot'.
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//
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// Returns a Promise that resolves when GC is done when asynchronous execution
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// is requested, and undefined otherwise.
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//
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// Frequent use cases (assuming --expose-gc):
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// 1. Just perform a GC to check whether things improve: `gc()`
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// 2. Test that certain objects indeed are reclaimed:
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// `await gc({type:'major', execution:'async'})`
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// 3. Same as 2. but with checking why things did go wrong in a snapshot:
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// `await gc({type:'major-snapshot', execution:'async'})`
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// 4. Synchronous last resort GC:
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// `gc({type:'major',execution:'sync',flavor:'last-resort'})`
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class GCExtension : public v8::Extension {
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public:
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explicit GCExtension(const char* fun_name)
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: v8::Extension("v8/gc",
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BuildSource(buffer_, sizeof(buffer_), fun_name)) {}
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v8::Local<v8::FunctionTemplate> GetNativeFunctionTemplate(
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v8::Isolate* isolate, v8::Local<v8::String> name) override;
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static void GC(const v8::FunctionCallbackInfo<v8::Value>& info);
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private:
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static const char* BuildSource(char* buf, size_t size, const char* fun_name) {
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base::SNPrintF(base::VectorOf(buf, size), "native function %s();",
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fun_name);
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return buf;
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}
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char buffer_[50];
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};
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} // namespace internal
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} // namespace v8
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#endif // V8_EXTENSIONS_GC_EXTENSION_H_
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