0ad/source/scriptinterface/ScriptContext.h
bb 157c6af18e Make the space in 0 A.D. non-breaking throughout the codebase.
Avoid cases of filenames
Update years in terms and other legal(ish) documents
Don't update years in license headers, since change is not meaningful

Will add linter rule in seperate commit

Happy recompiling everyone!

Original Patch By: Nescio
Comment By: Gallaecio
Differential Revision: D2620
This was SVN commit r27786.
2023-07-27 20:54:46 +00:00

103 lines
3.9 KiB
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/* Copyright (C) 2023 Wildfire Games.
* This file is part of 0 A.D.
*
* 0 A.D. is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 2 of the License, or
* (at your option) any later version.
*
* 0 A.D. is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with 0 A.D. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef INCLUDED_SCRIPTCONTEXT
#define INCLUDED_SCRIPTCONTEXT
#include "ScriptTypes.h"
#include "ScriptExtraHeaders.h"
#include <list>
// Those are minimal defaults. The runtime for the main game is larger and GCs upon a larger growth.
constexpr int DEFAULT_CONTEXT_SIZE = 16 * 1024 * 1024;
constexpr int DEFAULT_HEAP_GROWTH_BYTES_GCTRIGGER = 2 * 1024 * 1024;
/**
* Abstraction around a SpiderMonkey JSContext.
*
* A single ScriptContext, with the associated context,
* should only be used on a single thread.
*
* (One means to share data between threads and contexts is to create
* a Script::StructuredClone.)
*/
class ScriptContext
{
public:
ScriptContext(int contextSize, int heapGrowthBytesGCTrigger);
~ScriptContext();
/**
* Returns a context, in which any number of ScriptInterfaces compartments can live.
* Each context should only ever be used on a single thread.
* @param parentContext Parent context from the parent thread, with which we share some thread-safe data
* @param contextSize Maximum size in bytes of the new context
* @param heapGrowthBytesGCTrigger Size in bytes of cumulated allocations after which a GC will be triggered
*/
static std::shared_ptr<ScriptContext> CreateContext(
int contextSize = DEFAULT_CONTEXT_SIZE,
int heapGrowthBytesGCTrigger = DEFAULT_HEAP_GROWTH_BYTES_GCTRIGGER);
/**
* MaybeIncrementalGC tries to determine whether a context-wide garbage collection would free up enough memory to
* be worth the amount of time it would take. It does this with our own logic and NOT some predefined JSAPI logic because
* such functionality currently isn't available out of the box.
* It does incremental GC which means it will collect one slice each time it's called until the garbage collection is done.
* This can and should be called quite regularly. The delay parameter allows you to specify a minimum time since the last GC
* in seconds (the delay should be a fraction of a second in most cases though).
* It will only start a new incremental GC or another GC slice if this time is exceeded. The user of this function is
* responsible for ensuring that GC can run with a small enough delay to get done with the work.
*/
void MaybeIncrementalGC(double delay);
void ShrinkingGC();
/**
* This is used to keep track of realms which should be prepared for a GC.
*/
void RegisterRealm(JS::Realm* realm);
void UnRegisterRealm(JS::Realm* realm);
/**
* GetGeneralJSContext returns the context without starting a GC request and without
* entering any compartment. It should only be used in specific situations, such as
* creating a new compartment, or when initializing a persistent rooted.
* If you need the compartmented context of a ScriptInterface, you should create a
* ScriptRequest and use the context from that.
*/
JSContext* GetGeneralJSContext() const { return m_cx; }
private:
JSContext* m_cx;
void PrepareZonesForIncrementalGC() const;
std::list<JS::Realm*> m_Realms;
int m_ContextSize;
int m_HeapGrowthBytesGCTrigger;
int m_LastGCBytes;
double m_LastGCCheck;
};
// Using a global object for the context is a workaround until Simulation, AI, etc,
// use their own threads and also their own contexts.
extern thread_local std::shared_ptr<ScriptContext> g_ScriptContext;
#endif // INCLUDED_SCRIPTCONTEXT