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Diffstat (limited to 'js/public/Context.h')
| -rw-r--r-- | js/public/Context.h | 111 |
1 files changed, 111 insertions, 0 deletions
diff --git a/js/public/Context.h b/js/public/Context.h new file mode 100644 index 0000000000..ad0b725b3a --- /dev/null +++ b/js/public/Context.h @@ -0,0 +1,111 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- + * vim: set ts=8 sts=2 et sw=2 tw=80: + * This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +/* JavaScript API. */ + +#ifndef js_Context_h +#define js_Context_h + +#include "jspubtd.h" +// [SMDOC] Nested Thread Data Structures (JSContext, JSRuntime) +// +// Spidermonkey has two nested data structures for representing threads, +// JSContext and JSRuntime. All JS threads are represented by a context. +// Contexts can contain runtimes. A runtime however is not present for +// all threads. Threads also interact with the GC. See "Nested GC +// DataStructures" for more info. +// +// Context +// ------- +// JSContext represents a thread: there must be exactly one JSContext for each +// thread running JS/Wasm. +// +// Internally, helper threads can also have a JSContext. They do not always have +// an active context, but one may be requested by AutoSetHelperThreadContext, +// which activates a pre-allocated JSContext for the duration of its lifetime. +// +// Runtime +// ------- +// JSRuntime is very similar to JSContext: each runtime belongs to one context +// (thread), but helper threads don't have their own runtimes (they're shared by +// all runtimes in the process and use the runtime of the task they're +// executing). +// +// Note: +// Locking, contexts, and memory allocation. +// +// It is important that SpiderMonkey be initialized, and the first context +// be created, in a single-threaded fashion. Otherwise the behavior of the +// library is undefined. +// See: +// https://developer.mozilla.org/en-US/docs/Mozilla/Projects/SpiderMonkey/JSAPI_reference + +// Create a new context (and runtime) for this thread. +extern JS_PUBLIC_API JSContext* JS_NewContext( + uint32_t maxbytes, JSRuntime* parentRuntime = nullptr); + +// Destroy a context allocated with JS_NewContext. Must be called on the thread +// that called JS_NewContext. +extern JS_PUBLIC_API void JS_DestroyContext(JSContext* cx); + +JS_PUBLIC_API void* JS_GetContextPrivate(JSContext* cx); + +JS_PUBLIC_API void JS_SetContextPrivate(JSContext* cx, void* data); + +extern JS_PUBLIC_API JSRuntime* JS_GetParentRuntime(JSContext* cx); + +extern JS_PUBLIC_API JSRuntime* JS_GetRuntime(JSContext* cx); + +extern JS_PUBLIC_API void JS_SetFutexCanWait(JSContext* cx); + +namespace js { + +void AssertHeapIsIdle(); + +} /* namespace js */ + +namespace JS { + +/** + * Asserts (in debug and release builds) that `obj` belongs to the current + * thread's context. + */ +JS_PUBLIC_API void AssertObjectBelongsToCurrentThread(JSObject* obj); + +/** + * Install a process-wide callback to validate script filenames. The JS engine + * will invoke this callback for each JS script it parses or XDR decodes. + * + * If the callback returns |false|, an exception is thrown and parsing/decoding + * will be aborted. + * + * See also CompileOptions::setSkipFilenameValidation to opt-out of the callback + * for specific parse jobs. + */ +using FilenameValidationCallback = bool (*)(JSContext* cx, + const char* filename); +JS_PUBLIC_API void SetFilenameValidationCallback(FilenameValidationCallback cb); + +/** + * Install an context wide callback that implements the ECMA262 specification + * host hook `HostEnsureCanAddPrivateElement`. + * + * This hook, which should only be overriden for Web Browsers, examines the + * provided object to determine if the addition of a private field is allowed, + * throwing an exception and returning false if not. + * + * The default implementation of this hook, which will be used unless overriden, + * examines only proxy objects, and throws if the proxy handler returns true + * from the handler method `throwOnPrivateField()`. + */ +using EnsureCanAddPrivateElementOp = bool (*)(JSContext* cx, HandleValue val); + +JS_PUBLIC_API void SetHostEnsureCanAddPrivateElementHook( + JSContext* cx, EnsureCanAddPrivateElementOp op); + +} /* namespace JS */ + +#endif // js_Context_h |