libraries/source/spidermonkey/include-win32-release/js/Zone.h

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
   2  * vim: set ts=8 sts=2 et sw=2 tw=80:
   3  * This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 /* JavaScript API. */
   8
   9 #ifndef js_Zone_h
  10 #define js_Zone_h
  11
  12 #include "jspubtd.h"
  13 #include "js/Context.h"
  14
  15 // [SMDOC] Nested GC Data Structures (Compartments and Zones)
  16 //
  17 // The GC has two nested data structures, Zones and Compartents. Each has
  18 // distint responsibilities. Zones contain compartments, along with other GC
  19 // resources used by a tab. Compartments contain realms, which are specification
  20 // defined.
  21 //
  22 // See also the SMDoc on Realms.
  23 //
  24 // Compartment
  25 // -----------
  26 // Security membrane; when an object from compartment A is used in compartment
  27 // B, a cross-compartment wrapper (a kind of proxy) is used. In the browser,
  28 // same-origin realms can share a compartment.
  29 //
  30 // Zone
  31 // ----
  32 // A Zone is a group of compartments that share GC resources (arenas, strings,
  33 // etc) for memory usage and performance reasons. Zone is the GC unit: the GC
  34 // can operate on one or more zones at a time. The browser uses roughly one zone
  35 // per tab.
  36
  37 using JSDestroyZoneCallback = void (*)(JSFreeOp*, JS::Zone*);
  38
  39 using JSDestroyCompartmentCallback = void (*)(JSFreeOp*, JS::Compartment*);
  40
  41 using JSSizeOfIncludingThisCompartmentCallback =
  42     size_t (*)(mozilla::MallocSizeOf, JS::Compartment*);
  43
  44 extern JS_PUBLIC_API void JS_SetDestroyZoneCallback(
  45     JSContext* cx, JSDestroyZoneCallback callback);
  46
  47 extern JS_PUBLIC_API void JS_SetDestroyCompartmentCallback(
  48     JSContext* cx, JSDestroyCompartmentCallback callback);
  49
  50 extern JS_PUBLIC_API void JS_SetSizeOfIncludingThisCompartmentCallback(
  51     JSContext* cx, JSSizeOfIncludingThisCompartmentCallback callback);
  52
  53 extern JS_PUBLIC_API void JS_SetCompartmentPrivate(JS::Compartment* compartment,
  54                                                    void* data);
  55
  56 extern JS_PUBLIC_API void* JS_GetCompartmentPrivate(
  57     JS::Compartment* compartment);
  58
  59 extern JS_PUBLIC_API void JS_SetZoneUserData(JS::Zone* zone, void* data);
  60
  61 extern JS_PUBLIC_API void* JS_GetZoneUserData(JS::Zone* zone);
  62
  63 extern JS_PUBLIC_API bool JS_RefreshCrossCompartmentWrappers(
  64     JSContext* cx, JS::Handle<JSObject*> obj);
  65
  66 /**
  67  * Mark a jsid after entering a new compartment. Different zones separately
  68  * mark the ids in a runtime, and this must be used any time an id is obtained
  69  * from one compartment and then used in another compartment, unless the two
  70  * compartments are guaranteed to be in the same zone.
  71  */
  72 extern JS_PUBLIC_API void JS_MarkCrossZoneId(JSContext* cx, jsid id);
  73
  74 /**
  75  * If value stores a jsid (an atomized string or symbol), mark that id as for
  76  * JS_MarkCrossZoneId.
  77  */
  78 extern JS_PUBLIC_API void JS_MarkCrossZoneIdValue(JSContext* cx,
  79                                                   const JS::Value& value);
  80
  81 #endif  // js_Zone_h