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

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 /* Low-level memory-allocation functions. */
   7
   8 #ifndef js_MemoryFunctions_h
   9 #define js_MemoryFunctions_h
  10
  11 #include "mozilla/Assertions.h"  // MOZ_ASSERT
  12
  13 #include <stddef.h>  // size_t
  14
  15 #include "jstypes.h"  // JS_PUBLIC_API
  16
  17 struct JS_PUBLIC_API JSContext;
  18 class JS_PUBLIC_API JSFreeOp;
  19 class JS_PUBLIC_API JSObject;
  20 struct JS_PUBLIC_API JSRuntime;
  21
  22 extern JS_PUBLIC_API void* JS_malloc(JSContext* cx, size_t nbytes);
  23
  24 extern JS_PUBLIC_API void* JS_realloc(JSContext* cx, void* p, size_t oldBytes,
  25                                       size_t newBytes);
  26
  27 /**
  28  * A wrapper for |js_free(p)| that may delay |js_free(p)| invocation as a
  29  * performance optimization.  |cx| may be nullptr.
  30  */
  31 extern JS_PUBLIC_API void JS_free(JSContext* cx, void* p);
  32
  33 /**
  34  * Same as above, but for buffers that will be used with the BYOB
  35  * (Bring Your Own Buffer) JSString creation functions, such as
  36  * JS_NewLatin1String and JS_NewUCString
  37  */
  38 extern JS_PUBLIC_API void* JS_string_malloc(JSContext* cx, size_t nbytes);
  39
  40 extern JS_PUBLIC_API void* JS_string_realloc(JSContext* cx, void* p,
  41                                              size_t oldBytes, size_t newBytes);
  42
  43 extern JS_PUBLIC_API void JS_string_free(JSContext* cx, void* p);
  44
  45 /**
  46  * A wrapper for |js_free(p)| that may delay |js_free(p)| invocation as a
  47  * performance optimization as specified by the given JSFreeOp instance.
  48  */
  49 extern JS_PUBLIC_API void JS_freeop(JSFreeOp* fop, void* p);
  50
  51 namespace JS {
  52
  53 /**
  54  * The different possible memory uses to pass to Add/RemoveAssociatedMemory.
  55  */
  56 #define JS_FOR_EACH_PUBLIC_MEMORY_USE(_) \
  57   _(XPCWrappedNative)                    \
  58   _(DOMBinding)                          \
  59   _(CTypeFFIType)                        \
  60   _(CTypeFFITypeElements)                \
  61   _(CTypeFunctionInfo)                   \
  62   _(CTypeFieldInfo)                      \
  63   _(CDataBufferPtr)                      \
  64   _(CDataBuffer)                         \
  65   _(CClosureInfo)                        \
  66   _(CTypesInt64)                         \
  67   _(Embedding1)                          \
  68   _(Embedding2)                          \
  69   _(Embedding3)                          \
  70   _(Embedding4)                          \
  71   _(Embedding5)
  72
  73 enum class MemoryUse : uint8_t {
  74 #define DEFINE_MEMORY_USE(Name) Name,
  75   JS_FOR_EACH_PUBLIC_MEMORY_USE(DEFINE_MEMORY_USE)
  76 #undef DEFINE_MEMORY_USE
  77 };
  78
  79 /**
  80  * Advise the GC of external memory owned by a JSObject. This is used to
  81  * determine when to collect zones. Calls must be matched by calls to
  82  * RemoveAssociatedMemory() when the memory is deallocated or no longer owned by
  83  * the object.
  84  */
  85 extern JS_PUBLIC_API void AddAssociatedMemory(JSObject* obj, size_t nbytes,
  86                                               MemoryUse use);
  87
  88 /**
  89  * Advise the GC that external memory reported by JS::AddAssociatedMemory() is
  90  * no longer owned by a JSObject. Calls must match those to
  91  * AddAssociatedMemory().
  92  */
  93 extern JS_PUBLIC_API void RemoveAssociatedMemory(JSObject* obj, size_t nbytes,
  94                                                  MemoryUse use);
  95
  96 }  // namespace JS
  97
  98 #endif /* js_MemoryFunctions_h */