xpcom/glue/nsMemory.h@97036ab72558 (annotated)
xpcom/glue/nsMemory.h
Tue, 06 Jan 2015 21:39:09 +0100
- author
- Michael Schloh von Bennewitz <michael@schloh.com>
- date
- Tue, 06 Jan 2015 21:39:09 +0100
- branch
- TOR_BUG_9701
- changeset 8
- 97036ab72558
- permissions
- -rw-r--r--
Conditionally force memory storage according to privacy.thirdparty.isolate;
This solves Tor bug #9701, complying with disk avoidance documented in
https://www.torproject.org/projects/torbrowser/design/#disk-avoidance.
| michael@0 | 1 | /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */ |
| michael@0 | 2 | /* This Source Code Form is subject to the terms of the Mozilla Public |
| michael@0 | 3 | * License, v. 2.0. If a copy of the MPL was not distributed with this |
| michael@0 | 4 | * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ |
| michael@0 | 5 | |
| michael@0 | 6 | #ifndef nsMemory_h__ |
| michael@0 | 7 | #define nsMemory_h__ |
| michael@0 | 8 | |
| michael@0 | 9 | #include "nsXPCOM.h" |
| michael@0 | 10 | |
| michael@0 | 11 | class nsIMemory; |
| michael@0 | 12 | |
| michael@0 | 13 | #define NS_MEMORY_CONTRACTID "@mozilla.org/xpcom/memory-service;1" |
| michael@0 | 14 | #define NS_MEMORY_CID \ |
| michael@0 | 15 | { /* 30a04e40-38e7-11d4-8cf5-0060b0fc14a3 */ \ |
| michael@0 | 16 | 0x30a04e40, \ |
| michael@0 | 17 | 0x38e7, \ |
| michael@0 | 18 | 0x11d4, \ |
| michael@0 | 19 | {0x8c, 0xf5, 0x00, 0x60, 0xb0, 0xfc, 0x14, 0xa3} \ |
| michael@0 | 20 | } |
| michael@0 | 21 | |
| michael@0 | 22 | |
| michael@0 | 23 | /** |
| michael@0 | 24 | * Static helper routines to manage memory. These routines allow easy access |
| michael@0 | 25 | * to xpcom's built-in (global) nsIMemory implementation, without needing |
| michael@0 | 26 | * to go through the service manager to get it. However this requires clients |
| michael@0 | 27 | * to link with the xpcom DLL. |
| michael@0 | 28 | * |
| michael@0 | 29 | * This class is not threadsafe and is intented for use only on the main |
| michael@0 | 30 | * thread. |
| michael@0 | 31 | */ |
| michael@0 | 32 | class nsMemory |
| michael@0 | 33 | { |
| michael@0 | 34 | public: |
| michael@0 | 35 | static NS_HIDDEN_(void*) Alloc(size_t size) |
| michael@0 | 36 | { return NS_Alloc(size); } |
| michael@0 | 37 | |
| michael@0 | 38 | static NS_HIDDEN_(void*) Realloc(void* ptr, size_t size) |
| michael@0 | 39 | { return NS_Realloc(ptr, size); } |
| michael@0 | 40 | |
| michael@0 | 41 | static NS_HIDDEN_(void) Free(void* ptr) |
| michael@0 | 42 | { NS_Free(ptr); } |
| michael@0 | 43 | |
| michael@0 | 44 | static NS_COM_GLUE nsresult HeapMinimize(bool aImmediate); |
| michael@0 | 45 | static NS_COM_GLUE void* Clone(const void* ptr, size_t size); |
| michael@0 | 46 | static NS_COM_GLUE nsIMemory* GetGlobalMemoryService(); // AddRefs |
| michael@0 | 47 | }; |
| michael@0 | 48 | |
| michael@0 | 49 | /** |
| michael@0 | 50 | * Macro to free all elements of an XPCOM array of a given size using |
| michael@0 | 51 | * freeFunc, then frees the array itself using nsMemory::Free(). |
| michael@0 | 52 | * |
| michael@0 | 53 | * Note that this macro (and its wrappers) can be used to deallocate a |
| michael@0 | 54 | * partially- or completely-built array while unwinding an error |
| michael@0 | 55 | * condition inside the XPCOM routine that was going to return the |
| michael@0 | 56 | * array. For this to work on a partially-built array, your code |
| michael@0 | 57 | * needs to be building the array from index 0 upwards, and simply |
| michael@0 | 58 | * pass the number of elements that have already been built (and thus |
| michael@0 | 59 | * need to be freed) as |size|. |
| michael@0 | 60 | * |
| michael@0 | 61 | * Thanks to <alecf@netscape.com> for suggesting this form, which |
| michael@0 | 62 | * allows the macro to be used with NS_RELEASE / NS_RELEASE_IF in |
| michael@0 | 63 | * addition to nsMemory::Free. |
| michael@0 | 64 | * |
| michael@0 | 65 | * @param size Number of elements in the array. If not a constant, this |
| michael@0 | 66 | * should be a int32_t. Note that this means this macro |
| michael@0 | 67 | * will not work if size >= 2^31. |
| michael@0 | 68 | * @param array The array to be freed. |
| michael@0 | 69 | * @param freeFunc The function or macro to be used to free it. |
| michael@0 | 70 | * For arrays of nsISupports (or any class derived |
| michael@0 | 71 | * from it), NS_IF_RELEASE (or NS_RELEASE) should be |
| michael@0 | 72 | * passed as freeFunc. For most (all?) other pointer |
| michael@0 | 73 | * types (including XPCOM strings and wstrings), |
| michael@0 | 74 | * nsMemory::Free should be used, since the |
| michael@0 | 75 | * shared-allocator (nsMemory) is what will have been |
| michael@0 | 76 | * used to allocate the memory. |
| michael@0 | 77 | */ |
| michael@0 | 78 | #define NS_FREE_XPCOM_POINTER_ARRAY(size, array, freeFunc) \ |
| michael@0 | 79 | PR_BEGIN_MACRO \ |
| michael@0 | 80 | int32_t iter_ = int32_t(size); \ |
| michael@0 | 81 | while (--iter_ >= 0) \ |
| michael@0 | 82 | freeFunc((array)[iter_]); \ |
| michael@0 | 83 | NS_Free((array)); \ |
| michael@0 | 84 | PR_END_MACRO |
| michael@0 | 85 | |
| michael@0 | 86 | // convenience macros for commonly used calls. mmmmm. syntactic sugar. |
| michael@0 | 87 | |
| michael@0 | 88 | /** |
| michael@0 | 89 | * Macro to free arrays of non-refcounted objects allocated by the |
| michael@0 | 90 | * shared allocator (nsMemory) such as strings and wstrings. A |
| michael@0 | 91 | * convenience wrapper around NS_FREE_XPCOM_POINTER_ARRAY. |
| michael@0 | 92 | * |
| michael@0 | 93 | * @param size Number of elements in the array. If not a constant, this |
| michael@0 | 94 | * should be a int32_t. Note that this means this macro |
| michael@0 | 95 | * will not work if size >= 2^31. |
| michael@0 | 96 | * @param array The array to be freed. |
| michael@0 | 97 | */ |
| michael@0 | 98 | #define NS_FREE_XPCOM_ALLOCATED_POINTER_ARRAY(size, array) \ |
| michael@0 | 99 | NS_FREE_XPCOM_POINTER_ARRAY((size), (array), NS_Free) |
| michael@0 | 100 | |
| michael@0 | 101 | /** |
| michael@0 | 102 | * Macro to free an array of pointers to nsISupports (or classes |
| michael@0 | 103 | * derived from it). A convenience wrapper around |
| michael@0 | 104 | * NS_FREE_XPCOM_POINTER_ARRAY. |
| michael@0 | 105 | * |
| michael@0 | 106 | * Note that if you know that none of your nsISupports pointers are |
| michael@0 | 107 | * going to be 0, you can gain a bit of speed by calling |
| michael@0 | 108 | * NS_FREE_XPCOM_POINTER_ARRAY directly and using NS_RELEASE as your |
| michael@0 | 109 | * free function. |
| michael@0 | 110 | * |
| michael@0 | 111 | * @param size Number of elements in the array. If not a constant, this |
| michael@0 | 112 | * should be a int32_t. Note that this means this macro |
| michael@0 | 113 | * will not work if size >= 2^31. |
| michael@0 | 114 | * @param array The array to be freed. |
| michael@0 | 115 | */ |
| michael@0 | 116 | #define NS_FREE_XPCOM_ISUPPORTS_POINTER_ARRAY(size, array) \ |
| michael@0 | 117 | NS_FREE_XPCOM_POINTER_ARRAY((size), (array), NS_IF_RELEASE) |
| michael@0 | 118 | |
| michael@0 | 119 | /** |
| michael@0 | 120 | * A macro, NS_ALIGNMENT_OF(t_) that determines the alignment |
| michael@0 | 121 | * requirements of a type. |
| michael@0 | 122 | */ |
| michael@0 | 123 | namespace mozilla { |
| michael@0 | 124 | template <class T> |
| michael@0 | 125 | struct AlignmentTestStruct |
| michael@0 | 126 | { |
| michael@0 | 127 | char c; |
| michael@0 | 128 | T t; |
| michael@0 | 129 | }; |
| michael@0 | 130 | } |
| michael@0 | 131 | |
| michael@0 | 132 | #define NS_ALIGNMENT_OF(t_) \ |
| michael@0 | 133 | (sizeof(mozilla::AlignmentTestStruct<t_>) - sizeof(t_)) |
| michael@0 | 134 | |
| michael@0 | 135 | /** |
| michael@0 | 136 | * An enumeration type used to represent a method of assignment. |
| michael@0 | 137 | */ |
| michael@0 | 138 | enum nsAssignmentType { |
| michael@0 | 139 | NS_ASSIGNMENT_COPY, // copy by value |
| michael@0 | 140 | NS_ASSIGNMENT_DEPEND, // copy by reference |
| michael@0 | 141 | NS_ASSIGNMENT_ADOPT // copy by reference (take ownership of resource) |
| michael@0 | 142 | }; |
| michael@0 | 143 | |
| michael@0 | 144 | #endif // nsMemory_h__ |
| michael@0 | 145 |
