1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/xpcom/glue/nsMemory.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,145 @@
1.4 +/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
1.5 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.6 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.7 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.8 +
1.9 +#ifndef nsMemory_h__
1.10 +#define nsMemory_h__
1.11 +
1.12 +#include "nsXPCOM.h"
1.13 +
1.14 +class nsIMemory;
1.15 +
1.16 +#define NS_MEMORY_CONTRACTID "@mozilla.org/xpcom/memory-service;1"
1.17 +#define NS_MEMORY_CID \
1.18 +{ /* 30a04e40-38e7-11d4-8cf5-0060b0fc14a3 */ \
1.19 + 0x30a04e40, \
1.20 + 0x38e7, \
1.21 + 0x11d4, \
1.22 + {0x8c, 0xf5, 0x00, 0x60, 0xb0, 0xfc, 0x14, 0xa3} \
1.23 +}
1.24 +
1.25 +
1.26 +/**
1.27 + * Static helper routines to manage memory. These routines allow easy access
1.28 + * to xpcom's built-in (global) nsIMemory implementation, without needing
1.29 + * to go through the service manager to get it. However this requires clients
1.30 + * to link with the xpcom DLL.
1.31 + *
1.32 + * This class is not threadsafe and is intented for use only on the main
1.33 + * thread.
1.34 + */
1.35 +class nsMemory
1.36 +{
1.37 +public:
1.38 + static NS_HIDDEN_(void*) Alloc(size_t size)
1.39 + { return NS_Alloc(size); }
1.40 +
1.41 + static NS_HIDDEN_(void*) Realloc(void* ptr, size_t size)
1.42 + { return NS_Realloc(ptr, size); }
1.43 +
1.44 + static NS_HIDDEN_(void) Free(void* ptr)
1.45 + { NS_Free(ptr); }
1.46 +
1.47 + static NS_COM_GLUE nsresult HeapMinimize(bool aImmediate);
1.48 + static NS_COM_GLUE void* Clone(const void* ptr, size_t size);
1.49 + static NS_COM_GLUE nsIMemory* GetGlobalMemoryService(); // AddRefs
1.50 +};
1.51 +
1.52 +/**
1.53 + * Macro to free all elements of an XPCOM array of a given size using
1.54 + * freeFunc, then frees the array itself using nsMemory::Free().
1.55 + *
1.56 + * Note that this macro (and its wrappers) can be used to deallocate a
1.57 + * partially- or completely-built array while unwinding an error
1.58 + * condition inside the XPCOM routine that was going to return the
1.59 + * array. For this to work on a partially-built array, your code
1.60 + * needs to be building the array from index 0 upwards, and simply
1.61 + * pass the number of elements that have already been built (and thus
1.62 + * need to be freed) as |size|.
1.63 + *
1.64 + * Thanks to <alecf@netscape.com> for suggesting this form, which
1.65 + * allows the macro to be used with NS_RELEASE / NS_RELEASE_IF in
1.66 + * addition to nsMemory::Free.
1.67 + *
1.68 + * @param size Number of elements in the array. If not a constant, this
1.69 + * should be a int32_t. Note that this means this macro
1.70 + * will not work if size >= 2^31.
1.71 + * @param array The array to be freed.
1.72 + * @param freeFunc The function or macro to be used to free it.
1.73 + * For arrays of nsISupports (or any class derived
1.74 + * from it), NS_IF_RELEASE (or NS_RELEASE) should be
1.75 + * passed as freeFunc. For most (all?) other pointer
1.76 + * types (including XPCOM strings and wstrings),
1.77 + * nsMemory::Free should be used, since the
1.78 + * shared-allocator (nsMemory) is what will have been
1.79 + * used to allocate the memory.
1.80 + */
1.81 +#define NS_FREE_XPCOM_POINTER_ARRAY(size, array, freeFunc) \
1.82 + PR_BEGIN_MACRO \
1.83 + int32_t iter_ = int32_t(size); \
1.84 + while (--iter_ >= 0) \
1.85 + freeFunc((array)[iter_]); \
1.86 + NS_Free((array)); \
1.87 + PR_END_MACRO
1.88 +
1.89 +// convenience macros for commonly used calls. mmmmm. syntactic sugar.
1.90 +
1.91 +/**
1.92 + * Macro to free arrays of non-refcounted objects allocated by the
1.93 + * shared allocator (nsMemory) such as strings and wstrings. A
1.94 + * convenience wrapper around NS_FREE_XPCOM_POINTER_ARRAY.
1.95 + *
1.96 + * @param size Number of elements in the array. If not a constant, this
1.97 + * should be a int32_t. Note that this means this macro
1.98 + * will not work if size >= 2^31.
1.99 + * @param array The array to be freed.
1.100 + */
1.101 +#define NS_FREE_XPCOM_ALLOCATED_POINTER_ARRAY(size, array) \
1.102 + NS_FREE_XPCOM_POINTER_ARRAY((size), (array), NS_Free)
1.103 +
1.104 +/**
1.105 + * Macro to free an array of pointers to nsISupports (or classes
1.106 + * derived from it). A convenience wrapper around
1.107 + * NS_FREE_XPCOM_POINTER_ARRAY.
1.108 + *
1.109 + * Note that if you know that none of your nsISupports pointers are
1.110 + * going to be 0, you can gain a bit of speed by calling
1.111 + * NS_FREE_XPCOM_POINTER_ARRAY directly and using NS_RELEASE as your
1.112 + * free function.
1.113 + *
1.114 + * @param size Number of elements in the array. If not a constant, this
1.115 + * should be a int32_t. Note that this means this macro
1.116 + * will not work if size >= 2^31.
1.117 + * @param array The array to be freed.
1.118 + */
1.119 +#define NS_FREE_XPCOM_ISUPPORTS_POINTER_ARRAY(size, array) \
1.120 + NS_FREE_XPCOM_POINTER_ARRAY((size), (array), NS_IF_RELEASE)
1.121 +
1.122 +/**
1.123 + * A macro, NS_ALIGNMENT_OF(t_) that determines the alignment
1.124 + * requirements of a type.
1.125 + */
1.126 +namespace mozilla {
1.127 + template <class T>
1.128 + struct AlignmentTestStruct
1.129 + {
1.130 + char c;
1.131 + T t;
1.132 + };
1.133 +}
1.134 +
1.135 +#define NS_ALIGNMENT_OF(t_) \
1.136 + (sizeof(mozilla::AlignmentTestStruct<t_>) - sizeof(t_))
1.137 +
1.138 +/**
1.139 + * An enumeration type used to represent a method of assignment.
1.140 + */
1.141 +enum nsAssignmentType {
1.142 + NS_ASSIGNMENT_COPY, // copy by value
1.143 + NS_ASSIGNMENT_DEPEND, // copy by reference
1.144 + NS_ASSIGNMENT_ADOPT // copy by reference (take ownership of resource)
1.145 +};
1.146 +
1.147 +#endif // nsMemory_h__
1.148 +
