gecko-dev/memory/mozalloc/mozalloc.h

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8.7 KiB
C++

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
* vim: sw=4 ts=4 et :
*/
/* 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/. */
#ifndef mozilla_mozalloc_h
#define mozilla_mozalloc_h
/*
* https://bugzilla.mozilla.org/show_bug.cgi?id=427099
*/
#include <stdlib.h>
#include <string.h>
#if defined(__cplusplus)
# include <new>
#endif
#if defined(__cplusplus)
#include "mozilla/fallible.h"
#include "mozilla/TemplateLib.h"
#endif
#include "mozilla/Attributes.h"
#include "mozilla/Types.h"
#define MOZALLOC_HAVE_XMALLOC
#if defined(MOZ_ALWAYS_INLINE_EVEN_DEBUG)
# define MOZALLOC_INLINE MOZ_ALWAYS_INLINE_EVEN_DEBUG
#elif defined(HAVE_FORCEINLINE)
# define MOZALLOC_INLINE __forceinline
#else
# define MOZALLOC_INLINE inline
#endif
/* Workaround build problem with Sun Studio 12 */
#if defined(__SUNPRO_C) || defined(__SUNPRO_CC)
# undef MOZ_WARN_UNUSED_RESULT
# define MOZ_WARN_UNUSED_RESULT
# undef MOZ_ALLOCATOR
# define MOZ_ALLOCATOR
#endif
#if defined(__cplusplus)
extern "C" {
#endif /* ifdef __cplusplus */
/*
* We need to use malloc_impl and free_impl in this file when they are
* defined, because of how mozglue.dll is linked on Windows, where using
* malloc/free would end up using the symbols from the MSVCRT instead of
* ours.
*/
#ifndef free_impl
#define free_impl free
#define free_impl_
#endif
#ifndef malloc_impl
#define malloc_impl malloc
#define malloc_impl_
#endif
/*
* Each declaration below is analogous to a "standard" allocation
* function, except that the out-of-memory handling is made explicit.
* The |moz_x| versions will never return a NULL pointer; if memory
* is exhausted, they abort. The |moz_| versions may return NULL
* pointers if memory is exhausted: their return value must be checked.
*
* All these allocation functions are *guaranteed* to return a pointer
* to memory allocated in such a way that that memory can be freed by
* passing that pointer to |free()|.
*/
MFBT_API void* moz_xmalloc(size_t size)
MOZ_ALLOCATOR;
MFBT_API void* moz_xcalloc(size_t nmemb, size_t size)
MOZ_ALLOCATOR;
MFBT_API void* moz_xrealloc(void* ptr, size_t size)
MOZ_ALLOCATOR;
MFBT_API char* moz_xstrdup(const char* str)
MOZ_ALLOCATOR;
MFBT_API size_t moz_malloc_usable_size(void *ptr);
MFBT_API size_t moz_malloc_size_of(const void *ptr);
#if defined(HAVE_STRNDUP)
MFBT_API char* moz_xstrndup(const char* str, size_t strsize)
MOZ_ALLOCATOR;
#endif /* if defined(HAVE_STRNDUP) */
#if defined(HAVE_POSIX_MEMALIGN)
MFBT_API MOZ_WARN_UNUSED_RESULT
int moz_xposix_memalign(void **ptr, size_t alignment, size_t size);
MFBT_API MOZ_WARN_UNUSED_RESULT
int moz_posix_memalign(void **ptr, size_t alignment, size_t size);
#endif /* if defined(HAVE_POSIX_MEMALIGN) */
#if defined(HAVE_MEMALIGN)
MFBT_API void* moz_xmemalign(size_t boundary, size_t size)
MOZ_ALLOCATOR;
#endif /* if defined(HAVE_MEMALIGN) */
#if defined(HAVE_VALLOC)
MFBT_API void* moz_xvalloc(size_t size)
MOZ_ALLOCATOR;
#endif /* if defined(HAVE_VALLOC) */
#ifdef __cplusplus
} /* extern "C" */
#endif /* ifdef __cplusplus */
#ifdef __cplusplus
/*
* We implement the default operators new/delete as part of
* libmozalloc, replacing their definitions in libstdc++. The
* operator new* definitions in libmozalloc will never return a NULL
* pointer.
*
* Each operator new immediately below returns a pointer to memory
* that can be delete'd by any of
*
* (1) the matching infallible operator delete immediately below
* (2) the matching "fallible" operator delete further below
* (3) the matching system |operator delete(void*, std::nothrow)|
* (4) the matching system |operator delete(void*) throw(std::bad_alloc)|
*
* NB: these are declared |throw(std::bad_alloc)|, though they will never
* throw that exception. This declaration is consistent with the rule
* that |::operator new() throw(std::bad_alloc)| will never return NULL.
*/
/* NB: This is defined just to silence vacuous warnings about symbol
* visibility on OS X/gcc. These symbols are force-inline and not
* exported. */
#if defined(XP_MACOSX)
# define MOZALLOC_EXPORT_NEW MFBT_API
#else
# define MOZALLOC_EXPORT_NEW
#endif
#if defined(ANDROID)
/*
* It's important to always specify 'throw()' in GCC because it's used to tell
* GCC that 'new' may return null. That makes GCC null-check the result before
* potentially initializing the memory to zero.
* Also, the Android minimalistic headers don't include std::bad_alloc.
*/
#define MOZALLOC_THROW_IF_HAS_EXCEPTIONS throw()
#define MOZALLOC_THROW_BAD_ALLOC_IF_HAS_EXCEPTIONS
#elif defined(_MSC_VER)
/*
* Suppress build warning spam (bug 578546).
*/
#define MOZALLOC_THROW_IF_HAS_EXCEPTIONS
#define MOZALLOC_THROW_BAD_ALLOC_IF_HAS_EXCEPTIONS
#else
#define MOZALLOC_THROW_IF_HAS_EXCEPTIONS throw()
#define MOZALLOC_THROW_BAD_ALLOC_IF_HAS_EXCEPTIONS throw(std::bad_alloc)
#endif
#define MOZALLOC_THROW_BAD_ALLOC MOZALLOC_THROW_BAD_ALLOC_IF_HAS_EXCEPTIONS
MOZALLOC_EXPORT_NEW
#if defined(__GNUC__) && !defined(__clang__) && defined(__SANITIZE_ADDRESS__)
/* gcc's asan somehow doesn't like always_inline on this function. */
__attribute__((gnu_inline)) inline
#else
MOZALLOC_INLINE
#endif
void* operator new(size_t size) MOZALLOC_THROW_BAD_ALLOC
{
return moz_xmalloc(size);
}
MOZALLOC_EXPORT_NEW MOZALLOC_INLINE
void* operator new(size_t size, const std::nothrow_t&) MOZALLOC_THROW_IF_HAS_EXCEPTIONS
{
return malloc_impl(size);
}
MOZALLOC_EXPORT_NEW MOZALLOC_INLINE
void* operator new[](size_t size) MOZALLOC_THROW_BAD_ALLOC
{
return moz_xmalloc(size);
}
MOZALLOC_EXPORT_NEW MOZALLOC_INLINE
void* operator new[](size_t size, const std::nothrow_t&) MOZALLOC_THROW_IF_HAS_EXCEPTIONS
{
return malloc_impl(size);
}
MOZALLOC_EXPORT_NEW MOZALLOC_INLINE
void operator delete(void* ptr) MOZALLOC_THROW_IF_HAS_EXCEPTIONS
{
return free_impl(ptr);
}
MOZALLOC_EXPORT_NEW MOZALLOC_INLINE
void operator delete(void* ptr, const std::nothrow_t&) MOZALLOC_THROW_IF_HAS_EXCEPTIONS
{
return free_impl(ptr);
}
MOZALLOC_EXPORT_NEW MOZALLOC_INLINE
void operator delete[](void* ptr) MOZALLOC_THROW_IF_HAS_EXCEPTIONS
{
return free_impl(ptr);
}
MOZALLOC_EXPORT_NEW MOZALLOC_INLINE
void operator delete[](void* ptr, const std::nothrow_t&) MOZALLOC_THROW_IF_HAS_EXCEPTIONS
{
return free_impl(ptr);
}
/*
* We also add a new allocator variant: "fallible operator new."
* Unlike libmozalloc's implementations of the standard nofail
* allocators, this allocator is allowed to return NULL. It can be used
* as follows
*
* Foo* f = new (mozilla::fallible) Foo(...);
*
* operator delete(fallible) is defined for completeness only.
*
* Each operator new below returns a pointer to memory that can be
* delete'd by any of
*
* (1) the matching "fallible" operator delete below
* (2) the matching infallible operator delete above
* (3) the matching system |operator delete(void*, std::nothrow)|
* (4) the matching system |operator delete(void*) throw(std::bad_alloc)|
*/
MOZALLOC_INLINE
void* operator new(size_t size, const mozilla::fallible_t&) MOZALLOC_THROW_IF_HAS_EXCEPTIONS
{
return malloc_impl(size);
}
MOZALLOC_INLINE
void* operator new[](size_t size, const mozilla::fallible_t&) MOZALLOC_THROW_IF_HAS_EXCEPTIONS
{
return malloc_impl(size);
}
MOZALLOC_INLINE
void operator delete(void* ptr, const mozilla::fallible_t&) MOZALLOC_THROW_IF_HAS_EXCEPTIONS
{
free_impl(ptr);
}
MOZALLOC_INLINE
void operator delete[](void* ptr, const mozilla::fallible_t&) MOZALLOC_THROW_IF_HAS_EXCEPTIONS
{
free_impl(ptr);
}
/*
* This policy is identical to MallocAllocPolicy, except it uses
* moz_xmalloc/moz_xcalloc/moz_xrealloc instead of
* malloc/calloc/realloc.
*/
class InfallibleAllocPolicy
{
public:
template <typename T>
T* pod_malloc(size_t aNumElems)
{
if (aNumElems & mozilla::tl::MulOverflowMask<sizeof(T)>::value) {
return nullptr;
}
return static_cast<T*>(moz_xmalloc(aNumElems * sizeof(T)));
}
template <typename T>
T* pod_calloc(size_t aNumElems)
{
return static_cast<T*>(moz_xcalloc(aNumElems, sizeof(T)));
}
template <typename T>
T* pod_realloc(T* aPtr, size_t aOldSize, size_t aNewSize)
{
if (aNewSize & mozilla::tl::MulOverflowMask<sizeof(T)>::value) {
return nullptr;
}
return static_cast<T*>(moz_xrealloc(aPtr, aNewSize * sizeof(T)));
}
void free_(void* aPtr)
{
free_impl(aPtr);
}
void reportAllocOverflow() const
{
}
};
#endif /* ifdef __cplusplus */
#ifdef malloc_impl_
#undef malloc_impl_
#undef malloc_impl
#endif
#ifdef free_impl_
#undef free_impl_
#undef free_impl
#endif
#endif /* ifndef mozilla_mozalloc_h */