7ca9a74fef
The sk_throw macro is now an alias to SK_ABORT, but is often used when other macros better describe the situation. This change replaces sk_throw with SK_ABORT or SkASSERT_RELEASE as appropriate. Change-Id: I313facc6d535c8e8bec90ceeaf17ae3a381c48f3 Reviewed-on: https://skia-review.googlesource.com/35882 Reviewed-by: Yuqian Li <liyuqian@google.com> Commit-Queue: Ben Wagner <bungeman@google.com>
85 lines
3.0 KiB
C
85 lines
3.0 KiB
C
/*
|
|
* Copyright 2017 Google Inc.
|
|
*
|
|
* Use of this source code is governed by a BSD-style license that can be
|
|
* found in the LICENSE file.
|
|
*/
|
|
|
|
#ifndef SkMalloc_DEFINED
|
|
#define SkMalloc_DEFINED
|
|
|
|
#include <cstddef>
|
|
#include <cstring>
|
|
|
|
#include "SkPreConfig.h"
|
|
|
|
/*
|
|
memory wrappers to be implemented by the porting layer (platform)
|
|
*/
|
|
|
|
enum {
|
|
SK_MALLOC_TEMP = 0x01, //!< hint to sk_malloc that the requested memory will be freed in the scope of the stack frame
|
|
SK_MALLOC_THROW = 0x02 //!< instructs sk_malloc to not return normally if the memory cannot be allocated.
|
|
};
|
|
/** Return a block of memory (at least 4-byte aligned) of at least the
|
|
specified size. If the requested memory cannot be returned, either
|
|
return null (if SK_MALLOC_TEMP bit is clear) or throw an exception
|
|
(if SK_MALLOC_TEMP bit is set). To free the memory, call sk_free().
|
|
*/
|
|
SK_API extern void* sk_malloc_flags(size_t size, unsigned flags);
|
|
/** Same as sk_malloc(), but hard coded to pass SK_MALLOC_THROW as the flag
|
|
*/
|
|
SK_API extern void* sk_malloc_throw(size_t size);
|
|
/** Same as standard realloc(), but this one never returns null on failure. It will throw
|
|
an exception if it fails.
|
|
*/
|
|
SK_API extern void* sk_realloc_throw(void* buffer, size_t size);
|
|
/** Free memory returned by sk_malloc(). It is safe to pass null.
|
|
*/
|
|
SK_API extern void sk_free(void*);
|
|
|
|
/** Much like calloc: returns a pointer to at least size zero bytes, or NULL on failure.
|
|
*/
|
|
SK_API extern void* sk_calloc(size_t size);
|
|
|
|
/** Same as sk_calloc, but throws an exception instead of returning NULL on failure.
|
|
*/
|
|
SK_API extern void* sk_calloc_throw(size_t size);
|
|
|
|
/** Called internally if we run out of memory. The platform implementation must
|
|
not return, but should either throw an exception or otherwise exit.
|
|
*/
|
|
SK_API extern void sk_out_of_memory(void);
|
|
|
|
// bzero is safer than memset, but we can't rely on it, so... sk_bzero()
|
|
static inline void sk_bzero(void* buffer, size_t size) {
|
|
// Please c.f. sk_careful_memcpy. It's undefined behavior to call memset(null, 0, 0).
|
|
if (size) {
|
|
memset(buffer, 0, size);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* sk_careful_memcpy() is just like memcpy(), but guards against undefined behavior.
|
|
*
|
|
* It is undefined behavior to call memcpy() with null dst or src, even if len is 0.
|
|
* If an optimizer is "smart" enough, it can exploit this to do unexpected things.
|
|
* memcpy(dst, src, 0);
|
|
* if (src) {
|
|
* printf("%x\n", *src);
|
|
* }
|
|
* In this code the compiler can assume src is not null and omit the if (src) {...} check,
|
|
* unconditionally running the printf, crashing the program if src really is null.
|
|
* Of the compilers we pay attention to only GCC performs this optimization in practice.
|
|
*/
|
|
static inline void* sk_careful_memcpy(void* dst, const void* src, size_t len) {
|
|
// When we pass >0 len we had better already be passing valid pointers.
|
|
// So we just need to skip calling memcpy when len == 0.
|
|
if (len) {
|
|
memcpy(dst,src,len);
|
|
}
|
|
return dst;
|
|
}
|
|
|
|
#endif // SkMalloc_DEFINED
|