1//===-- allocator_interface.h ---------------------------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// Public interface header for allocator used in sanitizers (ASan/TSan/MSan).
10//===----------------------------------------------------------------------===//
11#ifndef SANITIZER_ALLOCATOR_INTERFACE_H
12#define SANITIZER_ALLOCATOR_INTERFACE_H
13
14#include <sanitizer/common_interface_defs.h>
15#include <stddef.h>
16
17#ifdef __cplusplus
18extern "C" {
19#endif
20/* Returns the estimated number of bytes that will be reserved by allocator
21   for request of "size" bytes. If allocator can't allocate that much
22   memory, returns the maximal possible allocation size, otherwise returns
23   "size". */
24size_t SANITIZER_CDECL __sanitizer_get_estimated_allocated_size(size_t size);
25
26/* Returns true if p was returned by the allocator and
27   is not yet freed. */
28int SANITIZER_CDECL __sanitizer_get_ownership(const volatile void *p);
29
30/* If a pointer lies within an allocation, it will return the start address
31   of the allocation. Otherwise, it returns nullptr. */
32const void *SANITIZER_CDECL __sanitizer_get_allocated_begin(const void *p);
33
34/* Returns the number of bytes reserved for the pointer p.
35   Requires (get_ownership(p) == true) or (p == 0). */
36size_t SANITIZER_CDECL __sanitizer_get_allocated_size(const volatile void *p);
37
38/* Returns the number of bytes reserved for the pointer p.
39   Requires __sanitizer_get_allocated_begin(p) == p. */
40size_t SANITIZER_CDECL
41__sanitizer_get_allocated_size_fast(const volatile void *p);
42
43/* Number of bytes, allocated and not yet freed by the application. */
44size_t SANITIZER_CDECL __sanitizer_get_current_allocated_bytes(void);
45
46/* Number of bytes, mmaped by the allocator to fulfill allocation requests.
47   Generally, for request of X bytes, allocator can reserve and add to free
48   lists a large number of chunks of size X to use them for future requests.
49   All these chunks count toward the heap size. Currently, allocator never
50   releases memory to OS (instead, it just puts freed chunks to free
51   lists). */
52size_t SANITIZER_CDECL __sanitizer_get_heap_size(void);
53
54/* Number of bytes, mmaped by the allocator, which can be used to fulfill
55   allocation requests. When a user program frees memory chunk, it can first
56   fall into quarantine and will count toward __sanitizer_get_free_bytes()
57   later. */
58size_t SANITIZER_CDECL __sanitizer_get_free_bytes(void);
59
60/* Number of bytes in unmapped pages, that are released to OS. Currently,
61   always returns 0. */
62size_t SANITIZER_CDECL __sanitizer_get_unmapped_bytes(void);
63
64/* Malloc hooks that may be optionally provided by user.
65   __sanitizer_malloc_hook(ptr, size) is called immediately after
66     allocation of "size" bytes, which returned "ptr".
67   __sanitizer_free_hook(ptr) is called immediately before
68     deallocation of "ptr". */
69void SANITIZER_CDECL __sanitizer_malloc_hook(const volatile void *ptr,
70                                             size_t size);
71void SANITIZER_CDECL __sanitizer_free_hook(const volatile void *ptr);
72
73/* Installs a pair of hooks for malloc/free.
74   Several (currently, 5) hook pairs may be installed, they are executed
75   in the order they were installed and after calling
76   __sanitizer_malloc_hook/__sanitizer_free_hook.
77   Unlike __sanitizer_malloc_hook/__sanitizer_free_hook these hooks can be
78   chained and do not rely on weak symbols working on the platform, but
79   require __sanitizer_install_malloc_and_free_hooks to be called at startup
80   and thus will not be called on malloc/free very early in the process.
81   Returns the number of hooks currently installed or 0 on failure.
82   Not thread-safe, should be called in the main thread before starting
83   other threads.
84*/
85int SANITIZER_CDECL __sanitizer_install_malloc_and_free_hooks(
86    void(SANITIZER_CDECL *malloc_hook)(const volatile void *, size_t),
87    void(SANITIZER_CDECL *free_hook)(const volatile void *));
88
89/* Drains allocator quarantines (calling thread's and global ones), returns
90   freed memory back to OS and releases other non-essential internal allocator
91   resources in attempt to reduce process RSS.
92   Currently available with ASan only.
93*/
94void SANITIZER_CDECL __sanitizer_purge_allocator(void);
95#ifdef __cplusplus
96} // extern "C"
97#endif
98
99#endif
100