1// Copyright (c) 2005, Google Inc.
2// All rights reserved.
3//
4// Redistribution and use in source and binary forms, with or without
5// modification, are permitted provided that the following conditions are
6// met:
7//
8//     * Redistributions of source code must retain the above copyright
9// notice, this list of conditions and the following disclaimer.
10//     * Redistributions in binary form must reproduce the above
11// copyright notice, this list of conditions and the following disclaimer
12// in the documentation and/or other materials provided with the
13// distribution.
14//     * Neither the name of Google Inc. nor the names of its
15// contributors may be used to endorse or promote products derived from
16// this software without specific prior written permission.
17//
18// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
21// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
22// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
23// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
24// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
28// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29
30// ---
31// Author: Sanjay Ghemawat
32//
33// Some of our malloc implementations can invoke the following hooks whenever
34// memory is allocated or deallocated.  MallocHook is thread-safe, and things
35// you do before calling AddFooHook(MyHook) are visible to any resulting calls
36// to MyHook.  Hooks must be thread-safe.  If you write:
37//
38//   CHECK(MallocHook::AddNewHook(&MyNewHook));
39//
40// MyNewHook will be invoked in subsequent calls in the current thread, but
41// there are no guarantees on when it might be invoked in other threads.
42//
43// There are a limited number of slots available for each hook type.  Add*Hook
44// will return false if there are no slots available.  Remove*Hook will return
45// false if the given hook was not already installed.
46//
47// The order in which individual hooks are called in Invoke*Hook is undefined.
48//
49// It is safe for a hook to remove itself within Invoke*Hook and add other
50// hooks.  Any hooks added inside a hook invocation (for the same hook type)
51// will not be invoked for the current invocation.
52//
53// One important user of these hooks is the heap profiler.
54//
55// CAVEAT: If you add new MallocHook::Invoke* calls then those calls must be
56// directly in the code of the (de)allocation function that is provided to the
57// user and that function must have an ATTRIBUTE_SECTION(malloc_hook) attribute.
58//
59// Note: the Invoke*Hook() functions are defined in malloc_hook-inl.h.  If you
60// need to invoke a hook (which you shouldn't unless you're part of tcmalloc),
61// be sure to #include malloc_hook-inl.h in addition to malloc_hook.h.
62//
63// NOTE FOR C USERS: If you want to use malloc_hook functionality from
64// a C program, #include malloc_hook_c.h instead of this file.
65
66#ifndef _MALLOC_HOOK_H_
67#define _MALLOC_HOOK_H_
68
69#include <stddef.h>
70#include <sys/types.h>
71extern "C" {
72#include <gperftools/malloc_hook_c.h>  // a C version of the malloc_hook interface
73}
74
75// Annoying stuff for windows -- makes sure clients can import these functions
76#ifndef PERFTOOLS_DLL_DECL
77# ifdef _WIN32
78#   define PERFTOOLS_DLL_DECL  __declspec(dllimport)
79# else
80#   define PERFTOOLS_DLL_DECL
81# endif
82#endif
83
84// The C++ methods below call the C version (MallocHook_*), and thus
85// convert between an int and a bool.  Windows complains about this
86// (a "performance warning") which we don't care about, so we suppress.
87#ifdef _MSC_VER
88#pragma warning(push)
89#pragma warning(disable:4800)
90#endif
91
92// Note: malloc_hook_c.h defines MallocHook_*Hook and
93// MallocHook_{Add,Remove}*Hook.  The version of these inside the MallocHook
94// class are defined in terms of the malloc_hook_c version.  See malloc_hook_c.h
95// for details of these types/functions.
96
97class PERFTOOLS_DLL_DECL MallocHook {
98 public:
99  // The NewHook is invoked whenever an object is allocated.
100  // It may be passed NULL if the allocator returned NULL.
101  typedef MallocHook_NewHook NewHook;
102  inline static bool AddNewHook(NewHook hook) {
103    return MallocHook_AddNewHook(hook);
104  }
105  inline static bool RemoveNewHook(NewHook hook) {
106    return MallocHook_RemoveNewHook(hook);
107  }
108  inline static void InvokeNewHook(const void* p, size_t s);
109
110  // The DeleteHook is invoked whenever an object is deallocated.
111  // It may be passed NULL if the caller is trying to delete NULL.
112  typedef MallocHook_DeleteHook DeleteHook;
113  inline static bool AddDeleteHook(DeleteHook hook) {
114    return MallocHook_AddDeleteHook(hook);
115  }
116  inline static bool RemoveDeleteHook(DeleteHook hook) {
117    return MallocHook_RemoveDeleteHook(hook);
118  }
119  inline static void InvokeDeleteHook(const void* p);
120
121  // The PreMmapHook is invoked with mmap or mmap64 arguments just
122  // before the call is actually made.  Such a hook may be useful
123  // in memory limited contexts, to catch allocations that will exceed
124  // a memory limit, and take outside actions to increase that limit.
125  typedef MallocHook_PreMmapHook PreMmapHook;
126  inline static bool AddPreMmapHook(PreMmapHook hook) {
127    return MallocHook_AddPreMmapHook(hook);
128  }
129  inline static bool RemovePreMmapHook(PreMmapHook hook) {
130    return MallocHook_RemovePreMmapHook(hook);
131  }
132  inline static void InvokePreMmapHook(const void* start,
133                                       size_t size,
134                                       int protection,
135                                       int flags,
136                                       int fd,
137                                       off_t offset);
138
139  // The MmapReplacement is invoked after the PreMmapHook but before
140  // the call is actually made. The MmapReplacement should return true
141  // if it handled the call, or false if it is still necessary to
142  // call mmap/mmap64.
143  // This should be used only by experts, and users must be be
144  // extremely careful to avoid recursive calls to mmap. The replacement
145  // should be async signal safe.
146  // Only one MmapReplacement is supported. After setting an MmapReplacement
147  // you must call RemoveMmapReplacement before calling SetMmapReplacement
148  // again.
149  typedef MallocHook_MmapReplacement MmapReplacement;
150  inline static bool SetMmapReplacement(MmapReplacement hook) {
151    return MallocHook_SetMmapReplacement(hook);
152  }
153  inline static bool RemoveMmapReplacement(MmapReplacement hook) {
154    return MallocHook_RemoveMmapReplacement(hook);
155  }
156  inline static bool InvokeMmapReplacement(const void* start,
157                                           size_t size,
158                                           int protection,
159                                           int flags,
160                                           int fd,
161                                           off_t offset,
162                                           void** result);
163
164
165  // The MmapHook is invoked whenever a region of memory is mapped.
166  // It may be passed MAP_FAILED if the mmap failed.
167  typedef MallocHook_MmapHook MmapHook;
168  inline static bool AddMmapHook(MmapHook hook) {
169    return MallocHook_AddMmapHook(hook);
170  }
171  inline static bool RemoveMmapHook(MmapHook hook) {
172    return MallocHook_RemoveMmapHook(hook);
173  }
174  inline static void InvokeMmapHook(const void* result,
175                                    const void* start,
176                                    size_t size,
177                                    int protection,
178                                    int flags,
179                                    int fd,
180                                    off_t offset);
181
182  // The MunmapReplacement is invoked with munmap arguments just before
183  // the call is actually made. The MunmapReplacement should return true
184  // if it handled the call, or false if it is still necessary to
185  // call munmap.
186  // This should be used only by experts. The replacement should be
187  // async signal safe.
188  // Only one MunmapReplacement is supported. After setting an
189  // MunmapReplacement you must call RemoveMunmapReplacement before
190  // calling SetMunmapReplacement again.
191  typedef MallocHook_MunmapReplacement MunmapReplacement;
192  inline static bool SetMunmapReplacement(MunmapReplacement hook) {
193    return MallocHook_SetMunmapReplacement(hook);
194  }
195  inline static bool RemoveMunmapReplacement(MunmapReplacement hook) {
196    return MallocHook_RemoveMunmapReplacement(hook);
197  }
198  inline static bool InvokeMunmapReplacement(const void* p,
199                                             size_t size,
200                                             int* result);
201
202  // The MunmapHook is invoked whenever a region of memory is unmapped.
203  typedef MallocHook_MunmapHook MunmapHook;
204  inline static bool AddMunmapHook(MunmapHook hook) {
205    return MallocHook_AddMunmapHook(hook);
206  }
207  inline static bool RemoveMunmapHook(MunmapHook hook) {
208    return MallocHook_RemoveMunmapHook(hook);
209  }
210  inline static void InvokeMunmapHook(const void* p, size_t size);
211
212  // The MremapHook is invoked whenever a region of memory is remapped.
213  typedef MallocHook_MremapHook MremapHook;
214  inline static bool AddMremapHook(MremapHook hook) {
215    return MallocHook_AddMremapHook(hook);
216  }
217  inline static bool RemoveMremapHook(MremapHook hook) {
218    return MallocHook_RemoveMremapHook(hook);
219  }
220  inline static void InvokeMremapHook(const void* result,
221                                      const void* old_addr,
222                                      size_t old_size,
223                                      size_t new_size,
224                                      int flags,
225                                      const void* new_addr);
226
227  // The PreSbrkHook is invoked just before sbrk is called -- except when
228  // the increment is 0.  This is because sbrk(0) is often called
229  // to get the top of the memory stack, and is not actually a
230  // memory-allocation call.  It may be useful in memory-limited contexts,
231  // to catch allocations that will exceed the limit and take outside
232  // actions to increase such a limit.
233  typedef MallocHook_PreSbrkHook PreSbrkHook;
234  inline static bool AddPreSbrkHook(PreSbrkHook hook) {
235    return MallocHook_AddPreSbrkHook(hook);
236  }
237  inline static bool RemovePreSbrkHook(PreSbrkHook hook) {
238    return MallocHook_RemovePreSbrkHook(hook);
239  }
240  inline static void InvokePreSbrkHook(ptrdiff_t increment);
241
242  // The SbrkHook is invoked whenever sbrk is called -- except when
243  // the increment is 0.  This is because sbrk(0) is often called
244  // to get the top of the memory stack, and is not actually a
245  // memory-allocation call.
246  typedef MallocHook_SbrkHook SbrkHook;
247  inline static bool AddSbrkHook(SbrkHook hook) {
248    return MallocHook_AddSbrkHook(hook);
249  }
250  inline static bool RemoveSbrkHook(SbrkHook hook) {
251    return MallocHook_RemoveSbrkHook(hook);
252  }
253  inline static void InvokeSbrkHook(const void* result, ptrdiff_t increment);
254
255  // Get the current stack trace.  Try to skip all routines up to and
256  // and including the caller of MallocHook::Invoke*.
257  // Use "skip_count" (similarly to GetStackTrace from stacktrace.h)
258  // as a hint about how many routines to skip if better information
259  // is not available.
260  inline static int GetCallerStackTrace(void** result, int max_depth,
261                                        int skip_count) {
262    return MallocHook_GetCallerStackTrace(result, max_depth, skip_count);
263  }
264
265  // Unhooked versions of mmap() and munmap().   These should be used
266  // only by experts, since they bypass heapchecking, etc.
267  // Note: These do not run hooks, but they still use the MmapReplacement
268  // and MunmapReplacement.
269  static void* UnhookedMMap(void *start, size_t length, int prot, int flags,
270                            int fd, off_t offset);
271  static int UnhookedMUnmap(void *start, size_t length);
272
273  // The following are DEPRECATED.
274  inline static NewHook GetNewHook();
275  inline static NewHook SetNewHook(NewHook hook) {
276    return MallocHook_SetNewHook(hook);
277  }
278
279  inline static DeleteHook GetDeleteHook();
280  inline static DeleteHook SetDeleteHook(DeleteHook hook) {
281    return MallocHook_SetDeleteHook(hook);
282  }
283
284  inline static PreMmapHook GetPreMmapHook();
285  inline static PreMmapHook SetPreMmapHook(PreMmapHook hook) {
286    return MallocHook_SetPreMmapHook(hook);
287  }
288
289  inline static MmapHook GetMmapHook();
290  inline static MmapHook SetMmapHook(MmapHook hook) {
291    return MallocHook_SetMmapHook(hook);
292  }
293
294  inline static MunmapHook GetMunmapHook();
295  inline static MunmapHook SetMunmapHook(MunmapHook hook) {
296    return MallocHook_SetMunmapHook(hook);
297  }
298
299  inline static MremapHook GetMremapHook();
300  inline static MremapHook SetMremapHook(MremapHook hook) {
301    return MallocHook_SetMremapHook(hook);
302  }
303
304  inline static PreSbrkHook GetPreSbrkHook();
305  inline static PreSbrkHook SetPreSbrkHook(PreSbrkHook hook) {
306    return MallocHook_SetPreSbrkHook(hook);
307  }
308
309  inline static SbrkHook GetSbrkHook();
310  inline static SbrkHook SetSbrkHook(SbrkHook hook) {
311    return MallocHook_SetSbrkHook(hook);
312  }
313  // End of DEPRECATED methods.
314
315 private:
316  // Slow path versions of Invoke*Hook.
317  static void InvokeNewHookSlow(const void* p, size_t s);
318  static void InvokeDeleteHookSlow(const void* p);
319  static void InvokePreMmapHookSlow(const void* start,
320                                    size_t size,
321                                    int protection,
322                                    int flags,
323                                    int fd,
324                                    off_t offset);
325  static void InvokeMmapHookSlow(const void* result,
326                                 const void* start,
327                                 size_t size,
328                                 int protection,
329                                 int flags,
330                                 int fd,
331                                 off_t offset);
332  static bool InvokeMmapReplacementSlow(const void* start,
333                                        size_t size,
334                                        int protection,
335                                        int flags,
336                                        int fd,
337                                        off_t offset,
338                                        void** result);
339  static void InvokeMunmapHookSlow(const void* p, size_t size);
340  static bool InvokeMunmapReplacementSlow(const void* p,
341                                          size_t size,
342                                          int* result);
343  static void InvokeMremapHookSlow(const void* result,
344                                   const void* old_addr,
345                                   size_t old_size,
346                                   size_t new_size,
347                                   int flags,
348                                   const void* new_addr);
349  static void InvokePreSbrkHookSlow(ptrdiff_t increment);
350  static void InvokeSbrkHookSlow(const void* result, ptrdiff_t increment);
351};
352
353#ifdef _MSC_VER
354#pragma warning(pop)
355#endif
356
357
358#endif /* _MALLOC_HOOK_H_ */
359