1// Copyright (c) 2005, Google Inc.
2// All rights reserved.
3//
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5// modification, are permitted provided that the following conditions are
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7//
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17//
18// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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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,
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28// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29
30// ---
31// Author: Sanjay Ghemawat
32//
33// This has the implementation details of malloc_hook that are needed
34// to use malloc-hook inside the tcmalloc system.  It does not hold
35// any of the client-facing calls that are used to add new hooks.
36
37#ifndef _MALLOC_HOOK_INL_H_
38#define _MALLOC_HOOK_INL_H_
39
40#include <stddef.h>
41#include <sys/types.h>
42#include "base/atomicops.h"
43#include "base/basictypes.h"
44#include <gperftools/malloc_hook.h>
45
46namespace base { namespace internal {
47
48// The following (implementation) code is DEPRECATED.
49// A simple atomic pointer class that can be initialized by the linker
50// when you define a namespace-scope variable as:
51//
52//   AtomicPtr<Foo*> my_global = { &initial_value };
53//
54// This isn't suitable for a general atomic<> class because of the
55// public access to data_.
56template<typename PtrT>
57class AtomicPtr {
58 public:
59  COMPILE_ASSERT(sizeof(PtrT) <= sizeof(AtomicWord),
60                 PtrT_should_fit_in_AtomicWord);
61
62  PtrT Get() const {
63    // Depending on the system, Acquire_Load(AtomicWord*) may have
64    // been defined to return an AtomicWord, Atomic32, or Atomic64.
65    // We hide that implementation detail here with an explicit cast.
66    // This prevents MSVC 2005, at least, from complaining (it has to
67    // do with __wp64; AtomicWord is __wp64, but Atomic32/64 aren't).
68    return reinterpret_cast<PtrT>(static_cast<AtomicWord>(
69      base::subtle::Acquire_Load(&data_)));
70  }
71
72  // Sets the contained value to new_val and returns the old value,
73  // atomically, with acquire and release semantics.
74  // This is a full-barrier instruction.
75  PtrT Exchange(PtrT new_val);
76
77  // Atomically executes:
78  //      result = data_
79  //      if (data_ == old_val)
80  //        data_ = new_val;
81  //      return result;
82  // This is a full-barrier instruction.
83  PtrT CompareAndSwap(PtrT old_val, PtrT new_val);
84
85  // Not private so that the class is an aggregate and can be
86  // initialized by the linker. Don't access this directly.
87  AtomicWord data_;
88};
89
90// These are initialized in malloc_hook.cc
91extern AtomicPtr<MallocHook::NewHook>     new_hook_;
92extern AtomicPtr<MallocHook::DeleteHook>  delete_hook_;
93extern AtomicPtr<MallocHook::PreMmapHook> premmap_hook_;
94extern AtomicPtr<MallocHook::MmapHook>    mmap_hook_;
95extern AtomicPtr<MallocHook::MunmapHook>  munmap_hook_;
96extern AtomicPtr<MallocHook::MremapHook>  mremap_hook_;
97extern AtomicPtr<MallocHook::PreSbrkHook> presbrk_hook_;
98extern AtomicPtr<MallocHook::SbrkHook>    sbrk_hook_;
99// End DEPRECATED code.
100
101// Maximum of 7 hooks means that HookList is 8 words.
102static const int kHookListMaxValues = 7;
103
104// HookList: a class that provides synchronized insertions and removals and
105// lockless traversal.  Most of the implementation is in malloc_hook.cc.
106template <typename T>
107struct PERFTOOLS_DLL_DECL HookList {
108  COMPILE_ASSERT(sizeof(T) <= sizeof(AtomicWord), T_should_fit_in_AtomicWord);
109
110  // Adds value to the list.  Note that duplicates are allowed.  Thread-safe and
111  // blocking (acquires hooklist_spinlock).  Returns true on success; false
112  // otherwise (failures include invalid value and no space left).
113  bool Add(T value);
114
115  // Removes the first entry matching value from the list.  Thread-safe and
116  // blocking (acquires hooklist_spinlock).  Returns true on success; false
117  // otherwise (failures include invalid value and no value found).
118  bool Remove(T value);
119
120  // Store up to n values of the list in output_array, and return the number of
121  // elements stored.  Thread-safe and non-blocking.  This is fast (one memory
122  // access) if the list is empty.
123  int Traverse(T* output_array, int n) const;
124
125  // Fast inline implementation for fast path of Invoke*Hook.
126  bool empty() const {
127    return base::subtle::Acquire_Load(&priv_end) == 0;
128  }
129
130  // This internal data is not private so that the class is an aggregate and can
131  // be initialized by the linker.  Don't access this directly.  Use the
132  // INIT_HOOK_LIST macro in malloc_hook.cc.
133
134  // One more than the index of the last valid element in priv_data.  During
135  // 'Remove' this may be past the last valid element in priv_data, but
136  // subsequent values will be 0.
137  AtomicWord priv_end;
138  AtomicWord priv_data[kHookListMaxValues];
139};
140
141extern HookList<MallocHook::NewHook> new_hooks_;
142extern HookList<MallocHook::DeleteHook> delete_hooks_;
143extern HookList<MallocHook::PreMmapHook> premmap_hooks_;
144extern HookList<MallocHook::MmapHook> mmap_hooks_;
145extern HookList<MallocHook::MmapReplacement> mmap_replacement_;
146extern HookList<MallocHook::MunmapHook> munmap_hooks_;
147extern HookList<MallocHook::MunmapReplacement> munmap_replacement_;
148extern HookList<MallocHook::MremapHook> mremap_hooks_;
149extern HookList<MallocHook::PreSbrkHook> presbrk_hooks_;
150extern HookList<MallocHook::SbrkHook> sbrk_hooks_;
151
152} }  // namespace base::internal
153
154// The following method is DEPRECATED
155inline MallocHook::NewHook MallocHook::GetNewHook() {
156  return base::internal::new_hook_.Get();
157}
158
159inline void MallocHook::InvokeNewHook(const void* p, size_t s) {
160  if (!base::internal::new_hooks_.empty()) {
161    InvokeNewHookSlow(p, s);
162  }
163  // The following code is DEPRECATED.
164  MallocHook::NewHook hook = MallocHook::GetNewHook();
165  if (hook != NULL) (*hook)(p, s);
166  // End DEPRECATED code.
167}
168
169// The following method is DEPRECATED
170inline MallocHook::DeleteHook MallocHook::GetDeleteHook() {
171  return base::internal::delete_hook_.Get();
172}
173
174inline void MallocHook::InvokeDeleteHook(const void* p) {
175  if (!base::internal::delete_hooks_.empty()) {
176    InvokeDeleteHookSlow(p);
177  }
178  // The following code is DEPRECATED.
179  MallocHook::DeleteHook hook = MallocHook::GetDeleteHook();
180  if (hook != NULL) (*hook)(p);
181  // End DEPRECATED code.
182}
183
184// The following method is DEPRECATED
185inline MallocHook::PreMmapHook MallocHook::GetPreMmapHook() {
186  return base::internal::premmap_hook_.Get();
187}
188
189inline void MallocHook::InvokePreMmapHook(const void* start,
190                                          size_t size,
191                                          int protection,
192                                          int flags,
193                                          int fd,
194                                          off_t offset) {
195  if (!base::internal::premmap_hooks_.empty()) {
196    InvokePreMmapHookSlow(start, size, protection, flags, fd, offset);
197  }
198  // The following code is DEPRECATED.
199  MallocHook::PreMmapHook hook = MallocHook::GetPreMmapHook();
200  if (hook != NULL) (*hook)(start, size,
201                            protection, flags,
202                            fd, offset);
203  // End DEPRECATED code.
204}
205
206// The following method is DEPRECATED
207inline MallocHook::MmapHook MallocHook::GetMmapHook() {
208  return base::internal::mmap_hook_.Get();
209}
210
211inline void MallocHook::InvokeMmapHook(const void* result,
212                                       const void* start,
213                                       size_t size,
214                                       int protection,
215                                       int flags,
216                                       int fd,
217                                       off_t offset) {
218  if (!base::internal::mmap_hooks_.empty()) {
219    InvokeMmapHookSlow(result, start, size, protection, flags, fd, offset);
220  }
221  // The following code is DEPRECATED.
222  MallocHook::MmapHook hook = MallocHook::GetMmapHook();
223  if (hook != NULL) (*hook)(result,
224                            start, size,
225                            protection, flags,
226                            fd, offset);
227  // End DEPRECATED code.
228}
229
230inline bool MallocHook::InvokeMmapReplacement(const void* start,
231                                              size_t size,
232                                              int protection,
233                                              int flags,
234                                              int fd,
235                                              off_t offset,
236                                              void** result) {
237  if (!base::internal::mmap_replacement_.empty()) {
238    return InvokeMmapReplacementSlow(start, size,
239                                     protection, flags,
240                                     fd, offset,
241                                     result);
242  }
243  return false;
244}
245
246// The following method is DEPRECATED
247inline MallocHook::MunmapHook MallocHook::GetMunmapHook() {
248  return base::internal::munmap_hook_.Get();
249}
250
251inline void MallocHook::InvokeMunmapHook(const void* p, size_t size) {
252  if (!base::internal::munmap_hooks_.empty()) {
253    InvokeMunmapHookSlow(p, size);
254  }
255  // The following code is DEPRECATED.
256  MallocHook::MunmapHook hook = MallocHook::GetMunmapHook();
257  if (hook != NULL) (*hook)(p, size);
258  // End DEPRECATED code.
259}
260
261inline bool MallocHook::InvokeMunmapReplacement(
262    const void* p, size_t size, int* result) {
263  if (!base::internal::mmap_replacement_.empty()) {
264    return InvokeMunmapReplacementSlow(p, size, result);
265  }
266  return false;
267}
268
269// The following method is DEPRECATED
270inline MallocHook::MremapHook MallocHook::GetMremapHook() {
271  return base::internal::mremap_hook_.Get();
272}
273
274inline void MallocHook::InvokeMremapHook(const void* result,
275                                         const void* old_addr,
276                                         size_t old_size,
277                                         size_t new_size,
278                                         int flags,
279                                         const void* new_addr) {
280  if (!base::internal::mremap_hooks_.empty()) {
281    InvokeMremapHookSlow(result, old_addr, old_size, new_size, flags, new_addr);
282  }
283  // The following code is DEPRECATED.
284  MallocHook::MremapHook hook = MallocHook::GetMremapHook();
285  if (hook != NULL) (*hook)(result,
286                            old_addr, old_size,
287                            new_size, flags, new_addr);
288  // End DEPRECATED code.
289}
290
291// The following method is DEPRECATED
292inline MallocHook::PreSbrkHook MallocHook::GetPreSbrkHook() {
293  return base::internal::presbrk_hook_.Get();
294}
295
296inline void MallocHook::InvokePreSbrkHook(ptrdiff_t increment) {
297  if (!base::internal::presbrk_hooks_.empty() && increment != 0) {
298    InvokePreSbrkHookSlow(increment);
299  }
300  // The following code is DEPRECATED.
301  MallocHook::PreSbrkHook hook = MallocHook::GetPreSbrkHook();
302  if (hook != NULL && increment != 0) (*hook)(increment);
303  // End DEPRECATED code.
304}
305
306// The following method is DEPRECATED
307inline MallocHook::SbrkHook MallocHook::GetSbrkHook() {
308  return base::internal::sbrk_hook_.Get();
309}
310
311inline void MallocHook::InvokeSbrkHook(const void* result,
312                                       ptrdiff_t increment) {
313  if (!base::internal::sbrk_hooks_.empty() && increment != 0) {
314    InvokeSbrkHookSlow(result, increment);
315  }
316  // The following code is DEPRECATED.
317  MallocHook::SbrkHook hook = MallocHook::GetSbrkHook();
318  if (hook != NULL && increment != 0) (*hook)(result, increment);
319  // End DEPRECATED code.
320}
321
322#endif /* _MALLOC_HOOK_INL_H_ */
323