(root)/
Python-3.12.0/
Include/
dynamic_annotations.h
       1  /* Copyright (c) 2008-2009, 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   *     * Neither the name of Google Inc. nor the names of its
      11   * contributors may be used to endorse or promote products derived from
      12   * this software without specific prior written permission.
      13   *
      14   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
      15   * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
      16   * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
      17   * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
      18   * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
      19   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
      20   * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
      21   * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
      22   * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
      23   * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
      24   * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
      25   *
      26   * ---
      27   * Author: Kostya Serebryany
      28   * Copied to CPython by Jeffrey Yasskin, with all macros renamed to
      29   * start with _Py_ to avoid colliding with users embedding Python, and
      30   * with deprecated macros removed.
      31   */
      32  
      33  /* This file defines dynamic annotations for use with dynamic analysis
      34     tool such as valgrind, PIN, etc.
      35  
      36     Dynamic annotation is a source code annotation that affects
      37     the generated code (that is, the annotation is not a comment).
      38     Each such annotation is attached to a particular
      39     instruction and/or to a particular object (address) in the program.
      40  
      41     The annotations that should be used by users are macros in all upper-case
      42     (e.g., _Py_ANNOTATE_NEW_MEMORY).
      43  
      44     Actual implementation of these macros may differ depending on the
      45     dynamic analysis tool being used.
      46  
      47     See https://code.google.com/p/data-race-test/  for more information.
      48  
      49     This file supports the following dynamic analysis tools:
      50     - None (DYNAMIC_ANNOTATIONS_ENABLED is not defined or zero).
      51        Macros are defined empty.
      52     - ThreadSanitizer, Helgrind, DRD (DYNAMIC_ANNOTATIONS_ENABLED is 1).
      53        Macros are defined as calls to non-inlinable empty functions
      54        that are intercepted by Valgrind. */
      55  
      56  #ifndef __DYNAMIC_ANNOTATIONS_H__
      57  #define __DYNAMIC_ANNOTATIONS_H__
      58  
      59  #ifndef DYNAMIC_ANNOTATIONS_ENABLED
      60  # define DYNAMIC_ANNOTATIONS_ENABLED 0
      61  #endif
      62  
      63  #if DYNAMIC_ANNOTATIONS_ENABLED != 0
      64  
      65    /* -------------------------------------------------------------
      66       Annotations useful when implementing condition variables such as CondVar,
      67       using conditional critical sections (Await/LockWhen) and when constructing
      68       user-defined synchronization mechanisms.
      69  
      70       The annotations _Py_ANNOTATE_HAPPENS_BEFORE() and
      71       _Py_ANNOTATE_HAPPENS_AFTER() can be used to define happens-before arcs in
      72       user-defined synchronization mechanisms: the race detector will infer an
      73       arc from the former to the latter when they share the same argument
      74       pointer.
      75  
      76       Example 1 (reference counting):
      77  
      78       void Unref() {
      79         _Py_ANNOTATE_HAPPENS_BEFORE(&refcount_);
      80         if (AtomicDecrementByOne(&refcount_) == 0) {
      81           _Py_ANNOTATE_HAPPENS_AFTER(&refcount_);
      82           delete this;
      83         }
      84       }
      85  
      86       Example 2 (message queue):
      87  
      88       void MyQueue::Put(Type *e) {
      89         MutexLock lock(&mu_);
      90         _Py_ANNOTATE_HAPPENS_BEFORE(e);
      91         PutElementIntoMyQueue(e);
      92       }
      93  
      94       Type *MyQueue::Get() {
      95         MutexLock lock(&mu_);
      96         Type *e = GetElementFromMyQueue();
      97         _Py_ANNOTATE_HAPPENS_AFTER(e);
      98         return e;
      99       }
     100  
     101       Note: when possible, please use the existing reference counting and message
     102       queue implementations instead of inventing new ones. */
     103  
     104    /* Report that wait on the condition variable at address "cv" has succeeded
     105       and the lock at address "lock" is held. */
     106  #define _Py_ANNOTATE_CONDVAR_LOCK_WAIT(cv, lock) \
     107      AnnotateCondVarWait(__FILE__, __LINE__, cv, lock)
     108  
     109    /* Report that wait on the condition variable at "cv" has succeeded.  Variant
     110       w/o lock. */
     111  #define _Py_ANNOTATE_CONDVAR_WAIT(cv) \
     112      AnnotateCondVarWait(__FILE__, __LINE__, cv, NULL)
     113  
     114    /* Report that we are about to signal on the condition variable at address
     115       "cv". */
     116  #define _Py_ANNOTATE_CONDVAR_SIGNAL(cv) \
     117      AnnotateCondVarSignal(__FILE__, __LINE__, cv)
     118  
     119    /* Report that we are about to signal_all on the condition variable at "cv". */
     120  #define _Py_ANNOTATE_CONDVAR_SIGNAL_ALL(cv) \
     121      AnnotateCondVarSignalAll(__FILE__, __LINE__, cv)
     122  
     123    /* Annotations for user-defined synchronization mechanisms. */
     124  #define _Py_ANNOTATE_HAPPENS_BEFORE(obj) _Py_ANNOTATE_CONDVAR_SIGNAL(obj)
     125  #define _Py_ANNOTATE_HAPPENS_AFTER(obj)  _Py_ANNOTATE_CONDVAR_WAIT(obj)
     126  
     127    /* Report that the bytes in the range [pointer, pointer+size) are about
     128       to be published safely. The race checker will create a happens-before
     129       arc from the call _Py_ANNOTATE_PUBLISH_MEMORY_RANGE(pointer, size) to
     130       subsequent accesses to this memory.
     131       Note: this annotation may not work properly if the race detector uses
     132       sampling, i.e. does not observe all memory accesses.
     133       */
     134  #define _Py_ANNOTATE_PUBLISH_MEMORY_RANGE(pointer, size) \
     135      AnnotatePublishMemoryRange(__FILE__, __LINE__, pointer, size)
     136  
     137    /* Instruct the tool to create a happens-before arc between mu->Unlock() and
     138       mu->Lock(). This annotation may slow down the race detector and hide real
     139       races. Normally it is used only when it would be difficult to annotate each
     140       of the mutex's critical sections individually using the annotations above.
     141       This annotation makes sense only for hybrid race detectors. For pure
     142       happens-before detectors this is a no-op. For more details see
     143       https://code.google.com/p/data-race-test/wiki/PureHappensBeforeVsHybrid . */
     144  #define _Py_ANNOTATE_PURE_HAPPENS_BEFORE_MUTEX(mu) \
     145      AnnotateMutexIsUsedAsCondVar(__FILE__, __LINE__, mu)
     146  
     147    /* -------------------------------------------------------------
     148       Annotations useful when defining memory allocators, or when memory that
     149       was protected in one way starts to be protected in another. */
     150  
     151    /* Report that a new memory at "address" of size "size" has been allocated.
     152       This might be used when the memory has been retrieved from a free list and
     153       is about to be reused, or when the locking discipline for a variable
     154       changes. */
     155  #define _Py_ANNOTATE_NEW_MEMORY(address, size) \
     156      AnnotateNewMemory(__FILE__, __LINE__, address, size)
     157  
     158    /* -------------------------------------------------------------
     159       Annotations useful when defining FIFO queues that transfer data between
     160       threads. */
     161  
     162    /* Report that the producer-consumer queue (such as ProducerConsumerQueue) at
     163       address "pcq" has been created.  The _Py_ANNOTATE_PCQ_* annotations should
     164       be used only for FIFO queues.  For non-FIFO queues use
     165       _Py_ANNOTATE_HAPPENS_BEFORE (for put) and _Py_ANNOTATE_HAPPENS_AFTER (for
     166       get). */
     167  #define _Py_ANNOTATE_PCQ_CREATE(pcq) \
     168      AnnotatePCQCreate(__FILE__, __LINE__, pcq)
     169  
     170    /* Report that the queue at address "pcq" is about to be destroyed. */
     171  #define _Py_ANNOTATE_PCQ_DESTROY(pcq) \
     172      AnnotatePCQDestroy(__FILE__, __LINE__, pcq)
     173  
     174    /* Report that we are about to put an element into a FIFO queue at address
     175       "pcq". */
     176  #define _Py_ANNOTATE_PCQ_PUT(pcq) \
     177      AnnotatePCQPut(__FILE__, __LINE__, pcq)
     178  
     179    /* Report that we've just got an element from a FIFO queue at address "pcq". */
     180  #define _Py_ANNOTATE_PCQ_GET(pcq) \
     181      AnnotatePCQGet(__FILE__, __LINE__, pcq)
     182  
     183    /* -------------------------------------------------------------
     184       Annotations that suppress errors.  It is usually better to express the
     185       program's synchronization using the other annotations, but these can
     186       be used when all else fails. */
     187  
     188    /* Report that we may have a benign race at "pointer", with size
     189       "sizeof(*(pointer))". "pointer" must be a non-void* pointer.  Insert at the
     190       point where "pointer" has been allocated, preferably close to the point
     191       where the race happens.  See also _Py_ANNOTATE_BENIGN_RACE_STATIC. */
     192  #define _Py_ANNOTATE_BENIGN_RACE(pointer, description) \
     193      AnnotateBenignRaceSized(__FILE__, __LINE__, pointer, \
     194                              sizeof(*(pointer)), description)
     195  
     196    /* Same as _Py_ANNOTATE_BENIGN_RACE(address, description), but applies to
     197       the memory range [address, address+size). */
     198  #define _Py_ANNOTATE_BENIGN_RACE_SIZED(address, size, description) \
     199      AnnotateBenignRaceSized(__FILE__, __LINE__, address, size, description)
     200  
     201    /* Request the analysis tool to ignore all reads in the current thread
     202       until _Py_ANNOTATE_IGNORE_READS_END is called.
     203       Useful to ignore intentional racey reads, while still checking
     204       other reads and all writes.
     205       See also _Py_ANNOTATE_UNPROTECTED_READ. */
     206  #define _Py_ANNOTATE_IGNORE_READS_BEGIN() \
     207      AnnotateIgnoreReadsBegin(__FILE__, __LINE__)
     208  
     209    /* Stop ignoring reads. */
     210  #define _Py_ANNOTATE_IGNORE_READS_END() \
     211      AnnotateIgnoreReadsEnd(__FILE__, __LINE__)
     212  
     213    /* Similar to _Py_ANNOTATE_IGNORE_READS_BEGIN, but ignore writes. */
     214  #define _Py_ANNOTATE_IGNORE_WRITES_BEGIN() \
     215      AnnotateIgnoreWritesBegin(__FILE__, __LINE__)
     216  
     217    /* Stop ignoring writes. */
     218  #define _Py_ANNOTATE_IGNORE_WRITES_END() \
     219      AnnotateIgnoreWritesEnd(__FILE__, __LINE__)
     220  
     221    /* Start ignoring all memory accesses (reads and writes). */
     222  #define _Py_ANNOTATE_IGNORE_READS_AND_WRITES_BEGIN() \
     223      do {\
     224        _Py_ANNOTATE_IGNORE_READS_BEGIN();\
     225        _Py_ANNOTATE_IGNORE_WRITES_BEGIN();\
     226      }while(0)\
     227  
     228    /* Stop ignoring all memory accesses. */
     229  #define _Py_ANNOTATE_IGNORE_READS_AND_WRITES_END() \
     230      do {\
     231        _Py_ANNOTATE_IGNORE_WRITES_END();\
     232        _Py_ANNOTATE_IGNORE_READS_END();\
     233      }while(0)\
     234  
     235    /* Similar to _Py_ANNOTATE_IGNORE_READS_BEGIN, but ignore synchronization events:
     236       RWLOCK* and CONDVAR*. */
     237  #define _Py_ANNOTATE_IGNORE_SYNC_BEGIN() \
     238      AnnotateIgnoreSyncBegin(__FILE__, __LINE__)
     239  
     240    /* Stop ignoring sync events. */
     241  #define _Py_ANNOTATE_IGNORE_SYNC_END() \
     242      AnnotateIgnoreSyncEnd(__FILE__, __LINE__)
     243  
     244  
     245    /* Enable (enable!=0) or disable (enable==0) race detection for all threads.
     246       This annotation could be useful if you want to skip expensive race analysis
     247       during some period of program execution, e.g. during initialization. */
     248  #define _Py_ANNOTATE_ENABLE_RACE_DETECTION(enable) \
     249      AnnotateEnableRaceDetection(__FILE__, __LINE__, enable)
     250  
     251    /* -------------------------------------------------------------
     252       Annotations useful for debugging. */
     253  
     254    /* Request to trace every access to "address". */
     255  #define _Py_ANNOTATE_TRACE_MEMORY(address) \
     256      AnnotateTraceMemory(__FILE__, __LINE__, address)
     257  
     258    /* Report the current thread name to a race detector. */
     259  #define _Py_ANNOTATE_THREAD_NAME(name) \
     260      AnnotateThreadName(__FILE__, __LINE__, name)
     261  
     262    /* -------------------------------------------------------------
     263       Annotations useful when implementing locks.  They are not
     264       normally needed by modules that merely use locks.
     265       The "lock" argument is a pointer to the lock object. */
     266  
     267    /* Report that a lock has been created at address "lock". */
     268  #define _Py_ANNOTATE_RWLOCK_CREATE(lock) \
     269      AnnotateRWLockCreate(__FILE__, __LINE__, lock)
     270  
     271    /* Report that the lock at address "lock" is about to be destroyed. */
     272  #define _Py_ANNOTATE_RWLOCK_DESTROY(lock) \
     273      AnnotateRWLockDestroy(__FILE__, __LINE__, lock)
     274  
     275    /* Report that the lock at address "lock" has been acquired.
     276       is_w=1 for writer lock, is_w=0 for reader lock. */
     277  #define _Py_ANNOTATE_RWLOCK_ACQUIRED(lock, is_w) \
     278      AnnotateRWLockAcquired(__FILE__, __LINE__, lock, is_w)
     279  
     280    /* Report that the lock at address "lock" is about to be released. */
     281  #define _Py_ANNOTATE_RWLOCK_RELEASED(lock, is_w) \
     282      AnnotateRWLockReleased(__FILE__, __LINE__, lock, is_w)
     283  
     284    /* -------------------------------------------------------------
     285       Annotations useful when implementing barriers.  They are not
     286       normally needed by modules that merely use barriers.
     287       The "barrier" argument is a pointer to the barrier object. */
     288  
     289    /* Report that the "barrier" has been initialized with initial "count".
     290     If 'reinitialization_allowed' is true, initialization is allowed to happen
     291     multiple times w/o calling barrier_destroy() */
     292  #define _Py_ANNOTATE_BARRIER_INIT(barrier, count, reinitialization_allowed) \
     293      AnnotateBarrierInit(__FILE__, __LINE__, barrier, count, \
     294                          reinitialization_allowed)
     295  
     296    /* Report that we are about to enter barrier_wait("barrier"). */
     297  #define _Py_ANNOTATE_BARRIER_WAIT_BEFORE(barrier) \
     298      AnnotateBarrierWaitBefore(__FILE__, __LINE__, barrier)
     299  
     300    /* Report that we just exited barrier_wait("barrier"). */
     301  #define _Py_ANNOTATE_BARRIER_WAIT_AFTER(barrier) \
     302      AnnotateBarrierWaitAfter(__FILE__, __LINE__, barrier)
     303  
     304    /* Report that the "barrier" has been destroyed. */
     305  #define _Py_ANNOTATE_BARRIER_DESTROY(barrier) \
     306      AnnotateBarrierDestroy(__FILE__, __LINE__, barrier)
     307  
     308    /* -------------------------------------------------------------
     309       Annotations useful for testing race detectors. */
     310  
     311    /* Report that we expect a race on the variable at "address".
     312       Use only in unit tests for a race detector. */
     313  #define _Py_ANNOTATE_EXPECT_RACE(address, description) \
     314      AnnotateExpectRace(__FILE__, __LINE__, address, description)
     315  
     316    /* A no-op. Insert where you like to test the interceptors. */
     317  #define _Py_ANNOTATE_NO_OP(arg) \
     318      AnnotateNoOp(__FILE__, __LINE__, arg)
     319  
     320    /* Force the race detector to flush its state. The actual effect depends on
     321     * the implementation of the detector. */
     322  #define _Py_ANNOTATE_FLUSH_STATE() \
     323      AnnotateFlushState(__FILE__, __LINE__)
     324  
     325  
     326  #else  /* DYNAMIC_ANNOTATIONS_ENABLED == 0 */
     327  
     328  #define _Py_ANNOTATE_RWLOCK_CREATE(lock) /* empty */
     329  #define _Py_ANNOTATE_RWLOCK_DESTROY(lock) /* empty */
     330  #define _Py_ANNOTATE_RWLOCK_ACQUIRED(lock, is_w) /* empty */
     331  #define _Py_ANNOTATE_RWLOCK_RELEASED(lock, is_w) /* empty */
     332  #define _Py_ANNOTATE_BARRIER_INIT(barrier, count, reinitialization_allowed) /* */
     333  #define _Py_ANNOTATE_BARRIER_WAIT_BEFORE(barrier) /* empty */
     334  #define _Py_ANNOTATE_BARRIER_WAIT_AFTER(barrier) /* empty */
     335  #define _Py_ANNOTATE_BARRIER_DESTROY(barrier) /* empty */
     336  #define _Py_ANNOTATE_CONDVAR_LOCK_WAIT(cv, lock) /* empty */
     337  #define _Py_ANNOTATE_CONDVAR_WAIT(cv) /* empty */
     338  #define _Py_ANNOTATE_CONDVAR_SIGNAL(cv) /* empty */
     339  #define _Py_ANNOTATE_CONDVAR_SIGNAL_ALL(cv) /* empty */
     340  #define _Py_ANNOTATE_HAPPENS_BEFORE(obj) /* empty */
     341  #define _Py_ANNOTATE_HAPPENS_AFTER(obj) /* empty */
     342  #define _Py_ANNOTATE_PUBLISH_MEMORY_RANGE(address, size) /* empty */
     343  #define _Py_ANNOTATE_UNPUBLISH_MEMORY_RANGE(address, size)  /* empty */
     344  #define _Py_ANNOTATE_SWAP_MEMORY_RANGE(address, size)  /* empty */
     345  #define _Py_ANNOTATE_PCQ_CREATE(pcq) /* empty */
     346  #define _Py_ANNOTATE_PCQ_DESTROY(pcq) /* empty */
     347  #define _Py_ANNOTATE_PCQ_PUT(pcq) /* empty */
     348  #define _Py_ANNOTATE_PCQ_GET(pcq) /* empty */
     349  #define _Py_ANNOTATE_NEW_MEMORY(address, size) /* empty */
     350  #define _Py_ANNOTATE_EXPECT_RACE(address, description) /* empty */
     351  #define _Py_ANNOTATE_BENIGN_RACE(address, description) /* empty */
     352  #define _Py_ANNOTATE_BENIGN_RACE_SIZED(address, size, description) /* empty */
     353  #define _Py_ANNOTATE_PURE_HAPPENS_BEFORE_MUTEX(mu) /* empty */
     354  #define _Py_ANNOTATE_MUTEX_IS_USED_AS_CONDVAR(mu) /* empty */
     355  #define _Py_ANNOTATE_TRACE_MEMORY(arg) /* empty */
     356  #define _Py_ANNOTATE_THREAD_NAME(name) /* empty */
     357  #define _Py_ANNOTATE_IGNORE_READS_BEGIN() /* empty */
     358  #define _Py_ANNOTATE_IGNORE_READS_END() /* empty */
     359  #define _Py_ANNOTATE_IGNORE_WRITES_BEGIN() /* empty */
     360  #define _Py_ANNOTATE_IGNORE_WRITES_END() /* empty */
     361  #define _Py_ANNOTATE_IGNORE_READS_AND_WRITES_BEGIN() /* empty */
     362  #define _Py_ANNOTATE_IGNORE_READS_AND_WRITES_END() /* empty */
     363  #define _Py_ANNOTATE_IGNORE_SYNC_BEGIN() /* empty */
     364  #define _Py_ANNOTATE_IGNORE_SYNC_END() /* empty */
     365  #define _Py_ANNOTATE_ENABLE_RACE_DETECTION(enable) /* empty */
     366  #define _Py_ANNOTATE_NO_OP(arg) /* empty */
     367  #define _Py_ANNOTATE_FLUSH_STATE() /* empty */
     368  
     369  #endif  /* DYNAMIC_ANNOTATIONS_ENABLED */
     370  
     371  /* Use the macros above rather than using these functions directly. */
     372  #ifdef __cplusplus
     373  extern "C" {
     374  #endif
     375  void AnnotateRWLockCreate(const char *file, int line,
     376                            const volatile void *lock);
     377  void AnnotateRWLockDestroy(const char *file, int line,
     378                             const volatile void *lock);
     379  void AnnotateRWLockAcquired(const char *file, int line,
     380                              const volatile void *lock, long is_w);
     381  void AnnotateRWLockReleased(const char *file, int line,
     382                              const volatile void *lock, long is_w);
     383  void AnnotateBarrierInit(const char *file, int line,
     384                           const volatile void *barrier, long count,
     385                           long reinitialization_allowed);
     386  void AnnotateBarrierWaitBefore(const char *file, int line,
     387                                 const volatile void *barrier);
     388  void AnnotateBarrierWaitAfter(const char *file, int line,
     389                                const volatile void *barrier);
     390  void AnnotateBarrierDestroy(const char *file, int line,
     391                              const volatile void *barrier);
     392  void AnnotateCondVarWait(const char *file, int line,
     393                           const volatile void *cv,
     394                           const volatile void *lock);
     395  void AnnotateCondVarSignal(const char *file, int line,
     396                             const volatile void *cv);
     397  void AnnotateCondVarSignalAll(const char *file, int line,
     398                                const volatile void *cv);
     399  void AnnotatePublishMemoryRange(const char *file, int line,
     400                                  const volatile void *address,
     401                                  long size);
     402  void AnnotateUnpublishMemoryRange(const char *file, int line,
     403                                    const volatile void *address,
     404                                    long size);
     405  void AnnotatePCQCreate(const char *file, int line,
     406                         const volatile void *pcq);
     407  void AnnotatePCQDestroy(const char *file, int line,
     408                          const volatile void *pcq);
     409  void AnnotatePCQPut(const char *file, int line,
     410                      const volatile void *pcq);
     411  void AnnotatePCQGet(const char *file, int line,
     412                      const volatile void *pcq);
     413  void AnnotateNewMemory(const char *file, int line,
     414                         const volatile void *address,
     415                         long size);
     416  void AnnotateExpectRace(const char *file, int line,
     417                          const volatile void *address,
     418                          const char *description);
     419  void AnnotateBenignRace(const char *file, int line,
     420                          const volatile void *address,
     421                          const char *description);
     422  void AnnotateBenignRaceSized(const char *file, int line,
     423                          const volatile void *address,
     424                          long size,
     425                          const char *description);
     426  void AnnotateMutexIsUsedAsCondVar(const char *file, int line,
     427                                    const volatile void *mu);
     428  void AnnotateTraceMemory(const char *file, int line,
     429                           const volatile void *arg);
     430  void AnnotateThreadName(const char *file, int line,
     431                          const char *name);
     432  void AnnotateIgnoreReadsBegin(const char *file, int line);
     433  void AnnotateIgnoreReadsEnd(const char *file, int line);
     434  void AnnotateIgnoreWritesBegin(const char *file, int line);
     435  void AnnotateIgnoreWritesEnd(const char *file, int line);
     436  void AnnotateEnableRaceDetection(const char *file, int line, int enable);
     437  void AnnotateNoOp(const char *file, int line,
     438                    const volatile void *arg);
     439  void AnnotateFlushState(const char *file, int line);
     440  
     441  /* Return non-zero value if running under valgrind.
     442  
     443    If "valgrind.h" is included into dynamic_annotations.c,
     444    the regular valgrind mechanism will be used.
     445    See http://valgrind.org/docs/manual/manual-core-adv.html about
     446    RUNNING_ON_VALGRIND and other valgrind "client requests".
     447    The file "valgrind.h" may be obtained by doing
     448       svn co svn://svn.valgrind.org/valgrind/trunk/include
     449  
     450    If for some reason you can't use "valgrind.h" or want to fake valgrind,
     451    there are two ways to make this function return non-zero:
     452      - Use environment variable: export RUNNING_ON_VALGRIND=1
     453      - Make your tool intercept the function RunningOnValgrind() and
     454        change its return value.
     455   */
     456  int RunningOnValgrind(void);
     457  
     458  #ifdef __cplusplus
     459  }
     460  #endif
     461  
     462  #if DYNAMIC_ANNOTATIONS_ENABLED != 0 && defined(__cplusplus)
     463  
     464    /* _Py_ANNOTATE_UNPROTECTED_READ is the preferred way to annotate racey reads.
     465  
     466       Instead of doing
     467          _Py_ANNOTATE_IGNORE_READS_BEGIN();
     468          ... = x;
     469          _Py_ANNOTATE_IGNORE_READS_END();
     470       one can use
     471          ... = _Py_ANNOTATE_UNPROTECTED_READ(x); */
     472    template <class T>
     473    inline T _Py_ANNOTATE_UNPROTECTED_READ(const volatile T &x) {
     474      _Py_ANNOTATE_IGNORE_READS_BEGIN();
     475      T res = x;
     476      _Py_ANNOTATE_IGNORE_READS_END();
     477      return res;
     478    }
     479    /* Apply _Py_ANNOTATE_BENIGN_RACE_SIZED to a static variable. */
     480  #define _Py_ANNOTATE_BENIGN_RACE_STATIC(static_var, description)        \
     481      namespace {                                                       \
     482        class static_var ## _annotator {                                \
     483         public:                                                        \
     484          static_var ## _annotator() {                                  \
     485            _Py_ANNOTATE_BENIGN_RACE_SIZED(&static_var,                     \
     486                                        sizeof(static_var),             \
     487              # static_var ": " description);                           \
     488          }                                                             \
     489        };                                                              \
     490        static static_var ## _annotator the ## static_var ## _annotator;\
     491      }
     492  #else /* DYNAMIC_ANNOTATIONS_ENABLED == 0 */
     493  
     494  #define _Py_ANNOTATE_UNPROTECTED_READ(x) (x)
     495  #define _Py_ANNOTATE_BENIGN_RACE_STATIC(static_var, description)  /* empty */
     496  
     497  #endif /* DYNAMIC_ANNOTATIONS_ENABLED */
     498  
     499  #endif  /* __DYNAMIC_ANNOTATIONS_H__ */