1/*
2  ----------------------------------------------------------------
3
4  Notice that the following BSD-style license applies to this one
5  file (drd.h) only.  The rest of Valgrind is licensed under the
6  terms of the GNU General Public License, version 2, unless
7  otherwise indicated.  See the COPYING file in the source
8  distribution for details.
9
10  ----------------------------------------------------------------
11
12  This file is part of DRD, a Valgrind tool for verification of
13  multithreaded programs.
14
15  Copyright (C) 2006-2012 Bart Van Assche <bvanassche@acm.org>.
16  All rights reserved.
17
18  Redistribution and use in source and binary forms, with or without
19  modification, are permitted provided that the following conditions
20  are met:
21
22  1. Redistributions of source code must retain the above copyright
23  notice, this list of conditions and the following disclaimer.
24
25  2. The origin of this software must not be misrepresented; you must
26  not claim that you wrote the original software.  If you use this
27  software in a product, an acknowledgment in the product
28  documentation would be appreciated but is not required.
29
30  3. Altered source versions must be plainly marked as such, and must
31  not be misrepresented as being the original software.
32
33  4. The name of the author may not be used to endorse or promote
34  products derived from this software without specific prior written
35  permission.
36
37  THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
38  OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
39  WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
40  ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
41  DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
42  DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
43  GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
44  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
45  WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
46  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
47  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
48
49  ----------------------------------------------------------------
50
51  Notice that the above BSD-style license applies to this one file
52  (drd.h) only.  The entire rest of Valgrind is licensed under
53  the terms of the GNU General Public License, version 2.  See the
54  COPYING file in the source distribution for details.
55
56  ----------------------------------------------------------------
57*/
58
59#ifndef __VALGRIND_DRD_H
60#define __VALGRIND_DRD_H
61
62
63#include "valgrind.h"
64
65
66/** Obtain the thread ID assigned by Valgrind's core. */
67#define DRD_GET_VALGRIND_THREADID                                          \
68    (unsigned)VALGRIND_DO_CLIENT_REQUEST_EXPR(0,                           \
69                                   VG_USERREQ__DRD_GET_VALGRIND_THREAD_ID, \
70                                   0, 0, 0, 0, 0)
71
72/** Obtain the thread ID assigned by DRD. */
73#define DRD_GET_DRD_THREADID                                            \
74    (unsigned)VALGRIND_DO_CLIENT_REQUEST_EXPR(0,                        \
75                                   VG_USERREQ__DRD_GET_DRD_THREAD_ID,   \
76                                   0, 0, 0, 0, 0)
77
78
79/** Tell DRD not to complain about data races for the specified variable. */
80#define DRD_IGNORE_VAR(x) ANNOTATE_BENIGN_RACE_SIZED(&(x), sizeof(x), "")
81
82/** Tell DRD to no longer ignore data races for the specified variable. */
83#define DRD_STOP_IGNORING_VAR(x)                                       \
84   VALGRIND_DO_CLIENT_REQUEST_STMT(VG_USERREQ__DRD_FINISH_SUPPRESSION, \
85                                   &(x), sizeof(x), 0, 0, 0)
86
87/**
88 * Tell DRD to trace all memory accesses for the specified variable
89 * until the memory that was allocated for the variable is freed.
90 */
91#define DRD_TRACE_VAR(x)                                             \
92   VALGRIND_DO_CLIENT_REQUEST_STMT(VG_USERREQ__DRD_START_TRACE_ADDR, \
93                                   &(x), sizeof(x), 0, 0, 0)
94
95/**
96 * Tell DRD to stop tracing memory accesses for the specified variable.
97 */
98#define DRD_STOP_TRACING_VAR(x)                                       \
99   VALGRIND_DO_CLIENT_REQUEST_STMT(VG_USERREQ__DRD_STOP_TRACE_ADDR, \
100                                   &(x), sizeof(x), 0, 0, 0)
101
102/**
103 * @defgroup RaceDetectionAnnotations Data race detection annotations.
104 *
105 * @see See also the source file <a href="http://code.google.com/p/data-race-test/source/browse/trunk/dynamic_annotations/dynamic_annotations.h</a>
106
107 * in the ThreadSanitizer project.
108 */
109/*@{*/
110
111#ifndef __HELGRIND_H
112
113/**
114 * Tell DRD to insert a happens-before mark. addr is the address of an object
115 * that is not a pthread synchronization object.
116 */
117#define ANNOTATE_HAPPENS_BEFORE(addr)                                       \
118   VALGRIND_DO_CLIENT_REQUEST_STMT(VG_USERREQ__DRD_ANNOTATE_HAPPENS_BEFORE, \
119                                   addr, 0, 0, 0, 0)
120
121/**
122 * Tell DRD that the memory accesses executed after this annotation will
123 * happen after all memory accesses performed before all preceding
124 * ANNOTATE_HAPPENS_BEFORE(addr). addr is the address of an object that is not
125 * a pthread synchronization object. Inserting a happens-after annotation
126 * before any other thread has passed by a happens-before annotation for the
127 * same address is an error.
128 */
129#define ANNOTATE_HAPPENS_AFTER(addr)                                       \
130   VALGRIND_DO_CLIENT_REQUEST_STMT(VG_USERREQ__DRD_ANNOTATE_HAPPENS_AFTER, \
131                                   addr, 0, 0, 0, 0)
132
133#else /* __HELGRIND_H */
134
135#undef ANNOTATE_CONDVAR_LOCK_WAIT
136#undef ANNOTATE_CONDVAR_WAIT
137#undef ANNOTATE_CONDVAR_SIGNAL
138#undef ANNOTATE_CONDVAR_SIGNAL_ALL
139#undef ANNOTATE_PURE_HAPPENS_BEFORE_MUTEX
140#undef ANNOTATE_PUBLISH_MEMORY_RANGE
141#undef ANNOTATE_BARRIER_INIT
142#undef ANNOTATE_BARRIER_WAIT_BEFORE
143#undef ANNOTATE_BARRIER_WAIT_AFTER
144#undef ANNOTATE_BARRIER_DESTROY
145#undef ANNOTATE_PCQ_CREATE
146#undef ANNOTATE_PCQ_DESTROY
147#undef ANNOTATE_PCQ_PUT
148#undef ANNOTATE_PCQ_GET
149#undef ANNOTATE_BENIGN_RACE
150#undef ANNOTATE_BENIGN_RACE_SIZED
151#undef ANNOTATE_IGNORE_READS_BEGIN
152#undef ANNOTATE_IGNORE_READS_END
153#undef ANNOTATE_IGNORE_WRITES_BEGIN
154#undef ANNOTATE_IGNORE_WRITES_END
155#undef ANNOTATE_IGNORE_READS_AND_WRITES_BEGIN
156#undef ANNOTATE_IGNORE_READS_AND_WRITES_END
157#undef ANNOTATE_NEW_MEMORY
158#undef ANNOTATE_TRACE_MEMORY
159#undef ANNOTATE_THREAD_NAME
160
161#endif /* __HELGRIND_H */
162
163/**
164 * Tell DRD that waiting on the condition variable at address cv has succeeded
165 * and a lock on the mutex at address mtx is now held. Since DRD always inserts
166 * a happens before relation between the pthread_cond_signal() or
167 * pthread_cond_broadcast() call that wakes up a pthread_cond_wait() or
168 * pthread_cond_timedwait() call and the woken up thread, this macro has been
169 * defined such that it has no effect.
170 */
171#define ANNOTATE_CONDVAR_LOCK_WAIT(cv, mtx) do { } while(0)
172
173/**
174 * Tell DRD that the condition variable at address cv is about to be signaled.
175 */
176#define ANNOTATE_CONDVAR_SIGNAL(cv) do { } while(0)
177
178/**
179 * Tell DRD that the condition variable at address cv is about to be signaled.
180 */
181#define ANNOTATE_CONDVAR_SIGNAL_ALL(cv) do { } while(0)
182
183/**
184 * Tell DRD that waiting on condition variable at address cv succeeded and that
185 * the memory operations performed after this annotation should be considered
186 * to happen after the matching ANNOTATE_CONDVAR_SIGNAL(cv). Since this is the
187 * default behavior of DRD, this macro and the macro above have been defined
188 * such that they have no effect.
189 */
190#define ANNOTATE_CONDVAR_WAIT(cv) do { } while(0)
191
192/**
193 * Tell DRD to consider the memory operations that happened before a mutex
194 * unlock event and after the subsequent mutex lock event on the same mutex as
195 * ordered. This is how DRD always behaves, so this macro has been defined
196 * such that it has no effect.
197 */
198#define ANNOTATE_PURE_HAPPENS_BEFORE_MUTEX(mtx) do { } while(0)
199
200/** Deprecated -- don't use this annotation. */
201#define ANNOTATE_MUTEX_IS_USED_AS_CONDVAR(mtx) do { } while(0)
202
203/**
204 * Tell DRD to handle the specified memory range like a pure happens-before
205 * detector would do. Since this is how DRD always behaves, this annotation
206 * has been defined such that it has no effect.
207 */
208#define ANNOTATE_PUBLISH_MEMORY_RANGE(addr, size) do { } while(0)
209
210/** Deprecated -- don't use this annotation. */
211#define ANNOTATE_UNPUBLISH_MEMORY_RANGE(addr, size) do { } while(0)
212
213/** Deprecated -- don't use this annotation. */
214#define ANNOTATE_SWAP_MEMORY_RANGE(addr, size) do { } while(0)
215
216#ifndef __HELGRIND_H
217
218/** Tell DRD that a reader-writer lock object has been initialized. */
219#define ANNOTATE_RWLOCK_CREATE(rwlock)                                     \
220   VALGRIND_DO_CLIENT_REQUEST_STMT(VG_USERREQ__DRD_ANNOTATE_RWLOCK_CREATE, \
221                                   rwlock, 0, 0, 0, 0);
222
223/** Tell DRD that a reader-writer lock object has been destroyed. */
224#define ANNOTATE_RWLOCK_DESTROY(rwlock)                                     \
225   VALGRIND_DO_CLIENT_REQUEST_STMT(VG_USERREQ__DRD_ANNOTATE_RWLOCK_DESTROY, \
226                                   rwlock, 0, 0, 0, 0);
227
228/**
229 * Tell DRD that a reader-writer lock has been acquired. is_w == 1 means that
230 * a write lock has been obtained, is_w == 0 means that a read lock has been
231 * obtained.
232 */
233#define ANNOTATE_RWLOCK_ACQUIRED(rwlock, is_w)                               \
234   VALGRIND_DO_CLIENT_REQUEST_STMT(VG_USERREQ__DRD_ANNOTATE_RWLOCK_ACQUIRED, \
235                                   rwlock, is_w, 0, 0, 0)
236
237#endif /* __HELGRIND_H */
238
239/**
240 * Tell DRD that a reader lock has been acquired on a reader-writer
241 * synchronization object.
242 */
243#define ANNOTATE_READERLOCK_ACQUIRED(rwlock) ANNOTATE_RWLOCK_ACQUIRED(rwlock, 0)
244
245/**
246 * Tell DRD that a writer lock has been acquired on a reader-writer
247 * synchronization object.
248 */
249#define ANNOTATE_WRITERLOCK_ACQUIRED(rwlock) ANNOTATE_RWLOCK_ACQUIRED(rwlock, 1)
250
251#ifndef __HELGRIND_H
252
253/**
254 * Tell DRD that a reader-writer lock is about to be released. is_w == 1 means
255 * that a write lock is about to be released, is_w == 0 means that a read lock
256 * is about to be released.
257 */
258#define ANNOTATE_RWLOCK_RELEASED(rwlock, is_w)                               \
259   VALGRIND_DO_CLIENT_REQUEST_STMT(VG_USERREQ__DRD_ANNOTATE_RWLOCK_RELEASED, \
260                                   rwlock, is_w, 0, 0, 0);
261
262#endif /* __HELGRIND_H */
263
264/**
265 * Tell DRD that a reader lock is about to be released.
266 */
267#define ANNOTATE_READERLOCK_RELEASED(rwlock) ANNOTATE_RWLOCK_RELEASED(rwlock, 0)
268
269/**
270 * Tell DRD that a writer lock is about to be released.
271 */
272#define ANNOTATE_WRITERLOCK_RELEASED(rwlock) ANNOTATE_RWLOCK_RELEASED(rwlock, 1)
273
274/*
275 * Report that a barrier has been initialized with a given barrier count.  The
276 * third argument specifies whether or not reinitialization is allowed, that
277 * is, whether or not it is allowed to call barrier_init() several times
278 * without calling barrier_destroy().
279 */
280#define ANNOTATE_BARRIER_INIT(barrier, count, reinitialization_allowed) \
281   VALGRIND_DO_CLIENT_REQUEST_STMT(VG_USERREQ__DRD_ANNOTATION_UNIMP,    \
282                                   "ANNOTATE_BARRIER_INIT", barrier,    \
283                                   count, reinitialization_allowed, 0)
284
285/* Report that a barrier has been destroyed. */
286#define ANNOTATE_BARRIER_DESTROY(barrier)                               \
287   VALGRIND_DO_CLIENT_REQUEST_STMT(VG_USERREQ__DRD_ANNOTATION_UNIMP,    \
288                                   "ANNOTATE_BARRIER_DESTROY",          \
289                                   barrier, 0, 0, 0)
290
291/* Report that the calling thread is about to start waiting for a barrier. */
292#define ANNOTATE_BARRIER_WAIT_BEFORE(barrier)                           \
293   VALGRIND_DO_CLIENT_REQUEST_STMT(VG_USERREQ__DRD_ANNOTATION_UNIMP,    \
294                                   "ANNOTATE_BARRIER_WAIT_BEFORE",      \
295                                   barrier, 0, 0, 0)
296
297/* Report that the calling thread has just finished waiting for a barrier. */
298#define ANNOTATE_BARRIER_WAIT_AFTER(barrier)                            \
299   VALGRIND_DO_CLIENT_REQUEST_STMT(VG_USERREQ__DRD_ANNOTATION_UNIMP,    \
300                                   "ANNOTATE_BARRIER_WAIT_AFTER",       \
301                                   barrier, 0, 0, 0)
302
303/**
304 * Tell DRD that a FIFO queue has been created. The abbreviation PCQ stands for
305 * <em>producer-consumer</em>.
306 */
307#define ANNOTATE_PCQ_CREATE(pcq) do { } while(0)
308
309/** Tell DRD that a FIFO queue has been destroyed. */
310#define ANNOTATE_PCQ_DESTROY(pcq) do { } while(0)
311
312/**
313 * Tell DRD that an element has been added to the FIFO queue at address pcq.
314 */
315#define ANNOTATE_PCQ_PUT(pcq) do { } while(0)
316
317/**
318 * Tell DRD that an element has been removed from the FIFO queue at address pcq,
319 * and that DRD should insert a happens-before relationship between the memory
320 * accesses that occurred before the corresponding ANNOTATE_PCQ_PUT(pcq)
321 * annotation and the memory accesses after this annotation. Correspondence
322 * between PUT and GET annotations happens in FIFO order. Since locking
323 * of the queue is needed anyway to add elements to or to remove elements from
324 * the queue, for DRD all four FIFO annotations are defined as no-ops.
325 */
326#define ANNOTATE_PCQ_GET(pcq) do { } while(0)
327
328/**
329 * Tell DRD that data races at the specified address are expected and must not
330 * be reported.
331 */
332#define ANNOTATE_BENIGN_RACE(addr, descr) \
333   ANNOTATE_BENIGN_RACE_SIZED(addr, sizeof(*addr), descr)
334
335/* Same as ANNOTATE_BENIGN_RACE(addr, descr), but applies to
336   the memory range [addr, addr + size). */
337#define ANNOTATE_BENIGN_RACE_SIZED(addr, size, descr)                   \
338   VALGRIND_DO_CLIENT_REQUEST_STMT(VG_USERREQ__DRD_START_SUPPRESSION,   \
339                                   addr, size, 0, 0, 0)
340
341/** Tell DRD to ignore all reads performed by the current thread. */
342#define ANNOTATE_IGNORE_READS_BEGIN()                                \
343   VALGRIND_DO_CLIENT_REQUEST_STMT(VG_USERREQ__DRD_RECORD_LOADS,     \
344                                   0, 0, 0, 0, 0);
345
346
347/** Tell DRD to no longer ignore the reads performed by the current thread. */
348#define ANNOTATE_IGNORE_READS_END()                                  \
349   VALGRIND_DO_CLIENT_REQUEST_STMT(VG_USERREQ__DRD_RECORD_LOADS,     \
350                                   1, 0, 0, 0, 0);
351
352/** Tell DRD to ignore all writes performed by the current thread. */
353#define ANNOTATE_IGNORE_WRITES_BEGIN()                                \
354   VALGRIND_DO_CLIENT_REQUEST_STMT(VG_USERREQ__DRD_RECORD_STORES,     \
355                                   0, 0, 0, 0, 0)
356
357/** Tell DRD to no longer ignore the writes performed by the current thread. */
358#define ANNOTATE_IGNORE_WRITES_END()                                  \
359   VALGRIND_DO_CLIENT_REQUEST_STMT(VG_USERREQ__DRD_RECORD_STORES,     \
360                                   1, 0, 0, 0, 0)
361
362/** Tell DRD to ignore all memory accesses performed by the current thread. */
363#define ANNOTATE_IGNORE_READS_AND_WRITES_BEGIN() \
364   do { ANNOTATE_IGNORE_READS_BEGIN(); ANNOTATE_IGNORE_WRITES_BEGIN(); } while(0)
365
366/**
367 * Tell DRD to no longer ignore the memory accesses performed by the current
368 * thread.
369 */
370#define ANNOTATE_IGNORE_READS_AND_WRITES_END() \
371   do { ANNOTATE_IGNORE_READS_END(); ANNOTATE_IGNORE_WRITES_END(); } while(0)
372
373/**
374 * Tell DRD that size bytes starting at addr has been allocated by a custom
375 * memory allocator.
376 */
377#define ANNOTATE_NEW_MEMORY(addr, size)                           \
378   VALGRIND_DO_CLIENT_REQUEST_STMT(VG_USERREQ__DRD_CLEAN_MEMORY,  \
379                                   addr, size, 0, 0, 0)
380
381/** Ask DRD to report every access to the specified address. */
382#define ANNOTATE_TRACE_MEMORY(addr) DRD_TRACE_VAR(*(char*)(addr))
383
384/**
385 * Tell DRD to assign the specified name to the current thread. This name will
386 * be used in error messages printed by DRD.
387 */
388#define ANNOTATE_THREAD_NAME(name)                                      \
389   VALGRIND_DO_CLIENT_REQUEST_STMT(VG_USERREQ__DRD_SET_THREAD_NAME,     \
390                                   name, 0, 0, 0, 0)
391
392/*@}*/
393
394
395/* !! ABIWARNING !! ABIWARNING !! ABIWARNING !! ABIWARNING !!
396   This enum comprises an ABI exported by Valgrind to programs
397   which use client requests.  DO NOT CHANGE THE ORDER OF THESE
398   ENTRIES, NOR DELETE ANY -- add new ones at the end.
399*/
400enum {
401   /* Ask the DRD tool to discard all information about memory accesses   */
402   /* and client objects for the specified range. This client request is  */
403   /* binary compatible with the similarly named Helgrind client request. */
404   VG_USERREQ__DRD_CLEAN_MEMORY = VG_USERREQ_TOOL_BASE('H','G'),
405   /* args: Addr, SizeT. */
406
407   /* Ask the DRD tool the thread ID assigned by Valgrind. */
408   VG_USERREQ__DRD_GET_VALGRIND_THREAD_ID = VG_USERREQ_TOOL_BASE('D','R'),
409   /* args: none. */
410   /* Ask the DRD tool the thread ID assigned by DRD. */
411   VG_USERREQ__DRD_GET_DRD_THREAD_ID,
412   /* args: none. */
413
414   /* To tell the DRD tool to suppress data race detection on the */
415   /* specified address range. */
416   VG_USERREQ__DRD_START_SUPPRESSION,
417   /* args: start address, size in bytes */
418   /* To tell the DRD tool no longer to suppress data race detection on */
419   /* the specified address range. */
420   VG_USERREQ__DRD_FINISH_SUPPRESSION,
421   /* args: start address, size in bytes */
422
423   /* To ask the DRD tool to trace all accesses to the specified range. */
424   VG_USERREQ__DRD_START_TRACE_ADDR,
425   /* args: Addr, SizeT. */
426   /* To ask the DRD tool to stop tracing accesses to the specified range. */
427   VG_USERREQ__DRD_STOP_TRACE_ADDR,
428   /* args: Addr, SizeT. */
429
430   /* Tell DRD whether or not to record memory loads in the calling thread. */
431   VG_USERREQ__DRD_RECORD_LOADS,
432   /* args: Bool. */
433   /* Tell DRD whether or not to record memory stores in the calling thread. */
434   VG_USERREQ__DRD_RECORD_STORES,
435   /* args: Bool. */
436
437   /* Set the name of the thread that performs this client request. */
438   VG_USERREQ__DRD_SET_THREAD_NAME,
439   /* args: null-terminated character string. */
440
441   /* Tell DRD that a DRD annotation has not yet been implemented. */
442   VG_USERREQ__DRD_ANNOTATION_UNIMP,
443   /* args: Char*. */
444
445   /* Tell DRD that a user-defined reader-writer synchronization object
446    * has been created. */
447   VG_USERREQ__DRD_ANNOTATE_RWLOCK_CREATE
448      = VG_USERREQ_TOOL_BASE('H','G') + 256 + 14,
449   /* args: Addr. */
450   /* Tell DRD that a user-defined reader-writer synchronization object
451    * is about to be destroyed. */
452   VG_USERREQ__DRD_ANNOTATE_RWLOCK_DESTROY
453      = VG_USERREQ_TOOL_BASE('H','G') + 256 + 15,
454   /* args: Addr. */
455   /* Tell DRD that a lock on a user-defined reader-writer synchronization
456    * object has been acquired. */
457   VG_USERREQ__DRD_ANNOTATE_RWLOCK_ACQUIRED
458      = VG_USERREQ_TOOL_BASE('H','G') + 256 + 17,
459   /* args: Addr, Int is_rw. */
460   /* Tell DRD that a lock on a user-defined reader-writer synchronization
461    * object is about to be released. */
462   VG_USERREQ__DRD_ANNOTATE_RWLOCK_RELEASED
463      = VG_USERREQ_TOOL_BASE('H','G') + 256 + 18,
464   /* args: Addr, Int is_rw. */
465
466   /* Tell DRD that a Helgrind annotation has not yet been implemented. */
467   VG_USERREQ__HELGRIND_ANNOTATION_UNIMP
468      = VG_USERREQ_TOOL_BASE('H','G') + 256 + 32,
469   /* args: Char*. */
470
471   /* Tell DRD to insert a happens-before annotation. */
472   VG_USERREQ__DRD_ANNOTATE_HAPPENS_BEFORE
473      = VG_USERREQ_TOOL_BASE('H','G') + 256 + 33,
474   /* args: Addr. */
475   /* Tell DRD to insert a happens-after annotation. */
476   VG_USERREQ__DRD_ANNOTATE_HAPPENS_AFTER
477      = VG_USERREQ_TOOL_BASE('H','G') + 256 + 34,
478   /* args: Addr. */
479
480};
481
482
483/**
484 * @addtogroup RaceDetectionAnnotations
485 */
486/*@{*/
487
488#ifdef __cplusplus
489/* ANNOTATE_UNPROTECTED_READ is the preferred way to annotate racy reads.
490
491   Instead of doing
492   ANNOTATE_IGNORE_READS_BEGIN();
493   ... = x;
494   ANNOTATE_IGNORE_READS_END();
495   one can use
496   ... = ANNOTATE_UNPROTECTED_READ(x); */
497template <typename T>
498inline T ANNOTATE_UNPROTECTED_READ(const volatile T& x) {
499   ANNOTATE_IGNORE_READS_BEGIN();
500   const T result = x;
501   ANNOTATE_IGNORE_READS_END();
502   return result;
503}
504/* Apply ANNOTATE_BENIGN_RACE_SIZED to a static variable. */
505#define ANNOTATE_BENIGN_RACE_STATIC(static_var, description)		\
506   namespace {								\
507      static class static_var##_annotator				\
508      {									\
509      public:								\
510	 static_var##_annotator()					\
511	 {								\
512	    ANNOTATE_BENIGN_RACE_SIZED(&static_var, sizeof(static_var),	\
513				       #static_var ": " description);	\
514	 }								\
515      } the_##static_var##_annotator;					\
516   }
517#endif
518
519/*@}*/
520
521#endif /* __VALGRIND_DRD_H */
522