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1 /*
2    ----------------------------------------------------------------
3 
4    Notice that the above BSD-style license applies to this one file
5    (helgrind.h) only.  The entire rest of Valgrind is licensed under
6    the terms of the GNU General Public License, version 2.  See the
7    COPYING file in the source distribution for details.
8 
9    ----------------------------------------------------------------
10 
11    This file is part of Helgrind, a Valgrind tool for detecting errors
12    in threaded programs.
13 
14    Copyright (C) 2007-2011 OpenWorks LLP
15       info@open-works.co.uk
16 
17    Redistribution and use in source and binary forms, with or without
18    modification, are permitted provided that the following conditions
19    are met:
20 
21    1. Redistributions of source code must retain the above copyright
22       notice, this list of conditions and the following disclaimer.
23 
24    2. The origin of this software must not be misrepresented; you must
25       not claim that you wrote the original software.  If you use this
26       software in a product, an acknowledgment in the product
27       documentation would be appreciated but is not required.
28 
29    3. Altered source versions must be plainly marked as such, and must
30       not be misrepresented as being the original software.
31 
32    4. The name of the author may not be used to endorse or promote
33       products derived from this software without specific prior written
34       permission.
35 
36    THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
37    OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
38    WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
39    ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
40    DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
41    DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
42    GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
43    INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
44    WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
45    NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
46    SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
47 
48    ----------------------------------------------------------------
49 
50    Notice that the above BSD-style license applies to this one file
51    (helgrind.h) only.  The entire rest of Valgrind is licensed under
52    the terms of the GNU General Public License, version 2.  See the
53    COPYING file in the source distribution for details.
54 
55    ----------------------------------------------------------------
56 */
57 
58 #ifndef __HELGRIND_H
59 #define __HELGRIND_H
60 
61 #include "valgrind.h"
62 
63 /* !! ABIWARNING !! ABIWARNING !! ABIWARNING !! ABIWARNING !!
64    This enum comprises an ABI exported by Valgrind to programs
65    which use client requests.  DO NOT CHANGE THE ORDER OF THESE
66    ENTRIES, NOR DELETE ANY -- add new ones at the end. */
67 typedef
68    enum {
69       VG_USERREQ__HG_CLEAN_MEMORY = VG_USERREQ_TOOL_BASE('H','G'),
70 
71       /* The rest are for Helgrind's internal use.  Not for end-user
72          use.  Do not use them unless you are a Valgrind developer. */
73 
74       /* Notify the tool what this thread's pthread_t is. */
75       _VG_USERREQ__HG_SET_MY_PTHREAD_T = VG_USERREQ_TOOL_BASE('H','G')
76                                          + 256,
77       _VG_USERREQ__HG_PTH_API_ERROR,              /* char*, int */
78       _VG_USERREQ__HG_PTHREAD_JOIN_POST,          /* pthread_t of quitter */
79       _VG_USERREQ__HG_PTHREAD_MUTEX_INIT_POST,    /* pth_mx_t*, long mbRec */
80       _VG_USERREQ__HG_PTHREAD_MUTEX_DESTROY_PRE,  /* pth_mx_t* */
81       _VG_USERREQ__HG_PTHREAD_MUTEX_UNLOCK_PRE,   /* pth_mx_t* */
82       _VG_USERREQ__HG_PTHREAD_MUTEX_UNLOCK_POST,  /* pth_mx_t* */
83       _VG_USERREQ__HG_PTHREAD_MUTEX_LOCK_PRE, /* pth_mx_t*, long isTryLock */
84       _VG_USERREQ__HG_PTHREAD_MUTEX_LOCK_POST,    /* pth_mx_t* */
85       _VG_USERREQ__HG_PTHREAD_COND_SIGNAL_PRE,    /* pth_cond_t* */
86       _VG_USERREQ__HG_PTHREAD_COND_BROADCAST_PRE, /* pth_cond_t* */
87       _VG_USERREQ__HG_PTHREAD_COND_WAIT_PRE,     /* pth_cond_t*, pth_mx_t* */
88       _VG_USERREQ__HG_PTHREAD_COND_WAIT_POST,    /* pth_cond_t*, pth_mx_t* */
89       _VG_USERREQ__HG_PTHREAD_COND_DESTROY_PRE,   /* pth_cond_t* */
90       _VG_USERREQ__HG_PTHREAD_RWLOCK_INIT_POST,   /* pth_rwlk_t* */
91       _VG_USERREQ__HG_PTHREAD_RWLOCK_DESTROY_PRE, /* pth_rwlk_t* */
92       _VG_USERREQ__HG_PTHREAD_RWLOCK_LOCK_PRE,    /* pth_rwlk_t*, long isW */
93       _VG_USERREQ__HG_PTHREAD_RWLOCK_LOCK_POST,   /* pth_rwlk_t*, long isW */
94       _VG_USERREQ__HG_PTHREAD_RWLOCK_UNLOCK_PRE,  /* pth_rwlk_t* */
95       _VG_USERREQ__HG_PTHREAD_RWLOCK_UNLOCK_POST, /* pth_rwlk_t* */
96       _VG_USERREQ__HG_POSIX_SEM_INIT_POST,        /* sem_t*, ulong value */
97       _VG_USERREQ__HG_POSIX_SEM_DESTROY_PRE,      /* sem_t* */
98       _VG_USERREQ__HG_POSIX_SEM_POST_PRE,         /* sem_t* */
99       _VG_USERREQ__HG_POSIX_SEM_WAIT_POST,        /* sem_t* */
100       _VG_USERREQ__HG_PTHREAD_BARRIER_INIT_PRE,   /* pth_bar_t*, ulong, ulong */
101       _VG_USERREQ__HG_PTHREAD_BARRIER_WAIT_PRE,   /* pth_bar_t* */
102       _VG_USERREQ__HG_PTHREAD_BARRIER_DESTROY_PRE, /* pth_bar_t* */
103       _VG_USERREQ__HG_PTHREAD_SPIN_INIT_OR_UNLOCK_PRE,  /* pth_slk_t* */
104       _VG_USERREQ__HG_PTHREAD_SPIN_INIT_OR_UNLOCK_POST, /* pth_slk_t* */
105       _VG_USERREQ__HG_PTHREAD_SPIN_LOCK_PRE,      /* pth_slk_t* */
106       _VG_USERREQ__HG_PTHREAD_SPIN_LOCK_POST,     /* pth_slk_t* */
107       _VG_USERREQ__HG_PTHREAD_SPIN_DESTROY_PRE,   /* pth_slk_t* */
108       _VG_USERREQ__HG_CLIENTREQ_UNIMP,            /* char* */
109       _VG_USERREQ__HG_USERSO_SEND_PRE,        /* arbitrary UWord SO-tag */
110       _VG_USERREQ__HG_USERSO_RECV_POST,       /* arbitrary UWord SO-tag */
111       _VG_USERREQ__HG_USERSO_FORGET_ALL,      /* arbitrary UWord SO-tag */
112       _VG_USERREQ__HG_RESERVED2,              /* Do not use */
113       _VG_USERREQ__HG_RESERVED3,              /* Do not use */
114       _VG_USERREQ__HG_RESERVED4,              /* Do not use */
115       _VG_USERREQ__HG_ARANGE_MAKE_UNTRACKED, /* Addr a, ulong len */
116       _VG_USERREQ__HG_ARANGE_MAKE_TRACKED,   /* Addr a, ulong len */
117       _VG_USERREQ__HG_PTHREAD_BARRIER_RESIZE_PRE, /* pth_bar_t*, ulong */
118       _VG_USERREQ__HG_CLEAN_MEMORY_HEAPBLOCK  /* Addr start_of_block */
119 
120    } Vg_TCheckClientRequest;
121 
122 
123 /*----------------------------------------------------------------*/
124 /*---                                                          ---*/
125 /*--- Implementation-only facilities.  Not for end-user use.   ---*/
126 /*--- For end-user facilities see below (the next section in   ---*/
127 /*--- this file.)                                              ---*/
128 /*---                                                          ---*/
129 /*----------------------------------------------------------------*/
130 
131 /* Do a client request.  These are macros rather than a functions so
132    as to avoid having an extra frame in stack traces.
133 
134    NB: these duplicate definitions in hg_intercepts.c.  But here, we
135    have to make do with weaker typing (no definition of Word etc) and
136    no assertions, whereas in helgrind.h we can use those facilities.
137    Obviously it's important the two sets of definitions are kept in
138    sync.
139 
140    The commented-out asserts should actually hold, but unfortunately
141    they can't be allowed to be visible here, because that would
142    require the end-user code to #include <assert.h>.
143 */
144 
145 #define DO_CREQ_v_W(_creqF, _ty1F,_arg1F)                \
146    do {                                                  \
147       long int _arg1;                                    \
148       /* assert(sizeof(_ty1F) == sizeof(long int)); */   \
149       _arg1 = (long int)(_arg1F);                        \
150       VALGRIND_DO_CLIENT_REQUEST_STMT(                   \
151                                  (_creqF),               \
152                                  _arg1, 0,0,0,0);        \
153    } while (0)
154 
155 #define DO_CREQ_W_W(_resF, _dfltF, _creqF, _ty1F,_arg1F) \
156    do {                                                  \
157       long int arg1;                                     \
158       /* assert(sizeof(_ty1F) == sizeof(long int)); */   \
159       _arg1 = (long int)(_arg1F);                        \
160       _qzz_res = VALGRIND_DO_CLIENT_REQUEST_EXPR(        \
161                                  (_dfltF),               \
162                                  (_creqF),               \
163                                  _arg1, 0,0,0,0);        \
164       _resF = _qzz_res;                                  \
165    } while (0)
166 
167 #define DO_CREQ_v_WW(_creqF, _ty1F,_arg1F, _ty2F,_arg2F) \
168    do {                                                  \
169       long int _arg1, _arg2;                             \
170       /* assert(sizeof(_ty1F) == sizeof(long int)); */   \
171       /* assert(sizeof(_ty2F) == sizeof(long int)); */   \
172       _arg1 = (long int)(_arg1F);                        \
173       _arg2 = (long int)(_arg2F);                        \
174       VALGRIND_DO_CLIENT_REQUEST_STMT(                   \
175                                  (_creqF),               \
176                                  _arg1,_arg2,0,0,0);     \
177    } while (0)
178 
179 #define DO_CREQ_v_WWW(_creqF, _ty1F,_arg1F,              \
180                       _ty2F,_arg2F, _ty3F, _arg3F)       \
181    do {                                                  \
182       long int _arg1, _arg2, _arg3;                      \
183       /* assert(sizeof(_ty1F) == sizeof(long int)); */   \
184       /* assert(sizeof(_ty2F) == sizeof(long int)); */   \
185       /* assert(sizeof(_ty3F) == sizeof(long int)); */   \
186       _arg1 = (long int)(_arg1F);                        \
187       _arg2 = (long int)(_arg2F);                        \
188       _arg3 = (long int)(_arg3F);                        \
189       VALGRIND_DO_CLIENT_REQUEST_STMT(                   \
190                                  (_creqF),               \
191                                  _arg1,_arg2,_arg3,0,0); \
192    } while (0)
193 
194 
195 #define _HG_CLIENTREQ_UNIMP(_qzz_str)                    \
196    DO_CREQ_v_W(_VG_USERREQ__HG_CLIENTREQ_UNIMP,          \
197                (char*),(_qzz_str))
198 
199 
200 /*----------------------------------------------------------------*/
201 /*---                                                          ---*/
202 /*--- Helgrind-native requests.  These allow access to         ---*/
203 /*--- the same set of annotation primitives that are used      ---*/
204 /*--- to build the POSIX pthread wrappers.                     ---*/
205 /*---                                                          ---*/
206 /*----------------------------------------------------------------*/
207 
208 /* ----------------------------------------------------------
209    For describing ordinary mutexes (non-rwlocks).  For rwlock
210    descriptions see ANNOTATE_RWLOCK_* below.
211    ---------------------------------------------------------- */
212 
213 /* Notify here immediately after mutex creation.  _mbRec == 0 for a
214    non-recursive mutex, 1 for a recursive mutex. */
215 #define VALGRIND_HG_MUTEX_INIT_POST(_mutex, _mbRec)          \
216    DO_CREQ_v_WW(_VG_USERREQ__HG_PTHREAD_MUTEX_INIT_POST,     \
217                 void*,(_mutex), long,(_mbRec))
218 
219 /* Notify here immediately before mutex acquisition.  _isTryLock == 0
220    for a normal acquisition, 1 for a "try" style acquisition. */
221 #define VALGRIND_HG_MUTEX_LOCK_PRE(_mutex, _isTryLock)       \
222    DO_CREQ_v_WW(_VG_USERREQ__HG_PTHREAD_MUTEX_LOCK_PRE,      \
223                 void*,(_mutex), long,(_isTryLock))
224 
225 /* Notify here immediately after a successful mutex acquisition. */
226 #define VALGRIND_HG_MUTEX_LOCK_POST(_mutex)                  \
227    DO_CREQ_v_W(_VG_USERREQ__HG_PTHREAD_MUTEX_LOCK_POST,      \
228                void*,(_mutex))
229 
230 /* Notify here immediately before a mutex release. */
231 #define VALGRIND_HG_MUTEX_UNLOCK_PRE(_mutex)                 \
232    DO_CREQ_v_W(_VG_USERREQ__HG_PTHREAD_MUTEX_UNLOCK_PRE,     \
233                void*,(_mutex))
234 
235 /* Notify here immediately after a mutex release. */
236 #define VALGRIND_HG_MUTEX_UNLOCK_POST(_mutex)                \
237    DO_CREQ_v_W(_VG_USERREQ__HG_PTHREAD_MUTEX_UNLOCK_POST,    \
238                void*,(_mutex))
239 
240 /* Notify here immediately before mutex destruction. */
241 #define VALGRIND_HG_MUTEX_DESTROY_PRE(_mutex)                \
242    DO_CREQ_v_W(_VG_USERREQ__HG_PTHREAD_MUTEX_DESTROY_PRE,    \
243                void*,(_mutex))
244 
245 /* ----------------------------------------------------------
246    For describing semaphores.
247    ---------------------------------------------------------- */
248 
249 /* Notify here immediately after semaphore creation. */
250 #define VALGRIND_HG_SEM_INIT_POST(_sem, _value)              \
251    DO_CREQ_v_WW(_VG_USERREQ__HG_POSIX_SEM_INIT_POST,         \
252                 void*, (_sem), unsigned long, (_value))
253 
254 /* Notify here immediately after a semaphore wait (an acquire-style
255    operation) */
256 #define VALGRIND_HG_SEM_WAIT_POST(_sem)                      \
257    DO_CREQ_v_W(_VG_USERREQ__HG_POSIX_SEM_WAIT_POST,          \
258                void*,(_sem))
259 
260 /* Notify here immediately before semaphore post (a release-style
261    operation) */
262 #define VALGRIND_HG_SEM_POST_PRE(_sem)                       \
263    DO_CREQ_v_W(_VG_USERREQ__HG_POSIX_SEM_POST_PRE,           \
264                void*,(_sem))
265 
266 /* Notify here immediately before semaphore destruction. */
267 #define VALGRIND_HG_SEM_DESTROY_PRE(_sem)                    \
268    DO_CREQ_v_W(_VG_USERREQ__HG_POSIX_SEM_DESTROY_PRE,        \
269                void*, (_sem))
270 
271 /* ----------------------------------------------------------
272    For describing barriers.
273    ---------------------------------------------------------- */
274 
275 /* Notify here immediately before barrier creation.  _count is the
276    capacity.  _resizable == 0 means the barrier may not be resized, 1
277    means it may be. */
278 #define VALGRIND_HG_BARRIER_INIT_PRE(_bar, _count, _resizable) \
279    DO_CREQ_v_WWW(_VG_USERREQ__HG_PTHREAD_BARRIER_INIT_PRE,   \
280                  void*,(_bar),                               \
281                  unsigned long,(_count),                     \
282                  unsigned long,(_resizable))
283 
284 /* Notify here immediately before arrival at a barrier. */
285 #define VALGRIND_HG_BARRIER_WAIT_PRE(_bar)                   \
286    DO_CREQ_v_W(_VG_USERREQ__HG_PTHREAD_BARRIER_WAIT_PRE,     \
287                void*,(_bar))
288 
289 /* Notify here immediately before a resize (change of barrier
290    capacity).  If _newcount >= the existing capacity, then there is no
291    change in the state of any threads waiting at the barrier.  If
292    _newcount < the existing capacity, and >= _newcount threads are
293    currently waiting at the barrier, then this notification is
294    considered to also have the effect of telling the checker that all
295    waiting threads have now moved past the barrier.  (I can't think of
296    any other sane semantics.) */
297 #define VALGRIND_HG_BARRIER_RESIZE_PRE(_bar, _newcount)      \
298    DO_CREQ_v_WW(_VG_USERREQ__HG_PTHREAD_BARRIER_RESIZE_PRE,  \
299                 void*,(_bar),                                \
300                 unsigned long,(_newcount))
301 
302 /* Notify here immediately before barrier destruction. */
303 #define VALGRIND_HG_BARRIER_DESTROY_PRE(_bar)                \
304    DO_CREQ_v_W(_VG_USERREQ__HG_PTHREAD_BARRIER_DESTROY_PRE,  \
305                void*,(_bar))
306 
307 /* ----------------------------------------------------------
308    For describing memory ownership changes.
309    ---------------------------------------------------------- */
310 
311 /* Clean memory state.  This makes Helgrind forget everything it knew
312    about the specified memory range.  Effectively this announces that
313    the specified memory range now "belongs" to the calling thread, so
314    that: (1) the calling thread can access it safely without
315    synchronisation, and (2) all other threads must sync with this one
316    to access it safely.  This is particularly useful for memory
317    allocators that wish to recycle memory. */
318 #define VALGRIND_HG_CLEAN_MEMORY(_qzz_start, _qzz_len)       \
319    DO_CREQ_v_WW(VG_USERREQ__HG_CLEAN_MEMORY,                 \
320                 void*,(_qzz_start),                          \
321                 unsigned long,(_qzz_len))
322 
323 /* The same, but for the heap block starting at _qzz_blockstart.  This
324    allows painting when we only know the address of an object, but not
325    its size, which is sometimes the case in C++ code involving
326    inheritance, and in which RTTI is not, for whatever reason,
327    available.  Returns the number of bytes painted, which can be zero
328    for a zero-sized block.  Hence, return values >= 0 indicate success
329    (the block was found), and the value -1 indicates block not
330    found, and -2 is returned when not running on Helgrind. */
331 #define VALGRIND_HG_CLEAN_MEMORY_HEAPBLOCK(_qzz_blockstart)  \
332    (__extension__                                            \
333    ({long int _npainted;                                     \
334      DO_CREQ_W_W(_npainted, (-2)/*default*/,                 \
335                  _VG_USERREQ__HG_CLEAN_MEMORY_HEAPBLOCK,     \
336                             void*,(_qzz_blockstart));        \
337      _npainted;                                              \
338    }))
339 
340 /* ----------------------------------------------------------
341    For error control.
342    ---------------------------------------------------------- */
343 
344 /* Tell H that an address range is not to be "tracked" until further
345    notice.  This puts it in the NOACCESS state, in which case we
346    ignore all reads and writes to it.  Useful for ignoring ranges of
347    memory where there might be races we don't want to see.  If the
348    memory is subsequently reallocated via malloc/new/stack allocation,
349    then it is put back in the trackable state.  Hence it is safe in
350    the situation where checking is disabled, the containing area is
351    deallocated and later reallocated for some other purpose. */
352 #define VALGRIND_HG_DISABLE_CHECKING(_qzz_start, _qzz_len)   \
353    DO_CREQ_v_WW(_VG_USERREQ__HG_ARANGE_MAKE_UNTRACKED,       \
354                  void*,(_qzz_start),                         \
355                  unsigned long,(_qzz_len))
356 
357 /* And put it back into the normal "tracked" state, that is, make it
358    once again subject to the normal race-checking machinery.  This
359    puts it in the same state as new memory allocated by this thread --
360    that is, basically owned exclusively by this thread. */
361 #define VALGRIND_HG_ENABLE_CHECKING(_qzz_start, _qzz_len)    \
362    DO_CREQ_v_WW(_VG_USERREQ__HG_ARANGE_MAKE_TRACKED,         \
363                  void*,(_qzz_start),                         \
364                  unsigned long,(_qzz_len))
365 
366 
367 /*----------------------------------------------------------------*/
368 /*---                                                          ---*/
369 /*--- ThreadSanitizer-compatible requests                      ---*/
370 /*--- (mostly unimplemented)                                   ---*/
371 /*---                                                          ---*/
372 /*----------------------------------------------------------------*/
373 
374 /* A quite-broad set of annotations, as used in the ThreadSanitizer
375    project.  This implementation aims to be a (source-level)
376    compatible implementation of the macros defined in:
377 
378    http://code.google.com/p/data-race-test/source
379           /browse/trunk/dynamic_annotations/dynamic_annotations.h
380 
381    (some of the comments below are taken from the above file)
382 
383    The implementation here is very incomplete, and intended as a
384    starting point.  Many of the macros are unimplemented.  Rather than
385    allowing unimplemented macros to silently do nothing, they cause an
386    assertion.  Intention is to implement them on demand.
387 
388    The major use of these macros is to make visible to race detectors,
389    the behaviour (effects) of user-implemented synchronisation
390    primitives, that the detectors could not otherwise deduce from the
391    normal observation of pthread etc calls.
392 
393    Some of the macros are no-ops in Helgrind.  That's because Helgrind
394    is a pure happens-before detector, whereas ThreadSanitizer uses a
395    hybrid lockset and happens-before scheme, which requires more
396    accurate annotations for correct operation.
397 
398    The macros are listed in the same order as in dynamic_annotations.h
399    (URL just above).
400 
401    I should point out that I am less than clear about the intended
402    semantics of quite a number of them.  Comments and clarifications
403    welcomed!
404 */
405 
406 /* ----------------------------------------------------------------
407    These four allow description of user-level condition variables,
408    apparently in the style of POSIX's pthread_cond_t.  Currently
409    unimplemented and will assert.
410    ----------------------------------------------------------------
411 */
412 /* Report that wait on the condition variable at address CV has
413    succeeded and the lock at address LOCK is now held.  CV and LOCK
414    are completely arbitrary memory addresses which presumably mean
415    something to the application, but are meaningless to Helgrind. */
416 #define ANNOTATE_CONDVAR_LOCK_WAIT(cv, lock) \
417    _HG_CLIENTREQ_UNIMP("ANNOTATE_CONDVAR_LOCK_WAIT")
418 
419 /* Report that wait on the condition variable at CV has succeeded.
420    Variant w/o lock. */
421 #define ANNOTATE_CONDVAR_WAIT(cv) \
422    _HG_CLIENTREQ_UNIMP("ANNOTATE_CONDVAR_WAIT")
423 
424 /* Report that we are about to signal on the condition variable at
425    address CV. */
426 #define ANNOTATE_CONDVAR_SIGNAL(cv) \
427    _HG_CLIENTREQ_UNIMP("ANNOTATE_CONDVAR_SIGNAL")
428 
429 /* Report that we are about to signal_all on the condition variable at
430    CV. */
431 #define ANNOTATE_CONDVAR_SIGNAL_ALL(cv) \
432    _HG_CLIENTREQ_UNIMP("ANNOTATE_CONDVAR_SIGNAL_ALL")
433 
434 
435 /* ----------------------------------------------------------------
436    Create completely arbitrary happens-before edges between threads.
437 
438    If threads T1 .. Tn all do ANNOTATE_HAPPENS_BEFORE(obj) and later
439    (w.r.t. some notional global clock for the computation) thread Tm
440    does ANNOTATE_HAPPENS_AFTER(obj), then Helgrind will regard all
441    memory accesses done by T1 .. Tn before the ..BEFORE.. call as
442    happening-before all memory accesses done by Tm after the
443    ..AFTER.. call.  Hence Helgrind won't complain about races if Tm's
444    accesses afterwards are to the same locations as accesses before by
445    any of T1 .. Tn.
446 
447    OBJ is a machine word (unsigned long, or void*), is completely
448    arbitrary, and denotes the identity of some synchronisation object
449    you're modelling.
450 
451    You must do the _BEFORE call just before the real sync event on the
452    signaller's side, and _AFTER just after the real sync event on the
453    waiter's side.
454 
455    If none of the rest of these macros make sense to you, at least
456    take the time to understand these two.  They form the very essence
457    of describing arbitrary inter-thread synchronisation events to
458    Helgrind.  You can get a long way just with them alone.
459 
460    See also, extensive discussion on semantics of this in
461    https://bugs.kde.org/show_bug.cgi?id=243935
462 
463    ANNOTATE_HAPPENS_BEFORE_FORGET_ALL(obj) is interim until such time
464    as bug 243935 is fully resolved.  It instructs Helgrind to forget
465    about any ANNOTATE_HAPPENS_BEFORE calls on the specified object, in
466    effect putting it back in its original state.  Once in that state,
467    a use of ANNOTATE_HAPPENS_AFTER on it has no effect on the calling
468    thread.
469 
470    An implementation may optionally release resources it has
471    associated with 'obj' when ANNOTATE_HAPPENS_BEFORE_FORGET_ALL(obj)
472    happens.  Users are recommended to use
473    ANNOTATE_HAPPENS_BEFORE_FORGET_ALL to indicate when a
474    synchronisation object is no longer needed, so as to avoid
475    potential indefinite resource leaks.
476    ----------------------------------------------------------------
477 */
478 #define ANNOTATE_HAPPENS_BEFORE(obj) \
479    DO_CREQ_v_W(_VG_USERREQ__HG_USERSO_SEND_PRE, void*,(obj))
480 
481 #define ANNOTATE_HAPPENS_AFTER(obj) \
482    DO_CREQ_v_W(_VG_USERREQ__HG_USERSO_RECV_POST, void*,(obj))
483 
484 #define ANNOTATE_HAPPENS_BEFORE_FORGET_ALL(obj) \
485    DO_CREQ_v_W(_VG_USERREQ__HG_USERSO_FORGET_ALL, void*,(obj))
486 
487 /* ----------------------------------------------------------------
488    Memory publishing.  The TSan sources say:
489 
490      Report that the bytes in the range [pointer, pointer+size) are about
491      to be published safely. The race checker will create a happens-before
492      arc from the call ANNOTATE_PUBLISH_MEMORY_RANGE(pointer, size) to
493      subsequent accesses to this memory.
494 
495    I'm not sure I understand what this means exactly, nor whether it
496    is relevant for a pure h-b detector.  Leaving unimplemented for
497    now.
498    ----------------------------------------------------------------
499 */
500 #define ANNOTATE_PUBLISH_MEMORY_RANGE(pointer, size) \
501    _HG_CLIENTREQ_UNIMP("ANNOTATE_PUBLISH_MEMORY_RANGE")
502 
503 /* DEPRECATED. Don't use it. */
504 /* #define ANNOTATE_UNPUBLISH_MEMORY_RANGE(pointer, size) */
505 
506 /* DEPRECATED. Don't use it. */
507 /* #define ANNOTATE_SWAP_MEMORY_RANGE(pointer, size) */
508 
509 
510 /* ----------------------------------------------------------------
511    TSan sources say:
512 
513      Instruct the tool to create a happens-before arc between
514      MU->Unlock() and MU->Lock().  This annotation may slow down the
515      race detector; normally it is used only when it would be
516      difficult to annotate each of the mutex's critical sections
517      individually using the annotations above.
518 
519    If MU is a posix pthread_mutex_t then Helgrind will do this anyway.
520    In any case, leave as unimp for now.  I'm unsure about the intended
521    behaviour.
522    ----------------------------------------------------------------
523 */
524 #define ANNOTATE_PURE_HAPPENS_BEFORE_MUTEX(mu) \
525    _HG_CLIENTREQ_UNIMP("ANNOTATE_PURE_HAPPENS_BEFORE_MUTEX")
526 
527 /* Deprecated. Use ANNOTATE_PURE_HAPPENS_BEFORE_MUTEX. */
528 /* #define ANNOTATE_MUTEX_IS_USED_AS_CONDVAR(mu) */
529 
530 
531 /* ----------------------------------------------------------------
532    TSan sources say:
533 
534      Annotations useful when defining memory allocators, or when
535      memory that was protected in one way starts to be protected in
536      another.
537 
538      Report that a new memory at "address" of size "size" has been
539      allocated.  This might be used when the memory has been retrieved
540      from a free list and is about to be reused, or when a the locking
541      discipline for a variable changes.
542 
543    AFAICS this is the same as VALGRIND_HG_CLEAN_MEMORY.
544    ----------------------------------------------------------------
545 */
546 #define ANNOTATE_NEW_MEMORY(address, size) \
547    VALGRIND_HG_CLEAN_MEMORY((address), (size))
548 
549 
550 /* ----------------------------------------------------------------
551    TSan sources say:
552 
553      Annotations useful when defining FIFO queues that transfer data
554      between threads.
555 
556    All unimplemented.  Am not claiming to understand this (yet).
557    ----------------------------------------------------------------
558 */
559 
560 /* Report that the producer-consumer queue object at address PCQ has
561    been created.  The ANNOTATE_PCQ_* annotations should be used only
562    for FIFO queues.  For non-FIFO queues use ANNOTATE_HAPPENS_BEFORE
563    (for put) and ANNOTATE_HAPPENS_AFTER (for get). */
564 #define ANNOTATE_PCQ_CREATE(pcq) \
565    _HG_CLIENTREQ_UNIMP("ANNOTATE_PCQ_CREATE")
566 
567 /* Report that the queue at address PCQ is about to be destroyed. */
568 #define ANNOTATE_PCQ_DESTROY(pcq) \
569    _HG_CLIENTREQ_UNIMP("ANNOTATE_PCQ_DESTROY")
570 
571 /* Report that we are about to put an element into a FIFO queue at
572    address PCQ. */
573 #define ANNOTATE_PCQ_PUT(pcq) \
574    _HG_CLIENTREQ_UNIMP("ANNOTATE_PCQ_PUT")
575 
576 /* Report that we've just got an element from a FIFO queue at address
577    PCQ. */
578 #define ANNOTATE_PCQ_GET(pcq) \
579    _HG_CLIENTREQ_UNIMP("ANNOTATE_PCQ_GET")
580 
581 
582 /* ----------------------------------------------------------------
583    Annotations that suppress errors.  It is usually better to express
584    the program's synchronization using the other annotations, but
585    these can be used when all else fails.
586 
587    Currently these are all unimplemented.  I can't think of a simple
588    way to implement them without at least some performance overhead.
589    ----------------------------------------------------------------
590 */
591 
592 /* Report that we may have a benign race at "pointer", with size
593    "sizeof(*(pointer))". "pointer" must be a non-void* pointer.  Insert at the
594    point where "pointer" has been allocated, preferably close to the point
595    where the race happens.  See also ANNOTATE_BENIGN_RACE_STATIC.
596 
597    XXX: what's this actually supposed to do?  And what's the type of
598    DESCRIPTION?  When does the annotation stop having an effect?
599 */
600 #define ANNOTATE_BENIGN_RACE(pointer, description) \
601    _HG_CLIENTREQ_UNIMP("ANNOTATE_BENIGN_RACE")
602 
603 /* Same as ANNOTATE_BENIGN_RACE(address, description), but applies to
604    the memory range [address, address+size). */
605 #define ANNOTATE_BENIGN_RACE_SIZED(address, size, description) \
606    _HG_CLIENTREQ_UNIMP("ANNOTATE_BENIGN_RACE_SIZED")
607 
608 /* Request the analysis tool to ignore all reads in the current thread
609    until ANNOTATE_IGNORE_READS_END is called.  Useful to ignore
610    intentional racey reads, while still checking other reads and all
611    writes. */
612 #define ANNOTATE_IGNORE_READS_BEGIN() \
613    _HG_CLIENTREQ_UNIMP("ANNOTATE_IGNORE_READS_BEGIN")
614 
615 /* Stop ignoring reads. */
616 #define ANNOTATE_IGNORE_READS_END() \
617    _HG_CLIENTREQ_UNIMP("ANNOTATE_IGNORE_READS_END")
618 
619 /* Similar to ANNOTATE_IGNORE_READS_BEGIN, but ignore writes. */
620 #define ANNOTATE_IGNORE_WRITES_BEGIN() \
621    _HG_CLIENTREQ_UNIMP("ANNOTATE_IGNORE_WRITES_BEGIN")
622 
623 /* Stop ignoring writes. */
624 #define ANNOTATE_IGNORE_WRITES_END() \
625    _HG_CLIENTREQ_UNIMP("ANNOTATE_IGNORE_WRITES_END")
626 
627 /* Start ignoring all memory accesses (reads and writes). */
628 #define ANNOTATE_IGNORE_READS_AND_WRITES_BEGIN() \
629    do { \
630       ANNOTATE_IGNORE_READS_BEGIN(); \
631       ANNOTATE_IGNORE_WRITES_BEGIN(); \
632    } while (0)
633 
634 /* Stop ignoring all memory accesses. */
635 #define ANNOTATE_IGNORE_READS_AND_WRITES_END() \
636    do { \
637       ANNOTATE_IGNORE_WRITES_END(); \
638       ANNOTATE_IGNORE_READS_END(); \
639    } while (0)
640 
641 
642 /* ----------------------------------------------------------------
643    Annotations useful for debugging.
644 
645    Again, so for unimplemented, partly for performance reasons.
646    ----------------------------------------------------------------
647 */
648 
649 /* Request to trace every access to ADDRESS. */
650 #define ANNOTATE_TRACE_MEMORY(address) \
651    _HG_CLIENTREQ_UNIMP("ANNOTATE_TRACE_MEMORY")
652 
653 /* Report the current thread name to a race detector. */
654 #define ANNOTATE_THREAD_NAME(name) \
655    _HG_CLIENTREQ_UNIMP("ANNOTATE_THREAD_NAME")
656 
657 
658 /* ----------------------------------------------------------------
659    Annotations for describing behaviour of user-implemented lock
660    primitives.  In all cases, the LOCK argument is a completely
661    arbitrary machine word (unsigned long, or void*) and can be any
662    value which gives a unique identity to the lock objects being
663    modelled.
664 
665    We just pretend they're ordinary posix rwlocks.  That'll probably
666    give some rather confusing wording in error messages, claiming that
667    the arbitrary LOCK values are pthread_rwlock_t*'s, when in fact
668    they are not.  Ah well.
669    ----------------------------------------------------------------
670 */
671 /* Report that a lock has just been created at address LOCK. */
672 #define ANNOTATE_RWLOCK_CREATE(lock)                         \
673    DO_CREQ_v_W(_VG_USERREQ__HG_PTHREAD_RWLOCK_INIT_POST,     \
674                void*,(lock))
675 
676 /* Report that the lock at address LOCK is about to be destroyed. */
677 #define ANNOTATE_RWLOCK_DESTROY(lock)                        \
678    DO_CREQ_v_W(_VG_USERREQ__HG_PTHREAD_RWLOCK_DESTROY_PRE,   \
679                void*,(lock))
680 
681 /* Report that the lock at address LOCK has just been acquired.
682    is_w=1 for writer lock, is_w=0 for reader lock. */
683 #define ANNOTATE_RWLOCK_ACQUIRED(lock, is_w)                 \
684   DO_CREQ_v_WW(_VG_USERREQ__HG_PTHREAD_RWLOCK_LOCK_POST,     \
685                void*,(lock), unsigned long,(is_w))
686 
687 /* Report that the lock at address LOCK is about to be released. */
688 #define ANNOTATE_RWLOCK_RELEASED(lock, is_w)                 \
689   DO_CREQ_v_W(_VG_USERREQ__HG_PTHREAD_RWLOCK_UNLOCK_PRE,     \
690               void*,(lock)) /* is_w is ignored */
691 
692 
693 /* -------------------------------------------------------------
694    Annotations useful when implementing barriers.  They are not
695    normally needed by modules that merely use barriers.
696    The "barrier" argument is a pointer to the barrier object.
697    ----------------------------------------------------------------
698 */
699 
700 /* Report that the "barrier" has been initialized with initial
701    "count".  If 'reinitialization_allowed' is true, initialization is
702    allowed to happen multiple times w/o calling barrier_destroy() */
703 #define ANNOTATE_BARRIER_INIT(barrier, count, reinitialization_allowed) \
704    _HG_CLIENTREQ_UNIMP("ANNOTATE_BARRIER_INIT")
705 
706 /* Report that we are about to enter barrier_wait("barrier"). */
707 #define ANNOTATE_BARRIER_WAIT_BEFORE(barrier) \
708    _HG_CLIENTREQ_UNIMP("ANNOTATE_BARRIER_DESTROY")
709 
710 /* Report that we just exited barrier_wait("barrier"). */
711 #define ANNOTATE_BARRIER_WAIT_AFTER(barrier) \
712    _HG_CLIENTREQ_UNIMP("ANNOTATE_BARRIER_DESTROY")
713 
714 /* Report that the "barrier" has been destroyed. */
715 #define ANNOTATE_BARRIER_DESTROY(barrier) \
716    _HG_CLIENTREQ_UNIMP("ANNOTATE_BARRIER_DESTROY")
717 
718 
719 /* ----------------------------------------------------------------
720    Annotations useful for testing race detectors.
721    ----------------------------------------------------------------
722 */
723 
724 /* Report that we expect a race on the variable at ADDRESS.  Use only
725    in unit tests for a race detector. */
726 #define ANNOTATE_EXPECT_RACE(address, description) \
727    _HG_CLIENTREQ_UNIMP("ANNOTATE_EXPECT_RACE")
728 
729 /* A no-op. Insert where you like to test the interceptors. */
730 #define ANNOTATE_NO_OP(arg) \
731    _HG_CLIENTREQ_UNIMP("ANNOTATE_NO_OP")
732 
733 /* Force the race detector to flush its state. The actual effect depends on
734  * the implementation of the detector. */
735 #define ANNOTATE_FLUSH_STATE() \
736    _HG_CLIENTREQ_UNIMP("ANNOTATE_FLUSH_STATE")
737 
738 #endif /* __HELGRIND_H */
739