| /* |
| This file is part of drd, a thread error detector. |
| |
| Copyright (C) 2006-2013 Bart Van Assche <bvanassche@acm.org>. |
| |
| This program is free software; you can redistribute it and/or |
| modify it under the terms of the GNU General Public License as |
| published by the Free Software Foundation; either version 2 of the |
| License, or (at your option) any later version. |
| |
| This program is distributed in the hope that it will be useful, but |
| WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with this program; if not, write to the Free Software |
| Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA |
| 02111-1307, USA. |
| |
| The GNU General Public License is contained in the file COPYING. |
| */ |
| |
| |
| #include "drd_clientobj.h" |
| #include "drd_error.h" |
| #include "drd_rwlock.h" |
| #include "pub_tool_vki.h" |
| #include "pub_tool_errormgr.h" // VG_(maybe_record_error)() |
| #include "pub_tool_libcassert.h" // tl_assert() |
| #include "pub_tool_libcprint.h" // VG_(message)() |
| #include "pub_tool_libcproc.h" // VG_(read_millisecond_timer)() |
| #include "pub_tool_machine.h" // VG_(get_IP)() |
| #include "pub_tool_mallocfree.h" // VG_(malloc)(), VG_(free)() |
| #include "pub_tool_threadstate.h" // VG_(get_running_tid)() |
| |
| |
| /* Local type definitions. */ |
| |
| struct rwlock_thread_info |
| { |
| UWord tid; // DrdThreadId. |
| UInt reader_nesting_count; |
| UInt writer_nesting_count; |
| // Segment of last unlock call by this thread that unlocked a writer lock. |
| Segment* latest_wrlocked_segment; |
| // Segment of last unlock call by this thread that unlocked a reader lock. |
| Segment* latest_rdlocked_segment; |
| }; |
| |
| |
| /* Local functions. */ |
| |
| static void rwlock_cleanup(struct rwlock_info* p); |
| static void rwlock_delete_thread(struct rwlock_info* const p, |
| const DrdThreadId tid); |
| |
| |
| /* Local variables. */ |
| |
| static Bool DRD_(s_trace_rwlock); |
| static UInt DRD_(s_exclusive_threshold_ms); |
| static UInt DRD_(s_shared_threshold_ms); |
| static ULong DRD_(s_rwlock_segment_creation_count); |
| |
| |
| /* Function definitions. */ |
| |
| void DRD_(rwlock_set_trace)(const Bool trace_rwlock) |
| { |
| tl_assert(trace_rwlock == False || trace_rwlock == True); |
| DRD_(s_trace_rwlock) = trace_rwlock; |
| } |
| |
| void DRD_(rwlock_set_exclusive_threshold)(const UInt exclusive_threshold_ms) |
| { |
| DRD_(s_exclusive_threshold_ms) = exclusive_threshold_ms; |
| } |
| |
| void DRD_(rwlock_set_shared_threshold)(const UInt shared_threshold_ms) |
| { |
| DRD_(s_shared_threshold_ms) = shared_threshold_ms; |
| } |
| |
| static Bool DRD_(rwlock_is_rdlocked)(struct rwlock_info* p) |
| { |
| struct rwlock_thread_info* q; |
| |
| VG_(OSetGen_ResetIter)(p->thread_info); |
| for ( ; (q = VG_(OSetGen_Next)(p->thread_info)) != 0; ) |
| { |
| return q->reader_nesting_count > 0; |
| } |
| return False; |
| } |
| |
| static Bool DRD_(rwlock_is_wrlocked)(struct rwlock_info* p) |
| { |
| struct rwlock_thread_info* q; |
| |
| VG_(OSetGen_ResetIter)(p->thread_info); |
| for ( ; (q = VG_(OSetGen_Next)(p->thread_info)) != 0; ) |
| { |
| return q->writer_nesting_count > 0; |
| } |
| return False; |
| } |
| |
| static Bool DRD_(rwlock_is_locked)(struct rwlock_info* p) |
| { |
| return DRD_(rwlock_is_rdlocked)(p) || DRD_(rwlock_is_wrlocked)(p); |
| } |
| |
| static Bool DRD_(rwlock_is_rdlocked_by)(struct rwlock_info* p, |
| const DrdThreadId tid) |
| { |
| const UWord uword_tid = tid; |
| struct rwlock_thread_info* q; |
| |
| q = VG_(OSetGen_Lookup)(p->thread_info, &uword_tid); |
| return q && q->reader_nesting_count > 0; |
| } |
| |
| static Bool DRD_(rwlock_is_wrlocked_by)(struct rwlock_info* p, |
| const DrdThreadId tid) |
| { |
| const UWord uword_tid = tid; |
| struct rwlock_thread_info* q; |
| |
| q = VG_(OSetGen_Lookup)(p->thread_info, &uword_tid); |
| return q && q->writer_nesting_count > 0; |
| } |
| |
| static Bool DRD_(rwlock_is_locked_by)(struct rwlock_info* p, |
| const DrdThreadId tid) |
| { |
| return (DRD_(rwlock_is_rdlocked_by)(p, tid) |
| || DRD_(rwlock_is_wrlocked_by)(p, tid)); |
| } |
| |
| /** Either look up or insert a node corresponding to DRD thread id 'tid'. */ |
| static |
| struct rwlock_thread_info* |
| DRD_(lookup_or_insert_node)(OSet* oset, const UWord tid) |
| { |
| struct rwlock_thread_info* q; |
| |
| q = VG_(OSetGen_Lookup)(oset, &tid); |
| if (q == 0) |
| { |
| q = VG_(OSetGen_AllocNode)(oset, sizeof(*q)); |
| q->tid = tid; |
| q->reader_nesting_count = 0; |
| q->writer_nesting_count = 0; |
| q->latest_wrlocked_segment = 0; |
| q->latest_rdlocked_segment = 0; |
| VG_(OSetGen_Insert)(oset, q); |
| } |
| tl_assert(q); |
| return q; |
| } |
| |
| /** |
| * Combine the vector clock corresponding to the last unlock operation of |
| * reader-writer lock p into the vector clock of thread 'tid'. |
| */ |
| static void DRD_(rwlock_combine_other_vc)(struct rwlock_info* const p, |
| const DrdThreadId tid, |
| const Bool readers_too) |
| { |
| struct rwlock_thread_info* q; |
| VectorClock old_vc; |
| |
| DRD_(vc_copy)(&old_vc, DRD_(thread_get_vc)(tid)); |
| VG_(OSetGen_ResetIter)(p->thread_info); |
| for ( ; (q = VG_(OSetGen_Next)(p->thread_info)) != 0; ) { |
| if (q->tid != tid) { |
| if (q->latest_wrlocked_segment) |
| DRD_(vc_combine)(DRD_(thread_get_vc)(tid), |
| &q->latest_wrlocked_segment->vc); |
| if (readers_too && q->latest_rdlocked_segment) |
| DRD_(vc_combine)(DRD_(thread_get_vc)(tid), |
| &q->latest_rdlocked_segment->vc); |
| } |
| } |
| DRD_(thread_update_conflict_set)(tid, &old_vc); |
| DRD_(vc_cleanup)(&old_vc); |
| } |
| |
| /** |
| * Compare the type of the rwlock specified at initialization time with |
| * the type passed as an argument, and complain if these two types do not |
| * match. |
| */ |
| static Bool drd_rwlock_check_type(struct rwlock_info* const p, |
| const RwLockT rwlock_type) |
| { |
| tl_assert(p); |
| /* The code below has to be updated if additional rwlock types are added. */ |
| tl_assert(rwlock_type == pthread_rwlock || rwlock_type == user_rwlock); |
| tl_assert(p->rwlock_type == pthread_rwlock || p->rwlock_type == user_rwlock); |
| |
| if (p->rwlock_type == rwlock_type) |
| return True; |
| |
| { |
| RwlockErrInfo REI = { DRD_(thread_get_running_tid)(), p->a1 }; |
| VG_(maybe_record_error) |
| (VG_(get_running_tid)(), |
| RwlockErr, |
| VG_(get_IP)(VG_(get_running_tid)()), |
| rwlock_type == pthread_rwlock |
| ? "Attempt to use a user-defined rwlock as a POSIX rwlock" |
| : "Attempt to use a POSIX rwlock as a user-defined rwlock", |
| &REI); |
| } |
| return False; |
| } |
| |
| /** Initialize the rwlock_info data structure *p. */ |
| static |
| void DRD_(rwlock_initialize)(struct rwlock_info* const p, const Addr rwlock, |
| const RwLockT rwlock_type) |
| { |
| tl_assert(rwlock != 0); |
| tl_assert(p->a1 == rwlock); |
| tl_assert(p->type == ClientRwlock); |
| |
| p->cleanup = (void(*)(DrdClientobj*))rwlock_cleanup; |
| p->delete_thread |
| = (void(*)(DrdClientobj*, DrdThreadId))rwlock_delete_thread; |
| p->rwlock_type = rwlock_type; |
| p->thread_info = VG_(OSetGen_Create)( |
| 0, 0, VG_(malloc), "drd.rwlock.ri.1", VG_(free)); |
| p->acquiry_time_ms = 0; |
| p->acquired_at = 0; |
| } |
| |
| /** Deallocate the memory that was allocated by rwlock_initialize(). */ |
| static void rwlock_cleanup(struct rwlock_info* p) |
| { |
| struct rwlock_thread_info* q; |
| |
| tl_assert(p); |
| |
| if (DRD_(s_trace_rwlock)) |
| DRD_(trace_msg)("[%d] rwlock_destroy 0x%lx", |
| DRD_(thread_get_running_tid)(), p->a1); |
| |
| if (DRD_(rwlock_is_locked)(p)) |
| { |
| RwlockErrInfo REI = { DRD_(thread_get_running_tid)(), p->a1 }; |
| VG_(maybe_record_error)(VG_(get_running_tid)(), |
| RwlockErr, |
| VG_(get_IP)(VG_(get_running_tid)()), |
| "Destroying locked rwlock", |
| &REI); |
| } |
| |
| VG_(OSetGen_ResetIter)(p->thread_info); |
| for ( ; (q = VG_(OSetGen_Next)(p->thread_info)) != 0; ) |
| { |
| DRD_(sg_put)(q->latest_wrlocked_segment); |
| DRD_(sg_put)(q->latest_rdlocked_segment); |
| } |
| |
| VG_(OSetGen_Destroy)(p->thread_info); |
| } |
| |
| static |
| struct rwlock_info* |
| DRD_(rwlock_get_or_allocate)(const Addr rwlock, const RwLockT rwlock_type) |
| { |
| struct rwlock_info* p; |
| |
| tl_assert(offsetof(DrdClientobj, rwlock) == 0); |
| p = &(DRD_(clientobj_get)(rwlock, ClientRwlock)->rwlock); |
| if (p) |
| { |
| drd_rwlock_check_type(p, rwlock_type); |
| return p; |
| } |
| |
| if (DRD_(clientobj_present)(rwlock, rwlock + 1)) |
| { |
| GenericErrInfo GEI = { |
| .tid = DRD_(thread_get_running_tid)(), |
| .addr = rwlock, |
| }; |
| VG_(maybe_record_error)(VG_(get_running_tid)(), |
| GenericErr, |
| VG_(get_IP)(VG_(get_running_tid)()), |
| "Not a reader-writer lock", |
| &GEI); |
| return 0; |
| } |
| |
| p = &(DRD_(clientobj_add)(rwlock, ClientRwlock)->rwlock); |
| DRD_(rwlock_initialize)(p, rwlock, rwlock_type); |
| return p; |
| } |
| |
| static struct rwlock_info* DRD_(rwlock_get)(const Addr rwlock) |
| { |
| tl_assert(offsetof(DrdClientobj, rwlock) == 0); |
| return &(DRD_(clientobj_get)(rwlock, ClientRwlock)->rwlock); |
| } |
| |
| /** Called before pthread_rwlock_init(). */ |
| struct rwlock_info* DRD_(rwlock_pre_init)(const Addr rwlock, |
| const RwLockT rwlock_type) |
| { |
| struct rwlock_info* p; |
| |
| if (DRD_(s_trace_rwlock)) |
| DRD_(trace_msg)("[%d] rwlock_init 0x%lx", |
| DRD_(thread_get_running_tid)(), rwlock); |
| |
| p = DRD_(rwlock_get)(rwlock); |
| |
| if (p) |
| drd_rwlock_check_type(p, rwlock_type); |
| |
| if (p) |
| { |
| const ThreadId vg_tid = VG_(get_running_tid)(); |
| RwlockErrInfo REI = { DRD_(thread_get_running_tid)(), p->a1 }; |
| VG_(maybe_record_error)(vg_tid, |
| RwlockErr, |
| VG_(get_IP)(vg_tid), |
| "Reader-writer lock reinitialization", |
| &REI); |
| return p; |
| } |
| |
| p = DRD_(rwlock_get_or_allocate)(rwlock, rwlock_type); |
| |
| return p; |
| } |
| |
| /** Called after pthread_rwlock_destroy(). */ |
| void DRD_(rwlock_post_destroy)(const Addr rwlock, const RwLockT rwlock_type) |
| { |
| struct rwlock_info* p; |
| |
| p = DRD_(rwlock_get)(rwlock); |
| if (p == 0) |
| { |
| GenericErrInfo GEI = { |
| .tid = DRD_(thread_get_running_tid)(), |
| .addr = rwlock, |
| }; |
| VG_(maybe_record_error)(VG_(get_running_tid)(), |
| GenericErr, |
| VG_(get_IP)(VG_(get_running_tid)()), |
| "Not a reader-writer lock", |
| &GEI); |
| return; |
| } |
| |
| drd_rwlock_check_type(p, rwlock_type); |
| |
| DRD_(clientobj_remove)(rwlock, ClientRwlock); |
| } |
| |
| /** |
| * Called before pthread_rwlock_rdlock() is invoked. If a data structure for |
| * the client-side object was not yet created, do this now. Also check whether |
| * an attempt is made to lock recursively a synchronization object that must |
| * not be locked recursively. |
| */ |
| void DRD_(rwlock_pre_rdlock)(const Addr rwlock, const RwLockT rwlock_type) |
| { |
| struct rwlock_info* p; |
| |
| if (DRD_(s_trace_rwlock)) |
| DRD_(trace_msg)("[%d] pre_rwlock_rdlock 0x%lx", |
| DRD_(thread_get_running_tid)(), rwlock); |
| |
| p = DRD_(rwlock_get_or_allocate)(rwlock, rwlock_type); |
| tl_assert(p); |
| |
| if (DRD_(rwlock_is_wrlocked_by)(p, DRD_(thread_get_running_tid)())) { |
| RwlockErrInfo REI = { DRD_(thread_get_running_tid)(), p->a1 }; |
| VG_(maybe_record_error)(VG_(get_running_tid)(), |
| RwlockErr, |
| VG_(get_IP)(VG_(get_running_tid)()), |
| "Already locked for writing by calling thread", |
| &REI); |
| } |
| } |
| |
| /** |
| * Update rwlock_info state when locking the pthread_rwlock_t mutex. |
| * Note: this function must be called after pthread_rwlock_rdlock() has been |
| * called, or a race condition is triggered ! |
| */ |
| void DRD_(rwlock_post_rdlock)(const Addr rwlock, const RwLockT rwlock_type, |
| const Bool took_lock) |
| { |
| const DrdThreadId drd_tid = DRD_(thread_get_running_tid)(); |
| struct rwlock_info* p; |
| struct rwlock_thread_info* q; |
| |
| if (DRD_(s_trace_rwlock)) |
| DRD_(trace_msg)("[%d] post_rwlock_rdlock 0x%lx", drd_tid, rwlock); |
| |
| p = DRD_(rwlock_get)(rwlock); |
| |
| if (! p || ! took_lock) |
| return; |
| |
| tl_assert(! DRD_(rwlock_is_wrlocked)(p)); |
| |
| q = DRD_(lookup_or_insert_node)(p->thread_info, drd_tid); |
| if (++q->reader_nesting_count == 1) |
| { |
| DRD_(thread_new_segment)(drd_tid); |
| DRD_(s_rwlock_segment_creation_count)++; |
| DRD_(rwlock_combine_other_vc)(p, drd_tid, False); |
| |
| p->acquiry_time_ms = VG_(read_millisecond_timer)(); |
| p->acquired_at = VG_(record_ExeContext)(VG_(get_running_tid)(), 0); |
| } |
| } |
| |
| /** |
| * Called before pthread_rwlock_wrlock() is invoked. If a data structure for |
| * the client-side object was not yet created, do this now. Also check whether |
| * an attempt is made to lock recursively a synchronization object that must |
| * not be locked recursively. |
| */ |
| void DRD_(rwlock_pre_wrlock)(const Addr rwlock, const RwLockT rwlock_type) |
| { |
| struct rwlock_info* p; |
| |
| p = DRD_(rwlock_get)(rwlock); |
| |
| if (DRD_(s_trace_rwlock)) |
| DRD_(trace_msg)("[%d] pre_rwlock_wrlock 0x%lx", |
| DRD_(thread_get_running_tid)(), rwlock); |
| |
| if (p == 0) |
| p = DRD_(rwlock_get_or_allocate)(rwlock, rwlock_type); |
| |
| tl_assert(p); |
| |
| if (DRD_(rwlock_is_wrlocked_by)(p, DRD_(thread_get_running_tid)())) |
| { |
| RwlockErrInfo REI = { DRD_(thread_get_running_tid)(), p->a1 }; |
| VG_(maybe_record_error)(VG_(get_running_tid)(), |
| RwlockErr, |
| VG_(get_IP)(VG_(get_running_tid)()), |
| "Recursive writer locking not allowed", |
| &REI); |
| } |
| } |
| |
| /** |
| * Update rwlock_info state when locking the pthread_rwlock_t rwlock. |
| * Note: this function must be called after pthread_rwlock_wrlock() has |
| * finished, or a race condition is triggered ! |
| */ |
| void DRD_(rwlock_post_wrlock)(const Addr rwlock, const RwLockT rwlock_type, |
| const Bool took_lock) |
| { |
| const DrdThreadId drd_tid = DRD_(thread_get_running_tid)(); |
| struct rwlock_info* p; |
| struct rwlock_thread_info* q; |
| |
| p = DRD_(rwlock_get)(rwlock); |
| |
| if (DRD_(s_trace_rwlock)) |
| DRD_(trace_msg)("[%d] post_rwlock_wrlock 0x%lx", drd_tid, rwlock); |
| |
| if (! p || ! took_lock) |
| return; |
| |
| q = DRD_(lookup_or_insert_node)(p->thread_info, |
| DRD_(thread_get_running_tid)()); |
| tl_assert(q->writer_nesting_count == 0); |
| q->writer_nesting_count++; |
| tl_assert(q->writer_nesting_count == 1); |
| DRD_(thread_new_segment)(drd_tid); |
| DRD_(s_rwlock_segment_creation_count)++; |
| DRD_(rwlock_combine_other_vc)(p, drd_tid, True); |
| p->acquiry_time_ms = VG_(read_millisecond_timer)(); |
| p->acquired_at = VG_(record_ExeContext)(VG_(get_running_tid)(), 0); |
| } |
| |
| /** |
| * Update rwlock_info state when unlocking the pthread_rwlock_t rwlock. |
| * |
| * @param rwlock Pointer to pthread_rwlock_t data structure in the client space. |
| * |
| * @return New value of the rwlock recursion count. |
| * |
| * @note This function must be called before pthread_rwlock_unlock() is called, |
| * or a race condition is triggered ! |
| */ |
| void DRD_(rwlock_pre_unlock)(const Addr rwlock, const RwLockT rwlock_type) |
| { |
| const DrdThreadId drd_tid = DRD_(thread_get_running_tid)(); |
| const ThreadId vg_tid = VG_(get_running_tid)(); |
| struct rwlock_info* p; |
| struct rwlock_thread_info* q; |
| |
| if (DRD_(s_trace_rwlock)) |
| DRD_(trace_msg)("[%d] rwlock_unlock 0x%lx", drd_tid, rwlock); |
| |
| p = DRD_(rwlock_get)(rwlock); |
| if (p == 0) |
| { |
| GenericErrInfo GEI = { |
| .tid = DRD_(thread_get_running_tid)(), |
| .addr = rwlock, |
| }; |
| VG_(maybe_record_error)(VG_(get_running_tid)(), |
| GenericErr, |
| VG_(get_IP)(VG_(get_running_tid)()), |
| "Not a reader-writer lock", |
| &GEI); |
| return; |
| } |
| |
| drd_rwlock_check_type(p, rwlock_type); |
| |
| if (! DRD_(rwlock_is_locked_by)(p, drd_tid)) |
| { |
| RwlockErrInfo REI = { DRD_(thread_get_running_tid)(), p->a1 }; |
| VG_(maybe_record_error)(vg_tid, |
| RwlockErr, |
| VG_(get_IP)(vg_tid), |
| "Reader-writer lock not locked by calling thread", |
| &REI); |
| return; |
| } |
| q = DRD_(lookup_or_insert_node)(p->thread_info, drd_tid); |
| tl_assert(q); |
| if (q->reader_nesting_count > 0) |
| { |
| q->reader_nesting_count--; |
| if (q->reader_nesting_count == 0 && DRD_(s_shared_threshold_ms) > 0) |
| { |
| Long held = VG_(read_millisecond_timer)() - p->acquiry_time_ms; |
| if (held > DRD_(s_shared_threshold_ms)) |
| { |
| HoldtimeErrInfo HEI |
| = { DRD_(thread_get_running_tid)(), |
| rwlock, p->acquired_at, held, DRD_(s_shared_threshold_ms) }; |
| VG_(maybe_record_error)(vg_tid, |
| HoldtimeErr, |
| VG_(get_IP)(vg_tid), |
| "rwlock", |
| &HEI); |
| } |
| } |
| if (q->reader_nesting_count == 0 && q->writer_nesting_count == 0) |
| { |
| /* |
| * This pthread_rwlock_unlock() call really unlocks the rwlock. Save |
| * the current vector clock of the thread such that it is available |
| * when this rwlock is locked again. |
| */ |
| DRD_(thread_get_latest_segment)(&q->latest_rdlocked_segment, drd_tid); |
| DRD_(thread_new_segment)(drd_tid); |
| DRD_(s_rwlock_segment_creation_count)++; |
| } |
| } |
| else if (q->writer_nesting_count > 0) |
| { |
| q->writer_nesting_count--; |
| if (q->writer_nesting_count == 0 && DRD_(s_exclusive_threshold_ms) > 0) |
| { |
| Long held = VG_(read_millisecond_timer)() - p->acquiry_time_ms; |
| if (held > DRD_(s_exclusive_threshold_ms)) |
| { |
| HoldtimeErrInfo HEI |
| = { DRD_(thread_get_running_tid)(), |
| rwlock, p->acquired_at, held, |
| DRD_(s_exclusive_threshold_ms) }; |
| VG_(maybe_record_error)(vg_tid, |
| HoldtimeErr, |
| VG_(get_IP)(vg_tid), |
| "rwlock", |
| &HEI); |
| } |
| } |
| if (q->reader_nesting_count == 0 && q->writer_nesting_count == 0) |
| { |
| /* |
| * This pthread_rwlock_unlock() call really unlocks the rwlock. Save |
| * the current vector clock of the thread such that it is available |
| * when this rwlock is locked again. |
| */ |
| DRD_(thread_get_latest_segment)(&q->latest_wrlocked_segment, drd_tid); |
| DRD_(thread_new_segment)(drd_tid); |
| DRD_(s_rwlock_segment_creation_count)++; |
| } |
| } |
| else |
| { |
| tl_assert(False); |
| } |
| } |
| |
| /** Called when thread tid stops to exist. */ |
| static void rwlock_delete_thread(struct rwlock_info* const p, |
| const DrdThreadId tid) |
| { |
| struct rwlock_thread_info* q; |
| |
| if (DRD_(rwlock_is_locked_by)(p, tid)) |
| { |
| RwlockErrInfo REI = { DRD_(thread_get_running_tid)(), p->a1 }; |
| VG_(maybe_record_error)(VG_(get_running_tid)(), |
| RwlockErr, |
| VG_(get_IP)(VG_(get_running_tid)()), |
| "Reader-writer lock still locked at thread exit", |
| &REI); |
| q = DRD_(lookup_or_insert_node)(p->thread_info, tid); |
| q->reader_nesting_count = 0; |
| q->writer_nesting_count = 0; |
| } |
| } |
| |
| ULong DRD_(get_rwlock_segment_creation_count)(void) |
| { |
| return DRD_(s_rwlock_segment_creation_count); |
| } |
