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ftmemsim-valgrind/drd/drd_thread.c
Bart Van Assche a2f849972f Wrapped DRD_() macro around all segment function names. 
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@9160
2009-02-14 17:19:58 +00:00

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/*
This file is part of drd, a data race detector.
Copyright (C) 2006-2008 Bart Van Assche
bart.vanassche@gmail.com
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_error.h"
#include "drd_barrier.h"
#include "drd_cond.h"
#include "drd_mutex.h"
#include "drd_segment.h"
#include "drd_semaphore.h"
#include "drd_suppression.h"
#include "drd_thread.h"
#include "pub_tool_vki.h"
#include "pub_tool_basics.h" // Addr, SizeT
#include "pub_tool_errormgr.h" // VG_(unique_error)()
#include "pub_tool_libcassert.h" // tl_assert()
#include "pub_tool_libcbase.h" // VG_(strlen)()
#include "pub_tool_libcprint.h" // VG_(printf)()
#include "pub_tool_libcproc.h" // VG_(getenv)()
#include "pub_tool_machine.h"
#include "pub_tool_mallocfree.h" // VG_(malloc)(), VG_(free)()
#include "pub_tool_options.h" // VG_(clo_backtrace_size)
#include "pub_tool_threadstate.h" // VG_(get_pthread_id)()
// Local functions.
static void thread_append_segment(const DrdThreadId tid,
Segment* const sg);
static void thread_discard_segment(const DrdThreadId tid, Segment* const sg);
static Bool thread_conflict_set_up_to_date(const DrdThreadId tid);
static void thread_compute_conflict_set(struct bitmap** conflict_set,
const DrdThreadId tid);
// Local variables.
static ULong s_context_switch_count;
static ULong s_discard_ordered_segments_count;
static ULong s_update_conflict_set_count;
static ULong s_conflict_set_new_segment_count;
static ULong s_conflict_set_combine_vc_count;
static ULong s_conflict_set_bitmap_creation_count;
static ULong s_conflict_set_bitmap2_creation_count;
static ThreadId s_vg_running_tid = VG_INVALID_THREADID;
DrdThreadId s_drd_running_tid = DRD_INVALID_THREADID;
ThreadInfo s_threadinfo[DRD_N_THREADS];
struct bitmap* s_conflict_set;
static Bool s_trace_context_switches = False;
static Bool s_trace_conflict_set = False;
static Bool s_trace_fork_join = False;
static Bool s_segment_merging = True;
// Function definitions.
void thread_trace_context_switches(const Bool t)
{
tl_assert(t == False || t == True);
s_trace_context_switches = t;
}
void thread_trace_conflict_set(const Bool t)
{
tl_assert(t == False || t == True);
s_trace_conflict_set = t;
}
Bool DRD_(thread_get_trace_fork_join)(void)
{
return s_trace_fork_join;
}
void DRD_(thread_set_trace_fork_join)(const Bool t)
{
tl_assert(t == False || t == True);
s_trace_fork_join = t;
}
void thread_set_segment_merging(const Bool m)
{
tl_assert(m == False || m == True);
s_segment_merging = m;
}
/**
* Convert Valgrind's ThreadId into a DrdThreadId. Report failure if
* Valgrind's ThreadId does not yet exist.
**/
DrdThreadId VgThreadIdToDrdThreadId(const ThreadId tid)
{
int i;
if (tid == VG_INVALID_THREADID)
return DRD_INVALID_THREADID;
for (i = 1; i < DRD_N_THREADS; i++)
{
if (s_threadinfo[i].vg_thread_exists == True
&& s_threadinfo[i].vg_threadid == tid)
{
return i;
}
}
return DRD_INVALID_THREADID;
}
static
DrdThreadId VgThreadIdToNewDrdThreadId(const ThreadId tid)
{
int i;
tl_assert(VgThreadIdToDrdThreadId(tid) == DRD_INVALID_THREADID);
for (i = 1; i < DRD_N_THREADS; i++)
{
if (s_threadinfo[i].vg_thread_exists == False
&& s_threadinfo[i].posix_thread_exists == False
&& s_threadinfo[i].detached_posix_thread == False)
{
s_threadinfo[i].vg_thread_exists = True;
s_threadinfo[i].vg_threadid = tid;
s_threadinfo[i].pt_threadid = INVALID_POSIX_THREADID;
s_threadinfo[i].stack_min = 0;
s_threadinfo[i].stack_min_min = 0;
s_threadinfo[i].stack_startup = 0;
s_threadinfo[i].stack_max = 0;
s_threadinfo[i].is_recording = True;
s_threadinfo[i].synchr_nesting = 0;
if (s_threadinfo[i].first != 0)
VG_(printf)("drd thread id = %d\n", i);
tl_assert(s_threadinfo[i].first == 0);
tl_assert(s_threadinfo[i].last == 0);
return i;
}
}
tl_assert(False);
return DRD_INVALID_THREADID;
}
DrdThreadId PtThreadIdToDrdThreadId(const PThreadId tid)
{
int i;
tl_assert(tid != INVALID_POSIX_THREADID);
for (i = 1; i < DRD_N_THREADS; i++)
{
if (s_threadinfo[i].posix_thread_exists
&& s_threadinfo[i].pt_threadid == tid)
{
return i;
}
}
return DRD_INVALID_THREADID;
}
ThreadId DrdThreadIdToVgThreadId(const DrdThreadId tid)
{
tl_assert(0 <= (int)tid && tid < DRD_N_THREADS
&& tid != DRD_INVALID_THREADID);
return (s_threadinfo[tid].vg_thread_exists
? s_threadinfo[tid].vg_threadid
: VG_INVALID_THREADID);
}
#if 0
/** Sanity check of the doubly linked list of segments referenced by a
* ThreadInfo struct.
* @return True if sane, False if not.
*/
static Bool sane_ThreadInfo(const ThreadInfo* const ti)
{
Segment* p;
for (p = ti->first; p; p = p->next) {
if (p->next && p->next->prev != p)
return False;
if (p->next == 0 && p != ti->last)
return False;
}
for (p = ti->last; p; p = p->prev) {
if (p->prev && p->prev->next != p)
return False;
if (p->prev == 0 && p != ti->first)
return False;
}
return True;
}
#endif
DrdThreadId thread_pre_create(const DrdThreadId creator,
const ThreadId vg_created)
{
DrdThreadId created;
tl_assert(VgThreadIdToDrdThreadId(vg_created) == DRD_INVALID_THREADID);
created = VgThreadIdToNewDrdThreadId(vg_created);
tl_assert(0 <= (int)created && created < DRD_N_THREADS
&& created != DRD_INVALID_THREADID);
tl_assert(s_threadinfo[created].first == 0);
tl_assert(s_threadinfo[created].last == 0);
thread_append_segment(created, DRD_(sg_new)(creator, created));
return created;
}
/* Process VG_USERREQ__POST_THREAD_JOIN. This client request is invoked just */
/* after thread drd_joiner joined thread drd_joinee. */
void DRD_(thread_post_join)(DrdThreadId drd_joiner, DrdThreadId drd_joinee)
{
tl_assert(IsValidDrdThreadId(drd_joiner));
tl_assert(IsValidDrdThreadId(drd_joinee));
thread_new_segment(drd_joinee);
thread_combine_vc(drd_joiner, drd_joinee);
thread_new_segment(drd_joiner);
if (s_trace_fork_join)
{
const ThreadId joiner = DrdThreadIdToVgThreadId(drd_joiner);
const ThreadId joinee = DrdThreadIdToVgThreadId(drd_joinee);
const unsigned msg_size = 256;
char* msg;
msg = VG_(malloc)("drd.main.dptj.1", msg_size);
tl_assert(msg);
VG_(snprintf)(msg, msg_size,
"drd_post_thread_join joiner = %d/%d, joinee = %d/%d",
joiner, drd_joiner, joinee, drd_joinee);
if (joiner)
{
VG_(snprintf)(msg + VG_(strlen)(msg), msg_size - VG_(strlen)(msg),
", new vc: ");
DRD_(vc_snprint)(msg + VG_(strlen)(msg), msg_size - VG_(strlen)(msg),
thread_get_vc(drd_joiner));
}
VG_(message)(Vg_DebugMsg, "%s", msg);
VG_(free)(msg);
}
if (! DRD_(get_check_stack_accesses)())
{
DRD_(finish_suppression)(thread_get_stack_max(drd_joinee)
- thread_get_stack_size(drd_joinee),
thread_get_stack_max(drd_joinee));
}
thread_delete(drd_joinee);
mutex_thread_delete(drd_joinee);
cond_thread_delete(drd_joinee);
semaphore_thread_delete(drd_joinee);
barrier_thread_delete(drd_joinee);
}
/** Allocate the first segment for a thread. Call this just after
* pthread_create().
*/
DrdThreadId thread_post_create(const ThreadId vg_created)
{
const DrdThreadId created = VgThreadIdToDrdThreadId(vg_created);
tl_assert(0 <= (int)created && created < DRD_N_THREADS
&& created != DRD_INVALID_THREADID);
s_threadinfo[created].stack_max = VG_(thread_get_stack_max)(vg_created);
s_threadinfo[created].stack_startup = s_threadinfo[created].stack_max;
s_threadinfo[created].stack_min = s_threadinfo[created].stack_max;
s_threadinfo[created].stack_min_min = s_threadinfo[created].stack_max;
s_threadinfo[created].stack_size = VG_(thread_get_stack_size)(vg_created);
tl_assert(s_threadinfo[created].stack_max != 0);
return created;
}
/* NPTL hack: NPTL allocates the 'struct pthread' on top of the stack, */
/* and accesses this data structure from multiple threads without locking. */
/* Any conflicting accesses in the range stack_startup..stack_max will be */
/* ignored. */
void thread_set_stack_startup(const DrdThreadId tid, const Addr stack_startup)
{
tl_assert(0 <= (int)tid && tid < DRD_N_THREADS
&& tid != DRD_INVALID_THREADID);
tl_assert(s_threadinfo[tid].stack_min <= stack_startup);
tl_assert(stack_startup <= s_threadinfo[tid].stack_max);
s_threadinfo[tid].stack_startup = stack_startup;
}
Addr thread_get_stack_min(const DrdThreadId tid)
{
tl_assert(0 <= (int)tid && tid < DRD_N_THREADS
&& tid != DRD_INVALID_THREADID);
return s_threadinfo[tid].stack_min;
}
Addr thread_get_stack_min_min(const DrdThreadId tid)
{
tl_assert(0 <= (int)tid && tid < DRD_N_THREADS
&& tid != DRD_INVALID_THREADID);
return s_threadinfo[tid].stack_min_min;
}
Addr thread_get_stack_max(const DrdThreadId tid)
{
tl_assert(0 <= (int)tid && tid < DRD_N_THREADS
&& tid != DRD_INVALID_THREADID);
return s_threadinfo[tid].stack_max;
}
SizeT thread_get_stack_size(const DrdThreadId tid)
{
tl_assert(0 <= (int)tid && tid < DRD_N_THREADS
&& tid != DRD_INVALID_THREADID);
return s_threadinfo[tid].stack_size;
}
/**
* Clean up thread-specific data structures. Call this just after
* pthread_join().
*/
void thread_delete(const DrdThreadId tid)
{
Segment* sg;
Segment* sg_prev;
tl_assert(0 <= (int)tid && tid < DRD_N_THREADS
&& tid != DRD_INVALID_THREADID);
tl_assert(s_threadinfo[tid].synchr_nesting >= 0);
for (sg = s_threadinfo[tid].last; sg; sg = sg_prev)
{
sg_prev = sg->prev;
sg->prev = 0;
sg->next = 0;
DRD_(sg_put)(sg);
}
s_threadinfo[tid].vg_thread_exists = False;
s_threadinfo[tid].posix_thread_exists = False;
tl_assert(s_threadinfo[tid].detached_posix_thread == False);
s_threadinfo[tid].first = 0;
s_threadinfo[tid].last = 0;
}
/* Called after a thread performed its last memory access and before */
/* thread_delete() is called. Note: thread_delete() is only called for */
/* joinable threads, not for detached threads. */
void thread_finished(const DrdThreadId tid)
{
tl_assert(0 <= (int)tid && tid < DRD_N_THREADS
&& tid != DRD_INVALID_THREADID);
s_threadinfo[tid].vg_thread_exists = False;
if (s_threadinfo[tid].detached_posix_thread)
{
/* Once a detached thread has finished, its stack is deallocated and */
/* should no longer be taken into account when computing the conflict set*/
s_threadinfo[tid].stack_min = s_threadinfo[tid].stack_max;
/* For a detached thread, calling pthread_exit() invalidates the */
/* POSIX thread ID associated with the detached thread. For joinable */
/* POSIX threads however, the POSIX thread ID remains live after the */
/* pthread_exit() call until pthread_join() is called. */
s_threadinfo[tid].posix_thread_exists = False;
}
}
/** Called just before pthread_cancel(). */
void thread_pre_cancel(const DrdThreadId tid)
{
tl_assert(0 <= (int)tid && tid < DRD_N_THREADS
&& tid != DRD_INVALID_THREADID);
tl_assert(s_threadinfo[tid].pt_threadid != INVALID_POSIX_THREADID);
s_threadinfo[tid].synchr_nesting = 0;
}
void thread_set_pthreadid(const DrdThreadId tid, const PThreadId ptid)
{
tl_assert(0 <= (int)tid && tid < DRD_N_THREADS
&& tid != DRD_INVALID_THREADID);
tl_assert(s_threadinfo[tid].pt_threadid == INVALID_POSIX_THREADID);
tl_assert(ptid != INVALID_POSIX_THREADID);
s_threadinfo[tid].posix_thread_exists = True;
s_threadinfo[tid].pt_threadid = ptid;
}
Bool thread_get_joinable(const DrdThreadId tid)
{
tl_assert(0 <= (int)tid && tid < DRD_N_THREADS
&& tid != DRD_INVALID_THREADID);
return ! s_threadinfo[tid].detached_posix_thread;
}
void thread_set_joinable(const DrdThreadId tid, const Bool joinable)
{
tl_assert(0 <= (int)tid && tid < DRD_N_THREADS
&& tid != DRD_INVALID_THREADID);
tl_assert(!! joinable == joinable);
tl_assert(s_threadinfo[tid].pt_threadid != INVALID_POSIX_THREADID);
#if 0
VG_(message)(Vg_DebugMsg,
"thread_set_joinable(%d/%d, %s)",
tid,
s_threadinfo[tid].vg_threadid,
joinable ? "joinable" : "detached");
#endif
s_threadinfo[tid].detached_posix_thread = ! joinable;
}
void thread_set_vg_running_tid(const ThreadId vg_tid)
{
tl_assert(vg_tid != VG_INVALID_THREADID);
if (vg_tid != s_vg_running_tid)
{
thread_set_running_tid(vg_tid, VgThreadIdToDrdThreadId(vg_tid));
}
tl_assert(s_vg_running_tid != VG_INVALID_THREADID);
tl_assert(s_drd_running_tid != DRD_INVALID_THREADID);
}
void thread_set_running_tid(const ThreadId vg_tid, const DrdThreadId drd_tid)
{
tl_assert(vg_tid != VG_INVALID_THREADID);
tl_assert(drd_tid != DRD_INVALID_THREADID);
if (vg_tid != s_vg_running_tid)
{
if (s_trace_context_switches
&& s_drd_running_tid != DRD_INVALID_THREADID)
{
VG_(message)(Vg_DebugMsg,
"Context switch from thread %d/%d to thread %d/%d;"
" segments: %llu",
s_vg_running_tid, s_drd_running_tid,
DrdThreadIdToVgThreadId(drd_tid), drd_tid,
DRD_(sg_get_segments_alive_count)());
}
s_vg_running_tid = vg_tid;
s_drd_running_tid = drd_tid;
thread_compute_conflict_set(&s_conflict_set, drd_tid);
s_context_switch_count++;
}
tl_assert(s_vg_running_tid != VG_INVALID_THREADID);
tl_assert(s_drd_running_tid != DRD_INVALID_THREADID);
}
int thread_enter_synchr(const DrdThreadId tid)
{
tl_assert(IsValidDrdThreadId(tid));
return s_threadinfo[tid].synchr_nesting++;
}
int thread_leave_synchr(const DrdThreadId tid)
{
tl_assert(IsValidDrdThreadId(tid));
tl_assert(s_threadinfo[tid].synchr_nesting >= 1);
return --s_threadinfo[tid].synchr_nesting;
}
int thread_get_synchr_nesting_count(const DrdThreadId tid)
{
tl_assert(IsValidDrdThreadId(tid));
return s_threadinfo[tid].synchr_nesting;
}
/** Append a new segment at the end of the segment list. */
static void thread_append_segment(const DrdThreadId tid, Segment* const sg)
{
tl_assert(0 <= (int)tid && tid < DRD_N_THREADS
&& tid != DRD_INVALID_THREADID);
// tl_assert(sane_ThreadInfo(&s_threadinfo[tid]));
sg->prev = s_threadinfo[tid].last;
sg->next = 0;
if (s_threadinfo[tid].last)
s_threadinfo[tid].last->next = sg;
s_threadinfo[tid].last = sg;
if (s_threadinfo[tid].first == 0)
s_threadinfo[tid].first = sg;
// tl_assert(sane_ThreadInfo(&s_threadinfo[tid]));
}
/** Remove a segment from the segment list of thread threadid, and free the
* associated memory.
*/
static void thread_discard_segment(const DrdThreadId tid, Segment* const sg)
{
tl_assert(0 <= (int)tid && tid < DRD_N_THREADS
&& tid != DRD_INVALID_THREADID);
//tl_assert(sane_ThreadInfo(&s_threadinfo[tid]));
if (sg->prev)
sg->prev->next = sg->next;
if (sg->next)
sg->next->prev = sg->prev;
if (sg == s_threadinfo[tid].first)
s_threadinfo[tid].first = sg->next;
if (sg == s_threadinfo[tid].last)
s_threadinfo[tid].last = sg->prev;
DRD_(sg_put)(sg);
//tl_assert(sane_ThreadInfo(&s_threadinfo[tid]));
}
VectorClock* thread_get_vc(const DrdThreadId tid)
{
tl_assert(0 <= (int)tid && tid < DRD_N_THREADS
&& tid != DRD_INVALID_THREADID);
tl_assert(s_threadinfo[tid].last);
return &s_threadinfo[tid].last->vc;
}
/** Return the latest segment of thread 'tid' and increment its reference
* count.
*/
void thread_get_latest_segment(Segment** sg, const DrdThreadId tid)
{
tl_assert(sg);
tl_assert(0 <= (int)tid && tid < DRD_N_THREADS
&& tid != DRD_INVALID_THREADID);
tl_assert(s_threadinfo[tid].last);
DRD_(sg_put)(*sg);
*sg = DRD_(sg_get)(s_threadinfo[tid].last);
}
/**
* Compute the minimum of all latest vector clocks of all threads
* (Michiel Ronsse calls this "clock snooping" in his papers about DIOTA).
* @param vc pointer to a vectorclock, holds result upon return.
*/
static void thread_compute_minimum_vc(VectorClock* vc)
{
unsigned i;
Bool first;
Segment* latest_sg;
first = True;
for (i = 0; i < sizeof(s_threadinfo) / sizeof(s_threadinfo[0]); i++)
{
latest_sg = s_threadinfo[i].last;
if (latest_sg)
{
if (first)
DRD_(vc_assign)(vc, &latest_sg->vc);
else
DRD_(vc_min)(vc, &latest_sg->vc);
first = False;
}
}
}
static void thread_compute_maximum_vc(VectorClock* vc)
{
unsigned i;
Bool first;
Segment* latest_sg;
first = True;
for (i = 0; i < sizeof(s_threadinfo) / sizeof(s_threadinfo[0]); i++)
{
latest_sg = s_threadinfo[i].last;
if (latest_sg)
{
if (first)
DRD_(vc_assign)(vc, &latest_sg->vc);
else
DRD_(vc_combine)(vc, &latest_sg->vc);
first = False;
}
}
}
/**
* Discard all segments that have a defined order against the latest vector
* clock of every thread -- these segments can no longer be involved in a
* data race.
*/
static void thread_discard_ordered_segments(void)
{
unsigned i;
VectorClock thread_vc_min;
s_discard_ordered_segments_count++;
DRD_(vc_init)(&thread_vc_min, 0, 0);
thread_compute_minimum_vc(&thread_vc_min);
if (DRD_(sg_get_trace)())
{
char msg[256];
VectorClock thread_vc_max;
DRD_(vc_init)(&thread_vc_max, 0, 0);
thread_compute_maximum_vc(&thread_vc_max);
VG_(snprintf)(msg, sizeof(msg),
"Discarding ordered segments -- min vc is ");
DRD_(vc_snprint)(msg + VG_(strlen)(msg), sizeof(msg) - VG_(strlen)(msg),
&thread_vc_min);
VG_(snprintf)(msg + VG_(strlen)(msg), sizeof(msg) - VG_(strlen)(msg),
", max vc is ");
DRD_(vc_snprint)(msg + VG_(strlen)(msg), sizeof(msg) - VG_(strlen)(msg),
&thread_vc_max);
VG_(message)(Vg_UserMsg, "%s", msg);
DRD_(vc_cleanup)(&thread_vc_max);
}
for (i = 0; i < sizeof(s_threadinfo) / sizeof(s_threadinfo[0]); i++)
{
Segment* sg;
Segment* sg_next;
for (sg = s_threadinfo[i].first;
sg && (sg_next = sg->next) && DRD_(vc_lte)(&sg->vc, &thread_vc_min);
sg = sg_next)
{
thread_discard_segment(i, sg);
}
}
DRD_(vc_cleanup)(&thread_vc_min);
}
/** Merge all segments that may be merged without triggering false positives
* or discarding real data races. For the theoretical background of segment
* merging, see also the following paper:
* Mark Christiaens, Michiel Ronsse and Koen De Bosschere.
* Bounding the number of segment histories during data race detection.
* Parallel Computing archive, Volume 28, Issue 9, pp 1221-1238,
* September 2002.
*/
static void thread_merge_segments(void)
{
unsigned i;
for (i = 0; i < sizeof(s_threadinfo) / sizeof(s_threadinfo[0]); i++)
{
Segment* sg;
// tl_assert(sane_ThreadInfo(&s_threadinfo[i]));
for (sg = s_threadinfo[i].first; sg; sg = sg->next)
{
if (DRD_(sg_get_refcnt)(sg) == 1
&& sg->next
&& DRD_(sg_get_refcnt)(sg->next) == 1
&& sg->next->next)
{
/* Merge sg and sg->next into sg. */
DRD_(sg_merge)(sg, sg->next);
thread_discard_segment(i, sg->next);
}
}
// tl_assert(sane_ThreadInfo(&s_threadinfo[i]));
}
}
/** Every change in the vector clock of a thread may cause segments that
* were previously ordered to this thread to become unordered. Hence,
* it may be necessary to recalculate the conflict set if the vector clock
* of the current thread is updated. This function check whether such a
* recalculation is necessary.
*
* @param tid Thread ID of the thread to which a new segment has been
* appended.
* @param new_sg Pointer to the most recent segment of thread tid.
*/
static Bool conflict_set_update_needed(const DrdThreadId tid,
const Segment* const new_sg)
{
#if 0
unsigned i;
const Segment* old_sg;
tl_assert(new_sg);
/* If a new segment was added to another thread than the running thread, */
/* just tell the caller to update the conflict set. */
if (tid != s_drd_running_tid)
return True;
/* Always let the caller update the conflict set after creation of the */
/* first segment. */
old_sg = new_sg->prev;
if (old_sg == 0)
return True;
for (i = 0; i < sizeof(s_threadinfo) / sizeof(s_threadinfo[0]); i++)
{
Segment* q;
if (i == s_drd_running_tid)
continue;
for (q = s_threadinfo[i].last; q; q = q->prev)
{
/* If the expression below evaluates to false, this expression will */
/* also evaluate to false for all subsequent iterations. So stop */
/* iterating. */
if (DRD_(vc_lte)(&q->vc, &old_sg->vc))
break;
/* If the vector clock of the 2nd the last segment is not ordered */
/* to the vector clock of segment q, and the last segment is, ask */
/* the caller to update the conflict set. */
if (! DRD_(vc_lte)(&old_sg->vc, &q->vc))
{
return True;
}
/* If the vector clock of the last segment is not ordered to the */
/* vector clock of segment q, ask the caller to update the conflict */
/* set. */
if (! DRD_(vc_lte)(&q->vc, &new_sg->vc) && ! DRD_(vc_lte)(&new_sg->vc, &q->vc))
{
return True;
}
}
}
return False;
#else
return True;
#endif
}
/** Create a new segment for the specified thread, and discard any segments
* that cannot cause races anymore.
*/
void thread_new_segment(const DrdThreadId tid)
{
Segment* new_sg;
tl_assert(0 <= (int)tid && tid < DRD_N_THREADS
&& tid != DRD_INVALID_THREADID);
new_sg = DRD_(sg_new)(tid, tid);
thread_append_segment(tid, new_sg);
if (conflict_set_update_needed(tid, new_sg))
{
thread_compute_conflict_set(&s_conflict_set, s_drd_running_tid);
s_conflict_set_new_segment_count++;
}
else if (tid == s_drd_running_tid)
{
tl_assert(thread_conflict_set_up_to_date(s_drd_running_tid));
}
thread_discard_ordered_segments();
if (s_segment_merging)
thread_merge_segments();
}
/** Call this function after thread 'joiner' joined thread 'joinee'. */
void thread_combine_vc(DrdThreadId joiner, DrdThreadId joinee)
{
tl_assert(joiner != joinee);
tl_assert(0 <= (int)joiner && joiner < DRD_N_THREADS
&& joiner != DRD_INVALID_THREADID);
tl_assert(0 <= (int)joinee && joinee < DRD_N_THREADS
&& joinee != DRD_INVALID_THREADID);
tl_assert(s_threadinfo[joiner].last);
tl_assert(s_threadinfo[joinee].last);
DRD_(vc_combine)(&s_threadinfo[joiner].last->vc, &s_threadinfo[joinee].last->vc);
thread_discard_ordered_segments();
if (joiner == s_drd_running_tid)
{
thread_compute_conflict_set(&s_conflict_set, joiner);
}
}
/** Call this function after thread 'tid' had to wait because of thread
* synchronization until the memory accesses in the segment with vector clock
* 'vc' finished.
*/
void thread_combine_vc2(DrdThreadId tid, const VectorClock* const vc)
{
tl_assert(0 <= (int)tid && tid < DRD_N_THREADS
&& tid != DRD_INVALID_THREADID);
tl_assert(s_threadinfo[tid].last);
tl_assert(vc);
DRD_(vc_combine)(&s_threadinfo[tid].last->vc, vc);
thread_compute_conflict_set(&s_conflict_set, tid);
thread_discard_ordered_segments();
s_conflict_set_combine_vc_count++;
}
/** Call this function whenever a thread is no longer using the memory
* [ a1, a2 [, e.g. because of a call to free() or a stack pointer
* increase.
*/
void thread_stop_using_mem(const Addr a1, const Addr a2)
{
DrdThreadId other_user;
unsigned i;
/* For all threads, mark the range [ a1, a2 [ as no longer in use. */
other_user = DRD_INVALID_THREADID;
for (i = 0; i < sizeof(s_threadinfo) / sizeof(s_threadinfo[0]); i++)
{
Segment* p;
for (p = s_threadinfo[i].first; p; p = p->next)
{
if (other_user == DRD_INVALID_THREADID
&& i != s_drd_running_tid)
{
if (UNLIKELY(bm_test_and_clear(p->bm, a1, a2)))
{
other_user = i;
}
continue;
}
bm_clear(p->bm, a1, a2);
}
}
/* If any other thread had accessed memory in [ a1, a2 [, update the */
/* conflict set. */
if (other_user != DRD_INVALID_THREADID
&& bm_has_any_access(s_conflict_set, a1, a2))
{
thread_compute_conflict_set(&s_conflict_set, thread_get_running_tid());
}
}
void thread_start_recording(const DrdThreadId tid)
{
tl_assert(0 <= (int)tid && tid < DRD_N_THREADS
&& tid != DRD_INVALID_THREADID);
tl_assert(! s_threadinfo[tid].is_recording);
s_threadinfo[tid].is_recording = True;
}
void thread_stop_recording(const DrdThreadId tid)
{
tl_assert(0 <= (int)tid && tid < DRD_N_THREADS
&& tid != DRD_INVALID_THREADID);
tl_assert(s_threadinfo[tid].is_recording);
s_threadinfo[tid].is_recording = False;
}
void thread_print_all(void)
{
unsigned i;
Segment* p;
for (i = 0; i < sizeof(s_threadinfo) / sizeof(s_threadinfo[0]); i++)
{
if (s_threadinfo[i].first)
{
VG_(printf)("**************\n"
"* thread %3d (%d/%d/%d/0x%lx/%d) *\n"
"**************\n",
i,
s_threadinfo[i].vg_thread_exists,
s_threadinfo[i].vg_threadid,
s_threadinfo[i].posix_thread_exists,
s_threadinfo[i].pt_threadid,
s_threadinfo[i].detached_posix_thread);
for (p = s_threadinfo[i].first; p; p = p->next)
{
DRD_(sg_print)(p);
}
}
}
}
static void show_call_stack(const DrdThreadId tid,
const Char* const msg,
ExeContext* const callstack)
{
const ThreadId vg_tid = DrdThreadIdToVgThreadId(tid);
VG_(message)(Vg_UserMsg, "%s (thread %d/%d)", msg, vg_tid, tid);
if (vg_tid != VG_INVALID_THREADID)
{
if (callstack)
{
VG_(pp_ExeContext)(callstack);
}
else
{
VG_(get_and_pp_StackTrace)(vg_tid, VG_(clo_backtrace_size));
}
}
else
{
VG_(message)(Vg_UserMsg,
" (thread finished, call stack no longer available)");
}
}
static void
thread_report_conflicting_segments_segment(const DrdThreadId tid,
const Addr addr,
const SizeT size,
const BmAccessTypeT access_type,
const Segment* const p)
{
unsigned i;
tl_assert(0 <= (int)tid && tid < DRD_N_THREADS
&& tid != DRD_INVALID_THREADID);
tl_assert(p);
for (i = 0; i < sizeof(s_threadinfo) / sizeof(s_threadinfo[0]); i++)
{
if (i != tid)
{
Segment* q;
for (q = s_threadinfo[i].last; q; q = q->prev)
{
// Since q iterates over the segments of thread i in order of
// decreasing vector clocks, if q->vc <= p->vc, then
// q->next->vc <= p->vc will also hold. Hence, break out of the
// loop once this condition is met.
if (DRD_(vc_lte)(&q->vc, &p->vc))
break;
if (! DRD_(vc_lte)(&p->vc, &q->vc))
{
if (bm_has_conflict_with(q->bm, addr, addr + size, access_type))
{
tl_assert(q->stacktrace);
show_call_stack(i, "Other segment start",
q->stacktrace);
show_call_stack(i, "Other segment end",
q->next ? q->next->stacktrace : 0);
}
}
}
}
}
}
void thread_report_conflicting_segments(const DrdThreadId tid,
const Addr addr,
const SizeT size,
const BmAccessTypeT access_type)
{
Segment* p;
tl_assert(0 <= (int)tid && tid < DRD_N_THREADS
&& tid != DRD_INVALID_THREADID);
for (p = s_threadinfo[tid].first; p; p = p->next)
{
if (bm_has(p->bm, addr, addr + size, access_type))
{
thread_report_conflicting_segments_segment(tid, addr, size,
access_type, p);
}
}
}
/** Verify whether the conflict set for thread tid is up to date. Only perform
* the check if the environment variable DRD_VERIFY_CONFLICT_SET has been set.
*/
static Bool thread_conflict_set_up_to_date(const DrdThreadId tid)
{
static int do_verify_conflict_set = -1;
Bool result;
struct bitmap* computed_conflict_set = 0;
if (do_verify_conflict_set < 0)
{
//VG_(message)(Vg_DebugMsg, "%s", VG_(getenv)("DRD_VERIFY_CONFLICT_SET"));
do_verify_conflict_set = VG_(getenv)("DRD_VERIFY_CONFLICT_SET") != 0;
}
if (do_verify_conflict_set == 0)
return True;
thread_compute_conflict_set(&computed_conflict_set, tid);
result = bm_equal(s_conflict_set, computed_conflict_set);
bm_delete(computed_conflict_set);
return result;
}
/** Compute a bitmap that represents the union of all memory accesses of all
* segments that are unordered to the current segment of the thread tid.
*/
static void thread_compute_conflict_set(struct bitmap** conflict_set,
const DrdThreadId tid)
{
Segment* p;
tl_assert(0 <= (int)tid && tid < DRD_N_THREADS
&& tid != DRD_INVALID_THREADID);
tl_assert(tid == s_drd_running_tid);
s_update_conflict_set_count++;
s_conflict_set_bitmap_creation_count -= bm_get_bitmap_creation_count();
s_conflict_set_bitmap2_creation_count -= bm_get_bitmap2_creation_count();
if (*conflict_set)
{
bm_delete(*conflict_set);
}
*conflict_set = bm_new();
if (s_trace_conflict_set)
{
char msg[256];
VG_(snprintf)(msg, sizeof(msg),
"computing conflict set for thread %d/%d with vc ",
DrdThreadIdToVgThreadId(tid), tid);
DRD_(vc_snprint)(msg + VG_(strlen)(msg),
sizeof(msg) - VG_(strlen)(msg),
&s_threadinfo[tid].last->vc);
VG_(message)(Vg_UserMsg, "%s", msg);
}
p = s_threadinfo[tid].last;
{
unsigned j;
if (s_trace_conflict_set)
{
char msg[256];
VG_(snprintf)(msg, sizeof(msg),
"conflict set: thread [%d] at vc ",
tid);
DRD_(vc_snprint)(msg + VG_(strlen)(msg),
sizeof(msg) - VG_(strlen)(msg),
&p->vc);
VG_(message)(Vg_UserMsg, "%s", msg);
}
for (j = 0; j < sizeof(s_threadinfo) / sizeof(s_threadinfo[0]); j++)
{
if (j != tid && IsValidDrdThreadId(j))
{
const Segment* q;
for (q = s_threadinfo[j].last; q; q = q->prev)
{
if (! DRD_(vc_lte)(&q->vc, &p->vc) && ! DRD_(vc_lte)(&p->vc, &q->vc))
{
if (s_trace_conflict_set)
{
char msg[256];
VG_(snprintf)(msg, sizeof(msg),
"conflict set: [%d] merging segment ", j);
DRD_(vc_snprint)(msg + VG_(strlen)(msg),
sizeof(msg) - VG_(strlen)(msg),
&q->vc);
VG_(message)(Vg_UserMsg, "%s", msg);
}
bm_merge2(*conflict_set, q->bm);
}
else
{
if (s_trace_conflict_set)
{
char msg[256];
VG_(snprintf)(msg, sizeof(msg),
"conflict set: [%d] ignoring segment ", j);
DRD_(vc_snprint)(msg + VG_(strlen)(msg),
sizeof(msg) - VG_(strlen)(msg),
&q->vc);
VG_(message)(Vg_UserMsg, "%s", msg);
}
}
}
}
}
}
s_conflict_set_bitmap_creation_count += bm_get_bitmap_creation_count();
s_conflict_set_bitmap2_creation_count += bm_get_bitmap2_creation_count();
if (0 && s_trace_conflict_set)
{
VG_(message)(Vg_UserMsg, "[%d] new conflict set:", tid);
bm_print(*conflict_set);
VG_(message)(Vg_UserMsg, "[%d] end of new conflict set.", tid);
}
}
ULong thread_get_context_switch_count(void)
{
return s_context_switch_count;
}
ULong thread_get_discard_ordered_segments_count(void)
{
return s_discard_ordered_segments_count;
}
ULong thread_get_update_conflict_set_count(ULong* dsnsc, ULong* dscvc)
{
tl_assert(dsnsc);
tl_assert(dscvc);
*dsnsc = s_conflict_set_new_segment_count;
*dscvc = s_conflict_set_combine_vc_count;
return s_update_conflict_set_count;
}
ULong thread_get_conflict_set_bitmap_creation_count(void)
{
return s_conflict_set_bitmap_creation_count;
}
ULong thread_get_conflict_set_bitmap2_creation_count(void)
{
return s_conflict_set_bitmap2_creation_count;
}
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