/*
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_error.h"
#include "drd_barrier.h"
#include "drd_clientobj.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_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 void thread_compute_conflict_set(struct bitmap** conflict_set,
const DrdThreadId tid);
static Bool thread_conflict_set_up_to_date(const DrdThreadId tid);
/* Local variables. */
static ULong s_context_switch_count;
static ULong s_discard_ordered_segments_count;
static ULong s_compute_conflict_set_count;
static ULong s_update_conflict_set_count;
static ULong s_update_conflict_set_new_sg_count;
static ULong s_update_conflict_set_sync_count;
static ULong s_update_conflict_set_join_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 DRD_(g_drd_running_tid) = DRD_INVALID_THREADID;
ThreadInfo DRD_(g_threadinfo)[DRD_N_THREADS];
struct bitmap* DRD_(g_conflict_set);
static Bool s_trace_context_switches = False;
static Bool s_trace_conflict_set = False;
static Bool s_trace_conflict_set_bm = False;
static Bool s_trace_fork_join = False;
static Bool s_segment_merging = True;
static Bool s_new_segments_since_last_merge;
static int s_segment_merge_interval = 10;
static unsigned s_join_list_vol = 10;
static unsigned s_deletion_head;
static unsigned s_deletion_tail;
/* Function definitions. */
/** Enables/disables context switch tracing. */
void DRD_(thread_trace_context_switches)(const Bool t)
{
tl_assert(t == False || t == True);
s_trace_context_switches = t;
}
/** Enables/disables conflict set tracing. */
void DRD_(thread_trace_conflict_set)(const Bool t)
{
tl_assert(t == False || t == True);
s_trace_conflict_set = t;
}
/** Enables/disables conflict set bitmap tracing. */
void DRD_(thread_trace_conflict_set_bm)(const Bool t)
{
tl_assert(t == False || t == True);
s_trace_conflict_set_bm = t;
}
/** Report whether fork/join tracing is enabled. */
Bool DRD_(thread_get_trace_fork_join)(void)
{
return s_trace_fork_join;
}
/** Enables/disables fork/join tracing. */
void DRD_(thread_set_trace_fork_join)(const Bool t)
{
tl_assert(t == False || t == True);
s_trace_fork_join = t;
}
/** Enables/disables segment merging. */
void DRD_(thread_set_segment_merging)(const Bool m)
{
tl_assert(m == False || m == True);
s_segment_merging = m;
}
/** Get the segment merging interval. */
int DRD_(thread_get_segment_merge_interval)(void)
{
return s_segment_merge_interval;
}
/** Set the segment merging interval. */
void DRD_(thread_set_segment_merge_interval)(const int i)
{
s_segment_merge_interval = i;
}
void DRD_(thread_set_join_list_vol)(const int jlv)
{
s_join_list_vol = jlv;
}
void DRD_(thread_init)(void)
{
}
/**
* Convert Valgrind's ThreadId into a DrdThreadId.
*
* @return DRD thread ID upon success and DRD_INVALID_THREADID if the passed
* Valgrind ThreadId does not yet exist.
*/
DrdThreadId DRD_(VgThreadIdToDrdThreadId)(const ThreadId tid)
{
int i;
if (tid == VG_INVALID_THREADID)
return DRD_INVALID_THREADID;
for (i = 1; i < DRD_N_THREADS; i++)
{
if (DRD_(g_threadinfo)[i].vg_thread_exists == True
&& DRD_(g_threadinfo)[i].vg_threadid == tid)
{
return i;
}
}
return DRD_INVALID_THREADID;
}
/** Allocate a new DRD thread ID for the specified Valgrind thread ID. */
static DrdThreadId DRD_(VgThreadIdToNewDrdThreadId)(const ThreadId tid)
{
int i;
tl_assert(DRD_(VgThreadIdToDrdThreadId)(tid) == DRD_INVALID_THREADID);
for (i = 1; i < DRD_N_THREADS; i++)
{
if (!DRD_(g_threadinfo)[i].valid)
{
tl_assert(! DRD_(IsValidDrdThreadId)(i));
DRD_(g_threadinfo)[i].valid = True;
DRD_(g_threadinfo)[i].vg_thread_exists = True;
DRD_(g_threadinfo)[i].vg_threadid = tid;
DRD_(g_threadinfo)[i].pt_threadid = INVALID_POSIX_THREADID;
DRD_(g_threadinfo)[i].stack_min = 0;
DRD_(g_threadinfo)[i].stack_min_min = 0;
DRD_(g_threadinfo)[i].stack_startup = 0;
DRD_(g_threadinfo)[i].stack_max = 0;
DRD_(thread_set_name)(i, "");
DRD_(g_threadinfo)[i].on_alt_stack = False;
DRD_(g_threadinfo)[i].is_recording_loads = True;
DRD_(g_threadinfo)[i].is_recording_stores = True;
DRD_(g_threadinfo)[i].pthread_create_nesting_level = 0;
DRD_(g_threadinfo)[i].synchr_nesting = 0;
DRD_(g_threadinfo)[i].deletion_seq = s_deletion_tail - 1;
tl_assert(DRD_(g_threadinfo)[i].sg_first == NULL);
tl_assert(DRD_(g_threadinfo)[i].sg_last == NULL);
tl_assert(DRD_(IsValidDrdThreadId)(i));
return i;
}
}
VG_(printf)(
"\nSorry, but the maximum number of threads supported by DRD has been exceeded."
"Aborting.\n");
tl_assert(False);
return DRD_INVALID_THREADID;
}
/** Convert a POSIX thread ID into a DRD thread ID. */
DrdThreadId DRD_(PtThreadIdToDrdThreadId)(const PThreadId tid)
{
int i;
if (tid != INVALID_POSIX_THREADID)
{
for (i = 1; i < DRD_N_THREADS; i++)
{
if (DRD_(g_threadinfo)[i].posix_thread_exists
&& DRD_(g_threadinfo)[i].pt_threadid == tid)
{
return i;
}
}
}
return DRD_INVALID_THREADID;
}
/** Convert a DRD thread ID into a Valgrind thread ID. */
ThreadId DRD_(DrdThreadIdToVgThreadId)(const DrdThreadId tid)
{
tl_assert(0 <= (int)tid && tid < DRD_N_THREADS
&& tid != DRD_INVALID_THREADID);
return (DRD_(g_threadinfo)[tid].vg_thread_exists
? DRD_(g_threadinfo)[tid].vg_threadid
: VG_INVALID_THREADID);
}
#ifdef ENABLE_DRD_CONSISTENCY_CHECKS
/**
* Sanity check of the doubly linked list of segments referenced by a
* ThreadInfo struct.
* @return True if sane, False if not.
*/
static Bool DRD_(sane_ThreadInfo)(const ThreadInfo* const ti)
{
Segment* p;
for (p = ti->sg_first; p; p = p->thr_next) {
if (p->thr_next && p->thr_next->thr_prev != p)
return False;
if (p->thr_next == 0 && p != ti->sg_last)
return False;
}
for (p = ti->sg_last; p; p = p->thr_prev) {
if (p->thr_prev && p->thr_prev->thr_next != p)
return False;
if (p->thr_prev == 0 && p != ti->sg_first)
return False;
}
return True;
}
#endif
/**
* Create the first segment for a newly started thread.
*
* This function is called from the handler installed via
* VG_(track_pre_thread_ll_create)(). The Valgrind core invokes this handler
* from the context of the creator thread, before the new thread has been
* created.
*
* @param[in] creator DRD thread ID of the creator thread.
* @param[in] vg_created Valgrind thread ID of the created thread.
*
* @return DRD thread ID of the created thread.
*/
DrdThreadId DRD_(thread_pre_create)(const DrdThreadId creator,
const ThreadId vg_created)
{
DrdThreadId created;
tl_assert(DRD_(VgThreadIdToDrdThreadId)(vg_created) == DRD_INVALID_THREADID);
created = DRD_(VgThreadIdToNewDrdThreadId)(vg_created);
tl_assert(0 <= (int)created && created < DRD_N_THREADS
&& created != DRD_INVALID_THREADID);
tl_assert(DRD_(g_threadinfo)[created].sg_first == NULL);
tl_assert(DRD_(g_threadinfo)[created].sg_last == NULL);
/* Create an initial segment for the newly created thread. */
thread_append_segment(created, DRD_(sg_new)(creator, created));
return created;
}
/**
* Initialize DRD_(g_threadinfo)[] for a newly created thread. Must be called
* after the thread has been created and before any client instructions are run
* on the newly created thread, e.g. from the handler installed via
* VG_(track_pre_thread_first_insn)().
*
* @param[in] vg_created Valgrind thread ID of the newly created thread.
*
* @return DRD thread ID for the new thread.
*/
DrdThreadId DRD_(thread_post_create)(const ThreadId vg_created)
{
const DrdThreadId created = DRD_(VgThreadIdToDrdThreadId)(vg_created);
tl_assert(0 <= (int)created && created < DRD_N_THREADS
&& created != DRD_INVALID_THREADID);
DRD_(g_threadinfo)[created].stack_max
= VG_(thread_get_stack_max)(vg_created);
DRD_(g_threadinfo)[created].stack_startup
= DRD_(g_threadinfo)[created].stack_max;
DRD_(g_threadinfo)[created].stack_min
= DRD_(g_threadinfo)[created].stack_max;
DRD_(g_threadinfo)[created].stack_min_min
= DRD_(g_threadinfo)[created].stack_max;
DRD_(g_threadinfo)[created].stack_size
= VG_(thread_get_stack_size)(vg_created);
tl_assert(DRD_(g_threadinfo)[created].stack_max != 0);
return created;
}
static void DRD_(thread_delayed_delete)(const DrdThreadId tid)
{
int j;
DRD_(g_threadinfo)[tid].vg_thread_exists = False;
DRD_(g_threadinfo)[tid].posix_thread_exists = False;
DRD_(g_threadinfo)[tid].deletion_seq = s_deletion_head++;
#if 0
VG_(message)(Vg_DebugMsg, "Adding thread %d to the deletion list\n", tid);
#endif
if (s_deletion_head - s_deletion_tail >= s_join_list_vol) {
for (j = 0; j < DRD_N_THREADS; ++j) {
if (DRD_(IsValidDrdThreadId)(j)
&& DRD_(g_threadinfo)[j].deletion_seq == s_deletion_tail)
{
s_deletion_tail++;
#if 0
VG_(message)(Vg_DebugMsg, "Delayed delete of thread %d\n", j);
#endif
DRD_(thread_delete)(j, False);
break;
}
}
}
}
/**
* 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(DRD_(IsValidDrdThreadId)(drd_joiner));
tl_assert(DRD_(IsValidDrdThreadId)(drd_joinee));
DRD_(thread_new_segment)(drd_joiner);
DRD_(thread_combine_vc_join)(drd_joiner, drd_joinee);
DRD_(thread_new_segment)(drd_joinee);
if (s_trace_fork_join)
{
const ThreadId joiner = DRD_(DrdThreadIdToVgThreadId)(drd_joiner);
const unsigned msg_size = 256;
HChar* msg;
msg = VG_(malloc)("drd.main.dptj.1", msg_size);
tl_assert(msg);
VG_(snprintf)(msg, msg_size,
"drd_post_thread_join joiner = %d, joinee = %d",
drd_joiner, drd_joinee);
if (joiner)
{
HChar* vc;
vc = DRD_(vc_aprint)(DRD_(thread_get_vc)(drd_joiner));
VG_(snprintf)(msg + VG_(strlen)(msg), msg_size - VG_(strlen)(msg),
", new vc: %s", vc);
VG_(free)(vc);
}
DRD_(trace_msg)("%pS", msg);
VG_(free)(msg);
}
if (! DRD_(get_check_stack_accesses)())
{
DRD_(finish_suppression)(DRD_(thread_get_stack_max)(drd_joinee)
- DRD_(thread_get_stack_size)(drd_joinee),
DRD_(thread_get_stack_max)(drd_joinee));
}
DRD_(clientobj_delete_thread)(drd_joinee);
DRD_(thread_delayed_delete)(drd_joinee);
}
/**
* 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 DRD_(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(DRD_(g_threadinfo)[tid].stack_min <= stack_startup);
tl_assert(stack_startup <= DRD_(g_threadinfo)[tid].stack_max);
DRD_(g_threadinfo)[tid].stack_startup = stack_startup;
}
/** Return the stack pointer for the specified thread. */
Addr DRD_(thread_get_stack_min)(const DrdThreadId tid)
{
tl_assert(0 <= (int)tid && tid < DRD_N_THREADS
&& tid != DRD_INVALID_THREADID);
return DRD_(g_threadinfo)[tid].stack_min;
}
/**
* Return the lowest value that was ever assigned to the stack pointer
* for the specified thread.
*/
Addr DRD_(thread_get_stack_min_min)(const DrdThreadId tid)
{
tl_assert(0 <= (int)tid && tid < DRD_N_THREADS
&& tid != DRD_INVALID_THREADID);
return DRD_(g_threadinfo)[tid].stack_min_min;
}
/** Return the top address for the stack of the specified thread. */
Addr DRD_(thread_get_stack_max)(const DrdThreadId tid)
{
tl_assert(0 <= (int)tid && tid < DRD_N_THREADS
&& tid != DRD_INVALID_THREADID);
return DRD_(g_threadinfo)[tid].stack_max;
}
/** Return the maximum stack size for the specified thread. */
SizeT DRD_(thread_get_stack_size)(const DrdThreadId tid)
{
tl_assert(0 <= (int)tid && tid < DRD_N_THREADS
&& tid != DRD_INVALID_THREADID);
return DRD_(g_threadinfo)[tid].stack_size;
}
Bool DRD_(thread_get_on_alt_stack)(const DrdThreadId tid)
{
tl_assert(0 <= (int)tid && tid < DRD_N_THREADS
&& tid != DRD_INVALID_THREADID);
return DRD_(g_threadinfo)[tid].on_alt_stack;
}
void DRD_(thread_set_on_alt_stack)(const DrdThreadId tid,
const Bool on_alt_stack)
{
tl_assert(0 <= (int)tid && tid < DRD_N_THREADS
&& tid != DRD_INVALID_THREADID);
tl_assert(on_alt_stack == !!on_alt_stack);
DRD_(g_threadinfo)[tid].on_alt_stack = on_alt_stack;
}
Int DRD_(thread_get_threads_on_alt_stack)(void)
{
int i, n = 0;
for (i = 1; i < DRD_N_THREADS; i++)
n += DRD_(g_threadinfo)[i].on_alt_stack;
return n;
}
/**
* Clean up thread-specific data structures.
*/
void DRD_(thread_delete)(const DrdThreadId tid, const Bool detached)
{
Segment* sg;
Segment* sg_prev;
tl_assert(DRD_(IsValidDrdThreadId)(tid));
tl_assert(DRD_(g_threadinfo)[tid].synchr_nesting >= 0);
for (sg = DRD_(g_threadinfo)[tid].sg_last; sg; sg = sg_prev) {
sg_prev = sg->thr_prev;
sg->thr_next = NULL;
sg->thr_prev = NULL;
DRD_(sg_put)(sg);
}
DRD_(g_threadinfo)[tid].valid = False;
DRD_(g_threadinfo)[tid].vg_thread_exists = False;
DRD_(g_threadinfo)[tid].posix_thread_exists = False;
if (detached)
DRD_(g_threadinfo)[tid].detached_posix_thread = False;
else
tl_assert(!DRD_(g_threadinfo)[tid].detached_posix_thread);
DRD_(g_threadinfo)[tid].sg_first = NULL;
DRD_(g_threadinfo)[tid].sg_last = NULL;
tl_assert(!DRD_(IsValidDrdThreadId)(tid));
}
/**
* 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 DRD_(thread_finished)(const DrdThreadId tid)
{
tl_assert(0 <= (int)tid && tid < DRD_N_THREADS
&& tid != DRD_INVALID_THREADID);
DRD_(g_threadinfo)[tid].vg_thread_exists = False;
if (DRD_(g_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.
*/
DRD_(g_threadinfo)[tid].stack_min = DRD_(g_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.
*/
DRD_(g_threadinfo)[tid].posix_thread_exists = False;
}
}
/** Called just after fork() in the child process. */
void DRD_(drd_thread_atfork_child)(const DrdThreadId tid)
{
unsigned i;
for (i = 1; i < DRD_N_THREADS; i++)
{
if (i == tid)
continue;
if (DRD_(IsValidDrdThreadId(i)))
DRD_(thread_delete)(i, True);
tl_assert(!DRD_(IsValidDrdThreadId(i)));
}
}
/** Called just before pthread_cancel(). */
void DRD_(thread_pre_cancel)(const DrdThreadId tid)
{
tl_assert(0 <= (int)tid && tid < DRD_N_THREADS
&& tid != DRD_INVALID_THREADID);
tl_assert(DRD_(g_threadinfo)[tid].pt_threadid != INVALID_POSIX_THREADID);
if (DRD_(thread_get_trace_fork_join)())
DRD_(trace_msg)("[%d] drd_thread_pre_cancel %d",
DRD_(g_drd_running_tid), tid);
}
/**
* Store the POSIX thread ID for the specified thread.
*
* @note This function can be called two times for the same thread -- see also
* the comment block preceding the pthread_create() wrapper in
* drd_pthread_intercepts.c.
*/
void DRD_(thread_set_pthreadid)(const DrdThreadId tid, const PThreadId ptid)
{
tl_assert(0 <= (int)tid && tid < DRD_N_THREADS
&& tid != DRD_INVALID_THREADID);
tl_assert(DRD_(g_threadinfo)[tid].pt_threadid == INVALID_POSIX_THREADID
|| DRD_(g_threadinfo)[tid].pt_threadid == ptid);
tl_assert(ptid != INVALID_POSIX_THREADID);
DRD_(g_threadinfo)[tid].posix_thread_exists = True;
DRD_(g_threadinfo)[tid].pt_threadid = ptid;
}
/** Returns true for joinable threads and false for detached threads. */
Bool DRD_(thread_get_joinable)(const DrdThreadId tid)
{
tl_assert(0 <= (int)tid && tid < DRD_N_THREADS
&& tid != DRD_INVALID_THREADID);
return ! DRD_(g_threadinfo)[tid].detached_posix_thread;
}
/** Store the thread mode: joinable or detached. */
#if defined(VGP_mips32_linux) || defined(VGP_mips64_linux)
/* There is a cse related issue in gcc for MIPS. Optimization level
has to be lowered, so cse related optimizations are not
included.*/
__attribute__((optimize("O1")))
#endif
void DRD_(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(DRD_(g_threadinfo)[tid].pt_threadid != INVALID_POSIX_THREADID);
DRD_(g_threadinfo)[tid].detached_posix_thread = ! joinable;
}
/** Tells DRD that the calling thread is about to enter pthread_create(). */
void DRD_(thread_entering_pthread_create)(const DrdThreadId tid)
{
tl_assert(0 <= (int)tid && tid < DRD_N_THREADS
&& tid != DRD_INVALID_THREADID);
tl_assert(DRD_(g_threadinfo)[tid].pt_threadid != INVALID_POSIX_THREADID);
tl_assert(DRD_(g_threadinfo)[tid].pthread_create_nesting_level >= 0);
DRD_(g_threadinfo)[tid].pthread_create_nesting_level++;
}
/** Tells DRD that the calling thread has left pthread_create(). */
void DRD_(thread_left_pthread_create)(const DrdThreadId tid)
{
tl_assert(0 <= (int)tid && tid < DRD_N_THREADS
&& tid != DRD_INVALID_THREADID);
tl_assert(DRD_(g_threadinfo)[tid].pt_threadid != INVALID_POSIX_THREADID);
tl_assert(DRD_(g_threadinfo)[tid].pthread_create_nesting_level > 0);
DRD_(g_threadinfo)[tid].pthread_create_nesting_level--;
}
/** Obtain the thread number and the user-assigned thread name. */
const HChar* DRD_(thread_get_name)(const DrdThreadId tid)
{
tl_assert(0 <= (int)tid && tid < DRD_N_THREADS
&& tid != DRD_INVALID_THREADID);
return DRD_(g_threadinfo)[tid].name;
}
/** Set the name of the specified thread. */
void DRD_(thread_set_name)(const DrdThreadId tid, const HChar* const name)
{
tl_assert(0 <= (int)tid && tid < DRD_N_THREADS
&& tid != DRD_INVALID_THREADID);
if (name == NULL || name[0] == 0)
VG_(snprintf)(DRD_(g_threadinfo)[tid].name,
sizeof(DRD_(g_threadinfo)[tid].name),
"Thread %d",
tid);
else
VG_(snprintf)(DRD_(g_threadinfo)[tid].name,
sizeof(DRD_(g_threadinfo)[tid].name),
"Thread %d (%s)",
tid, name);
DRD_(g_threadinfo)[tid].name[sizeof(DRD_(g_threadinfo)[tid].name) - 1] = 0;
}
/**
* Update s_vg_running_tid, DRD_(g_drd_running_tid) and recalculate the
* conflict set.
*/
void DRD_(thread_set_vg_running_tid)(const ThreadId vg_tid)
{
tl_assert(vg_tid != VG_INVALID_THREADID);
if (vg_tid != s_vg_running_tid)
{
DRD_(thread_set_running_tid)(vg_tid,
DRD_(VgThreadIdToDrdThreadId)(vg_tid));
}
tl_assert(s_vg_running_tid != VG_INVALID_THREADID);
tl_assert(DRD_(g_drd_running_tid) != DRD_INVALID_THREADID);
}
/**
* Update s_vg_running_tid, DRD_(g_drd_running_tid) and recalculate the
* conflict set.
*/
void DRD_(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
&& DRD_(g_drd_running_tid) != DRD_INVALID_THREADID)
{
VG_(message)(Vg_DebugMsg,
"Context switch from thread %d to thread %d;"
" segments: %llu\n",
DRD_(g_drd_running_tid), drd_tid,
DRD_(sg_get_segments_alive_count)());
}
s_vg_running_tid = vg_tid;
DRD_(g_drd_running_tid) = drd_tid;
thread_compute_conflict_set(&DRD_(g_conflict_set), drd_tid);
s_context_switch_count++;
}
tl_assert(s_vg_running_tid != VG_INVALID_THREADID);
tl_assert(DRD_(g_drd_running_tid) != DRD_INVALID_THREADID);
}
/**
* Increase the synchronization nesting counter. Must be called before the
* client calls a synchronization function.
*/
int DRD_(thread_enter_synchr)(const DrdThreadId tid)
{
tl_assert(DRD_(IsValidDrdThreadId)(tid));
return DRD_(g_threadinfo)[tid].synchr_nesting++;
}
/**
* Decrease the synchronization nesting counter. Must be called after the
* client left a synchronization function.
*/
int DRD_(thread_leave_synchr)(const DrdThreadId tid)
{
tl_assert(DRD_(IsValidDrdThreadId)(tid));
tl_assert(DRD_(g_threadinfo)[tid].synchr_nesting >= 1);
return --DRD_(g_threadinfo)[tid].synchr_nesting;
}
/** Returns the synchronization nesting counter. */
int DRD_(thread_get_synchr_nesting_count)(const DrdThreadId tid)
{
tl_assert(DRD_(IsValidDrdThreadId)(tid));
return DRD_(g_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);
#ifdef ENABLE_DRD_CONSISTENCY_CHECKS
tl_assert(DRD_(sane_ThreadInfo)(&DRD_(g_threadinfo)[tid]));
#endif
// add at tail
sg->thr_prev = DRD_(g_threadinfo)[tid].sg_last;
sg->thr_next = NULL;
if (DRD_(g_threadinfo)[tid].sg_last)
DRD_(g_threadinfo)[tid].sg_last->thr_next = sg;
DRD_(g_threadinfo)[tid].sg_last = sg;
if (DRD_(g_threadinfo)[tid].sg_first == NULL)
DRD_(g_threadinfo)[tid].sg_first = sg;
#ifdef ENABLE_DRD_CONSISTENCY_CHECKS
tl_assert(DRD_(sane_ThreadInfo)(&DRD_(g_threadinfo)[tid]));
#endif
}
/**
* 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);
#ifdef ENABLE_DRD_CONSISTENCY_CHECKS
tl_assert(DRD_(sane_ThreadInfo)(&DRD_(g_threadinfo)[tid]));
#endif
if (sg->thr_prev)
sg->thr_prev->thr_next = sg->thr_next;
if (sg->thr_next)
sg->thr_next->thr_prev = sg->thr_prev;
if (sg == DRD_(g_threadinfo)[tid].sg_first)
DRD_(g_threadinfo)[tid].sg_first = sg->thr_next;
if (sg == DRD_(g_threadinfo)[tid].sg_last)
DRD_(g_threadinfo)[tid].sg_last = sg->thr_prev;
DRD_(sg_put)(sg);
#ifdef ENABLE_DRD_CONSISTENCY_CHECKS
tl_assert(DRD_(sane_ThreadInfo)(&DRD_(g_threadinfo)[tid]));
#endif
}
/**
* Returns a pointer to the vector clock of the most recent segment associated
* with thread 'tid'.
*/
VectorClock* DRD_(thread_get_vc)(const DrdThreadId tid)
{
Segment* latest_sg;
tl_assert(0 <= (int)tid && tid < DRD_N_THREADS
&& tid != DRD_INVALID_THREADID);
latest_sg = DRD_(g_threadinfo)[tid].sg_last;
tl_assert(latest_sg);
return &latest_sg->vc;
}
/**
* Return the latest segment of thread 'tid' and increment its reference count.
*/
void DRD_(thread_get_latest_segment)(Segment** sg, const DrdThreadId tid)
{
Segment* latest_sg;
tl_assert(sg);
tl_assert(0 <= (int)tid && tid < DRD_N_THREADS
&& tid != DRD_INVALID_THREADID);
latest_sg = DRD_(g_threadinfo)[tid].sg_last;
tl_assert(latest_sg);
DRD_(sg_put)(*sg);
*sg = DRD_(sg_get)(latest_sg);
}
/**
* 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 DRD_(thread_compute_minimum_vc)(VectorClock* vc)
{
unsigned i;
Bool first;
Segment* latest_sg;
first = True;
for (i = 0; i < DRD_N_THREADS; i++)
{
latest_sg = DRD_(g_threadinfo)[i].sg_last;
if (latest_sg) {
if (first)
DRD_(vc_assign)(vc, &latest_sg->vc);
else
DRD_(vc_min)(vc, &latest_sg->vc);
first = False;
}
}
}
/**
* Compute the maximum of all latest vector clocks of all threads.
*
* @param vc pointer to a vectorclock, holds result upon return.
*/
static void DRD_(thread_compute_maximum_vc)(VectorClock* vc)
{
unsigned i;
Bool first;
Segment* latest_sg;
first = True;
for (i = 0; i < DRD_N_THREADS; i++)
{
latest_sg = DRD_(g_threadinfo)[i].sg_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 all threads -- 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);
DRD_(thread_compute_minimum_vc)(&thread_vc_min);
if (DRD_(sg_get_trace)())
{
HChar *vc_min, *vc_max;
VectorClock thread_vc_max;
DRD_(vc_init)(&thread_vc_max, 0, 0);
DRD_(thread_compute_maximum_vc)(&thread_vc_max);
vc_min = DRD_(vc_aprint)(&thread_vc_min);
vc_max = DRD_(vc_aprint)(&thread_vc_max);
VG_(message)(Vg_DebugMsg,
"Discarding ordered segments -- min vc is %s, max vc is %s\n",
vc_min, vc_max);
VG_(free)(vc_min);
VG_(free)(vc_max);
DRD_(vc_cleanup)(&thread_vc_max);
}
for (i = 0; i < DRD_N_THREADS; i++) {
Segment* sg;
Segment* sg_next;
for (sg = DRD_(g_threadinfo)[i].sg_first;
sg && (sg_next = sg->thr_next)
&& DRD_(vc_lte)(&sg->vc, &thread_vc_min);
sg = sg_next)
{
thread_discard_segment(i, sg);
}
}
DRD_(vc_cleanup)(&thread_vc_min);
}
/**
* An implementation of the property 'equiv(sg1, sg2)' as defined in the paper
* by Mark Christiaens e.a. The property equiv(sg1, sg2) holds if and only if
* all segments in the set CS are ordered consistently against both sg1 and
* sg2. The set CS is defined as the set of segments that can immediately
* precede future segments via inter-thread synchronization operations. In
* DRD the set CS consists of the latest segment of each thread combined with
* all segments for which the reference count is strictly greater than one.
* The code below is an optimized version of the following:
*
* for (i = 0; i < DRD_N_THREADS; i++)
* {
* Segment* sg;
*
* for (sg = DRD_(g_threadinfo)[i].first; sg; sg = sg->next)
* {
* if (sg == DRD_(g_threadinfo)[i].last || DRD_(sg_get_refcnt)(sg) > 1)
* {
* if ( DRD_(vc_lte)(&sg1->vc, &sg->vc)
* != DRD_(vc_lte)(&sg2->vc, &sg->vc)
* || DRD_(vc_lte)(&sg->vc, &sg1->vc)
* != DRD_(vc_lte)(&sg->vc, &sg2->vc))
* {
* return False;
* }
* }
* }
* }
*/
static Bool thread_consistent_segment_ordering(const DrdThreadId tid,
Segment* const sg1,
Segment* const sg2)
{
unsigned i;
tl_assert(sg1->thr_next);
tl_assert(sg2->thr_next);
tl_assert(sg1->thr_next == sg2);
tl_assert(DRD_(vc_lte)(&sg1->vc, &sg2->vc));
for (i = 0; i < DRD_N_THREADS; i++)
{
Segment* sg;
for (sg = DRD_(g_threadinfo)[i].sg_first; sg; sg = sg->thr_next) {
if (!sg->thr_next || DRD_(sg_get_refcnt)(sg) > 1) {
if (DRD_(vc_lte)(&sg2->vc, &sg->vc))
break;
if (DRD_(vc_lte)(&sg1->vc, &sg->vc))
return False;
}
}
for (sg = DRD_(g_threadinfo)[i].sg_last; sg; sg = sg->thr_prev) {
if (!sg->thr_next || DRD_(sg_get_refcnt)(sg) > 1) {
if (DRD_(vc_lte)(&sg->vc, &sg1->vc))
break;
if (DRD_(vc_lte)(&sg->vc, &sg2->vc))
return False;
}
}
}
return True;
}
/**
* 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. This paper contains a proof that merging
* consecutive segments for which the property equiv(s1,s2) holds can be
* merged without reducing the accuracy of datarace detection. Furthermore
* it is also proven that the total number of all segments will never grow
* unbounded if all segments s1, s2 for which equiv(s1, s2) holds are merged
* every time a new segment is created. The property equiv(s1, s2) is defined
* as follows: equiv(s1, s2) <=> for all segments in the set CS, the vector
* clocks of segments s and s1 are ordered in the same way as those of segments
* s and s2. The set CS is defined as the set of existing segments s that have
* the potential to conflict with not yet created segments, either because the
* segment s is the latest segment of a thread or because it can become the
* immediate predecessor of a new segment due to a synchronization operation.
*/
static void thread_merge_segments(void)
{
unsigned i;
s_new_segments_since_last_merge = 0;
for (i = 0; i < DRD_N_THREADS; i++)
{
Segment* sg;
#ifdef ENABLE_DRD_CONSISTENCY_CHECKS
tl_assert(DRD_(sane_ThreadInfo)(&DRD_(g_threadinfo)[i]));
#endif
for (sg = DRD_(g_threadinfo)[i].sg_first; sg; sg = sg->thr_next) {
if (DRD_(sg_get_refcnt)(sg) == 1 && sg->thr_next) {
Segment* const sg_next = sg->thr_next;
if (DRD_(sg_get_refcnt)(sg_next) == 1
&& sg_next->thr_next
&& thread_consistent_segment_ordering(i, sg, sg_next))
{
/* Merge sg and sg_next into sg. */
DRD_(sg_merge)(sg, sg_next);
thread_discard_segment(i, sg_next);
}
}
}
#ifdef ENABLE_DRD_CONSISTENCY_CHECKS
tl_assert(DRD_(sane_ThreadInfo)(&DRD_(g_threadinfo)[i]));
#endif
}
}
/**
* Create a new segment for the specified thread, and discard any segments
* that cannot cause races anymore.
*/
void DRD_(thread_new_segment)(const DrdThreadId tid)
{
Segment* last_sg;
Segment* new_sg;
tl_assert(0 <= (int)tid && tid < DRD_N_THREADS
&& tid != DRD_INVALID_THREADID);
tl_assert(thread_conflict_set_up_to_date(DRD_(g_drd_running_tid)));
last_sg = DRD_(g_threadinfo)[tid].sg_last;
new_sg = DRD_(sg_new)(tid, tid);
thread_append_segment(tid, new_sg);
if (tid == DRD_(g_drd_running_tid) && last_sg)
{
DRD_(thread_update_conflict_set)(tid, &last_sg->vc);
s_update_conflict_set_new_sg_count++;
}
tl_assert(thread_conflict_set_up_to_date(DRD_(g_drd_running_tid)));
if (s_segment_merging
&& ++s_new_segments_since_last_merge >= s_segment_merge_interval)
{
thread_discard_ordered_segments();
thread_merge_segments();
}
}
/** Call this function after thread 'joiner' joined thread 'joinee'. */
void DRD_(thread_combine_vc_join)(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(DRD_(g_threadinfo)[joiner].sg_first);
tl_assert(DRD_(g_threadinfo)[joiner].sg_last);
tl_assert(DRD_(g_threadinfo)[joinee].sg_first);
tl_assert(DRD_(g_threadinfo)[joinee].sg_last);
if (DRD_(sg_get_trace)())
{
HChar *str1, *str2;
str1 = DRD_(vc_aprint)(DRD_(thread_get_vc)(joiner));
str2 = DRD_(vc_aprint)(DRD_(thread_get_vc)(joinee));
VG_(message)(Vg_DebugMsg, "Before join: joiner %s, joinee %s\n",
str1, str2);
VG_(free)(str1);
VG_(free)(str2);
}
if (joiner == DRD_(g_drd_running_tid)) {
VectorClock old_vc;
DRD_(vc_copy)(&old_vc, DRD_(thread_get_vc)(joiner));
DRD_(vc_combine)(DRD_(thread_get_vc)(joiner),
DRD_(thread_get_vc)(joinee));
DRD_(thread_update_conflict_set)(joiner, &old_vc);
s_update_conflict_set_join_count++;
DRD_(vc_cleanup)(&old_vc);
} else {
DRD_(vc_combine)(DRD_(thread_get_vc)(joiner),
DRD_(thread_get_vc)(joinee));
}
thread_discard_ordered_segments();
if (DRD_(sg_get_trace)()) {
HChar* str;
str = DRD_(vc_aprint)(DRD_(thread_get_vc)(joiner));
VG_(message)(Vg_DebugMsg, "After join: %s\n", str);
VG_(free)(str);
}
}
/**
* Update the vector clock of the last segment of thread tid with the
* the vector clock of segment sg.
*/
static void thread_combine_vc_sync(DrdThreadId tid, const Segment* sg)
{
const VectorClock* const vc = &sg->vc;
tl_assert(0 <= (int)tid && tid < DRD_N_THREADS
&& tid != DRD_INVALID_THREADID);
tl_assert(DRD_(g_threadinfo)[tid].sg_first);
tl_assert(DRD_(g_threadinfo)[tid].sg_last);
tl_assert(sg);
tl_assert(vc);
if (tid != sg->tid) {
VectorClock old_vc;
DRD_(vc_copy)(&old_vc, DRD_(thread_get_vc)(tid));
DRD_(vc_combine)(DRD_(thread_get_vc)(tid), vc);
if (DRD_(sg_get_trace)()) {
HChar *str1, *str2;
str1 = DRD_(vc_aprint)(&old_vc);
str2 = DRD_(vc_aprint)(DRD_(thread_get_vc)(tid));
VG_(message)(Vg_DebugMsg, "thread %d: vc %s -> %s\n", tid, str1, str2);
VG_(free)(str1);
VG_(free)(str2);
}
thread_discard_ordered_segments();
DRD_(thread_update_conflict_set)(tid, &old_vc);
s_update_conflict_set_sync_count++;
DRD_(vc_cleanup)(&old_vc);
} else {
tl_assert(DRD_(vc_lte)(vc, DRD_(thread_get_vc)(tid)));
}
}
/**
* Create a new segment for thread tid and update the vector clock of the last
* segment of this thread with the the vector clock of segment sg. Call this
* function after thread tid had to wait because of thread synchronization
* until the memory accesses in the segment sg finished.
*/
void DRD_(thread_new_segment_and_combine_vc)(DrdThreadId tid, const Segment* sg)
{
tl_assert(0 <= (int)tid && tid < DRD_N_THREADS
&& tid != DRD_INVALID_THREADID);
tl_assert(thread_conflict_set_up_to_date(DRD_(g_drd_running_tid)));
tl_assert(sg);
thread_append_segment(tid, DRD_(sg_new)(tid, tid));
thread_combine_vc_sync(tid, sg);
if (s_segment_merging
&& ++s_new_segments_since_last_merge >= s_segment_merge_interval)
{
thread_discard_ordered_segments();
thread_merge_segments();
}
}
/**
* 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 DRD_(thread_stop_using_mem)(const Addr a1, const Addr a2)
{
Segment* p;
for (p = DRD_(g_sg_list); p; p = p->g_next)
DRD_(bm_clear)(DRD_(sg_bm)(p), a1, a2);
DRD_(bm_clear)(DRD_(g_conflict_set), a1, a2);
}
/** Specify whether memory loads should be recorded. */
void DRD_(thread_set_record_loads)(const DrdThreadId tid, const Bool enabled)
{
tl_assert(0 <= (int)tid && tid < DRD_N_THREADS
&& tid != DRD_INVALID_THREADID);
tl_assert(enabled == !! enabled);
DRD_(g_threadinfo)[tid].is_recording_loads = enabled;
}
/** Specify whether memory stores should be recorded. */
void DRD_(thread_set_record_stores)(const DrdThreadId tid, const Bool enabled)
{
tl_assert(0 <= (int)tid && tid < DRD_N_THREADS
&& tid != DRD_INVALID_THREADID);
tl_assert(enabled == !! enabled);
DRD_(g_threadinfo)[tid].is_recording_stores = enabled;
}
/**
* Print the segment information for all threads.
*
* This function is only used for debugging purposes.
*/
void DRD_(thread_print_all)(void)
{
unsigned i;
Segment* p;
for (i = 0; i < DRD_N_THREADS; i++)
{
p = DRD_(g_threadinfo)[i].sg_first;
if (p) {
VG_(printf)("**************\n"
"* thread %3d (%d/%d/%d/%d/0x%lx/%d) *\n"
"**************\n",
i,
DRD_(g_threadinfo)[i].valid,
DRD_(g_threadinfo)[i].vg_thread_exists,
DRD_(g_threadinfo)[i].vg_threadid,
DRD_(g_threadinfo)[i].posix_thread_exists,
DRD_(g_threadinfo)[i].pt_threadid,
DRD_(g_threadinfo)[i].detached_posix_thread);
for ( ; p; p = p->thr_next)
DRD_(sg_print)(p);
}
}
}
/** Show a call stack involved in a data race. */
static void show_call_stack(const DrdThreadId tid, ExeContext* const callstack)
{
const ThreadId vg_tid = DRD_(DrdThreadIdToVgThreadId)(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 {
if (!VG_(clo_xml))
VG_(message)(Vg_UserMsg,
" (thread finished, call stack no longer available)\n");
}
}
/** Print information about the segments involved in a data race. */
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 < DRD_N_THREADS; i++) {
if (i != tid) {
Segment* q;
for (q = DRD_(g_threadinfo)[i].sg_last; q; q = q->thr_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 (DRD_(bm_has_conflict_with)(DRD_(sg_bm)(q), addr, addr + size,
access_type)) {
Segment* q_next;
tl_assert(q->stacktrace);
if (VG_(clo_xml))
VG_(printf_xml)(" <other_segment_start>\n");
else
VG_(message)(Vg_UserMsg,
"Other segment start (thread %d)\n", i);
show_call_stack(i, q->stacktrace);
if (VG_(clo_xml))
VG_(printf_xml)(" </other_segment_start>\n"
" <other_segment_end>\n");
else
VG_(message)(Vg_UserMsg,
"Other segment end (thread %d)\n", i);
q_next = q->thr_next;
show_call_stack(i, q_next ? q_next->stacktrace : 0);
if (VG_(clo_xml))
VG_(printf_xml)(" </other_segment_end>\n");
}
}
}
}
}
}
/** Print information about all segments involved in a data race. */
void DRD_(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 = DRD_(g_threadinfo)[tid].sg_first; p; p = p->thr_next) {
if (DRD_(bm_has)(DRD_(sg_bm)(p), 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)
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 = DRD_(bm_equal)(DRD_(g_conflict_set), computed_conflict_set);
if (! result)
{
VG_(printf)("actual conflict set:\n");
DRD_(bm_print)(DRD_(g_conflict_set));
VG_(printf)("\n");
VG_(printf)("computed conflict set:\n");
DRD_(bm_print)(computed_conflict_set);
VG_(printf)("\n");
}
DRD_(bm_delete)(computed_conflict_set);
return result;
}
/**
* Compute the conflict set: 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 == DRD_(g_drd_running_tid));
s_compute_conflict_set_count++;
s_conflict_set_bitmap_creation_count
-= DRD_(bm_get_bitmap_creation_count)();
s_conflict_set_bitmap2_creation_count
-= DRD_(bm_get_bitmap2_creation_count)();
if (*conflict_set) {
DRD_(bm_cleanup)(*conflict_set);
DRD_(bm_init)(*conflict_set);
} else {
*conflict_set = DRD_(bm_new)();
}
if (s_trace_conflict_set) {
HChar* str;
str = DRD_(vc_aprint)(DRD_(thread_get_vc)(tid));
VG_(message)(Vg_DebugMsg,
"computing conflict set for thread %d with vc %s\n",
tid, str);
VG_(free)(str);
}
p = DRD_(g_threadinfo)[tid].sg_last;
{
unsigned j;
if (s_trace_conflict_set) {
HChar* vc;
vc = DRD_(vc_aprint)(&p->vc);
VG_(message)(Vg_DebugMsg, "conflict set: thread [%d] at vc %s\n",
tid, vc);
VG_(free)(vc);
}
for (j = 0; j < DRD_N_THREADS; j++) {
if (j != tid && DRD_(IsValidDrdThreadId)(j)) {
Segment* q;
for (q = DRD_(g_threadinfo)[j].sg_last; q; q = q->thr_prev) {
if (!DRD_(vc_lte)(&q->vc, &p->vc)
&& !DRD_(vc_lte)(&p->vc, &q->vc)) {
if (s_trace_conflict_set) {
HChar* str;
str = DRD_(vc_aprint)(&q->vc);
VG_(message)(Vg_DebugMsg,
"conflict set: [%d] merging segment %s\n",
j, str);
VG_(free)(str);
}
DRD_(bm_merge2)(*conflict_set, DRD_(sg_bm)(q));
} else {
if (s_trace_conflict_set) {
HChar* str;
str = DRD_(vc_aprint)(&q->vc);
VG_(message)(Vg_DebugMsg,
"conflict set: [%d] ignoring segment %s\n",
j, str);
VG_(free)(str);
}
}
}
}
}
}
s_conflict_set_bitmap_creation_count
+= DRD_(bm_get_bitmap_creation_count)();
s_conflict_set_bitmap2_creation_count
+= DRD_(bm_get_bitmap2_creation_count)();
if (s_trace_conflict_set_bm) {
VG_(message)(Vg_DebugMsg, "[%d] new conflict set:\n", tid);
DRD_(bm_print)(*conflict_set);
VG_(message)(Vg_DebugMsg, "[%d] end of new conflict set.\n", tid);
}
}
/**
* Update the conflict set after the vector clock of thread tid has been
* updated from old_vc to its current value, either because a new segment has
* been created or because of a synchronization operation.
*/
void DRD_(thread_update_conflict_set)(const DrdThreadId tid,
const VectorClock* const old_vc)
{
const VectorClock* new_vc;
Segment* p;
unsigned j;
tl_assert(0 <= (int)tid && tid < DRD_N_THREADS
&& tid != DRD_INVALID_THREADID);
tl_assert(old_vc);
tl_assert(tid == DRD_(g_drd_running_tid));
tl_assert(DRD_(g_conflict_set));
if (s_trace_conflict_set) {
HChar* str;
str = DRD_(vc_aprint)(DRD_(thread_get_vc)(tid));
VG_(message)(Vg_DebugMsg,
"updating conflict set for thread %d with vc %s\n",
tid, str);
VG_(free)(str);
}
new_vc = DRD_(thread_get_vc)(tid);
tl_assert(DRD_(vc_lte)(old_vc, new_vc));
DRD_(bm_unmark)(DRD_(g_conflict_set));
for (j = 0; j < DRD_N_THREADS; j++)
{
Segment* q;
if (j == tid || ! DRD_(IsValidDrdThreadId)(j))
continue;
for (q = DRD_(g_threadinfo)[j].sg_last;
q && !DRD_(vc_lte)(&q->vc, new_vc);
q = q->thr_prev) {
const Bool included_in_old_conflict_set
= !DRD_(vc_lte)(old_vc, &q->vc);
const Bool included_in_new_conflict_set
= !DRD_(vc_lte)(new_vc, &q->vc);
if (UNLIKELY(s_trace_conflict_set)) {
HChar* str;
str = DRD_(vc_aprint)(&q->vc);
VG_(message)(Vg_DebugMsg,
"conflict set: [%d] %s segment %s\n", j,
included_in_old_conflict_set
!= included_in_new_conflict_set
? "merging" : "ignoring", str);
VG_(free)(str);
}
if (included_in_old_conflict_set != included_in_new_conflict_set)
DRD_(bm_mark)(DRD_(g_conflict_set), DRD_(sg_bm)(q));
}
for ( ; q && !DRD_(vc_lte)(&q->vc, old_vc); q = q->thr_prev) {
const Bool included_in_old_conflict_set
= !DRD_(vc_lte)(old_vc, &q->vc);
const Bool included_in_new_conflict_set
= !DRD_(vc_lte)(&q->vc, new_vc)
&& !DRD_(vc_lte)(new_vc, &q->vc);
if (UNLIKELY(s_trace_conflict_set)) {
HChar* str;
str = DRD_(vc_aprint)(&q->vc);
VG_(message)(Vg_DebugMsg,
"conflict set: [%d] %s segment %s\n", j,
included_in_old_conflict_set
!= included_in_new_conflict_set
? "merging" : "ignoring", str);
VG_(free)(str);
}
if (included_in_old_conflict_set != included_in_new_conflict_set)
DRD_(bm_mark)(DRD_(g_conflict_set), DRD_(sg_bm)(q));
}
}
DRD_(bm_clear_marked)(DRD_(g_conflict_set));
p = DRD_(g_threadinfo)[tid].sg_last;
for (j = 0; j < DRD_N_THREADS; j++) {
if (j != tid && DRD_(IsValidDrdThreadId)(j)) {
Segment* q;
for (q = DRD_(g_threadinfo)[j].sg_last;
q && !DRD_(vc_lte)(&q->vc, &p->vc);
q = q->thr_prev) {
if (!DRD_(vc_lte)(&p->vc, &q->vc))
DRD_(bm_merge2_marked)(DRD_(g_conflict_set), DRD_(sg_bm)(q));
}
}
}
DRD_(bm_remove_cleared_marked)(DRD_(g_conflict_set));
s_update_conflict_set_count++;
if (s_trace_conflict_set_bm)
{
VG_(message)(Vg_DebugMsg, "[%d] updated conflict set:\n", tid);
DRD_(bm_print)(DRD_(g_conflict_set));
VG_(message)(Vg_DebugMsg, "[%d] end of updated conflict set.\n", tid);
}
tl_assert(thread_conflict_set_up_to_date(DRD_(g_drd_running_tid)));
}
/** Report the number of context switches performed. */
ULong DRD_(thread_get_context_switch_count)(void)
{
return s_context_switch_count;
}
/** Report the number of ordered segments that have been discarded. */
ULong DRD_(thread_get_discard_ordered_segments_count)(void)
{
return s_discard_ordered_segments_count;
}
/** Return how many times the conflict set has been updated entirely. */
ULong DRD_(thread_get_compute_conflict_set_count)()
{
return s_compute_conflict_set_count;
}
/** Return how many times the conflict set has been updated partially. */
ULong DRD_(thread_get_update_conflict_set_count)(void)
{
return s_update_conflict_set_count;
}
/**
* Return how many times the conflict set has been updated partially
* because a new segment has been created.
*/
ULong DRD_(thread_get_update_conflict_set_new_sg_count)(void)
{
return s_update_conflict_set_new_sg_count;
}
/**
* Return how many times the conflict set has been updated partially
* because of combining vector clocks due to synchronization operations
* other than reader/writer lock or barrier operations.
*/
ULong DRD_(thread_get_update_conflict_set_sync_count)(void)
{
return s_update_conflict_set_sync_count;
}
/**
* Return how many times the conflict set has been updated partially
* because of thread joins.
*/
ULong DRD_(thread_get_update_conflict_set_join_count)(void)
{
return s_update_conflict_set_join_count;
}
/**
* Return the number of first-level bitmaps that have been created during
* conflict set updates.
*/
ULong DRD_(thread_get_conflict_set_bitmap_creation_count)(void)
{
return s_conflict_set_bitmap_creation_count;
}
/**
* Return the number of second-level bitmaps that have been created during
* conflict set updates.
*/
ULong DRD_(thread_get_conflict_set_bitmap2_creation_count)(void)
{
return s_conflict_set_bitmap2_creation_count;
}