/* -*- mode: C; c-basic-offset: 3; indent-tabs-mode: nil; -*- */
/*
This file is part of drd, a thread error detector.
Copyright (C) 2006-2011 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_basics.h"
#include "drd_clientobj.h"
#include "drd_error.h"
#include "drd_mutex.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_libcbase.h" /* VG_(strlen) */
#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_threadstate.h" /* VG_(get_running_tid)() */
/* Local functions. */
static void mutex_cleanup(struct mutex_info* p);
static Bool mutex_is_locked(struct mutex_info* const p);
static void mutex_delete_thread(struct mutex_info* p, const DrdThreadId tid);
/* Local variables. */
static Bool s_trace_mutex;
static ULong s_mutex_lock_count;
static ULong s_mutex_segment_creation_count;
static UInt s_mutex_lock_threshold_ms;
/* Function definitions. */
void DRD_(mutex_set_trace)(const Bool trace_mutex)
{
tl_assert(!! trace_mutex == trace_mutex);
s_trace_mutex = trace_mutex;
}
void DRD_(mutex_set_lock_threshold)(const UInt lock_threshold_ms)
{
s_mutex_lock_threshold_ms = lock_threshold_ms;
}
static
void DRD_(mutex_initialize)(struct mutex_info* const p,
const Addr mutex, const MutexT mutex_type)
{
tl_assert(mutex);
tl_assert(p->a1 == mutex);
p->cleanup = (void(*)(DrdClientobj*))mutex_cleanup;
p->delete_thread
= (void(*)(DrdClientobj*, DrdThreadId))mutex_delete_thread;
p->mutex_type = mutex_type;
p->recursion_count = 0;
p->owner = DRD_INVALID_THREADID;
p->last_locked_segment = 0;
p->acquiry_time_ms = 0;
p->acquired_at = 0;
}
/** Deallocate the memory that was allocated by mutex_initialize(). */
static void mutex_cleanup(struct mutex_info* p)
{
tl_assert(p);
if (s_trace_mutex)
DRD_(trace_msg)("[%d] mutex_destroy %s 0x%lx rc %d owner %d",
DRD_(thread_get_running_tid)(),
DRD_(mutex_get_typename)(p), p->a1,
p ? p->recursion_count : -1,
p ? p->owner : DRD_INVALID_THREADID);
if (mutex_is_locked(p))
{
MutexErrInfo MEI = { DRD_(thread_get_running_tid)(),
p->a1, p->recursion_count, p->owner };
VG_(maybe_record_error)(VG_(get_running_tid)(),
MutexErr,
VG_(get_IP)(VG_(get_running_tid)()),
"Destroying locked mutex",
&MEI);
}
DRD_(sg_put)(p->last_locked_segment);
p->last_locked_segment = 0;
}
/** Report that address 'mutex' is not the address of a mutex object. */
void DRD_(not_a_mutex)(const Addr mutex)
{
MutexErrInfo MEI = { DRD_(thread_get_running_tid)(),
mutex, -1, DRD_INVALID_THREADID };
VG_(maybe_record_error)(VG_(get_running_tid)(),
MutexErr,
VG_(get_IP)(VG_(get_running_tid)()),
"Not a mutex",
&MEI);
}
/**
* Report that address 'mutex' is not the address of a mutex object of the
* expected type.
*/
static void wrong_mutex_type(const Addr mutex)
{
MutexErrInfo MEI = { DRD_(thread_get_running_tid)(),
mutex, -1, DRD_INVALID_THREADID };
VG_(maybe_record_error)(VG_(get_running_tid)(),
MutexErr,
VG_(get_IP)(VG_(get_running_tid)()),
"Mutex type mismatch",
&MEI);
}
static
struct mutex_info*
DRD_(mutex_get_or_allocate)(const Addr mutex, const MutexT mutex_type)
{
struct mutex_info* p;
tl_assert(offsetof(DrdClientobj, mutex) == 0);
p = &(DRD_(clientobj_get)(mutex, ClientMutex)->mutex);
if (p)
{
if (mutex_type == mutex_type_unknown || p->mutex_type == mutex_type)
return p;
else
{
wrong_mutex_type(mutex);
return 0;
}
}
if (DRD_(clientobj_present)(mutex, mutex + 1))
{
DRD_(not_a_mutex)(mutex);
return 0;
}
p = &(DRD_(clientobj_add)(mutex, ClientMutex)->mutex);
DRD_(mutex_initialize)(p, mutex, mutex_type);
return p;
}
struct mutex_info* DRD_(mutex_get)(const Addr mutex)
{
tl_assert(offsetof(DrdClientobj, mutex) == 0);
return &(DRD_(clientobj_get)(mutex, ClientMutex)->mutex);
}
/** Called before pthread_mutex_init(). */
struct mutex_info*
DRD_(mutex_init)(const Addr mutex, const MutexT mutex_type)
{
struct mutex_info* p;
if (s_trace_mutex)
DRD_(trace_msg)("[%d] mutex_init %s 0x%lx",
DRD_(thread_get_running_tid)(),
DRD_(mutex_type_name)(mutex_type),
mutex);
if (mutex_type == mutex_type_invalid_mutex)
{
DRD_(not_a_mutex)(mutex);
return 0;
}
p = DRD_(mutex_get)(mutex);
if (p)
{
const ThreadId vg_tid = VG_(get_running_tid)();
MutexErrInfo MEI = { DRD_(thread_get_running_tid)(),
p->a1, p->recursion_count, p->owner };
VG_(maybe_record_error)(vg_tid,
MutexErr,
VG_(get_IP)(vg_tid),
"Mutex reinitialization",
&MEI);
p->mutex_type = mutex_type;
return p;
}
p = DRD_(mutex_get_or_allocate)(mutex, mutex_type);
return p;
}
/** Called after pthread_mutex_destroy(). */
void DRD_(mutex_post_destroy)(const Addr mutex)
{
struct mutex_info* p;
p = DRD_(mutex_get)(mutex);
if (p == 0)
{
DRD_(not_a_mutex)(mutex);
return;
}
DRD_(clientobj_remove)(mutex, ClientMutex);
}
/**
* Called before pthread_mutex_lock() 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_(mutex_pre_lock)(const Addr mutex, MutexT mutex_type,
const Bool trylock)
{
struct mutex_info* p;
p = DRD_(mutex_get_or_allocate)(mutex, mutex_type);
if (p && mutex_type == mutex_type_unknown)
mutex_type = p->mutex_type;
if (s_trace_mutex)
DRD_(trace_msg)("[%d] %s %s 0x%lx rc %d owner %d",
DRD_(thread_get_running_tid)(),
trylock ? "pre_mutex_lock " : "mutex_trylock ",
p ? DRD_(mutex_get_typename)(p) : "(?)",
mutex, p ? p->recursion_count : -1,
p ? p->owner : DRD_INVALID_THREADID);
if (p == 0)
{
DRD_(not_a_mutex)(mutex);
return;
}
tl_assert(p);
if (mutex_type == mutex_type_invalid_mutex)
{
DRD_(not_a_mutex)(mutex);
return;
}
if (! trylock
&& p->owner == DRD_(thread_get_running_tid)()
&& p->recursion_count >= 1
&& mutex_type != mutex_type_recursive_mutex)
{
MutexErrInfo MEI = { DRD_(thread_get_running_tid)(),
p->a1, p->recursion_count, p->owner };
VG_(maybe_record_error)(VG_(get_running_tid)(),
MutexErr,
VG_(get_IP)(VG_(get_running_tid)()),
"Recursive locking not allowed",
&MEI);
}
}
/**
* Update mutex_info state when locking the pthread_mutex_t mutex.
* Note: this function must be called after pthread_mutex_lock() has been
* called, or a race condition is triggered !
*/
void DRD_(mutex_post_lock)(const Addr mutex, const Bool took_lock,
const Bool post_cond_wait)
{
const DrdThreadId drd_tid = DRD_(thread_get_running_tid)();
struct mutex_info* p;
p = DRD_(mutex_get)(mutex);
if (s_trace_mutex)
DRD_(trace_msg)("[%d] %s %s 0x%lx rc %d owner %d%s",
drd_tid,
post_cond_wait ? "cond_post_wait " : "post_mutex_lock",
p ? DRD_(mutex_get_typename)(p) : "(?)",
mutex, p ? p->recursion_count : 0,
p ? p->owner : VG_INVALID_THREADID,
took_lock ? "" : " (locking failed)");
if (! p || ! took_lock)
return;
if (p->recursion_count == 0) {
if (p->owner != drd_tid && p->owner != DRD_INVALID_THREADID)
{
tl_assert(p->last_locked_segment);
DRD_(thread_new_segment_and_combine_vc)(drd_tid,
p->last_locked_segment);
}
else
DRD_(thread_new_segment)(drd_tid);
s_mutex_segment_creation_count++;
p->owner = drd_tid;
p->acquiry_time_ms = VG_(read_millisecond_timer)();
p->acquired_at = VG_(record_ExeContext)(VG_(get_running_tid)(), 0);
s_mutex_lock_count++;
} else if (p->owner != drd_tid) {
const ThreadId vg_tid = VG_(get_running_tid)();
MutexErrInfo MEI = { DRD_(thread_get_running_tid)(),
p->a1, p->recursion_count, p->owner };
VG_(maybe_record_error)(vg_tid,
MutexErr,
VG_(get_IP)(vg_tid),
"The impossible happened: mutex is locked"
" simultaneously by two threads",
&MEI);
p->owner = drd_tid;
}
p->recursion_count++;
}
/**
* Update mutex_info state when unlocking the pthread_mutex_t mutex.
*
* @param[in] mutex Address of the client mutex.
* @param[in] mutex_type Mutex type.
*
* @return New value of the mutex recursion count.
*
* @note This function must be called before pthread_mutex_unlock() is called,
* or a race condition is triggered !
*/
void DRD_(mutex_unlock)(const Addr mutex, MutexT mutex_type)
{
const DrdThreadId drd_tid = DRD_(thread_get_running_tid)();
const ThreadId vg_tid = VG_(get_running_tid)();
struct mutex_info* p;
p = DRD_(mutex_get)(mutex);
if (p && mutex_type == mutex_type_unknown)
mutex_type = p->mutex_type;
if (s_trace_mutex) {
DRD_(trace_msg)("[%d] mutex_unlock %s 0x%lx rc %d",
drd_tid, p ? DRD_(mutex_get_typename)(p) : "(?)",
mutex, p ? p->recursion_count : 0);
}
if (p == 0 || mutex_type == mutex_type_invalid_mutex)
{
DRD_(not_a_mutex)(mutex);
return;
}
if (p->owner == DRD_INVALID_THREADID)
{
MutexErrInfo MEI = { DRD_(thread_get_running_tid)(),
p->a1, p->recursion_count, p->owner };
VG_(maybe_record_error)(vg_tid,
MutexErr,
VG_(get_IP)(vg_tid),
"Mutex not locked",
&MEI);
return;
}
tl_assert(p);
if (p->mutex_type != mutex_type) {
MutexErrInfo MEI = { DRD_(thread_get_running_tid)(),
p->a1, p->recursion_count, p->owner };
VG_(maybe_record_error)(vg_tid, MutexErr, VG_(get_IP)(vg_tid),
"Mutex type changed", &MEI);
}
tl_assert(p->mutex_type == mutex_type);
tl_assert(p->owner != DRD_INVALID_THREADID);
if (p->owner != drd_tid || p->recursion_count <= 0)
{
MutexErrInfo MEI = { DRD_(thread_get_running_tid)(),
p->a1, p->recursion_count, p->owner };
VG_(maybe_record_error)(vg_tid,
MutexErr,
VG_(get_IP)(vg_tid),
"Mutex not locked by calling thread",
&MEI);
return;
}
tl_assert(p->recursion_count > 0);
p->recursion_count--;
tl_assert(p->recursion_count >= 0);
if (p->recursion_count == 0)
{
if (s_mutex_lock_threshold_ms > 0)
{
Long held = VG_(read_millisecond_timer)() - p->acquiry_time_ms;
if (held > s_mutex_lock_threshold_ms)
{
HoldtimeErrInfo HEI
= { DRD_(thread_get_running_tid)(),
mutex, p->acquired_at, held, s_mutex_lock_threshold_ms };
VG_(maybe_record_error)(vg_tid,
HoldtimeErr,
VG_(get_IP)(vg_tid),
"mutex",
&HEI);
}
}
/* This pthread_mutex_unlock() call really unlocks the mutex. Save the */
/* current vector clock of the thread such that it is available when */
/* this mutex is locked again. */
DRD_(thread_get_latest_segment)(&p->last_locked_segment, drd_tid);
DRD_(thread_new_segment)(drd_tid);
p->acquired_at = 0;
s_mutex_segment_creation_count++;
}
}
void DRD_(spinlock_init_or_unlock)(const Addr spinlock)
{
struct mutex_info* mutex_p = DRD_(mutex_get)(spinlock);
if (mutex_p)
{
DRD_(mutex_unlock)(spinlock, mutex_type_spinlock);
}
else
{
DRD_(mutex_init)(spinlock, mutex_type_spinlock);
}
}
const char* DRD_(mutex_get_typename)(struct mutex_info* const p)
{
tl_assert(p);
return DRD_(mutex_type_name)(p->mutex_type);
}
const char* DRD_(mutex_type_name)(const MutexT mt)
{
switch (mt)
{
case mutex_type_unknown:
return "mutex";
case mutex_type_invalid_mutex:
return "invalid mutex";
case mutex_type_recursive_mutex:
return "recursive mutex";
case mutex_type_errorcheck_mutex:
return "error checking mutex";
case mutex_type_default_mutex:
return "mutex";
case mutex_type_spinlock:
return "spinlock";
}
tl_assert(0);
return "?";
}
/** Return true if the specified mutex is locked by any thread. */
static Bool mutex_is_locked(struct mutex_info* const p)
{
tl_assert(p);
return (p->recursion_count > 0);
}
Bool DRD_(mutex_is_locked_by)(const Addr mutex, const DrdThreadId tid)
{
struct mutex_info* const p = DRD_(mutex_get)(mutex);
if (p)
{
return (p->recursion_count > 0 && p->owner == tid);
}
return False;
}
int DRD_(mutex_get_recursion_count)(const Addr mutex)
{
struct mutex_info* const p = DRD_(mutex_get)(mutex);
tl_assert(p);
return p->recursion_count;
}
/**
* Call this function when thread tid stops to exist, such that the
* "last owner" field can be cleared if it still refers to that thread.
*/
static void mutex_delete_thread(struct mutex_info* p, const DrdThreadId tid)
{
tl_assert(p);
if (p->owner == tid && p->recursion_count > 0)
{
MutexErrInfo MEI = { DRD_(thread_get_running_tid)(),
p->a1, p->recursion_count, p->owner };
VG_(maybe_record_error)(VG_(get_running_tid)(),
MutexErr,
VG_(get_IP)(VG_(get_running_tid)()),
"Mutex still locked at thread exit",
&MEI);
p->owner = VG_INVALID_THREADID;
}
}
ULong DRD_(get_mutex_lock_count)(void)
{
return s_mutex_lock_count;
}
ULong DRD_(get_mutex_segment_creation_count)(void)
{
return s_mutex_segment_creation_count;
}