/**
* testcode/checklocks.c - wrapper on locks that checks access.
*
* Copyright (c) 2007, NLnet Labs. All rights reserved.
*
* This software is open source.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* Neither the name of the NLNET LABS nor the names of its contributors may
* be used to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
* TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "config.h"
#include <signal.h>
#include "util/locks.h" /* include before checklocks.h */
#include "testcode/checklocks.h"
/**
* \file
* Locks that are checked.
*
* Ugly hack: uses the fact that workers start with an int thread_num, and
* are passed to thread_create to make the thread numbers here the same as
* those used for logging which is nice.
*
* Todo:
* - debug status print, of thread lock stacks, and current waiting.
*/
#ifdef USE_THREAD_DEBUG
/** How long to wait before lock attempt is a failure. */
#define CHECK_LOCK_TIMEOUT 120 /* seconds */
/** How long to wait before join attempt is a failure. */
#define CHECK_JOIN_TIMEOUT 120 /* seconds */
/** if key has been created */
static int key_created = 0;
/** if the key was deleted, i.e. we have quit */
static int key_deleted = 0;
/** we hide the thread debug info with this key. */
static ub_thread_key_type thr_debug_key;
/** the list of threads, so all threads can be examined. NULL if unused. */
static struct thr_check* thread_infos[THRDEBUG_MAX_THREADS];
/** do we check locking order */
int check_locking_order = 1;
/** the pid of this runset, reasonably unique. */
static pid_t check_lock_pid;
/** print all possible debug info on the state of the system */
static void total_debug_info(void);
/** print pretty lock error and exit */
static void lock_error(struct checked_lock* lock,
const char* func, const char* file, int line, const char* err)
{
log_err("lock error (description follows)");
log_err("Created at %s %s:%d", lock->create_func,
lock->create_file, lock->create_line);
if(lock->holder_func && lock->holder_file)
log_err("Previously %s %s:%d", lock->holder_func,
lock->holder_file, lock->holder_line);
log_err("At %s %s:%d", func, file, line);
log_err("Error for %s lock: %s",
(lock->type==check_lock_mutex)?"mutex": (
(lock->type==check_lock_spinlock)?"spinlock": (
(lock->type==check_lock_rwlock)?"rwlock": "badtype")), err);
log_err("complete status display:");
total_debug_info();
fatal_exit("bailing out");
}
/**
* Obtain lock on debug lock structure. This could be a deadlock by the caller.
* The debug code itself does not deadlock. Anyway, check with timeouts.
* @param lock: on what to acquire lock.
* @param func: user level caller identification.
* @param file: user level caller identification.
* @param line: user level caller identification.
*/
static void
acquire_locklock(struct checked_lock* lock,
const char* func, const char* file, int line)
{
struct timespec to;
int err;
int contend = 0;
/* first try; inc contention counter if not immediately */
if((err = pthread_mutex_trylock(&lock->lock))) {
if(err==EBUSY)
contend++;
else fatal_exit("error in mutex_trylock: %s", strerror(err));
}
if(!err)
return; /* immediate success */
to.tv_sec = time(NULL) + CHECK_LOCK_TIMEOUT;
to.tv_nsec = 0;
err = pthread_mutex_timedlock(&lock->lock, &to);
if(err) {
log_err("in acquiring locklock: %s", strerror(err));
lock_error(lock, func, file, line, "acquire locklock");
}
/* since we hold the lock, we can edit the contention_count */
lock->contention_count += contend;
}
/** add protected region */
void
lock_protect(void *p, void* area, size_t size)
{
struct checked_lock* lock = *(struct checked_lock**)p;
struct protected_area* e = (struct protected_area*)malloc(
sizeof(struct protected_area));
if(!e)
fatal_exit("lock_protect: out of memory");
e->region = area;
e->size = size;
e->hold = malloc(size);
if(!e->hold)
fatal_exit("lock_protect: out of memory");
memcpy(e->hold, e->region, e->size);
acquire_locklock(lock, __func__, __FILE__, __LINE__);
e->next = lock->prot;
lock->prot = e;
LOCKRET(pthread_mutex_unlock(&lock->lock));
}
/** remove protected region */
void
lock_unprotect(void* mangled, void* area)
{
struct checked_lock* lock = *(struct checked_lock**)mangled;
struct protected_area* p, **prevp;
if(!lock)
return;
acquire_locklock(lock, __func__, __FILE__, __LINE__);
p = lock->prot;
prevp = &lock->prot;
while(p) {
if(p->region == area) {
*prevp = p->next;
free(p->hold);
free(p);
LOCKRET(pthread_mutex_unlock(&lock->lock));
return;
}
prevp = &p->next;
p = p->next;
}
LOCKRET(pthread_mutex_unlock(&lock->lock));
}
/**
* Check protected memory region. Memory compare. Exit on error.
* @param lock: which lock to check.
* @param func: location we are now (when failure is detected).
* @param file: location we are now (when failure is detected).
* @param line: location we are now (when failure is detected).
*/
static void
prot_check(struct checked_lock* lock,
const char* func, const char* file, int line)
{
struct protected_area* p = lock->prot;
while(p) {
if(memcmp(p->hold, p->region, p->size) != 0) {
log_hex("memory prev", p->hold, p->size);
log_hex("memory here", p->region, p->size);
lock_error(lock, func, file, line,
"protected area modified");
}
p = p->next;
}
}
/** Copy protected memory region */
static void
prot_store(struct checked_lock* lock)
{
struct protected_area* p = lock->prot;
while(p) {
memcpy(p->hold, p->region, p->size);
p = p->next;
}
}
/** get memory held by lock */
size_t
lock_get_mem(void* pp)
{
size_t s;
struct checked_lock* lock = *(struct checked_lock**)pp;
struct protected_area* p;
s = sizeof(struct checked_lock);
acquire_locklock(lock, __func__, __FILE__, __LINE__);
for(p = lock->prot; p; p = p->next) {
s += sizeof(struct protected_area);
s += p->size;
}
LOCKRET(pthread_mutex_unlock(&lock->lock));
return s;
}
/** write lock trace info to file, while you hold those locks */
static void
ordercheck_locklock(struct thr_check* thr, struct checked_lock* lock)
{
int info[4];
if(!check_locking_order) return;
if(!thr->holding_first) return; /* no older lock, no info */
/* write: <lock id held> <lock id new> <file> <line> */
info[0] = thr->holding_first->create_thread;
info[1] = thr->holding_first->create_instance;
info[2] = lock->create_thread;
info[3] = lock->create_instance;
if(fwrite(info, 4*sizeof(int), 1, thr->order_info) != 1 ||
fwrite(lock->holder_file, strlen(lock->holder_file)+1, 1,
thr->order_info) != 1 ||
fwrite(&lock->holder_line, sizeof(int), 1,
thr->order_info) != 1)
log_err("fwrite: %s", strerror(errno));
}
/** write ordercheck lock creation details to file */
static void
ordercheck_lockcreate(struct thr_check* thr, struct checked_lock* lock)
{
/* write: <ffff = create> <lock id> <file> <line> */
int cmd = -1;
if(!check_locking_order) return;
if( fwrite(&cmd, sizeof(int), 1, thr->order_info) != 1 ||
fwrite(&lock->create_thread, sizeof(int), 1,
thr->order_info) != 1 ||
fwrite(&lock->create_instance, sizeof(int), 1,
thr->order_info) != 1 ||
fwrite(lock->create_file, strlen(lock->create_file)+1, 1,
thr->order_info) != 1 ||
fwrite(&lock->create_line, sizeof(int), 1,
thr->order_info) != 1)
log_err("fwrite: %s", strerror(errno));
}
/** alloc struct, init lock empty */
void
checklock_init(enum check_lock_type type, struct checked_lock** lock,
const char* func, const char* file, int line)
{
struct checked_lock* e = (struct checked_lock*)calloc(1,
sizeof(struct checked_lock));
struct thr_check *thr = (struct thr_check*)pthread_getspecific(
thr_debug_key);
if(!e)
fatal_exit("%s %s %d: out of memory", func, file, line);
if(!thr) {
/* this is called when log_init() calls lock_init()
* functions, and the test check code has not yet
* been initialised. But luckily, the checklock_start()
* routine can be called multiple times without ill effect.
*/
checklock_start();
thr = (struct thr_check*)pthread_getspecific(thr_debug_key);
}
if(!thr)
fatal_exit("%s %s %d: lock_init no thread info", func, file,
line);
*lock = e;
e->type = type;
e->create_func = func;
e->create_file = file;
e->create_line = line;
e->create_thread = thr->num;
e->create_instance = thr->locks_created++;
ordercheck_lockcreate(thr, e);
LOCKRET(pthread_mutex_init(&e->lock, NULL));
switch(e->type) {
case check_lock_mutex:
LOCKRET(pthread_mutex_init(&e->u.mutex, NULL));
break;
case check_lock_spinlock:
LOCKRET(pthread_spin_init(&e->u.spinlock, PTHREAD_PROCESS_PRIVATE));
break;
case check_lock_rwlock:
LOCKRET(pthread_rwlock_init(&e->u.rwlock, NULL));
break;
default:
log_assert(0);
}
}
/** delete prot items */
static void
prot_clear(struct checked_lock* lock)
{
struct protected_area* p=lock->prot, *np;
while(p) {
np = p->next;
free(p->hold);
free(p);
p = np;
}
}
/** check if type is OK for the lock given */
static void
checktype(enum check_lock_type type, struct checked_lock* lock,
const char* func, const char* file, int line)
{
if(!lock)
fatal_exit("use of null/deleted lock at %s %s:%d",
func, file, line);
if(type != lock->type) {
lock_error(lock, func, file, line, "wrong lock type");
}
}
/** check if OK, free struct */
void
checklock_destroy(enum check_lock_type type, struct checked_lock** lock,
const char* func, const char* file, int line)
{
const size_t contention_interest = 1; /* promille contented locks */
struct checked_lock* e;
if(!lock)
return;
e = *lock;
if(!e)
return;
checktype(type, e, func, file, line);
/* check if delete is OK */
acquire_locklock(e, func, file, line);
if(e->hold_count != 0)
lock_error(e, func, file, line, "delete while locked.");
if(e->wait_count != 0)
lock_error(e, func, file, line, "delete while waited on.");
prot_check(e, func, file, line);
*lock = NULL; /* use after free will fail */
LOCKRET(pthread_mutex_unlock(&e->lock));
/* contention, look at fraction in trouble. */
if(e->history_count > 1 &&
1000*e->contention_count/e->history_count > contention_interest) {
log_info("lock created %s %s %d has contention %u of %u (%d%%)",
e->create_func, e->create_file, e->create_line,
(unsigned int)e->contention_count,
(unsigned int)e->history_count,
(int)(100*e->contention_count/e->history_count));
}
/* delete it */
LOCKRET(pthread_mutex_destroy(&e->lock));
prot_clear(e);
/* since nobody holds the lock - see check above, no need to unlink
* from the thread-held locks list. */
switch(e->type) {
case check_lock_mutex:
LOCKRET(pthread_mutex_destroy(&e->u.mutex));
break;
case check_lock_spinlock:
LOCKRET(pthread_spin_destroy(&e->u.spinlock));
break;
case check_lock_rwlock:
LOCKRET(pthread_rwlock_destroy(&e->u.rwlock));
break;
default:
log_assert(0);
}
memset(e, 0, sizeof(struct checked_lock));
free(e);
}
/** finish acquiring lock, shared between _(rd|wr||)lock() routines */
static void
finish_acquire_lock(struct thr_check* thr, struct checked_lock* lock,
const char* func, const char* file, int line)
{
thr->waiting = NULL;
lock->wait_count --;
lock->holder = thr;
lock->hold_count ++;
lock->holder_func = func;
lock->holder_file = file;
lock->holder_line = line;
ordercheck_locklock(thr, lock);
/* insert in thread lock list, as first */
lock->prev_held_lock[thr->num] = NULL;
lock->next_held_lock[thr->num] = thr->holding_first;
if(thr->holding_first)
/* no need to lock it, since this thread already holds the
* lock (since it is on this list) and we only edit thr->num
* member in array. So it is safe. */
thr->holding_first->prev_held_lock[thr->num] = lock;
else thr->holding_last = lock;
thr->holding_first = lock;
}
/**
* Locking routine.
* @param type: as passed by user.
* @param lock: as passed by user.
* @param func: caller location.
* @param file: caller location.
* @param line: caller location.
* @param tryfunc: the pthread_mutex_trylock or similar function.
* @param timedfunc: the pthread_mutex_timedlock or similar function.
* Uses absolute timeout value.
* @param arg: what to pass to tryfunc and timedlock.
* @param exclusive: if lock must be exclusive (only one allowed).
* @param getwr: if attempts to get writelock (or readlock) for rwlocks.
*/
static void
checklock_lockit(enum check_lock_type type, struct checked_lock* lock,
const char* func, const char* file, int line,
int (*tryfunc)(void*), int (*timedfunc)(void*, struct timespec*),
void* arg, int exclusive, int getwr)
{
int err;
int contend = 0;
struct thr_check *thr = (struct thr_check*)pthread_getspecific(
thr_debug_key);
checktype(type, lock, func, file, line);
if(!thr) lock_error(lock, func, file, line, "no thread info");
acquire_locklock(lock, func, file, line);
lock->wait_count ++;
thr->waiting = lock;
if(exclusive && lock->hold_count > 0 && lock->holder == thr)
lock_error(lock, func, file, line, "thread already owns lock");
if(type==check_lock_rwlock && getwr && lock->writeholder == thr)
lock_error(lock, func, file, line, "thread already has wrlock");
LOCKRET(pthread_mutex_unlock(&lock->lock));
/* first try; if busy increase contention counter */
if((err=tryfunc(arg))) {
struct timespec to;
if(err != EBUSY) log_err("trylock: %s", strerror(err));
to.tv_sec = time(NULL) + CHECK_LOCK_TIMEOUT;
to.tv_nsec = 0;
if((err=timedfunc(arg, &to))) {
if(err == ETIMEDOUT)
lock_error(lock, func, file, line,
"timeout possible deadlock");
log_err("timedlock: %s", strerror(err));
}
contend ++;
}
/* got the lock */
acquire_locklock(lock, func, file, line);
lock->contention_count += contend;
lock->history_count++;
if(exclusive && lock->hold_count > 0)
lock_error(lock, func, file, line, "got nonexclusive lock");
if(type==check_lock_rwlock && getwr && lock->writeholder)
lock_error(lock, func, file, line, "got nonexclusive wrlock");
if(type==check_lock_rwlock && getwr)
lock->writeholder = thr;
/* check the memory areas for unauthorized changes,
* between last unlock time and current lock time.
* we check while holding the lock (threadsafe).
*/
if(getwr || exclusive)
prot_check(lock, func, file, line);
finish_acquire_lock(thr, lock, func, file, line);
LOCKRET(pthread_mutex_unlock(&lock->lock));
}
/** helper for rdlock: try */
static int try_rd(void* arg)
{ return pthread_rwlock_tryrdlock((pthread_rwlock_t*)arg); }
/** helper for rdlock: timed */
static int timed_rd(void* arg, struct timespec* to)
{ return pthread_rwlock_timedrdlock((pthread_rwlock_t*)arg, to); }
/** check if OK, lock */
void
checklock_rdlock(enum check_lock_type type, struct checked_lock* lock,
const char* func, const char* file, int line)
{
if(key_deleted)
return;
log_assert(type == check_lock_rwlock);
checklock_lockit(type, lock, func, file, line,
try_rd, timed_rd, &lock->u.rwlock, 0, 0);
}
/** helper for wrlock: try */
static int try_wr(void* arg)
{ return pthread_rwlock_trywrlock((pthread_rwlock_t*)arg); }
/** helper for wrlock: timed */
static int timed_wr(void* arg, struct timespec* to)
{ return pthread_rwlock_timedwrlock((pthread_rwlock_t*)arg, to); }
/** check if OK, lock */
void
checklock_wrlock(enum check_lock_type type, struct checked_lock* lock,
const char* func, const char* file, int line)
{
if(key_deleted)
return;
log_assert(type == check_lock_rwlock);
checklock_lockit(type, lock, func, file, line,
try_wr, timed_wr, &lock->u.rwlock, 0, 1);
}
/** helper for lock mutex: try */
static int try_mutex(void* arg)
{ return pthread_mutex_trylock((pthread_mutex_t*)arg); }
/** helper for lock mutex: timed */
static int timed_mutex(void* arg, struct timespec* to)
{ return pthread_mutex_timedlock((pthread_mutex_t*)arg, to); }
/** helper for lock spinlock: try */
static int try_spinlock(void* arg)
{ return pthread_spin_trylock((pthread_spinlock_t*)arg); }
/** helper for lock spinlock: timed */
static int timed_spinlock(void* arg, struct timespec* to)
{
int err;
/* spin for 5 seconds. (ouch for the CPU, but it beats forever) */
while( (err=try_spinlock(arg)) == EBUSY) {
#ifndef S_SPLINT_S
if(time(NULL) >= to->tv_sec)
return ETIMEDOUT;
usleep(1000); /* in 1/1000000s of a second */
#endif
}
return err;
}
/** check if OK, lock */
void
checklock_lock(enum check_lock_type type, struct checked_lock* lock,
const char* func, const char* file, int line)
{
if(key_deleted)
return;
log_assert(type != check_lock_rwlock);
switch(type) {
case check_lock_mutex:
checklock_lockit(type, lock, func, file, line,
try_mutex, timed_mutex, &lock->u.mutex, 1, 0);
break;
case check_lock_spinlock:
/* void* cast needed because 'volatile' on some OS */
checklock_lockit(type, lock, func, file, line,
try_spinlock, timed_spinlock,
(void*)&lock->u.spinlock, 1, 0);
break;
default:
log_assert(0);
}
}
/** check if OK, unlock */
void
checklock_unlock(enum check_lock_type type, struct checked_lock* lock,
const char* func, const char* file, int line)
{
struct thr_check *thr;
if(key_deleted)
return;
thr = (struct thr_check*)pthread_getspecific(thr_debug_key);
checktype(type, lock, func, file, line);
if(!thr) lock_error(lock, func, file, line, "no thread info");
acquire_locklock(lock, func, file, line);
/* was this thread even holding this lock? */
if(thr->holding_first != lock &&
lock->prev_held_lock[thr->num] == NULL) {
lock_error(lock, func, file, line, "unlock nonlocked lock");
}
if(lock->hold_count <= 0)
lock_error(lock, func, file, line, "too many unlocks");
/* store this point as last touched by */
lock->holder = thr;
lock->hold_count --;
lock->holder_func = func;
lock->holder_file = file;
lock->holder_line = line;
/* delete from thread holder list */
/* no need to lock other lockstructs, because they are all on the
* held-locks list, and this thread holds their locks.
* we only touch the thr->num members, so it is safe. */
if(thr->holding_first == lock)
thr->holding_first = lock->next_held_lock[thr->num];
if(thr->holding_last == lock)
thr->holding_last = lock->prev_held_lock[thr->num];
if(lock->next_held_lock[thr->num])
lock->next_held_lock[thr->num]->prev_held_lock[thr->num] =
lock->prev_held_lock[thr->num];
if(lock->prev_held_lock[thr->num])
lock->prev_held_lock[thr->num]->next_held_lock[thr->num] =
lock->next_held_lock[thr->num];
lock->next_held_lock[thr->num] = NULL;
lock->prev_held_lock[thr->num] = NULL;
if(type==check_lock_rwlock && lock->writeholder == thr) {
lock->writeholder = NULL;
prot_store(lock);
} else if(type != check_lock_rwlock) {
/* store memory areas that are protected, for later checks */
prot_store(lock);
}
LOCKRET(pthread_mutex_unlock(&lock->lock));
/* unlock it */
switch(type) {
case check_lock_mutex:
LOCKRET(pthread_mutex_unlock(&lock->u.mutex));
break;
case check_lock_spinlock:
LOCKRET(pthread_spin_unlock(&lock->u.spinlock));
break;
case check_lock_rwlock:
LOCKRET(pthread_rwlock_unlock(&lock->u.rwlock));
break;
default:
log_assert(0);
}
}
/** open order info debug file, thr->num must be valid */
static void
open_lockorder(struct thr_check* thr)
{
char buf[24];
time_t t;
snprintf(buf, sizeof(buf), "ublocktrace.%d", thr->num);
thr->order_info = fopen(buf, "w");
if(!thr->order_info)
fatal_exit("could not open %s: %s", buf, strerror(errno));
thr->locks_created = 0;
t = time(NULL);
/* write: <time_stamp> <runpid> <thread_num> */
if(fwrite(&t, sizeof(t), 1, thr->order_info) != 1 ||
fwrite(&thr->num, sizeof(thr->num), 1, thr->order_info) != 1 ||
fwrite(&check_lock_pid, sizeof(check_lock_pid), 1,
thr->order_info) != 1)
log_err("fwrite: %s", strerror(errno));
}
/** checklock thread main, Inits thread structure */
static void* checklock_main(void* arg)
{
struct thr_check* thr = (struct thr_check*)arg;
void* ret;
thr->id = pthread_self();
/* Hack to get same numbers as in log file */
thr->num = *(int*)(thr->arg);
log_assert(thr->num < THRDEBUG_MAX_THREADS);
/* as an aside, due to this, won't work for libunbound bg thread */
if(thread_infos[thr->num] != NULL)
log_warn("thread warning, thr->num %d not NULL", thr->num);
thread_infos[thr->num] = thr;
LOCKRET(pthread_setspecific(thr_debug_key, thr));
if(check_locking_order)
open_lockorder(thr);
ret = thr->func(thr->arg);
thread_infos[thr->num] = NULL;
if(check_locking_order)
fclose(thr->order_info);
free(thr);
return ret;
}
/** init the main thread */
void checklock_start(void)
{
if(key_deleted)
return;
if(!key_created) {
struct thr_check* thisthr = (struct thr_check*)calloc(1,
sizeof(struct thr_check));
if(!thisthr)
fatal_exit("thrcreate: out of memory");
key_created = 1;
check_lock_pid = getpid();
LOCKRET(pthread_key_create(&thr_debug_key, NULL));
LOCKRET(pthread_setspecific(thr_debug_key, thisthr));
thread_infos[0] = thisthr;
if(check_locking_order)
open_lockorder(thisthr);
}
}
/** stop checklocks */
void checklock_stop(void)
{
if(key_created) {
int i;
key_deleted = 1;
if(check_locking_order)
fclose(thread_infos[0]->order_info);
free(thread_infos[0]);
thread_infos[0] = NULL;
for(i = 0; i < THRDEBUG_MAX_THREADS; i++)
log_assert(thread_infos[i] == NULL);
/* should have been cleaned up. */
LOCKRET(pthread_key_delete(thr_debug_key));
key_created = 0;
}
}
/** allocate debug info and create thread */
void
checklock_thrcreate(pthread_t* id, void* (*func)(void*), void* arg)
{
struct thr_check* thr = (struct thr_check*)calloc(1,
sizeof(struct thr_check));
if(!thr)
fatal_exit("thrcreate: out of memory");
if(!key_created) {
checklock_start();
}
thr->func = func;
thr->arg = arg;
LOCKRET(pthread_create(id, NULL, checklock_main, thr));
}
/** count number of thread infos */
static int
count_thread_infos(void)
{
int cnt = 0;
int i;
for(i=0; i<THRDEBUG_MAX_THREADS; i++)
if(thread_infos[i])
cnt++;
return cnt;
}
/** print lots of info on a lock */
static void
lock_debug_info(struct checked_lock* lock)
{
if(!lock) return;
log_info("+++ Lock %llx, %d %d create %s %s %d",
(unsigned long long)(size_t)lock,
lock->create_thread, lock->create_instance,
lock->create_func, lock->create_file, lock->create_line);
log_info("lock type: %s",
(lock->type==check_lock_mutex)?"mutex": (
(lock->type==check_lock_spinlock)?"spinlock": (
(lock->type==check_lock_rwlock)?"rwlock": "badtype")));
log_info("lock contention %u, history:%u, hold:%d, wait:%d",
(unsigned)lock->contention_count, (unsigned)lock->history_count,
lock->hold_count, lock->wait_count);
log_info("last touch %s %s %d", lock->holder_func, lock->holder_file,
lock->holder_line);
log_info("holder thread %d, writeholder thread %d",
lock->holder?lock->holder->num:-1,
lock->writeholder?lock->writeholder->num:-1);
}
/** print debug locks held by a thread */
static void
held_debug_info(struct thr_check* thr, struct checked_lock* lock)
{
if(!lock) return;
lock_debug_info(lock);
held_debug_info(thr, lock->next_held_lock[thr->num]);
}
/** print debug info for a thread */
static void
thread_debug_info(struct thr_check* thr)
{
struct checked_lock* w = NULL;
struct checked_lock* f = NULL;
struct checked_lock* l = NULL;
if(!thr) return;
log_info("pthread id is %x", (int)thr->id);
log_info("thread func is %llx", (unsigned long long)(size_t)thr->func);
log_info("thread arg is %llx (%d)",
(unsigned long long)(size_t)thr->arg,
(thr->arg?*(int*)thr->arg:0));
log_info("thread num is %d", thr->num);
log_info("locks created %d", thr->locks_created);
log_info("open file for lockinfo: %s",
thr->order_info?"yes, flushing":"no");
fflush(thr->order_info);
w = thr->waiting;
f = thr->holding_first;
l = thr->holding_last;
log_info("thread waiting for a lock: %s %llx", w?"yes":"no",
(unsigned long long)(size_t)w);
lock_debug_info(w);
log_info("thread holding first: %s, last: %s", f?"yes":"no",
l?"yes":"no");
held_debug_info(thr, f);
}
static void
total_debug_info(void)
{
int i;
log_info("checklocks: supervising %d threads.",
count_thread_infos());
if(!key_created) {
log_info("No thread debug key created yet");
}
for(i=0; i<THRDEBUG_MAX_THREADS; i++) {
if(thread_infos[i]) {
log_info("*** Thread %d information: ***", i);
thread_debug_info(thread_infos[i]);
}
}
}
/** signal handler for join timeout, Exits */
static RETSIGTYPE joinalarm(int ATTR_UNUSED(sig))
{
log_err("join thread timeout. hangup or deadlock. Info follows.");
total_debug_info();
fatal_exit("join thread timeout. hangup or deadlock.");
}
/** wait for thread with a timeout */
void
checklock_thrjoin(pthread_t thread)
{
/* wait with a timeout */
if(signal(SIGALRM, joinalarm) == SIG_ERR)
fatal_exit("signal(): %s", strerror(errno));
(void)alarm(CHECK_JOIN_TIMEOUT);
LOCKRET(pthread_join(thread, NULL));
(void)alarm(0);
}
#endif /* USE_THREAD_DEBUG */
