monero/external/unbound/testcode/checklocks.c
Erik de Castro Lopo a85b5759f3 Upgrade unbound library
These files were pulled from the 1.6.3 release tarball.

This new version builds against OpenSSL version 1.1 which will be
the default in the new Debian Stable which is due to be released
RealSoonNow (tm).
2017-06-17 23:04:00 +10:00

859 lines
26 KiB
C

/**
* 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 */