diff options
Diffstat (limited to 'external/unbound/testcode/checklocks.c')
| -rw-r--r-- | external/unbound/testcode/checklocks.c | 848 |
1 files changed, 848 insertions, 0 deletions
diff --git a/external/unbound/testcode/checklocks.c b/external/unbound/testcode/checklocks.c new file mode 100644 index 000000000..5815e4fd0 --- /dev/null +++ b/external/unbound/testcode/checklocks.c @@ -0,0 +1,848 @@ +/** + * 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_t 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 exlusive (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) +{ + + 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) +{ + 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) +{ + 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 = (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 %x, %d %d create %s %s %d", (int)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 %x", (int)thr->func); + log_info("thread arg is %x (%d)", (int)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 %x", w?"yes":"no", (int)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 */ |