/*
* locks.c
*
* Created on: 16.07.2013
* Author: sr
*/
#include "locks.h"
#include "helper.h"
#include "../shared/timing.h"
#ifdef _DEBUG
#define MAXLOCKS (SERVER_MAX_CLIENTS * 2 + SERVER_MAX_ALTS + 200 + SERVER_MAX_IMAGES)
#define MAXTHREADS (SERVER_MAX_CLIENTS + 100)
#define MAXLPT 20
#define LOCKLEN 60
typedef struct
{
void * _Atomic lock;
ticks locktime;
bool _Atomic locked;
pthread_t _Atomic thread;
int lockId;
int prio;
char name[LOCKLEN];
char where[LOCKLEN];
} debug_lock_t;
typedef struct
{
pthread_t _Atomic tid;
ticks time;
char name[LOCKLEN];
char where[LOCKLEN];
debug_lock_t *locks[MAXLPT];
} debug_thread_t;
int debugThreadCount = 0;
static debug_lock_t locks[MAXLOCKS];
static debug_thread_t threads[MAXTHREADS];
static pthread_mutex_t initdestory = PTHREAD_MUTEX_INITIALIZER;
static int lockId = 0;
#define ULDE(...) do { \
pthread_mutex_unlock( &initdestory ); \
logadd( LOG_ERROR, __VA_ARGS__ ); \
debug_dump_lock_stats(); \
exit( 4 ); \
} while(0)
int debug_mutex_init(const char *name, const char *file, int line, pthread_mutex_t *lock, int priority)
{
int first = -1;
pthread_mutex_lock( &initdestory );
for (int i = 0; i < MAXLOCKS; ++i) {
if ( locks[i].lock == lock ) {
logadd( LOG_ERROR, "Lock %p (%s) already initialized (%s:%d)\n", (void*)lock, name, file, line );
exit( 4 );
}
if ( first == -1 && locks[i].lock == NULL ) first = i;
}
if ( first == -1 ) {
ULDE( "No more free debug locks (%s:%d)\n", file, line );
}
locks[first].lock = (void*)lock;
locks[first].locked = false;
locks[first].prio = priority;
snprintf( locks[first].name, LOCKLEN, "%s", name );
snprintf( locks[first].where, LOCKLEN, "I %s:%d", file, line );
pthread_mutex_unlock( &initdestory );
return pthread_mutex_init( lock, NULL );
}
int debug_mutex_lock(const char *name, const char *file, int line, pthread_mutex_t *lock, bool try)
{
debug_lock_t *l = NULL;
pthread_mutex_lock( &initdestory );
for (int i = 0; i < MAXLOCKS; ++i) {
if ( locks[i].lock == lock ) {
l = &locks[i];
break;
}
}
if ( l == NULL ) {
ULDE( "Tried to lock uninitialized lock %p (%s) at %s:%d\n", (void*)lock, name, file, line );
}
debug_thread_t *t = NULL;
int first = -1;
const pthread_t self = pthread_self();
for (int i = 0; i < MAXTHREADS; ++i) {
if ( threads[i].tid == self ) {
t = &threads[i];
break;
}
if ( first == -1 && threads[i].tid == 0 ) {
first = i;
}
}
int idx;
if ( t == NULL ) {
if ( first == -1 ) {
ULDE( "Lock sanity check: Too many waiting threads for lock %p (%s) at %s:%d\n", (void*)lock, name, file, line );
}
t = &threads[first];
timing_get( &t->time );
t->tid = self;
snprintf( t->name, LOCKLEN, "%s", name );
snprintf( t->where, LOCKLEN, "%s:%d", file, line );
memset( t->locks, 0, sizeof(t->locks) );
idx = 0;
} else {
// Thread already has locks, check for order violation
idx = -1;
for (int i = 0; i < MAXLPT; ++i) {
if ( t->locks[i] == NULL ) {
if ( idx == -1 ) {
idx = i;
}
continue;
}
if ( t->locks[i]->prio >= l->prio ) {
ULDE( "Lock priority violation: %s at %s:%d (%d) when already holding %s at %s (%d)",
name, file, line, l->prio,
t->locks[i]->name, t->locks[i]->where, t->locks[i]->prio );
}
if ( t->locks[i] == l ) {
ULDE( "Tried to recusively lock %s in the same thread. Tried at %s:%d, when already locked at %s",
name, file, line, t->locks[i]->name );
}
}
if ( idx == -1 ) {
ULDE( "Thread %d tried to lock more than %d locks.", (int)self, (int)MAXLPT );
}
}
pthread_mutex_unlock( &initdestory );
const int retval = try ? pthread_mutex_trylock( lock ) : pthread_mutex_lock( lock );
if ( retval == 0 ) {
timing_get( &l->locktime );
l->thread = self;
snprintf( l->where, LOCKLEN, "L %s:%d", file, line );
pthread_mutex_lock( &initdestory );
if ( l->locked ) {
logadd( LOG_ERROR, "Lock sanity check: lock %p (%s) already locked at %s:%d\n", (void*)lock, name, file, line );
exit( 4 );
}
l->locked = true;
t->locks[idx] = l;
l->lockId = ++lockId;
pthread_mutex_unlock( &initdestory );
} else if ( !try || retval != EBUSY ) {
logadd( LOG_ERROR, "Acquiring lock %s at %s:%d failed with error code %d", name, file, line, retval );
debug_dump_lock_stats();
exit( 4 );
}
return retval;
}
int debug_mutex_unlock(const char *name, const char *file, int line, pthread_mutex_t *lock)
{
debug_thread_t *t = NULL;
pthread_t self = pthread_self();
pthread_mutex_lock( &initdestory );
for (int i = 0; i < MAXTHREADS; ++i) {
if ( threads[i].tid == self ) {
t = &threads[i];
break;
}
}
if ( t == NULL ) {
ULDE( "Unlock called from unknown thread for %s at %s:%d", name, file, line );
}
int idx = -1;
int cnt = 0;
for (int i = 0; i < MAXLPT; ++i) {
if ( t->locks[i] == NULL )
continue;
cnt++;
if ( t->locks[i]->lock == lock ) {
idx = i;
}
}
if ( idx == -1 ) {
ULDE( "Unlock: Calling thread doesn't hold lock %s at %s:%d", name, file, line );
}
debug_lock_t *l = t->locks[idx];
if ( l->thread != self || !l->locked ) {
ULDE( "Unlock sanity check for lock debugger failed! Lock %s is assigned to calling thread, but lock's meta data doesn't match up at %s:%d", name, file, line );
}
l->locked = false;
l->thread = 0;
t->locks[idx] = NULL;
if ( cnt == 1 ) {
t->tid = 0; // No more locks held, free up slot
}
snprintf( l->where, LOCKLEN, "U %s:%d", file, line );
pthread_mutex_unlock( &initdestory );
const int retval = pthread_mutex_unlock( lock );
if ( retval != 0 ) {
logadd( LOG_ERROR, "pthread_mutex_unlock returned %d for %s at %s:%d", retval, name, file, line );
exit( 4 );
}
return retval;
}
int debug_mutex_cond_wait(const char *name, const char *file, int line, pthread_cond_t *restrict cond, pthread_mutex_t *restrict lock)
{
debug_lock_t *l = NULL;
debug_thread_t *t = NULL;
pthread_t self = pthread_self();
pthread_mutex_lock( &initdestory );
for (int i = 0; i < MAXTHREADS; ++i) {
if ( threads[i].tid == self ) {
t = &threads[i];
break;
}
}
if ( t == NULL ) {
ULDE( "Unlock called from unknown thread for %s at %s:%d", name, file, line );
}
int mp = 0, mpi = -1;
for (int i = 0; i < MAXLPT; ++i) {
if ( t->locks[i] == NULL )
continue;
if ( t->locks[i]->lock == lock ) {
l = t->locks[i];
} else if ( t->locks[i]->prio > mp ) {
mp = t->locks[i]->prio;
mpi = i;
}
}
if ( l == NULL ) {
ULDE( "cond_wait: Calling thread doesn't hold lock %s at %s:%d", name, file, line );
}
if ( l->thread != self || !l->locked ) {
ULDE( "cond_wait: Sanity check for lock debugger failed! Lock %s is assigned to calling thread, but lock's meta data doesn't match up at %s:%d", name, file, line );
}
if ( mp >= l->prio ) {
ULDE( "cond_wait: Yielding a mutex while holding another one with higher prio: %s at %s:%d (%d) while also holding %s at %s (%d)",
name, file, line, l->prio,
t->locks[mpi]->name, t->locks[mpi]->where, mp );
}
l->locked = false;
l->thread = 0;
snprintf( l->where, LOCKLEN, "CWU %s:%d", file, line );
pthread_mutex_unlock( &initdestory );
int retval = pthread_cond_wait( cond, lock );
if ( retval != 0 ) {
logadd( LOG_ERROR, "pthread_cond_wait returned %d for lock %p (%s) at %s:%d\n", retval, (void*)lock, name, file, line );
exit( 4 );
}
if ( l->locked || l->thread != 0 ) {
logadd( LOG_ERROR, "Lock is not free after returning from pthread_cond_wait for %p (%s) at %s:%d\n", (void*)lock, name, file, line );
exit( 4 );
}
l->thread = self;
timing_get( &l->locktime );
l->locked = true;
pthread_mutex_lock( &initdestory );
l->lockId = ++lockId;
pthread_mutex_unlock( &initdestory );
return retval;
}
int debug_mutex_destroy(const char *name, const char *file, int line, pthread_mutex_t *lock)
{
pthread_mutex_lock( &initdestory );
for (int i = 0; i < MAXLOCKS; ++i) {
if ( locks[i].lock == lock ) {
if ( locks[i].locked ) {
logadd( LOG_ERROR, "Tried to destroy lock %p (%s) at %s:%d when it is still locked\n", (void*)lock, name, file, line );
logadd( LOG_ERROR, "Currently locked by: %s", locks[i].where );
exit( 4 );
}
locks[i].lock = NULL;
snprintf( locks[i].where, LOCKLEN, "D %s:%d", file, line );
pthread_mutex_unlock( &initdestory );
return pthread_mutex_destroy( lock );
}
}
logadd( LOG_ERROR, "Tried to destroy non-existent lock %p (%s) at %s:%d\n", (void*)lock, name, file, line );
exit( 4 );
}
void debug_dump_lock_stats()
{
declare_now;
pthread_mutex_lock( &initdestory );
printf( "\n **** LOCKS ****\n\n" );
for (int i = 0; i < MAXLOCKS; ++i) {
if ( locks[i].lock == NULL ) continue;
if ( locks[i].locked ) {
printf( "* *** %s ***\n"
"* Where: %s\n"
"* When: %d secs ago\n"
"* Locked: %d\n"
"* Serial: %d\n"
"* Thread: %d\n", locks[i].name, locks[i].where, (int)timing_diff( &locks[i].locktime, &now ), (int)locks[i].locked, locks[i].lockId,
(int)locks[i].thread );
} else {
printf( "* *** %s ***\n"
"* Where: %s\n"
"* Locked: %d\n", locks[i].name, locks[i].where, (int)locks[i].locked );
}
}
printf( "\n **** ACTIVE THREADS ****\n\n" );
for (int i = 0; i < MAXTHREADS; ++i) {
if ( threads[i].tid == 0 )
continue;
printf( "* *** Thread %d ***\n"
"* Lock: %s\n"
"* Where: %s\n"
"* How long: %d secs\n", (int)threads[i].tid, threads[i].name, threads[i].where, (int)timing_diff( &threads[i].time, &now ) );
for (int j = 0; j < MAXLPT; ++j) {
if ( threads[i].locks[j] == NULL )
continue;
printf( " * Lock %s @ %s\n", threads[i].locks[j]->name, threads[i].locks[j]->where );
}
}
pthread_mutex_unlock( &initdestory );
}
#endif
