/* threads.c
** - Thread Abstraction Functions
**
** Copyright (c) 1999, 2000 the icecast team
**
** 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 latfer 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.
*/

#ifdef HAVE_CONFIG_H
 #include <config.h>
#endif

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <time.h>
#include <sys/types.h>

#include <pthread.h>

#ifndef _WIN32
#include <unistd.h>
#include <sys/time.h>
#else
#include <windows.h>
#include <winbase.h>
#include <implement.h>
#endif

#include <signal.h>

#include <thread/thread.h>
#include <avl/avl.h>
#ifdef THREAD_DEBUG
#include <log/log.h>
#endif

#ifdef _WIN32
#define __FUNCTION__ __FILE__
#endif

#ifdef THREAD_DEBUG
#define CATMODULE "thread"
#define LOG_ERROR(y) log_write(_logid, 1, CATMODULE "/", __FUNCTION__, y)
#define LOG_ERROR3(y, z1, z2, z3) log_write(_logid, 1, CATMODULE "/", __FUNCTION__, y, z1, z2, z3)
#define LOG_ERROR7(y, z1, z2, z3, z4, z5, z6, z7) log_write(_logid, 1, CATMODULE "/", __FUNCTION__, y, z1, z2, z3, z4, z5, z6, z7)

#define LOG_WARN(y) log_write(_logid, 2, CATMODULE "/", __FUNCTION__, y)
#define LOG_WARN3(y, z1, z2, z3) log_write(_logid, 2, CATMODULE "/", __FUNCTION__, y, z1, z2, z3)
#define LOG_WARN5(y, z1, z2, z3, z4, z5) log_write(_logid, 2, CATMODULE "/", __FUNCTION__, y, z1, z2, z3, z4, z5)
#define LOG_WARN7(y, z1, z2, z3, z4, z5, z6, z7) log_write(_logid, 2, CATMODULE "/", __FUNCTION__, y, z1, z2, z3, z4, z5, z6, z7)

#define LOG_INFO(y) log_write(_logid, 3, CATMODULE "/", __FUNCTION__, y)
#define LOG_INFO4(y, z1, z2, z3, z4) log_write(_logid, 3, CATMODULE "/", __FUNCTION__, y, z1, z2, z3, z4)
#define LOG_INFO5(y, z1, z2, z3, z4, z5) log_write(_logid, 3, CATMODULE "/", __FUNCTION__, y, z1, z2, z3, z4, z5)

#define LOG_DEBUG(y) log_write(_logid, 4, CATMODULE "/", __FUNCTION__, y)
#define LOG_DEBUG2(y, z1, z2) log_write(_logid, 4, CATMODULE "/", __FUNCTION__, y, z1, z2)
#define LOG_DEBUG5(y, z1, z2, z3, z4, z5) log_write(_logid, 4, CATMODULE "/", __FUNCTION__, y, z1, z2, z3, z4, z5)
#endif

/* thread starting structure */
typedef struct thread_start_tag {
    /* the real start routine and arg */
    void *(*start_routine)(void *);
    void *arg;

    /* whether to create the threaded in detached state */
    int detached;

    /* the other stuff we need to make sure this thread is inserted into
    ** the thread tree
    */
    thread_type *thread;
    pthread_t sys_thread;
} thread_start_t;

static long _next_thread_id = 0;
static int _initialized = 0;
static avl_tree *_threadtree = NULL;

#ifdef DEBUG_MUTEXES
static mutex_t _threadtree_mutex = { -1, NULL, MUTEX_STATE_UNINIT, NULL, -1, 
    PTHREAD_MUTEX_INITIALIZER};
#else
static mutex_t _threadtree_mutex = { PTHREAD_MUTEX_INITIALIZER };
#endif



#ifdef DEBUG_MUTEXES
static int _logid = -1;
static long _next_mutex_id = 0;

static avl_tree *_mutextree = NULL;
static mutex_t _mutextree_mutex = { -1, NULL, MUTEX_STATE_UNINIT, NULL, -1,
    PTHREAD_MUTEX_INITIALIZER};
#endif

#ifdef DEBUG_MUTEXES
static mutex_t _library_mutex = { -1, NULL, MUTEX_STATE_UNINIT, NULL, -1,
    PTHREAD_MUTEX_INITIALIZER};
#else
static mutex_t _library_mutex = { PTHREAD_MUTEX_INITIALIZER };
#endif

/* INTERNAL FUNCTIONS */

/* avl tree functions */
#ifdef DEBUG_MUTEXES
static int _compare_mutexes(void *compare_arg, void *a, void *b);
static int _free_mutex(void *key);
#endif

static int _compare_threads(void *compare_arg, void *a, void *b);
static int _free_thread(void *key);
static int _free_thread_if_detached(void *key);

/* mutex fuctions */
static void _mutex_create(mutex_t *mutex);
static void _mutex_lock(mutex_t *mutex);
static void _mutex_unlock(mutex_t *mutex);

/* misc thread stuff */
static void *_start_routine(void *arg);
static void _catch_signals(void);
static void _block_signals(void);

/* LIBRARY INITIALIZATION */

void thread_initialize(void)
{
    thread_type *thread;

    /* set up logging */

#ifdef THREAD_DEBUG
    log_initialize();
    _logid = log_open("thread.log");
    log_set_level(_logid, THREAD_DEBUG);
#endif

#ifdef DEBUG_MUTEXES
    /* create all the internal mutexes, and initialize the mutex tree */

    _mutextree = avl_tree_new(_compare_mutexes, NULL);

    /* we have to create this one by hand, because there's no
    ** mutextree_mutex to lock yet! 
    */
    _mutex_create(&_mutextree_mutex);

    _mutextree_mutex.mutex_id = _next_mutex_id++;
    avl_insert(_mutextree, (void *)&_mutextree_mutex);
#endif

    thread_mutex_create(&_threadtree_mutex);
    thread_mutex_create(&_library_mutex);    

    /* initialize the thread tree and insert the main thread */

    _threadtree = avl_tree_new(_compare_threads, NULL);

    thread = (thread_type *)malloc(sizeof(thread_type));

    thread->thread_id = _next_thread_id++;
    thread->line = 0;
    thread->file = strdup("main.c");
    thread->sys_thread = pthread_self();
    thread->create_time = time(NULL);
    thread->name = strdup("Main Thread");

    avl_insert(_threadtree, (void *)thread);

    _catch_signals();

    _initialized = 1;
}

void thread_shutdown(void)
{
    if (_initialized == 1) {
        thread_mutex_destroy(&_library_mutex);
        thread_mutex_destroy(&_threadtree_mutex);
#ifdef THREAD_DEBUG
        thread_mutex_destroy(&_mutextree_mutex);
        
        avl_tree_free(_mutextree, _free_mutex);
#endif
        avl_tree_free(_threadtree, _free_thread);
    }

#ifdef THREAD_DEBUG
    log_close(_logid);
    log_shutdown();
#endif

}

/*
 * Signals should be handled by the main thread, nowhere else.
 * I'm using POSIX signal interface here, until someone tells me
 * that I should use signal/sigset instead
 *
 * This function only valid for non-Win32
 */
static void _block_signals(void)
{
#ifndef _WIN32
        sigset_t ss;

        sigfillset(&ss);

        /* These ones we want */
        sigdelset(&ss, SIGKILL);
        sigdelset(&ss, SIGSTOP);
        sigdelset(&ss, SIGTERM);
        sigdelset(&ss, SIGSEGV);
        sigdelset(&ss, SIGBUS);
        if (pthread_sigmask(SIG_BLOCK, &ss, NULL) != 0) {
#ifdef THREAD_DEBUG
                LOG_ERROR("Pthread_sigmask() failed for blocking signals");
#endif
        }
#endif
}

/*
 * Let the calling thread catch all the relevant signals
 *
 * This function only valid for non-Win32
 */
static void _catch_signals(void)
{
#ifndef _WIN32
        sigset_t ss;

        sigemptyset(&ss);

        /* These ones should only be accepted by the signal handling thread (main thread) */
        sigaddset(&ss, SIGHUP);
        sigaddset(&ss, SIGCHLD);
        sigaddset(&ss, SIGINT);
        sigaddset(&ss, SIGPIPE);

        if (pthread_sigmask(SIG_UNBLOCK, &ss, NULL) != 0) {
#ifdef THREAD_DEBUG
                LOG_ERROR("pthread_sigmask() failed for catching signals!");
#endif
        }
#endif
}


thread_type *thread_create_c(char *name, void *(*start_routine)(void *), 
        void *arg, int detached, int line, char *file)
{
    int created;
    thread_type *thread;
    thread_start_t *start;

    thread = (thread_type *)malloc(sizeof(thread_type));    
    start = (thread_start_t *)malloc(sizeof(thread_start_t));
    thread->line = line;
    thread->file = strdup(file);

    _mutex_lock(&_threadtree_mutex);    
    thread->thread_id = _next_thread_id++;
    _mutex_unlock(&_threadtree_mutex);

    thread->name = strdup(name);
    thread->create_time = time(NULL);
    thread->detached = 0;

    start->start_routine = start_routine;
    start->arg = arg;
    start->thread = thread;
    start->detached = detached;

    created = 0;
    if (pthread_create(&thread->sys_thread, NULL, _start_routine, start) == 0)
        created = 1;
#ifdef THREAD_DEBUG
    else
        LOG_ERROR("Could not create new thread");
#endif

    if (created == 0) {
#ifdef THREAD_DEBUG
        LOG_ERROR("System won't let me create more threads, giving up");
#endif
        return NULL;
    }

    return thread;
}

/* _mutex_create
** 
** creates a mutex
*/
static void _mutex_create(mutex_t *mutex)
{
#ifdef DEBUG_MUTEXES
    mutex->thread_id = MUTEX_STATE_NEVERLOCKED;
    mutex->line = -1;
#endif

    pthread_mutex_init(&mutex->sys_mutex, NULL);
}

void thread_mutex_create_c(mutex_t *mutex, int line, char *file)
{
    _mutex_create(mutex);

#ifdef DEBUG_MUTEXES
    _mutex_lock(&_mutextree_mutex);
    mutex->mutex_id = _next_mutex_id++;
    avl_insert(_mutextree, (void *)mutex);
    _mutex_unlock(&_mutextree_mutex);
#endif
}

void thread_mutex_destroy (mutex_t *mutex)
{
    pthread_mutex_destroy(&mutex->sys_mutex);

#ifdef DEBUG_MUTEXES
    _mutex_lock(&_mutextree_mutex);
    avl_delete(_mutextree, mutex, _free_mutex);
    _mutex_unlock(&_mutextree_mutex);
#endif
}

void thread_mutex_lock_c(mutex_t *mutex, int line, char *file)
{
#ifdef DEBUG_MUTEXES
    thread_type *th = thread_self();

    if (!th) LOG_WARN("No mt record for %u in lock [%s:%d]", thread_self(), file, line);

    LOG_DEBUG5("Locking %p (%s) on line %d in file %s by thread %d", mutex, mutex->name, line, file, th ? th->thread_id : -1);

# ifdef CHECK_MUTEXES
    /* Just a little sanity checking to make sure that we're locking
    ** mutexes correctly
    */

    if (th) {
        int locks = 0;
        avl_node *node;
        mutex_t *tmutex;

        _mutex_lock(&_mutextree_mutex);

        node = avl_get_first (_mutextree);
        
        while (node) {
            tmutex = (mutex_t *)node->key;

            if (tmutex->mutex_id == mutex->mutex_id) {
                if (tmutex->thread_id == th->thread_id) { 
                    /* Deadlock, same thread can't lock the same mutex twice */
                    LOG_ERROR7("DEADLOCK AVOIDED (%d == %d) on mutex [%s] in file %s line %d by thread %d [%s]", 
                         tmutex->thread_id, th->thread_id, mutex->name ? mutex->name : "undefined", file, line, th->thread_id, th->name);

                    _mutex_unlock(&_mutextree_mutex);
                    return;
                }
            } else if (tmutex->thread_id == th->thread_id) { 
                /* Mutex locked by this thread (not this mutex) */
                locks++;
            }

            node = avl_get_next(node);
        }

        if (locks > 0) { 
            /* Has already got a mutex locked */
            if (_multi_mutex.thread_id != th->thread_id) {
                /* Tries to lock two mutexes, but has not got the double mutex, norty boy! */
                LOG_WARN("(%d != %d) Thread %d [%s] tries to lock a second mutex [%s] in file %s line %d, without locking double mutex!",
                     _multi_mutex.thread_id, th->thread_id, th->thread_id, th->name, mutex->name ? mutex->name : "undefined", file, line);
            }
        }
        
        _mutex_unlock(&_mutextree_mutex);
    }
# endif /* CHECK_MUTEXES */
    
    _mutex_lock(mutex);
    
    _mutex_lock(&_mutextree_mutex);

    LOG_DEBUG2("Locked %p by thread %d", mutex, th ? th->thread_id : -1);
    mutex->line = line;
    if (th) {
        mutex->thread_id = th->thread_id;
    }

    _mutex_unlock(&_mutextree_mutex);
#else
    _mutex_lock(mutex);
#endif /* DEBUG_MUTEXES */
}

void thread_mutex_unlock_c(mutex_t *mutex, int line, char *file)
{
#ifdef DEBUG_MUTEXES
    thread_type *th = thread_self();

    if (!th) {
        LOG_ERROR3("No record for %u in unlock [%s:%d]", thread_self(), file, line);
    }

    LOG_DEBUG5("Unlocking %p (%s) on line %d in file %s by thread %d", mutex, mutex->name, line, file, th ? th->thread_id : -1);

    mutex->line = line;

# ifdef CHECK_MUTEXES
    if (th) {
        int locks = 0;
        avl_node *node;
        mutex_t *tmutex;

        _mutex_lock(&_mutextree_mutex);

        while (node) {
            tmutex = (mutex_t *)node->key;

            if (tmutex->mutex_id == mutex->mutex_id) {
                if (tmutex->thread_id != th->thread_id) {
                    LOG_ERROR7("ILLEGAL UNLOCK (%d != %d) on mutex [%s] in file %s line %d by thread %d [%s]", tmutex->thread_id, th->thread_id, 
                         mutex->name ? mutex->name : "undefined", file, line, th->thread_id, th->name);
                    _mutex_unlock(&_mutextree_mutex);
                    return;
                }
            } else if (tmutex->thread_id == th->thread_id) {
                locks++;
            }

            node = avl_get_next (node);
        }

        if ((locks > 0) && (_multi_mutex.thread_id != th->thread_id)) {
            /* Don't have double mutex, has more than this mutex left */
        
            LOG_WARN("(%d != %d) Thread %d [%s] tries to unlock a mutex [%s] in file %s line %d, without owning double mutex!",
                 _multi_mutex.thread_id, th->thread_id, th->thread_id, th->name, mutex->name ? mutex->name : "undefined", file, line);
        }

        _mutex_unlock(&_mutextree_mutex);
    }
# endif  /* CHECK_MUTEXES */

    _mutex_unlock(mutex);

    _mutex_lock(&_mutextree_mutex);

    LOG_DEBUG2("Unlocked %p by thread %d", mutex, th ? th->thread_id : -1);
    mutex->line = -1;
    if (mutex->thread_id == th->thread_id) {
        mutex->thread_id = MUTEX_STATE_NOTLOCKED;
    }

    _mutex_unlock(&_mutextree_mutex);
#else
    _mutex_unlock(mutex);
#endif /* DEBUG_MUTEXES */
}

void thread_cond_create_c(cond_t *cond, int line, char *file)
{
    pthread_cond_init(&cond->sys_cond, NULL);
    pthread_mutex_init(&cond->cond_mutex, NULL);
}

void thread_cond_destroy(cond_t *cond)
{
    pthread_mutex_destroy(&cond->cond_mutex);
    pthread_cond_destroy(&cond->sys_cond);
}

void thread_cond_signal_c(cond_t *cond, int line, char *file)
{
    pthread_cond_signal(&cond->sys_cond);
}

void thread_cond_broadcast_c(cond_t *cond, int line, char *file)
{
    pthread_cond_broadcast(&cond->sys_cond);
}

void thread_cond_timedwait_c(cond_t *cond, int millis, int line, char *file)
{
    struct timespec time;

    time.tv_sec = millis/1000;
    time.tv_nsec = (millis - time.tv_sec*1000)*1000000;

    pthread_mutex_lock(&cond->cond_mutex);
    pthread_cond_timedwait(&cond->sys_cond, &cond->cond_mutex, &time);
    pthread_mutex_unlock(&cond->cond_mutex);
}

void thread_cond_wait_c(cond_t *cond, int line, char *file)
{
    pthread_mutex_lock(&cond->cond_mutex);
    pthread_cond_wait(&cond->sys_cond, &cond->cond_mutex);
    pthread_mutex_unlock(&cond->cond_mutex);
}

void thread_rwlock_create_c(rwlock_t *rwlock, int line, char *file)
{
    pthread_rwlock_init(&rwlock->sys_rwlock, NULL);
}

void thread_rwlock_destroy(rwlock_t *rwlock)
{
    pthread_rwlock_destroy(&rwlock->sys_rwlock);
}

void thread_rwlock_rlock_c(rwlock_t *rwlock, int line, char *file)
{
    pthread_rwlock_rdlock(&rwlock->sys_rwlock);
}

void thread_rwlock_wlock_c(rwlock_t *rwlock, int line, char *file)
{
    pthread_rwlock_wrlock(&rwlock->sys_rwlock);
}

void thread_rwlock_unlock_c(rwlock_t *rwlock, int line, char *file)
{
    pthread_rwlock_unlock(&rwlock->sys_rwlock);
}

void thread_exit_c(int val, int line, char *file)
{
    thread_type *th = thread_self();

#if defined(DEBUG_MUTEXES) && defined(CHECK_MUTEXES)
    if (th) {
        avl_node *node;
        mutex_t *tmutex;
        char name[40];

        _mutex_lock(&_mutextree_mutex);

        while (node) {
            tmutex = (mutex_t *)node->key;

            if (tmutex->thread_id == th->thread_id) {
                LOG_WARN("Thread %d [%s] exiting in file %s line %d, without unlocking mutex [%s]", 
                     th->thread_id, th->name, file, line, mutex_to_string(tmutex, name));
            }

            node = avl_get_next (node);
        }

        _mutex_unlock(&_mutextree_mutex);
    }
#endif
    
    if (th)    {
#ifdef THREAD_DEBUG
        LOG_INFO4("Removing thread %d [%s] started at [%s:%d], reason: 'Thread Exited'", th->thread_id, th->name, th->file, th->line);
#endif

        _mutex_lock(&_threadtree_mutex);
        avl_delete(_threadtree, th, _free_thread_if_detached);
        _mutex_unlock(&_threadtree_mutex);
    }
    
    pthread_exit((void *)val);
}

/* sleep for a number of microseconds */
void thread_sleep(unsigned long len)
{
#ifdef _WIN32
    Sleep(len / 1000);
#else
# ifdef HAVE_NANOSLEEP
    struct timespec time_sleep;
    struct timespec time_remaining;
    int ret;

    time_sleep.tv_sec = len / 1000000;
    time_sleep.tv_nsec = (len % 1000000) * 1000;

    ret = nanosleep(&time_sleep, &time_remaining);
    while (ret != 0 && errno == EINTR) {
        time_sleep.tv_sec = time_remaining.tv_sec;
        time_sleep.tv_nsec = time_remaining.tv_nsec;
        
        ret = nanosleep(&time_sleep, &time_remaining);
    }
# else
    struct timeval tv;

    tv.tv_sec = len / 1000000;
    tv.tv_usec = (len % 1000000);

    select(0, NULL, NULL, NULL, &tv);
# endif
#endif
}

static void *_start_routine(void *arg)
{
    thread_start_t *start = (thread_start_t *)arg;
    void *(*start_routine)(void *) = start->start_routine;
    void *real_arg = start->arg;
    thread_type *thread = start->thread;
    int detach = start->detached;

    _block_signals();

    free(start);

    /* insert thread into thread tree here */
    _mutex_lock(&_threadtree_mutex);
    thread->sys_thread = pthread_self();
    avl_insert(_threadtree, (void *)thread);
    _mutex_unlock(&_threadtree_mutex);

#ifdef THREAD_DEBUG
    LOG_INFO4("Added thread %d [%s] started at [%s:%d]", thread->thread_id, thread->name, thread->file, thread->line);
#endif

    if (detach) {
        pthread_detach(thread->sys_thread);
        thread->detached = 1;
    }
    pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, NULL);

    /* call the real start_routine and start the thread
    ** this should never exit!
    */
    (start_routine)(real_arg);

#ifdef THREAD_DEBUG
    LOG_WARN("Thread x should never exit from here!!!");
#endif

    return NULL;
}

thread_type *thread_self(void)
{
    avl_node *node;
    thread_type *th;
    pthread_t sys_thread = pthread_self();

    _mutex_lock(&_threadtree_mutex);

    if (_threadtree == NULL) {
#ifdef THREAD_DEBUG
        LOG_WARN("Thread tree is empty, this must be wrong!");
#endif
        _mutex_unlock(&_threadtree_mutex);
        return NULL;
    }
    
    node = avl_get_first(_threadtree);
    
    while (node) {
        th = (thread_type *)node->key;

        if (th && pthread_equal(sys_thread, th->sys_thread)) {
            _mutex_unlock(&_threadtree_mutex);
            return th;
        }
        
        node = avl_get_next(node);
    }
    _mutex_unlock(&_threadtree_mutex);


#ifdef THREAD_DEBUG
    LOG_ERROR("Nonexistant thread alive...");
#endif
    
    return NULL;
}

void thread_rename(const char *name)
{
    thread_type *th;

    th = thread_self();
    if (th->name) free(th->name);

    th->name = strdup(name);
}

static void _mutex_lock(mutex_t *mutex) 
{
    pthread_mutex_lock(&mutex->sys_mutex);
}

static void _mutex_unlock(mutex_t *mutex)
{
    pthread_mutex_unlock(&mutex->sys_mutex);
}


void thread_library_lock(void)
{
    _mutex_lock(&_library_mutex);
}

void thread_library_unlock(void)
{
    _mutex_unlock(&_library_mutex);
}

void thread_join(thread_type *thread)
{
    void *ret;
    int i;

    i = pthread_join(thread->sys_thread, &ret);
    _mutex_lock(&_threadtree_mutex);
    avl_delete(_threadtree, thread, _free_thread);
    _mutex_unlock(&_threadtree_mutex);
}

/* AVL tree functions */

#ifdef DEBUG_MUTEXES
static int _compare_mutexes(void *compare_arg, void *a, void *b)
{
    mutex_t *m1, *m2;

    m1 = (mutex_t *)a;
    m2 = (mutex_t *)b;

    if (m1->mutex_id > m2->mutex_id)
        return 1;
    if (m1->mutex_id < m2->mutex_id)
        return -1;
    return 0;
}
#endif

static int _compare_threads(void *compare_arg, void *a, void *b)
{
    thread_type *t1, *t2;

    t1 = (thread_type *)a;
    t2 = (thread_type *)b;

    if (t1->thread_id > t2->thread_id)
        return 1;
    if (t1->thread_id < t2->thread_id)
        return -1;
    return 0;
}

#ifdef DEBUG_MUTEXES
static int _free_mutex(void *key)
{
    mutex_t *m;

    m = (mutex_t *)key;

    if (m && m->file) {
        free(m->file);
        m->file = NULL;
    }

    /* all mutexes are static.  don't need to free them */

    return 1;
}
#endif

static int _free_thread(void *key)
{
    thread_type *t;

    t = (thread_type *)key;

    if (t->file)
        free(t->file);
    if (t->name)
        free(t->name);

    free(t);

    return 1;
}

static int _free_thread_if_detached(void *key)
{
    thread_type *t = key;
    if(t->detached)
        return _free_thread(key);
    return 1;
}