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#pike __REAL_VERSION__ 
 
#if constant(thread_create) 
constant Thread=__builtin.thread_id; 
 
// The reason for this inherit is rather simple. 
// It's now possible to write Thread Thread( ... ); 
// 
// This makes the interface look somewhat more thought-through. 
// 
inherit Thread; 
 
optional Thread `()( mixed f, mixed ... args ) 
{ 
  return thread_create( f, @args ); 
} 
 
optional constant MutexKey=__builtin.mutex_key; 
optional constant Mutex=__builtin.mutex; 
optional constant Condition=__builtin.condition; 
optional constant _Disabled=__builtin.threads_disabled; 
optional constant Local=__builtin.thread_local; 
 
//! @decl Thread.Thread Thread.Thread(function(mixed...:void) f, 
//!                                   mixed ... args) 
//! 
//! This function creates a new thread which will run simultaneously 
//! to the rest of the program. The new thread will call the function 
//! @[f] with the arguments @[args]. When @[f] returns the thread will cease 
//! to exist. 
//! 
//! All Pike functions are 'thread safe' meaning that running 
//! a function at the same time from different threads will not corrupt 
//! any internal data in the Pike process. 
//! 
//! @returns 
//! The returned value will be the same as the return value of 
//! @[Thread.this_thread()] for the new thread. 
//! 
//! @note 
//! This function is only available on systems with POSIX or UNIX or WIN32 
//! threads support. 
//! 
//! @seealso 
//! @[Mutex], @[Condition], @[this_thread()] 
//! 
optional constant thread_create = predef::thread_create; 
 
//! @decl Thread.Thread this_thread() 
//! 
//! This function returns the object that identifies this thread. 
//! 
//! @seealso 
//! @[Thread.Thread()] 
//! 
optional constant this_thread = predef::this_thread; 
 
//! @decl array(Thread.Thread) all_threads() 
//! 
//! This function returns an array with the thread ids of all threads. 
//! 
//! @seealso 
//! @[Thread.Thread()] 
//! 
optional constant all_threads = predef::all_threads; 
 
 
 
//! @[Thread.Fifo] implements a fixed length first-in, first-out queue. 
//! A fifo is a queue of values and is often used as a stream of data 
//! between two threads. 
//! 
//! @note 
//! Fifos are only available on systems with threads support. 
//! 
//! @seealso 
//! @[Thread.Queue] 
//! 
optional class Fifo { 
  inherit Condition : r_cond; 
  inherit Condition : w_cond; 
  inherit Mutex : lock; 
   
  array buffer; 
  int ptr, num; 
  int read_tres, write_tres; 
 
  //! This function returns the number of elements currently in the fifo. 
  //! 
  //! @seealso 
  //! @[read()], @[write()] 
  //! 
  int size() {  return num; } 
 
  //! This function retrieves a value from the fifo. Values will be 
  //! returned in the order they were written. If there are no values 
  //! present in the fifo the current thread will sleep until some other 
  //! thread writes a value to the fifo. 
  //! 
  //! @seealso 
  //! @[write()], @[read_array()] 
  //! 
  mixed read() 
  { 
    mixed tmp; 
    object key=lock::lock(2); 
    while(!num) r_cond::wait(key); 
    tmp=buffer[ptr]; 
    buffer[ptr++] = 0;  // Throw away any references. 
    ptr%=sizeof(buffer); 
    if(read_tres < sizeof(buffer)) 
    { 
      if(num-- == read_tres) 
        w_cond::broadcast(); 
    }else{ 
      num--; 
      w_cond::broadcast(); 
    } 
    key = 0; 
    return tmp; 
  } 
 
  //! This function returns all values currently in the fifo. Values in 
  //! the array will be in the order they were written. If there are no 
  //! values present in the fifo the current thread will sleep until 
  //! some other thread writes a value to the fifo. 
  //! 
  //! @seealso 
  //! @[write()], @[read()] 
  //! 
  array read_array() 
  { 
    array ret; 
    object key=lock::lock(2); 
    while(!num) r_cond::wait(key); 
    if(num==1) 
    { 
      ret=buffer[ptr..ptr]; 
      buffer[ptr++] = 0;        // Throw away any references. 
      ptr%=sizeof(buffer); 
      num--; 
    }else{ 
      if (ptr+num < sizeof(buffer)) { 
        ret = buffer[ptr..ptr+num-1]; 
      } else { 
        ret = buffer[ptr..]+buffer[..num-(sizeof(buffer)-ptr)-1]; 
      } 
      ptr=num=0; 
      buffer=allocate(sizeof(buffer)); // Throw away any references. 
    } 
    key = 0; 
    w_cond::broadcast(); 
    return ret; 
  } 
 
  //! Append a @[value] to the end of the fifo. If there is no more 
  //! room in the fifo the current thread will sleep until space is 
  //! available. 
  //! 
  //! @seealso 
  //! @[read()] 
  //! 
  void write(mixed value) 
  { 
    object key=lock::lock(2); 
    while(num == sizeof(buffer)) w_cond::wait(key); 
    buffer[(ptr + num) % sizeof(buffer)] = value; 
    if(write_tres) 
    { 
      if(num++ == write_tres) 
        r_cond::broadcast(); 
    }else{ 
      num++; 
      r_cond::broadcast(); 
    } 
    key = 0; 
  } 
 
  //! @decl void create() 
  //! @decl void create(int size) 
  //! 
  //! Create a fifo. If the optional @[size] argument is present it 
  //! sets how many values can be written to the fifo without blocking. 
  //! The default @[size] is 128. 
  //! 
  static void create(int|void size) 
  { 
    write_tres=0; 
    buffer=allocate(read_tres=size || 128); 
  } 
 
  static string _sprintf( int f ) 
  { 
    switch( f ) 
    { 
      case 't': 
        return "Thread.Fifo"; 
      case 'O': 
        return sprintf( "%t(%d / %d)", this_object(), size(), read_tres ); 
    } 
  } 
}; 
 
//! @[Thread.Queue] implements a queue, or a pipeline. The main difference 
//! between @[Thread.Queue] and @[Thread.Fifo] is that @[Thread.Queue] 
//! will never block in write(), only allocate more memory. 
//! 
//! @note 
//! Queues are only available on systems with POSIX or UNIX or WIN32 
//! thread support. 
//! 
//! @seealso 
//! @[Thread.Fifo] 
//! 
optional class Queue { 
  inherit Condition : r_cond; 
  inherit Mutex : lock; 
   
  array buffer=allocate(16); 
  int r_ptr, w_ptr; 
   
  //! This function returns the number of elements currently in the queue. 
  //! 
  //! @seealso 
  //! @[read()], @[write()] 
  //! 
  int size() {  return w_ptr - r_ptr;  } 
 
  //! This function retrieves a value from the queue. Values will be 
  //! returned in the order they were written. If there are no values 
  //! present in the queue the current thread will sleep until some other 
  //! thread writes a value to the queue. 
  //! 
  //! @seealso 
  //! @[write()] 
  //! 
  mixed read() 
  { 
    mixed tmp; 
    object key=lock::lock(); 
    while(!size()) r_cond::wait(key); 
    tmp=buffer[r_ptr]; 
    buffer[r_ptr++] = 0;        // Throw away any references. 
    key=0; 
    return tmp; 
  } 
 
  //! This function puts a @[value] last in the queue. If the queue is 
  //! too small to hold the @[value] the queue will be expanded to make 
  //! room for it. 
  //! 
  //! @seealso 
  //! @[read()] 
  //! 
  void write(mixed value) 
  { 
    object key=lock::lock(); 
    if(w_ptr >= sizeof(buffer)) 
    { 
      buffer=buffer[r_ptr..]; 
      buffer+=allocate(sizeof(buffer)+1); 
      w_ptr-=r_ptr; 
      r_ptr=0; 
    } 
    buffer[w_ptr] = value; 
    w_ptr++; 
    key=0; // Must free this one _before_ the signal... 
    r_cond::signal(); 
  } 
 
  static string _sprintf( int f ) 
  { 
    switch( f ) 
    { 
      case 't': 
        return "Thread.Queue"; 
      case 'O': 
        return sprintf( "%t(%d)", this_object(), size() ); 
    } 
  } 
} 
 
 
 
optional class Farm 
{ 
  class Result 
  { 
    int ready; 
    mixed value; 
    function done_cb; 
 
    int status() 
    { 
      return ready; 
    } 
 
    mixed result() 
    { 
      return value; 
    } 
 
    mixed `()() 
    { 
      while(!ready)     ft_cond->wait(); 
      if( ready < 0 )   throw( value ); 
      return value; 
    } 
 
    void set_done_cb( function to ) 
    { 
      if( ready ) 
        to( value, ready<0 ); 
      else 
        done_cb = to; 
    } 
 
    void provide_error( mixed what ) 
    { 
      value = what; 
      ready = -1; 
      if( done_cb ) 
        done_cb( what, 1 ); 
    } 
       
    void provide( mixed what ) 
    { 
      ready = 1; 
      value = what; 
      if( done_cb ) 
        done_cb( what, 0 ); 
    } 
 
 
    static string _sprintf( int f ) 
    { 
      switch( f ) 
      { 
        case 't': 
          return "Thread.Farm().Result"; 
        case 'O': 
          return sprintf( "%t(%d %O)", this_object(), ready, value ); 
      } 
    } 
  } 
 
  static class Handler 
  { 
    Condition cond = Condition(); 
    array(object|array(function|array)) job; 
    object thread; 
 
    float total_time; 
    int handled, max_time; 
 
    static int ready; 
 
    void handler() 
    { 
      array(object|array(function|array)) q; 
      while( 1 ) 
      { 
        ready = 1; 
        cond->wait(); 
        if( q = job ) 
        { 
          mixed res, err; 
          int st = gethrtime(); 
          if( err = catch(res = q[1][0]( @q[1][1] )) && q[0]) 
            ([object]q[0])->provide_error( err ); 
          else if( q[0] ) 
            ([object]q[0])->provide( res ); 
          object lock = mutex->lock(); 
          free_threads += ({ this_object() }); 
          lock = 0; 
          st = gethrtime()-st; 
          total_time += st/1000.0; 
          handled++; 
          job = 0; 
          if( st > max_time ) 
            max_time = st; 
          ft_cond->broadcast(); 
        } else  { 
          object lock = mutex->lock(); 
          threads -= ({ this_object() }); 
          free_threads -= ({ this_object() }); 
          lock = 0; 
          destruct(); 
          return; 
        } 
      } 
    } 
 
    void run( array(function|array) what, object|void resobj ) 
    { 
      while(!ready) sleep(0.1); 
      job = ({ resobj, what }); 
      cond->signal(); 
    } 
 
    string debug_status() 
    { 
      return ("Thread:\n" 
              " Handled works: "+handled+"\n"+ 
              (handled? 
               " Average time:  "+((int)(total_time / handled))+"ms\n" 
               " Max time:      "+sprintf("%2.2fms\n", max_time/1000.0):"")+ 
              " Status:        "+(job?"Working":"Idle" )+"\n"+ 
              (job? 
               ("    "+ 
                replace( describe_backtrace(thread->backtrace()), 
                         "\n", 
                         "\n    ")):"") 
              +"\n\n"); 
    } 
 
    static void create() 
    { 
      thread = thread_create( handler ); 
    } 
 
 
    static string _sprintf( int f ) 
    { 
      switch( f ) 
      { 
        case 't': 
          return "Thread.Farm().Handler"; 
        case 'O': 
          return sprintf( "%t(%f / %d,  %d)", total_time, max_time,handled ); 
      } 
    } 
  } 
 
  static Mutex mutex = Mutex(); 
  static Condition ft_cond = Condition(); 
  static Queue job_queue = Queue(); 
 
  static array(Handler) threads = ({}); 
  static array(Handler) free_threads = ({}); 
  static int max_num_threads = 20; 
 
  static Handler aquire_thread() 
  { 
    object lock = mutex->lock(); 
    while( !sizeof(free_threads) ) 
    { 
      if( sizeof(threads) < max_num_threads ) 
      { 
        threads += ({ Handler() }); 
        free_threads += ({ threads[-1] }); 
      } else { 
        lock = 0; 
        ft_cond->wait( ); 
        mutex->lock(); 
      } 
    } 
    object(Handler) t = free_threads[0]; 
    free_threads = free_threads[1..]; 
    return t; 
  } 
         
 
  static void dispatcher() 
  { 
    while( array q = [array]job_queue->read() ) 
      aquire_thread()->run( q[1], q[0] ); 
  } 
 
  static class ValueAdjuster( object r, object r2, int i, mapping v ) 
  { 
    void go(mixed vn, int err) 
    { 
      ([array]r->value)[ i ] = vn; 
      if( err ) 
        r->provide_error( err ); 
      if( !--v->num_left ) 
        r->provide( r->value ); 
      destruct(); 
    } 
  } 
 
  object run_multiple( array fun_args ) 
  { 
    Result r = Result(); // private result.. 
    r->value = allocate( sizeof( fun_args ) ); 
    mapping nl = ([ "num_left":sizeof( fun_args ) ]); 
    for( int i=0; i<sizeof( fun_args ); i++ ) 
    { 
      Result  r2 = Result(); 
      r2->set_done_cb( ValueAdjuster( r, r2, i, nl )->go ); 
      job_queue->write( ({ r2, fun_args[i] }) ); 
    } 
    return r; 
  } 
 
 
  void run_multiple_async( array fun_args ) 
  { 
    for( int i=0; i<sizeof( fun_args ); i++ ) 
      job_queue->write( ({ 0, fun_args[i] }) ); 
  } 
 
 
  object run( function f, mixed ... args ) 
  { 
    object ro = Result(); 
    job_queue->write( ({ 0, ({f, args }) }) ); 
    return ro; 
  } 
 
  void run_async( function f, mixed ... args ) 
  { 
    job_queue->write( ({ 0, ({f, args }) }) ); 
  } 
 
  int set_max_num_threads( int to ) 
  { 
    int omnt = max_num_threads; 
    if( to <= 0 ) 
      error("Illegal argument 1 to set_max_num_threads," 
            "num_threads must be > 0\n"); 
 
    max_num_threads = to; 
    while( sizeof( threads ) > max_num_threads ) 
    { 
      object key = mutex->lock(); 
      while( sizeof( free_threads ) ) 
        free_threads[0]->cond->signal(); 
      key = 0; 
      if( sizeof( threads ) > max_num_threads) 
        ft_cond->wait(); 
    } 
    ft_cond->broadcast( ); 
    return omnt; 
  } 
 
  string debug_status() 
  { 
    string res = sprintf("Thread farm\n" 
                         "  Max threads     = %d\n" 
                         "  Current threads = %d\n" 
                         "  Working threads = %d\n" 
                         "  Jobs in queue   = %d\n\n", 
                         max_num_threads, sizeof(threads),  
                         (sizeof(threads)-sizeof(free_threads)), 
                         job_queue->size() ); 
     
    foreach( threads, Handler t ) 
      res += t->debug_status(); 
    return res; 
  } 
 
 
  static string _sprintf( int f ) 
  { 
    switch( f ) 
    { 
      case 't': 
        return "Thread.Farm"; 
      case 'O': 
        return sprintf( "%t(/* %s */)", this_object, debug_status() ); 
    } 
  } 
 
 
 
  static void create() 
  { 
    thread_create( dispatcher ); 
  } 
} 
 
#else /* !constant(thread_create) */ 
 
// Simulations of some of the classes for nonthreaded use. 
 
class Local 
{ 
  static mixed data; 
  mixed get() {return data;} 
  mixed set (mixed val) {return data = val;} 
} 
 
class MutexKey (static function(:void) dec_locks) 
{ 
  int `!() 
  { 
    // Should be destructed when the mutex is, but we can't pull that 
    // off. Try to simulate it as well as possible. 
    if (dec_locks) return 0; 
    destruct (this_object()); 
    return 1; 
  } 
 
  static void destroy() 
  { 
    if (dec_locks) dec_locks(); 
  } 
} 
 
//! @[Thread.Mutex] is a class that implements mutual exclusion locks. 
//! Mutex locks are used to prevent multiple threads from simultaneously 
//! execute sections of code which access or change shared data. The basic 
//! operations for a mutex is locking and unlocking. If a thread attempts 
//! to lock an already locked mutex the thread will sleep until the mutex 
//! is unlocked. 
//! 
//! @note 
//! This class is simulated when Pike is compiled without thread support, 
//! so it's always available. 
//! 
//! In POSIX threads, mutex locks can only be unlocked by the same thread 
//! that locked them. In Pike any thread can unlock a locked mutex. 
//! 
class Mutex 
{ 
  static int locks = 0; 
  static void dec_locks() {locks--;} 
 
  //! @decl MutexKey lock() 
  //! @decl MutexKey lock(int type) 
  //! 
  //! This function attempts to lock the mutex. If the mutex is already 
  //! locked by a different thread the current thread will sleep until the 
  //! mutex is unlocked. The value returned is the 'key' to the lock. When 
  //! the key is destructed or has no more references the lock will 
  //! automatically be unlocked. The key will also be destructed if the lock 
  //! is destructed. 
  //! 
  //! The @[type] argument specifies what @[lock()] should do if the 
  //! mutex is already locked by this thread: 
  //! @integer 
  //!   @value 0 (default) 
  //!     Throw an error. 
  //!   @value 1 
  //!     Sleep until the mutex is unlocked. Useful if some 
  //!     other thread will unlock it. 
  //!   @value 2 
  //!     Return zero. This allows recursion within a locked region of 
  //!     code, but in conjunction with other locks it easily leads 
  //!     to unspecified locking order and therefore a risk for deadlocks. 
  //! 
  //! @seealso 
  //! @[trylock()] 
  //! 
  MutexKey lock (int|void type) 
  { 
    switch (type) { 
      default: 
        error ("Unknown mutex locking style: %d\n", type); 
      case 0: 
        if (locks) error ("Recursive mutex locks.\n"); 
        break; 
      case 1: 
        if (locks) 
          // To be really accurate we should hang now, but somehow 
          // that doesn't seem too useful. 
          error ("Deadlock detected.\n"); 
        break; 
      case 2: 
        if (locks) { 
          locks++; 
          return 0; 
        } 
    } 
    locks++; 
    return MutexKey (dec_locks); 
  } 
 
  //! @decl MutexKey trylock() 
  //! @decl MutexKey trylock(int type) 
  //! 
  //! This function performs the same operation as @[lock()], but if the mutex 
  //! is already locked, it will return zero instead of sleeping until it's 
  //! unlocked. 
  //! 
  //! @seealso 
  //! @[lock()] 
  //! 
  MutexKey trylock (int|void type) 
  { 
    switch (type) { 
      default: 
        error ("Unknown mutex locking style: %d\n", type); 
      case 0: 
        if (locks) error ("Recursive mutex locks.\n"); 
        break; 
      case 1: 
      case 2: 
    } 
    if (locks) return 0; 
    locks++; 
    return MutexKey (dec_locks); 
  } 
} 
 
#endif /* !constant(thread_create) */