SizedQueue

This class represents queues of specified size capacity. The push operation may be blocked if the capacity is full.

See Queue for an example of how a SizedQueue works.

Public Class Methods

new(max) click to toggle source

Creates a fixed-length queue with a maximum size of max.

 
 static VALUE
rb_szqueue_initialize(VALUE self, VALUE vmax)
{
 long max;
 struct rb_szqueue *sq = szqueue_ptr(self);
 max = NUM2LONG(vmax);
 if (max <= 0) {
 rb_raise(rb_eArgError, "queue size must be positive");
 }
 RB_OBJ_WRITE(self, &sq->q.que, ary_buf_new());
 list_head_init(szqueue_waitq(sq));
 list_head_init(szqueue_pushq(sq));
 sq->max = max;
 return self;
}

Public Instance Methods

<<(*args) click to toggle source

Alias for: push

clear() click to toggle source

Removes all objects from the queue.

 
 static VALUE
rb_szqueue_clear(VALUE self)
{
 struct rb_szqueue *sq = szqueue_ptr(self);
 rb_ary_clear(check_array(self, sq->q.que));
 wakeup_all(szqueue_pushq(sq));
 return self;
}

close click to toggle source

Similar to Queue#close.

The difference is behavior with waiting enqueuing threads.

If there are waiting enqueuing threads, they are interrupted by raising ClosedQueueError('queue closed').

 
 static VALUE
rb_szqueue_close(VALUE self)
{
 if (!queue_closed_p(self)) {
 struct rb_szqueue *sq = szqueue_ptr(self);
 FL_SET(self, QUEUE_CLOSED);
 wakeup_all(szqueue_waitq(sq));
 wakeup_all(szqueue_pushq(sq));
 }
 return self;
}

deq(*args) click to toggle source

Alias for: pop

empty? click to toggle source

Returns true if the queue is empty.

 
 static VALUE
rb_szqueue_empty_p(VALUE self)
{
 struct rb_szqueue *sq = szqueue_ptr(self);
 return queue_length(self, &sq->q) == 0 ? Qtrue : Qfalse;
}

enq(*args) click to toggle source

Alias for: push

length() click to toggle source

 
 static VALUE
rb_szqueue_length(VALUE self)
{
 struct rb_szqueue *sq = szqueue_ptr(self);
 return LONG2NUM(queue_length(self, &sq->q));
}

Also aliased as: size

max() click to toggle source

Returns the maximum size of the queue.

 
 static VALUE
rb_szqueue_max_get(VALUE self)
{
 return LONG2NUM(szqueue_ptr(self)->max);
}

max=(number) click to toggle source

Sets the maximum size of the queue to the given number.

 
 static VALUE
rb_szqueue_max_set(VALUE self, VALUE vmax)
{
 long max = NUM2LONG(vmax);
 long diff = 0;
 struct rb_szqueue *sq = szqueue_ptr(self);
 if (max <= 0) {
 rb_raise(rb_eArgError, "queue size must be positive");
 }
 if (max > sq->max) {
 diff = max - sq->max;
 }
 sq->max = max;
 while (diff-- > 0 && wakeup_one(szqueue_pushq(sq))) {
 /* keep waking more up */
 }
 return vmax;
}

num_waiting() click to toggle source

Returns the number of threads waiting on the queue.

 
 static VALUE
rb_szqueue_num_waiting(VALUE self)
{
 struct rb_szqueue *sq = szqueue_ptr(self);
 return INT2NUM(sq->q.num_waiting + sq->num_waiting_push);
}

pop(non_block=false) click to toggle source

deq(non_block=false)

shift(non_block=false)

Retrieves data from the queue.

If the queue is empty, the calling thread is suspended until data is pushed onto the queue. If non_block is true, the thread isn't suspended, and ThreadError is raised.

 
 static VALUE
rb_szqueue_pop(int argc, VALUE *argv, VALUE self)
{
 int should_block = queue_pop_should_block(argc, argv);
 return szqueue_do_pop(self, should_block);
}

Also aliased as: deq, shift

push(object, non_block=false) click to toggle source

enq(object, non_block=false)

<<(object)

Pushes object to the queue.

If there is no space left in the queue, waits until space becomes available, unless non_block is true. If non_block is true, the thread isn't suspended, and ThreadError is raised.

 
 static VALUE
rb_szqueue_push(int argc, VALUE *argv, VALUE self)
{
 struct rb_szqueue *sq = szqueue_ptr(self);
 int should_block = szqueue_push_should_block(argc, argv);
 while (queue_length(self, &sq->q) >= sq->max) {
 if (!should_block) {
 rb_raise(rb_eThreadError, "queue full");
 }
 else if (queue_closed_p(self)) {
 goto closed;
 }
 else {
 struct queue_waiter qw;
 struct list_head *pushq = szqueue_pushq(sq);
 qw.w.th = GET_THREAD();
 qw.as.sq = sq;
 list_add_tail(pushq, &qw.w.node);
 sq->num_waiting_push++;
 rb_ensure(queue_sleep, Qfalse, szqueue_sleep_done, (VALUE)&qw);
 }
 }
 if (queue_closed_p(self)) {
 closed:
 raise_closed_queue_error(self);
 }
 return queue_do_push(self, &sq->q, argv[0]);
}