conv::msgQ Class Template Reference

Charm Message Queue: Holds msg pointers and returns the next message to execute on a PE. More...

#include <msgq.h>

Collaboration diagram for conv::msgQ:


Public Types
typedef P	prio_t
	The datatype for msg priorities.
typedef P	prio_t
Public Member Functions
	msgQ ()
	Hardly any initialization required.
void	enq (const msg_t *msg, const prio_t &prio=prio_t(), const bool isFifo=true)
	Given a message (optionally with a priority and queuing policy), enqueue it for delivery.
const msg_t *	deq ()
	Pop (and return) the next message to deliver.
size_t	size () const
	Number of messages in the queue.
size_t	max_size () const
bool	empty () const
	Is the queue empty?
void	enumerate (msg_t first, msg_t last) const
	Just so that we can support CqsEnumerateQueue().
	msgQ ()
size_t	size () const
size_t	max_size () const
bool	empty () const
void	enumerate (msg_t first, msg_t last) const
void	enq (const msg_t *msg, const prio_t &prio=prio_t(), const bool isFifo=true)
const msg_t *	deq ()
Private Types
typedef std::deque< const msg_t * >	bkt_t
	Message bucket type.
typedef std::pair< prio_t, bkt_t * >	prioidx_t
	A key-val pair of a priority value and a handle to the bucket of msgs of that priority.
typedef std::unordered_map < prio_t, bkt_t >	bktmap_t
	A type for mapping between priority values and msg buckets.
Private Attributes
std::vector< const msg_t * >	randQ
	All the messages go in one bin when we're picking them out randomly.
size_t	qSize
	The size of this message queue.
bktmap_t	msgbuckets
	Collection of msg buckets, each holding msgs of a given priority (maps priorities to buckets).
std::priority_queue< prioidx_t, std::vector< prioidx_t > , std::greater< prioidx_t > >	prioQ
	A _min_ heap of distinct msg priorities along with handles to matching buckets.
std::deque< const msg_t * >	bkt
Friends
std::ostream &	operator<< (std::ostream &out, const msgQ &q)
	An ostream operator overload, that currently just prints q size.
std::ostream &	operator<< (std::ostream &out, const msgQ &q)

Detailed Description

template<typename P = int>
class conv::msgQ

Charm Message Queue: Holds msg pointers and returns the next message to execute on a PE.

Templated on the type of the priority field. Defaults to int priority. All scheduling policies are encapsulated behind this queue interface.

All messages of a given priority p are stored in a single container. Since each message can be enqueued either to the front or back of this container, a dequeue is used. Each such dequeue is referred to as a bucket. The set of priority values of all the messages in the container is stored in a min-heap. A deq() operation simply peeks at the most important prio value, and finds the bucket associated with that value. It then dequeues the message at the front of this bucket. A mapping between the priority values and the corresponding buckets is maintained. enq() operations simply find the bucket corresponding to a prio value and place the msg into it.

Definition at line 37 of file msgq.h.

Member Typedef Documentation

template<typename P = int>

typedef P conv::msgQ::prio_t

The datatype for msg priorities.

Definition at line 41 of file msgq.h.

template<typename P = int>

typedef std::deque<const msg_t*> conv::msgQ::bkt_t [private]

Message bucket type.

Definition at line 77 of file msgq.h.

template<typename P = int>

typedef std::pair<prio_t, bkt_t*> conv::msgQ::prioidx_t [private]

A key-val pair of a priority value and a handle to the bucket of msgs of that priority.

Definition at line 79 of file msgq.h.

template<typename P = int>

typedef std::unordered_map<prio_t, bkt_t> conv::msgQ::bktmap_t [private]

A type for mapping between priority values and msg buckets.

Definition at line 81 of file msgq.h.

template<typename P = int>

typedef P conv::msgQ::prio_t

Definition at line 222 of file msgq.h.

Constructor & Destructor Documentation

template<typename P = int>

conv::msgQ::msgQ ( ) [inline]

Hardly any initialization required.

Definition at line 44 of file msgq.h.

template<typename P = int>

conv::msgQ::msgQ ( ) [inline]

Definition at line 223 of file msgq.h.

Member Function Documentation

template<typename P>

void conv::msgQ< P >::enq	(	const msg_t *	msg,
		const prio_t &	prio = `prio_t()`,
		const bool	isFifo = `true`
	)			`[inline]`

Given a message (optionally with a priority and queuing policy), enqueue it for delivery.

Definition at line 94 of file msgq.h.

References conv::msgQ::bkt, conv::msgQ::msgbuckets, conv::msgQ::prioQ, conv::msgQ::qSize, and conv::msgQ::randQ.

template<typename P>

const msg_t * conv::msgQ::deq ( void ) [inline]

Pop (and return) the next message to deliver.

For detecting races, and for a general check that applications dont depend on priorities or message ordering for correctness, charm can be built with a randomized scheduler queue.

In this case, this container's deq() operation will not actually respect priorities. Instead it simply returns a randomly selected msg.

Definition at line 140 of file msgq.h.

References conv::msgQ::bkt, conv::msgQ::empty(), msg, conv::msgQ::msgbuckets, conv::msgQ::prioQ, and conv::msgQ::qSize.

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