Message queue datatype. More...

#include <datatypes/msg_queue.h>
#include <core/sync.h>
#include <datatypes/heap.h>
#include <lp/lp.h>
#include <mm/msg_allocator.h>
#include <stdalign.h>
#include <stdatomic.h>

Include dependency graph for msg_queue.c:

Classes
struct	q_elem
	An element in the message queue. More...

struct	msg_buffer
	The multi-threaded message buffer, implemented as a non-blocking list. More...

Macros
#define	q_elem_is_before(ma, mb) ((ma).t < (mb).t \|\| ((ma).t == (mb).t && msg_is_before_extended(ma.m, mb.m)))
	Determine an ordering between two elements in a queue.

Functions
static __thread	heap_declare (struct q_elem)
	The private thread queue. More...

void	msg_queue_init (void)
	Initializes the message queue for the current thread.

void	msg_queue_fini (void)
	Finalizes the message queue for the current thread.

void	msg_queue_global_fini (void)
	Finalizes the message queue at the node level.

static void	msg_queue_insert_queued (void)
	Move the messages from the thread specific list into the thread private queue.

struct lp_msg *	msg_queue_extract (void)
	Extracts the next message from the queue. More...

simtime_t	msg_queue_time_peek (void)
	Peeks the timestamp of the next message from the queue. More...

void	msg_queue_insert (struct lp_msg *msg)
	Inserts a message in the queue. More...

Variables
static struct msg_buffer *	queues
	The buffers vector.

Detailed Description

Message queue datatype.

This is the message queue for the parallel runtime. The design is pretty simple. A queue for n threads is composed of a vector of n simpler private thread queues plus n public buffers. If thread t1 wants to send a message to thread t2 it puts a message in its buffer. Insertions are then cheap, while extractions simply empty the buffer into the private queue. This way the critically thread locked code is minimal.

Copyright: Copyright (C) 2008-2022 HPDCS Group https://hpdcs.github.io

Function Documentation

◆ heap_declare()

static __thread heap_declare ( struct q_elem )

static

The private thread queue.

Initializes the message queue at the node level

◆ msg_queue_extract()

struct lp_msg* msg_queue_extract ( void )

Extracts the next message from the queue.

Returns: a pointer to the message to be processed or NULL if there isn't one

The extracted message is a best effort lowest timestamp for the current thread. Guaranteeing the lowest timestamp may increase the contention on the queues.

◆ msg_queue_insert()

void msg_queue_insert ( struct lp_msg * msg )

Inserts a message in the queue.

Parameters

msg	the message to insert in the queue

◆ msg_queue_time_peek()

simtime_t msg_queue_time_peek ( void )

Peeks the timestamp of the next message from the queue.

Returns: the lowest timestamp of the next message to be processed or SIMTIME_MAX is there's no message to process

This returns the lowest timestamp of the next message to be processed for the current thread. This is calculated in a precise fashion since this value is used in the gvt calculation.

Classes

Macros