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// ============================================================================
// $Id$
//
// = LIBRARY
// tests
//
// = FILENAME
// Priority_Buffer_Test.cpp
//
// = DESCRIPTION
// This is a simple test to illustrate the priority mechanism of
// ACE Message_Queues. The producer uses an ASX Message_Queue to
// enqueue a bunch of messages with different priorities which
// are then dequeued by the consumer.
//
// = AUTHOR
// Prashant Jain and Doug Schmidt
//
// ============================================================================
#include "ace/Log_Msg.h"
#include "ace/Message_Queue.h"
#include "ace/Service_Config.h"
#include "test_config.h"
#if defined (ACE_HAS_THREADS)
// Global thread manager.
static int count = 0;
// Make the queue be capable of being *very* large.
static const long max_queue = LONG_MAX;
// The consumer dequeues a message from the ACE_Message_Queue, writes
// the message to the stderr stream, and deletes the message. The
// producer sends a 0-sized message to inform the consumer to stop
// reading and exit.
static void *
consumer (void *args)
{
ACE_Message_Queue<ACE_MT_SYNCH> *msg_queue = (ACE_Message_Queue<ACE_MT_SYNCH> *) args;
u_long cur_priority = 27;
int local_count = 0;
// Keep looping, reading a message out of the queue, until we
// get a message with a length == 0, which signals us to quit.
for (char c = 'z'; ; c--)
{
ACE_Message_Block *mb = 0;
int result = msg_queue->dequeue_head (mb);
if (result == -1)
break;
local_count++;
int length = mb->length ();
ACE_ASSERT (mb->msg_priority () < cur_priority);
cur_priority = mb->msg_priority ();
if (length > 0)
ACE_ASSERT (c == *mb->rd_ptr ());
// Free up the buffer memory and the Message_Block. Note that
// the destructor of Message Block will delete the the actual
// buffer.
delete mb;
if (length == 0)
break;
}
ACE_ASSERT (local_count == count);
return 0;
}
// The producer reads data from the stdin stream, creates a message,
// and then queues the message in the message list, where it is
// removed by the consumer thread. A 0-sized message is enqueued when
// there is no more data to read. The consumer uses this as a flag to
// know when to exit.
static void *
producer (void *args)
{
ACE_Message_Queue<ACE_MT_SYNCH> *msg_queue = (ACE_Message_Queue<ACE_MT_SYNCH> *) args;
// Insert thread into thr_mgr.
ACE_Thread_Control thread_control (ACE_Service_Config::thr_mgr ());
ACE_NEW_THREAD;
ACE_Message_Block *mb = 0;
for (char c = 'a'; c <= 'z'; c++)
{
count++;
// Allocate a new message
ACE_NEW_RETURN (mb, ACE_Message_Block (1), 0);
*mb->rd_ptr () = c;
// Set the priority.
mb->msg_priority (count);
mb->wr_ptr (1);
// Enqueue in priority order.
if (msg_queue->enqueue (mb) == -1)
ACE_ERROR_RETURN ((LM_ERROR, "(%t) %p\n", "put_next"), 0);
}
// Now send a 0-sized shutdown message to the other thread
ACE_NEW_RETURN (mb, ACE_Message_Block ((size_t) 0), 0);
if (msg_queue->enqueue_tail (mb) == -1)
ACE_ERROR ((LM_ERROR, "(%t) %p\n", "put_next"));
count++;
// Now read all the items out in priority order (i.e., ordered by
// the size of the lines!).
consumer (msg_queue);
// The destructor of ACE_Thread_Control removes the exiting thread
// from the thr_mgr automatically.
return 0;
}
#endif /* ACE_HAS_THREADS */
// Spawn off one thread that copies stdin to stdout in order of the
// size of each line.
int
main (int, char *argv[])
{
ACE_START_TEST ("Priority_Buffer_Test.cpp");
#if defined (ACE_HAS_THREADS)
// Message queue.
ACE_Message_Queue<ACE_MT_SYNCH> msg_queue (max_queue);
if (ACE_Service_Config::thr_mgr ()->spawn (ACE_THR_FUNC (producer),
(void *) &msg_queue,
THR_NEW_LWP | THR_DETACHED) == -1)
ACE_ERROR_RETURN ((LM_ERROR, "%p\n", "spawn"), 1);
// Wait for producer and consumer threads to exit.
ACE_Service_Config::thr_mgr ()->wait ();
#else
ACE_ERROR ((LM_ERROR, "threads not supported on this platform\n"));
#endif /* ACE_HAS_THREADS */
ACE_END_TEST;
return 0;
}
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