cmlabs::MessageQueue Class Reference

Static facade over shared-memory message queues and a request/reply matcher. More...

#include <MemoryQueues.h>

Collaboration diagram for cmlabs::MessageQueue:

Public Member Functions
	MessageQueue (char *data, uint32 size)
	Attach this wrapper to a raw queue region.
	~MessageQueue ()
	changeSize (uint32 size)
	Update the wrapper's notion of the region size.
	changeData (char *data)
	Re-point the wrapper at a new mapped address.

Static Public Member Functions
static bool	CreateMessageQueue (uint32 &qid, const char *name=NULL)
	Create a new shared queue.
static bool	AddMessageToQueue (uint32 qid, DataMessage *msg)
	Append a message (copied into shared memory).
static DataMessage *	WaitForMessageQueue (uint32 qid, uint32 ms)
	Block up to ms milliseconds for a message.
static uint32	GetMessageQueueSize (uint32 qid)
static bool	GetMessageQueueByName (uint32 &qid, const char *name)
	Look up a queue id by its global name.
static bool	DestroyMessageQueue (uint32 qid)
	Destroy a queue and release its shared memory.
static bool	AddRequest (DataMessage *msg, uint32 &reqID)
	Submit a request message.
static bool	AddReply (uint32 reqID, bool success, DataMessage *msg)
	Post the reply for request reqID.
static bool	WaitForReply (uint32 reqID, uint32 ms, uint8 &status, DataMessage **outMsg)
	Block up to ms for the reply to reqID.
static uint32	GetRequestCount ()
static bool	UnitTest ()
	Self-test of queue + request logic.
static bool	UnitTestQueues ()
	Self-test of the raw queue ring buffer.

Protected Attributes
MessageQueueHeader *	header
	Mapped queue header (points into shared memory; not owned).

Friends
THREAD_RET THREAD_FUNCTION_CALL	QueueTest (THREAD_ARG arg)

Detailed Description

Static facade over shared-memory message queues and a request/reply matcher.

Queues are addressed by queue id (qid) or an optional global name. All static calls are safe from any process/thread; waits block on named semaphores with a timeout. Returned DataMessages are heap copies owned by the caller.

uint32 qid;
MessageQueue::CreateMessageQueue(qid, "vision.in");
MessageQueue::AddMessageToQueue(qid, msg);            // producer process
DataMessage* m = MessageQueue::WaitForMessageQueue(qid, 100); // consumer, 100 ms
if (m) { ...; delete m; }

Definition at line 48 of file MemoryQueues.h.

Constructor & Destructor Documentation

MessageQueue()

cmlabs::MessageQueue::MessageQueue	(	char *	data,
		uint32	size )

Attach this wrapper to a raw queue region.

Parameters

data	Mapped region.
size	Region bytes.

~MessageQueue()

cmlabs::MessageQueue::~MessageQueue

(

)

Member Function Documentation

AddMessageToQueue()

bool cmlabs::MessageQueue::AddMessageToQueue ( uint32 qid, DataMessage * msg )

static

Append a message (copied into shared memory).

Caller keeps ownership of msg.

Returns

true on success.

AddReply()

bool cmlabs::MessageQueue::AddReply ( uint32 reqID, bool success, DataMessage * msg )

static

Post the reply for request reqID.

Parameters

reqID	Request id being answered.
success	Outcome flag.
msg	Reply payload (copied).

Returns

true on success.

AddRequest()

bool cmlabs::MessageQueue::AddRequest ( DataMessage * msg, uint32 & reqID )

static

Submit a request message.

Parameters

msg	Request (caller keeps ownership).
reqID	Receives the request id.

Returns

true on success.

changeData()

cmlabs::MessageQueue::changeData

(

char *

data

)

Re-point the wrapper at a new mapped address.

Note

Missing return type — pre-C++11 implicit int; left untouched.

changeSize()

cmlabs::MessageQueue::changeSize

(

uint32

size

)

Update the wrapper's notion of the region size.

Note

Missing return type — pre-C++11 implicit int; left untouched.

CreateMessageQueue()

bool cmlabs::MessageQueue::CreateMessageQueue ( uint32 & qid, const char * name = NULL )

static

Create a new shared queue.

Parameters

qid	Receives the queue id.
name	Optional global name.

Returns

true on success.

DestroyMessageQueue()

bool cmlabs::MessageQueue::DestroyMessageQueue ( uint32 qid )

static

Destroy a queue and release its shared memory.

Returns

true on success.

GetMessageQueueByName()

bool cmlabs::MessageQueue::GetMessageQueueByName ( uint32 & qid, const char * name )

static

Look up a queue id by its global name.

Returns

true if found.

GetMessageQueueSize()

uint32 cmlabs::MessageQueue::GetMessageQueueSize ( uint32 qid )

static

Returns

Number of messages currently queued in qid.

GetRequestCount()

uint32 cmlabs::MessageQueue::GetRequestCount ( )

static

Returns

Number of requests currently outstanding.

UnitTest()

bool cmlabs::MessageQueue::UnitTest ( )

static

Self-test of queue + request logic.

Returns

true if all checks pass.

UnitTestQueues()

bool cmlabs::MessageQueue::UnitTestQueues ( )

static

Self-test of the raw queue ring buffer.

Returns

true if all checks pass.

References THREAD_ARG, THREAD_FUNCTION_CALL, and THREAD_RET.

WaitForMessageQueue()

DataMessage * cmlabs::MessageQueue::WaitForMessageQueue ( uint32 qid, uint32 ms )

static

Block up to ms milliseconds for a message.

Returns

Heap copy owned by caller, or NULL on timeout.

WaitForReply()

bool cmlabs::MessageQueue::WaitForReply ( uint32 reqID, uint32 ms, uint8 & status, DataMessage ** outMsg )

static

Block up to ms for the reply to reqID.

Parameters

reqID	Request id to wait for.
ms	Timeout in ms.
status	Receives the request status.
outMsg	Receives a caller-owned reply copy (may be NULL).

Returns

true if a reply arrived.

Friends And Related Symbol Documentation

QueueTest

THREAD_RET THREAD_FUNCTION_CALL QueueTest ( THREAD_ARG arg )

friend

Definition at line 1698 of file ProcessMemory.cpp.

References cmlabs::ProcessMemory::addToSigQ(), cmlabs::g_processTestStop, cmlabs::MemoryManager::processMemory, THREAD_ARG, THREAD_FUNCTION_CALL, THREAD_RET, thread_ret_val, and cmlabs::ProcessMemory::waitForCmdQ().

Member Data Documentation

header

MessageQueueHeader* cmlabs::MessageQueue::header

protected

Mapped queue header (points into shared memory; not owned).

Definition at line 85 of file MemoryQueues.h.

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The documentation for this class was generated from the following file:

• /home/ubuntu/c/partner/psyclone2/CMSDK/include/MemoryQueues.h