Mbox Class Reference

create mailbox More...

#include <Mbox.h>

Collaboration diagram for Mbox:

Public Member Functions
	Mbox ()
virtual	~Mbox ()
class Message *	receive (int timeout)
	consume a Message More...

Static Public Member Functions
static __int128	getInt128FromPointer (class Message *ptr, uint64_t count)
	create 128bit integer from Message object More...
static class Message *	getPtr (__int128 i128)
	return Message pointer from 128bit integer More...
static uint64_t	getCount (__int128 i128)
	return count component from 128bit integer More...

Private Attributes
pthread_mutex_t	mutexLast
class Message *	firstMsg
class Message *	currentMsg
class Message *	lastMsg
class Message *	myLastMsg
__int128	head
__int128	tail
__int128	current
__int128	mytail
uint64_t	counter

Friends
class	MboxProducer

Detailed Description

create mailbox

this is a queue, lockfree multi-producer single consumer adapted from: http://www.cs.rochester.edu/research/synchronization/pseudocode/queues.html

Definition at line 46 of file Mbox.h.

Constructor & Destructor Documentation

Mbox::Mbox

(

)

lockfree producer adapted from: http://www.cs.rochester.edu/research/synchronization/pseudocode/queues.html

Definition at line 37 of file Mbox.cc.

References current, currentMsg, firstMsg, getInt128FromPointer(), head, lastMsg, Message::messageStruct, mutexLast, myLastMsg, mytail, Message::nextmsg, PAYLOADNONE, Message::message_s::payloadtype, and tail.

           : counter(8888)
{
    firstMsg = new class Message();
    firstMsg->messageStruct.payloadtype = PAYLOADNONE;
    firstMsg->nextmsg = getInt128FromPointer(NULL, 5000);
    currentMsg = firstMsg;
    lastMsg = firstMsg;
    myLastMsg = firstMsg;

    head = getInt128FromPointer(firstMsg, 10000);
    tail = head;
    current = head;
    mytail = head;

    pthread_mutexattr_t attr;
    attr.__align = PTHREAD_MUTEX_ADAPTIVE_NP;
    pthread_mutex_init(&mutexLast, &attr);
}

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Mbox::~Mbox ( )

virtual

Definition at line 56 of file Mbox.cc.

References firstMsg.

{
    delete firstMsg;
}

Member Function Documentation

uint64_t Mbox::getCount ( __int128  i128)

static

return count component from 128bit integer

Parameters

i128	input 128bit integer

Returns

count

Definition at line 120 of file Mbox.cc.

Referenced by receive(), and TransactionAgent::TransactionAgent().

{
    return *((uint64_t *)&i128+1);
}

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__int128 Mbox::getInt128FromPointer ( class Message *  ptr, uint64_t  count  )

static

create 128bit integer from Message object

Parameters

ptr	Message variant
count	count component

Returns

Definition at line 106 of file Mbox.cc.

Referenced by Mbox(), and MboxProducer::sendMsg().

{
    __int128 i128;
    memcpy(&i128, &ptr, sizeof(ptr));
    memcpy((uint64_t *)&i128+1, &count, sizeof(count));

    return i128;
}

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class Message * Mbox::getPtr ( __int128  i128)

static

return Message pointer from 128bit integer

Parameters

i128	input 128bit integer

Returns

Message

Definition at line 115 of file Mbox.cc.

Referenced by receive(), MboxProducer::sendMsg(), and TransactionAgent::TransactionAgent().

{
    return (class Message *)i128;
}

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class Message * Mbox::receive

(

int

timeout)

consume a Message

Parameters

timeout

timeout in microseconds

Returns

Message object

Definition at line 66 of file Mbox.cc.

References current, getCount(), getPtr(), and Message::nextmsg.

Referenced by ObGateway::ObGateway().

{
    __int128 mynext;

    while (1)
    {
        mynext = __atomic_load_n(&(getPtr(current)->nextmsg), __ATOMIC_SEQ_CST);

        if (getPtr(mynext)==NULL)
        {
            switch (timeout)
            {
            case -1:
                break;

            case 0:
                return NULL;
                break;

            default:
                struct timespec ts = {0, timeout * 1000};
                nanosleep(&ts, NULL);
                return NULL;
            }
        }
        else
        {
            if (getPtr(current)==getPtr(mynext))
            {
                printf("%s %i WTF found it i guess count current %lu next %lu\n",
                       __FILE__, __LINE__, getCount(current), getCount(mynext));
            }

            delete getPtr(current);
            current = mynext;
            return getPtr(current);      
        }
    }
}

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Friends And Related Function Documentation

friend class MboxProducer

friend

Definition at line 87 of file Mbox.h.

Member Data Documentation

uint64_t Mbox::counter

private

Definition at line 102 of file Mbox.h.

Referenced by MboxProducer::sendMsg().

__int128 Mbox::current

private

Definition at line 99 of file Mbox.h.

Referenced by Mbox(), and receive().

class Message* Mbox::currentMsg

private

Definition at line 93 of file Mbox.h.

Referenced by Mbox().

class Message* Mbox::firstMsg

private

Definition at line 92 of file Mbox.h.

Referenced by Mbox(), and ~Mbox().

__int128 Mbox::head

private

Definition at line 97 of file Mbox.h.

Referenced by Mbox().

class Message* Mbox::lastMsg

private

Definition at line 94 of file Mbox.h.

Referenced by Mbox().

pthread_mutex_t Mbox::mutexLast

private

Definition at line 90 of file Mbox.h.

Referenced by Mbox().

class Message* Mbox::myLastMsg

private

Definition at line 95 of file Mbox.h.

Referenced by Mbox().

__int128 Mbox::mytail

private

Definition at line 100 of file Mbox.h.

Referenced by Mbox().

__int128 Mbox::tail

private

Definition at line 98 of file Mbox.h.

Referenced by Mbox(), and MboxProducer::sendMsg().

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

• /home/infinisql/build/infinisql/infinisqld/Mbox.h
• /home/infinisql/build/infinisql/infinisqld/Mbox.cc