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[AudioMonster]

Hello,

I'm trying to receive some data sent by my PC UDP client over WiFi.
I would like to receive them in a separate thread :


bool PspUDPrx::StartListening()
{

sceNetInetBind( _socketRX, (struct sockaddr* )&_addr, sizeof(_addr));


int tmp = sceKernelCreateThread("PspUDPrx",PspUDPrx::UdpRxThread, 0x18, 0x10000, 0, 0);

if(tmp >= 0)
{
sceKernelStartThread(tmp, sizeof(PspUDPrx*), this);
}
else
return false;

// ListenInOwnThread();

return true;
}

// ----------------------------------------------------------------------------
//
// ----------------------------------------------------------------------------
int PspUDPrx::UdpRxThread(SceSize args, void *argp)
{

PspUDPrx* pRx = (PspUDPrx*)argp;
pRx->ListenInOwnThread();

return 0;
}


Unfortunately, the sceNetInetRecv of the method ListenInOwnThread() does not work if i create that thread. It works fine if i don't create the thread and just call that method instead.

I presume i don't initialize the thread properly, is there some special parameter i should pass ? i tried PSP_THREAD_ATTR_USBWLAN without success.
Or maybe it's inside UdpRxThread(SceSize args, void *argp) that i don't cast properly the argp ?

[AudioMonster]

It seems my problem is about passing "this" to sceKernelStartThread.
So inside the function ListenInOwnThread() i don't have access to the real data member of that instance of my object.

in StartListening() i do

if(tmp >= 0)
{
printf("this = %x\n",(unsigned int)this);
sceKernelStartThread(tmp, sizeof(PspUDPrx*), this);
}

and in UdpRxThread() i do

PspUDPrx* pRx = (PspUDPrx*)argp;
printf("pRx = %x\n",(unsigned int)pRx);
pRx->ListenInOwnThread();

the 2 printf give a different value for the address of the instance of my object. Do i do something wrong in the way i cast ?

[PspPet]

re: sceKernelStartThread
BTW: If you want to access any global variables (or static variables in your class) you need a smaller assembler stub that sets the GP register before calling "PspUDPrx::UdpRxThread"

The args passed between threads are a *COPY* of the data you pass to "sceKernelStartThread". Your existing code can't handle that.

Add a "&" and "*" it should work. Instead use:
sceKernelStartThread(tmp, sizeof(PspUDPrx*), &this);
and:
PspUDPrx* pRx = *(*PspUDPrx*)argp;

Ideally put them into a structure

[AudioMonster]

int sceKernelStartThread (SceUID thid, SceSize args, void* argp)

Aaah so sceKernelStartThread actually contains a buffer of size

[mrbrown]

[AudioMonster]

Opps sorry for last post.

int sceKernelStartThread (SceUID thid, SceSize args, void* argp)

Aaah so the thread actually contains a buffer of size args and do an actually copy of argp into that internal buffer and pass it to the thread function ? That's very unusual ! :-P
Well, so i guess i was receiving the first 4 bytes of my object and not the actual address...

BTW: If you want to access any global variables (or static variables in your class) you need a smaller assembler stub that sets the GP register before calling "PspUDPrx::UdpRxThread"
What do you mean by that ?

[AudioMonster]

sceKernelStartThread(tmp, sizeof(PspUDPrx*), &this);

PspUDPrx.cpp:163: error: invalid lvalue in unary '&'

It seems like i need to use and intermediate variable.

PspUDPrx* pThis = this;
sceKernelStartThread(tmp, sizeof(PspUDPrx*), &pThis);

Any direct way to do this ?

[mrbrown]