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BSD tcp socket - send error with large data size

atrocan

Hi,
I use Thread X with RA6M3.
FSP version 5.1


I want to send via tcp 119k byte using BSD wrapper, but:

If i try to send with a single call to send() function i get an error errno = 107 and the tcp socket disconnect.

bytes_to_send = 118784;

status = send(accepted_socket, ((const char*)p_SCmos), bytes_to_send, 0);

I thought it was a problem with the number of packet pool and their size but even setting the size to 1568 with 32 packets even trying to send only 15k bytes at a time I get an error.

The only wait to make it to go is to split with small send():

#define MAX_ONE_TIME_SEND_BYTES 1000

remaining_bytes = 118784

while(remaining_bytes > 0){

if(remaining_bytes > MAX_ONE_TIME_SEND_BYTES){

bytes_to_send = MAX_ONE_TIME_SEND_BYTES;

} else {

bytes_to_send = remaining_bytes;

}

status = send(accepted_socket, ((const char*)p_SCmos + (118784 - remaining_bytes)), bytes_to_send, 0);

if(status == -1){

SetLed(RED);

D(printf("Error sending body GetRawImage!\n"));

 }


What is the connection with  the BSD send() and packet pools? 
I thought that BSD send() took care of dividing my data to send it and not having to do it myself.
The only limit i think may be space due to the number of packets * packet size, but even if i use 1568 * 32 = 50176 a send with only 15k at a time it should work but it doesn't.
Can you explain to me why?

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  • 0 in reply to IK_Renesas

    Hi,
    1)IP fragmentation in our case is irrelevant because we have a point-to-point connection,. Anyhow, with or without fragmentation the behavior is unpredictable.
    2)With our application we try to use g_packet_pool1 ( just to avoid confusion we reserved a proper packet pool for BSD communication ) configured with 16 packets of 1568.
    Next we define MAX_ONE_TIME_SEND_BITES = 20000 as a maximum block to send. With this configuration two sends are successful while the third fails with error 107.
    If you try to test this behaviour setting MAX_ONE_TIME_SEND_BITES to 15000 more sends are successful but sooner or later the error comes...
    With 16 packets of 1568 bytes we should be covered up to 25k so 15k shouldn't have any problems.
    Can you tell me the correlation between maximum send size and how large the pool needs to be? 1:1, 1:2 or how much?

    Is it possible to have a new example for eval where you use BSD with blocking tcp socket and do a send() with 120k of payload in one send()?
    I mean without the need to cut my payload in pieces and using a loop?

    Thanks

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