NDK hello world example - A_invalidFree exception

David Aldrich92784

Other Parts Discussed in Thread: SYSBIOS

I am using NDK version 2.20.4.26 with SYS/BIOS version 6.34.2.18 on a C66x dsp.

I have adapted the NDK helloWorld example to implement TCP server. The server works fine the first time that an external TCP client connects to it. The client then closes the connection and opens a new connection. When the client closes that second connection the server gives an exception:

ti.sysbios.heaps.HeapMem: line 350: assertion failure: A_invalidFree: Invalid free

xdc.runtime.Error.raise: terminating execution

I would like some help to find the reason for that exception please.

Below is console output from my code that shows what is going on. The server daemon does a malloc to create a receive message buffer, which it passes to recv(). The buffer is free'd when the connection closes. As you can see, the free appears to succeed but it is interesting that the buffer is allocated at a different address the second time around.

[C66xx_0] QMSS successfully initialized

CPPI successfully initialized

PA successfully initialized

TCP/IP Stack 'Hello World!' Application

PASS successfully initialized

Ethernet subsystem successfully initialized

Ethernet eventId : 48 and vectId (Interrupt) : 7

Registration of the EMAC Successful, waiting for link up ..

Network Added: If-1:172.29.68.187

Allocated buffer: 0xC0C92B0

dtask_tcpip_server called

Message received (length: 400 bytes, type: 0)

[snip]

Connection closed

Freeing buffer: 0xC0C92B0

Closing socket

dtask_tcpip_server called

Allocated buffer: 0xC0C1AA0

Message received (length: 400 bytes, type: 0)

[snip]

Connection closed

Freeing buffer: 0xC0C1AA0

Closing socket

ti.sysbios.heaps.HeapMem: line 350: assertion failure: A_invalidFree: Invalid free

xdc.runtime.Error.raise: terminating execution

Any suggestions for how to fix the exception would be much appreciated.

David

over 12 years ago

0 Steven Connell over 12 years ago

TI__Mastermind 45025 points

David,

Can you put break points at each of your alloc + free calls and check ROV? Check the HeapMem module and make sure you see what's expected (addresses, sizes, etc.) happening in the heap and the free list.

Here's the description of the assertion you are seeing for HeapMem:

       "Assert raised when the free detects that an invalid addr or size

       This could arise when multiple frees are done on the same buffer or
       if corruption occurred.

       This also could occur when an alloc is made with size N and the
       free for this buffer specifies size M where M > N. Note: not every
       case is detectable.

       This assert can also be caused when passing an invalid addr to free
       or if the size is causing the end of the buffer to be
       out of the expected range."

Can you tell if any of these scenarios are happening in your application?

David Aldrich92784 said:

Network Added: If-1:172.29.68.187

Allocated buffer: 0xC0C92B0

dtask_tcpip_server called

Message received (length: 400 bytes, type: 0)

[snip]

Connection closed

Freeing buffer: 0xC0C92B0

Closing socket

The above output makes it look like you are allocating your buffer *before* dtask_tcpip_server is called. Then it looks like the buffer is freed inside the dtask_tcpip_server function exits. Can you confirm?

Steve

0 David Aldrich92784 over 12 years ago in reply to Steven Connell

Genius 3720 points

Hi Steve

Thanks for your reply. The malloc actually occurs are dtask_tcpip_server is called, but the malloc message is printed using printf() (because I wanted to use %X) and the dtask_tcpip_server message is printed using System_printf(), hence the confusing order.

I will consider whether the error scenarios you listed are applicable.

David

Processors

Processors forum

NDK hello world example - A_invalidFree exception