I have a TCPSocket* object which holds a connection to a client. This object is passed to another object to send data back to the client:
uint32_t count = 10;
char message[4];
message[0] = count & 0xff;
message[1] = (count >> 8) & 0xff;
message[2] = (count >> 16) & 0xff;
message[3] = (count >> 24) & 0xff;
client->send(&message, strlen(message));
When this part of the program is called, the following appears on the serial line, and no data is received by the client:
++ MbedOS Fault Handler ++
FaultType: HardFault
Context:
R0 : 00000000
R1 : 10008000
R2 : 00000004
R3 : 2007C000
R4 : 10000914
R5 : 00000000
R6 : 00000000
R7 : 10004330
R8 : 10004320
R9 : FFFFF435
R10 : 00000000
R11 : 00000000
R12 : 00012AC1
SP : 10002AF0
LR : 0000D1A1
PC : 00005938
xPSR : 21000000
PSP : 10002AD0
MSP : 10007FD8
CPUID: 412FC230
HFSR : 40000000
MMFSR: 00000000
BFSR : 00000082
UFSR : 00000000
DFSR : 0000000A
AFSR : 00000000
BFAR : 10008010
Mode : Thread
Priv : Privileged
Stack: PSP
-- MbedOS Fault Handler --
++ MbedOS Error Info ++
Error Status: 0x80FF013D Code: 317 Module: 255
Error Message: Fault exception
Location: 0xD337
Error Value: 0x5938
Current Thread: main Id: 0x10002B48 Entry: 0xD7D7 StackSize: 0x1000 StackMem: 0x10001B48 SP: 0x10007F88
For more info, visit: https://armmbed.github.io/mbedos-error/?error=0x80FF013D
-- MbedOS Error Info --
Everything is in one thread so I cant see what could be causing this.
These are the relevant parts of the program:
main:
// Network interface
EthernetInterface net;
TCPSocket listener; //listens for incoming connection requests
TCPSocket* client;
CommandProcessor commandProcessor(client);
int main(){
int remaining;
int rcount;
char *p;
char *buffer = new char[16];
nsapi_size_or_error_t result;
int n = net.set_network("192.168.1.103","255.255.255.0","192.168.1.2");
pc.printf("\n Success? %d\n", n);
net.connect();
listener.open(&net);
listener.bind(3045);
listener.listen(1);
client = listener.accept(NULL);
client->set_timeout(1000);
led1 = 1;
while(1) {
int remaining = 16;
int rcount = 0;
p = buffer;
while (remaining > 0 && 0 < (result = client->recv(p, remaining))) {
p += result;
rcount += result;
remaining -= result;
}
if (remaining == 0) //full message received
{
commandProcessor.process(buffer);
}
}
}
CommandProcessor:
CommandProcessor::CommandProcessor(TCPSocket* client)
{
this->client = client;
}
void CommandProcessor::process(char* message)
{
switch(message[0]) { //Command is first byte of message
case 0x3: {
uint32_t count = 10 ;
char* message = new char[4];
message[0] = count & 0xff;
message[1] = (count >> 8) & 0xff;
message[2] = (count >> 16) & 0xff;
message[3] = (count >> 24) & 0xff;
client->send(message, sizeof(message));
}
}
Best Answer
[Referring to initial question where
message
was defined aschar message[4];
]message[] is being put on the stack. By the time the TCP stack comes to send the data is the stack still valid?
strlen is not the way to determine the length of something that is not a string! Use sizeof(message) instead.
Check the lifetime of the TCPSocket object as well.