System crash

[dushantha12]

Hi,

I have a function call "process". I want to call this function in a multi threaded environment. When I call to this function inside a thread it was executed successfully. But the problem is the memory usage of the application was increasing at the same time.

#define EXTRA_INFOF_CODES_FINAL_RESPONSE_TRUE            255

struct REQUEST_MESSAGE{
	char messageStarter[4];
	char messageTypeIndicator[4];
	char extraInfo[4];
	int messageCounter;
	char commandCode[4];
	char tocken[18];
	int dataLength;
	char *data;
};

char* process(struct REQUEST_MESSAGE* message,char *respData,int tokenID,int finalResponse){
	char response[1024];
	char tempStr[1024];
	int len = 0;

	strcpy(response,message->messageStarter);
	strcat(response,message->messageTypeIndicator);

	 message->messageCounter++;

	 if(99 <= message->messageCounter){
		message->messageCounter = 1;
	}

	sprintf(tempStr,"%02d",message->messageCounter);
	strcat(response,tempStr);

	sprintf(tempStr,"%02X",finalResponse);
	strcat(response,tempStr);

	strcat(response,message->commandCode);

	sprintf(tempStr,"%016d",tokenID);
	strcat(response,tempStr);

	len = strlen(respData);
	sprintf(tempStr,"%04d",len);
	strcat(response,tempStr);

	strcat(response,respData);

	return strdup(response);
}


void* threadFunction(void *threadId){
    // this is the thread (thread pool)
        char data[16];
        struct REQUEST *request_obj = getNextObjectFromQueue();
        strcpy(data,"SUCCESS");
        char *response = process(request_obj->reqMessage,data,0,EXTRA_INFOF_CODES_FINAL_RESPONSE_TRUE);
        free(response);
        response = 0;
}

Any idea??

Thank you.

[kbw]

But the problem is the memory usage of the application was increasing at the same time.

Increased by how much?

You could improve the safety by replacing strcpy/strcat/sprintf with strncpy/strncat/snprintf.

You can also increase the efficiency by passing in response and its size as a parameter, avoiding a call to strdup/free, and make a single call to snprintf rather than 4.

Also, you need a lock around

	message->messageCounter++;
	if (99 <= message->messageCounter) {
		message->messageCounter = 1;
	}

which probably should be:

	if (++message->messageCounter > 99) {
		message->messageCounter = 1;
	}

[modoran]

getNextObjectFromQueue() returns a pointer to a struct. Where is that memory freed ? You leak that memory every time threadFunction runs.

You can verify that is your process() function as you have tought by just commenting out lines 55 - 57 in the above code to see what happens.