crash at connection

[sunarc123]

Hello Martin,

After a long time I am getting again crashes due to sql library in my app. Please check below screen shot for details.

[martinrybak]

Does this happen every time or just sometimes? Can you include me more of the stack trace? Thanks.

[ramsince88]

This happens every time.

[martinrybak]

Please tell me if anything changed since the last time you said everything was working fine. Also please attach the full stack trace.

[ramsince88]

I have not made any change just deploy code on another machine.

[ramsince88]

Did you get any solution????

[ramsince88]

Hii Sorry for inconvenience.

• (void)execute:(NSString)sql completion:(void (^)(NSArray results))completion

{

//Execute query on worker queue

[self.workerQueue addOperationWithBlock:^{

//Prepare SQL statement

dbcmd(connection, [sql UTF8String]);

//Execute SQL statement

if (dbsqlexec(connection) == FAIL)

return [self executionFailure:completion];

//Create array to contain the tables

NSMutableArray* output = [[NSMutableArray alloc] init];

struct COL* columns;

struct COL* pcol;

int erc;

//Loop through each table

while ((erc = dbresults(connection)) != NO_MORE_RESULTS)

{

int ncols;

int row_code;

//Create array to contain the rows for this table

NSMutableArray* table = [[NSMutableArray alloc] init];

//Get number of columns

ncols = dbnumcols(connection);

//Allocate C-style array of COL structs

if ((columns = calloc(ncols, sizeof(struct COL))) == NULL)

return [self executionFailure:completion];

//Bind the column info

for (pcol = columns; pcol - columns < ncols; pcol++)

{

//Get column number

int c = pcol - columns + 1;

//Get column metadata

pcol->name = dbcolname(connection, c);

pcol->type = dbcoltype(connection, c);

pcol->size = dbcollen(connection, c);

//If the column is [VAR]CHAR, we want the column's defined size, otherwise we want

//its maximum size when represented as a string, which FreeTDS's dbwillconvert()

//returns (for fixed-length datatypes).

if (pcol->type != SYBCHAR)

pcol->size = dbwillconvert(pcol->type, SYBCHAR);

//Allocate memory in the current pcol struct for a buffer

if ((pcol->buffer = calloc(1, pcol->size + 1)) == NULL)

return [self executionFailure:completion];

//Bind column name

erc = dbbind(connection, c, NTBSTRINGBIND, pcol->size + 1, (BYTE*)pcol->buffer);

if (erc == FAIL)

return [self executionFailure:completion];

//Bind column status

erc = dbnullbind(connection, c, &pcol->status);

if (erc == FAIL)

return [self executionFailure:completion];

//printf("%s is type %d with value %s\n", pcol->name, pcol->type, pcol->buffer);

}

//printf("\n");

//Loop through each row

while ((row_code = dbnextrow(connection)) != NO_MORE_ROWS)

{

//Check row type

switch (row_code)

{

//Regular row

case REG_ROW:

{

//Create a new dictionary to contain the column names and vaues

NSMutableDictionary* row = [[NSMutableDictionary alloc] initWithCapacity:ncols];

//Loop through each column and create an entry where dictionary[columnName] = columnValue

for (pcol = columns; pcol - columns < ncols; pcol++)

{

NSString* column = [NSString stringWithUTF8String:pcol->name];

id value = [NSString stringWithUTF8String:pcol->buffer] ?: [NSNull null];

row[column] = value;

                        //printf("%@=%@\n", column, value);

}

                    //Add an immutable copy to the table

[table addObject:[row copy]];

//printf("\n");

break;

}

//Buffer full

case BUF_FULL:

return [self executionFailure:completion];

//Error

case FAIL:

return [self executionFailure:completion];

default:

[self message:SQLClientRowIgnoreMessage];

}

}

//Clean up

for (pcol = columns; pcol - columns < ncols; pcol++)

free(pcol->buffer);

free(columns);

//Add immutable copy of table to output

[output addObject:[table copy]];

}

    //Success! Send an immutable copy of the results array

[self executionSuccess:completion results:[output copy]];

}];

}

this code where crashing exist. and screen shot of stack is below

[ramsince88]

Martin please reply. My whole app depend on your code.

[martinrybak]

You said your code works on one machine and not the other? Can you tell me what is different between them?

[ramsince88]

No difference. That time I was working at dubai and now in india. And now testing on simulator and that time testing on device. Thats all.

[martinrybak]

So it works on the device but not in the simulator?

[ramsince88]

YES . But once let me confirm again.

[ramsince88]

Yes. This happened only in simulator.