On Wed, Jan 25, 2012 at 1:37 AM, ranjith kumar <ranjithproxy@xxxxxxxxx> wrote:
> Hi,
> I have a program like
>
> 1)printf("%s %d",__FILE__,__LINE__);
> 2)printf("%s %d",__FILE__,__LINE__);
> 3)printf("%s %d",__FILE__,__LINE__);
> 4)assert(0);
>
>
> 1)My question is : are the printf/cout statements are run by separate threads?
> 2)In the above program some time prinrf statement on line1 is printed.
> some times upto line 2, some time upto line3.
> why?
> 3) How to make sure that all the print statements, before the line
> causing the crash , are printed ?
Asserts are diagnostic aides, which are suppose to help the programmer
[1, 2]. assert calls abort(), which is useless (especially under a
debugger).
In release code (ie, when NDEBUG is defined), assertions are not
compiled into the program. But some folks leave asserts in their
production code [3], which is a mis-use of the diagnostic and leads to
a DoS on a server.
Try the following for sane behavior when using asserts. Your program
won't crash, and you can continue stepping to see how it handles
negative test cases.
Jeff
[1] www.open-std.org/jtc1/sc22/wg14/www/C99RationaleV5.10.pdf
[2] http://pubs.opengroup.org/onlinepubs/000095399/functions/assert.html
[3] http://www.isc.org/software/bind/advisories/cve-2011-4313
# define ASSERT(exp) { \
if(!(exp)) { \
std::ostringstream oss; \
oss << "Assertion failed: " << (char*)(__FILE__) << "(" \
<< (int)__LINE__ << "): " << (char*)(__func__) \
<< std::endl; \
std::cerr << oss.str(); \
raise(SIGTRAP); \
} \
}
