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| <h5 class="subsubsection">3.2.3.3 Some more or less clever ideas</h5> |
| |
| <p>You know the situation. The program is prepared for debugging and in |
| all debugging sessions it runs well. But once it is started without |
| debugging the error shows up. A typical example is a memory leak that |
| becomes visible only when we turn off the debugging. If you foresee |
| such situations you can still win. Simply use something equivalent to |
| the following little program: |
| |
| <pre class="example"> #include <mcheck.h> |
| #include <signal.h> |
| |
| static void |
| enable (int sig) |
| { |
| mtrace (); |
| signal (SIGUSR1, enable); |
| } |
| |
| static void |
| disable (int sig) |
| { |
| muntrace (); |
| signal (SIGUSR2, disable); |
| } |
| |
| int |
| main (int argc, char *argv[]) |
| { |
| ... |
| |
| signal (SIGUSR1, enable); |
| signal (SIGUSR2, disable); |
| |
| ... |
| } |
| </pre> |
| <p>I.e., the user can start the memory debugger any time s/he wants if the |
| program was started with <code>MALLOC_TRACE</code> set in the environment. |
| The output will of course not show the allocations which happened before |
| the first signal but if there is a memory leak this will show up |
| nevertheless. |
| |
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