Information Technology Reference
In-Depth Information
Debugging multiple threads
Debugging becomes more complex when an application has multiple parallel threads. Breakpoints suspend exe-
cution in a single thread, but other threads continue to run. It can be useful to suspend them so other events
don't interfere as you step through your application. Figure 15.21 illustrates the Debug Navigator's thread dis-
play. To suspend a thread, right-click it and select the Suspend Thread option from the menu.
CAUTION
The lowest few threads in the display are usually system threads. Xcode lets you suspend system threads, but un-
less you have a very good reason for stopping OS threads, it's better to leave them running.
FIGURE 15.21
Suspending a thread in the Debug Navigator
