Associating a Core File With a Loaded Program

As mentioned in Chapter 2, Using Prism, you can have Prism associate a core file with a program by specifying its name after the name of the program on the prism command line.

You can also do this by loading the program and then issuing the core command, specifying the name of the corresponding core file as its argument.

Note that the core command is not available in MP Prism. Instead, you must specify the name of the process core file from the Prism command line; as below.

% prism a.out corefile 

In either case, Prism reports the error that caused the core dump and loads the program with a stopped status at the location where the error occurred. You can then work with the program within Prism. You can, for example, examine the stack and print the values of variables. You cannot, however, continue execution from the current location.

Examining Local Process Core Files

You can use Prism to examine a core file created for a message-passing program. To do this, specify the core file name on the command line, after the name of the executable program. For example,

% prism a.out corefile

When Prism comes up, you can issue commands like where and print to inspect the state of your process at the time the core dump was taken. But note these restrictions:

• You actually start scalar Prism rather than MP Prism, since there is only one core file. Thus, you cannot use process sets (psets) or other features of MP Prism.

• You cannot issue any execution commands (for example, run, cont, or step).

• You cannot change the values of variables via the assign command.

• You cannot use the core command to examine a core file once you have started MP Prism. If multiple processes dumped core, the resulting core file may be overwritten, and therefore invalid.