International Business Machines Corporation

Rodney Lee Rabe

Cary Lee Bates

Timothy Roy Block

David Lee Hermsmeier

Paula A Kavanagh

Debugging of code of a computer program is facilitated by implementing a step-type operation using internal breakpoints to ensure debugger control of the code. During a debugging session, a step-type operation is implemented by setting active internal breakpoints on every line of code of every routine currently on the call stack referenced by the processor and on entry points of the code being debugged, and subsequently leaving in place, upon completion of the step-type operation, active internal breakpoints. Subsequent to implementing the step-type operation any active internal breakpoints encountered during execution of one or more other operations of the code and deemed unnecessary to completion of the other operation(s) are disabled, and the location of any internal breakpoints disabled during execution of the one or more other operations are tracked in a data structure(s) for subsequent use in reestablishing needed internal breakpoints for implementation of another step-type operation.

Implementing a step-type operation during debugging of code using internal breakpoints

A debugger allows a programmer to select the granularity of a line step function. Using a debugger step statement, the programmer can specify line step, statement step, or automatic selection. When the user specifies line step in the debugger statement, the debugger functions in true line step mode, where a line of source code is executed for each step. When the user specifies statement step in the debugger statement, the debugger functions in statement step mode, where a statement is executed for each step. When the user specifies automatic selection in the debugger statement, the program is analyzed, and a decision regarding whether to use line step or statement step is made based on the characteristics of the program and based on user-specified selection criteria. In this manner the function of the debugger when line stepping can vary according to the programmer's needs.

Step granularity selection in a software debugger

The preferred embodiment of the present invention provides a cluster node distress system and method that improves the reliability of a cluster. The cluster node distress system provides a cluster node distress signal when a node on the cluster is about to fail. This allows the cluster to better to determine whether a non-communicating node has failed or has merely been partitioned from the cluster. The preferred cluster node distress system is embedded deeply into the operating system and provides a pre-built node distress signal that can be quickly sent to other nodes in the cluster when an imminent failure of that node is detected, improving the probability that the node distress signal will get out before the node totally fails. When the node distress signal is effectively sent to other nodes in the cluster, the cluster can accurately determine that the node has failed and has not just partitioned from the cluster. This allows the cluster to respond correctly, i.e., by assigning other nodes primary responsibility, with less intervention needed by administrators.

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Byron, MN, United States of America

Rodney Lee Rabe