TotalView Users Guide - CI Wiki

About Action Points
Figure 221: Action Point
Symbols
� Barrier points
Barrier points are similar to simple breakpoints, differing in that you use
them to synchronize a group of processes or threads. A barrier point
holds each thread or process that reaches it until all threads or processes
reach it. Barrier points work together with the TotalView hold-and-release
feature. TotalView supports thread barrier and process barrier points.
� Eval points
An eval point is a breakpoint that has a code fragment associated with it.
When a thread or process encounters an eval point, it executes this code.
You can use eval points in a variety of ways, including conditional breakpoints,
thread-specific breakpoints, countdown breakpoints, and patching
code fragments into and out of your program.
� Watchpoints
A watchpoint tells TotalView to either stop the thread so that you can
interact with your program (unconditional watchpoint), or evaluate an
expression (conditional watchpoint).
All action points share the following common properties.
� You can independently enable or disable action points. A disabled action
isn’t deleted; however, when your program reaches a disabled action
point, TotalView ignores it.
� You can share action points across multiple processes or set them in individual
processes.
� Action points apply to the process. In a multi-threaded process, the action
point applies to all of the threads contained in the process.
� TotalView assigns unique ID numbers to each action point. These IDs appear
in several places, including the Root Window, the Action Points Tab
of the Process Window, and the Action Point > Properties Dialog Box.
The following figure shows the symbol that TotalView displays for an action
point:.
CLI: dactions shows information about action points.
Assembler-level action point
Breakpoint
Disabled breakpoint
Barrier breakpoint
Disabled barrier breakpoint
Eval point
Disabled eval point
350 Chapter 16: Setting Action Points