TotalView Users Guide - CI Wiki

Figure 236: Stopped
Execution of Compiled
Expressions
Defining Eval Points and Conditional Breakpoints
If the expression executes a $stop function, TotalView stops executing the
compiled expression. At this time, you can single-step through it and continue
executing the expression as you would the rest of your code.
If you plan to use many compiled expressions or your expressions are long,
you may need to think about allocating patch space.
Allocating Patch Space for Compiled Expressions
Compiled
expression
gets its own
stack frame
Compiled
expression in
Source Pane
TotalView must either allocate or find space in your program to hold the
code that it generates for compiled expressions. Since this patch space is
part of your program’s address space, the location, size, and allocation
scheme that TotalView uses might conflict with your program. As a result,
you may need to change how TotalView allocates this space.
You can choose one of the following patch space allocation schemes:
� Dynamic patch space allocation: Tells TotalView to dynamically find
the space for your expression’s code.
� Static patch space allocation: Tells TotalView to use a statically allocated
area of memory.
Allocating Dynamic Patch Space
Dynamic patch space allocation means that TotalView dynamically allocates
patch space for code fragments. If you do not specify the size and location
for this space, TotalView allocates 1 MB. TotalView creates this space using
system calls.
TotalView allocates memory for read, write, and execute access in the
addresses shown in the following table:
TotalView Users Guide: version 8.7 371