Allocating Static Patch Space

TotalView can statically allocate patch space if you add a specially named array to your program. When TotalView needs to use patch space, it uses the space created for this array.

You can include, for example, a 1 MB statically allocated patch space in your program by adding the TVDB_patch_base_address data object in a C module. Because this object must be 8-byte aligned, declare it as an array of doubles; for example:

/* 1 megabyte == size TV expects */

#define PATCH_LEN 0x100000

double TVDB_patch_base_address [PATCH_LEN / sizeof(double)]

If you need to use a static patch space size that differs from the 1 MB default, you must use assembler language. The following table shows sample assembler code for IBM AIX:

 

Platform	Assembler Code
IBM AIX	.csect .data{RW}, 3 .globl TVDB_patch_base_address .globl TVDB_patch_end_address TVDB_patch_base_address: .space PATCH_SIZE TVDB_patch_end_address:

To use the static patch space assembler code:

1	Use an ASCII editor and place the assembler code into a file named tvdb_patch_space.s.

2	Replace the PATCH_SIZE tag with the decimal number of bytes you want. This value must be a multiple of 8.

3	Assemble the file into an object file by using a command such as:

cc –c tvdb_patch_space.s

4	Link the resulting tvdb_patch_space.o into your program.