dld.so.5 (2010 09)

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dld.so(5)

Itanium(R)-based Systems Only

dld.so(5)

the linker.

Use the

+gst options, +gst, +gstsize, and

+nodynhash, to control the behavior of the global symbol

table hash mechanism. See the ld(1) and chatr (1) commands for information on these options.

With these options, you can tune the size to reach a balance of performance and memory use. To maxim-

ize for performance, tune the table size for an average chain length of one. For maximum memory use, at

the expense of performance, tune the size of the table to minimize the number of empty entries. In gen-

eral, use prime numbers for the table size.

To get statistical information about hash table performance, set the environment variable

_HP_DLDOPTS

to contain the -symtab_stat option. This option provides a message for each library that contains the

following information:

• Operation (load/unload)

• Name of library

• Number of exports

• Number of entries in table with no stored symbols

• Average length of non-zero chains

• Calculated performance of the hash table

• Amount of memory used by the hash table

Dynamic Loader Behavior in PA-RISC 32-bit Compatibility Mode

The dynamic loader maintains certain behaviors to support compatibility with earlier PA-RISC 32-bit

releases. These operations apply to programs created with the

ld +compat command and the

shl_load() library management routines.

Dynamic Path List

There are two ways to specify a dynamic path list :

• by storing a directory path list in the executable using the +b path_list option to ld

• by linking the executable with

ld option +s, enabling the executable to use the path list deﬁned by

the SHLIB_PATH environment variable at run time.

The path list is a list of one or more path names separated by colons (

:). The dynamic path list works

only for libraries speciﬁed with the

-l or -l: options to ld. However, it can be enabled for libraries

speciﬁed with a full path name using the -l option to chatr (see chatr (1)). If both

+s and +b are used,

their relative order on the command line indicates which path list is searched ﬁrst in compatibility mode.

See the

+help option to ld (1) or the HP-UX Linker and Libraries User’s Guide for more details.

Depth-ﬁrst Searching

This is the search behavior used by the compatibility mode, and is used if doing a

shl_load() or if the

incomplete executable was linked with

+compat. The dynamic loader searches the incomplete execut-

able followed by the ﬁrst library in its library load list. The ﬁrst dependent library of this library is then

searched, followed by the ﬁrst dependent of this dependent, and so on. When there are no more depen-

dents, the siblings and their dependents are searched until eventually the second library in the program’s

library load list is searched, followed by the ﬁrst dependent of this library, and so on.

Diagnostics and Warnings

In compatibility mode, if you wish to see all of the messages, set the environment variable

_HP_DLDOPTS to contain one or more options. The following options are supported:

-warnings Display additional dynamic loader warning messages. Some of these include:

• Symbols of the same name but different types, such as CODE and DATA. See

the WARNINGS section in ld (1) for more details on this warning.

• Using certain ﬂags or routines described in shl_load (3X).

-fbverbose See fastbind (1).

-nofastbind See fastbind (1).

4 Hewlett-Packard Company − 4 − HP-UX 11i Version 3: September 2010