D.1 DECthreads Debugger

The DECthreads Debugger is a powerful tool designed to complement your existing debugger. It provides you with thread-specific command-string debugging, statistical and historical thread information on request, and many useful thread debugging commands and qualifiers. To invoke the DECthreads Debugger:

• From ladebug or dbx on Digital UNIX systems, enter:

  print pthread_debug()
  or
  call pthread_debug()

• From the OpenVMS debugger, enter:

  SET IMAGE PTHREAD$RTL
  CALL PTHREAD_DEBUG
  

  Note that PTHREAD_DEBUG must be entered in capital letters if the language is set to C or C++.

  You may wish to define a DEBUG command symbol, such as the following:

  define/command pthread_debug= "set image pthread$rtl; call PTHREAD_DEBUG"
  

• A client program may call the function pthread_debug() at any point during its execution.

Notes

• The DECthreads Debugger must be run within the context of a program being debugged. You cannot apply it to a core dump.

• The syntax of commands (and the list of supported commands) will change over time according to the needs of individual platforms. Never use calls to pthread_debug or pthread_debug_cmd as a part of a production application. It is for debugging use only, and may be phased out when system debuggers take on all required debugging capabilities.

• On Digital UNIX, when pthread_debug() or pthread_ debug_cmd() is called for the first time within a process, DECthreads may need to dynamically load the DECthreads debug image (libpthreaddebug.so). Because the dlopen() function uses DECthreads synchronization, there are situations when this may not succeed. In this case, try loading the image early - call pthread_debug_cmd() in main(), for example. Or, use ladebug thread commands, as described in Section D.2.