Kinds of IDs

Multithreaded, multiprocess, distributed program contain a variety of IDs. Here is some background on the kinds used in the CLI and TotalView:

System PID

This is the process ID and is generally called the PID. This ID usually has a value between 100 and 32,000. However, it can be higher on some systems.

Debugger PID

This is an ID created by TotalView that lets it identify processes. It is a sequentially numbered value beginning at 1 that is incremented for each new process. Note that if the target process is killed and restarted (that is, you use the dkill and drun commands), the debugger PID does not change. The system PID, however, changes since the operating system has created a new target process.

System TID

This is the ID of the system kernel or user thread. On some systems (for example, AIX), the TIDs have no obvious meaning. On other systems, they start at 1 and are incremented by 1 for each thread.

TotalView thread ID

This is usually identical to the system TID. On some systems (such as AIX where the threads have no obvious meaning), TotalView uses its own IDs.

pthread ID

This is the ID assigned by the Posix pthreads package. On most systems, this differs from the system TID. In these cases, it is a pointer value that points to the pthread ID.