pthread_t - what does it return?

[scorpio2002]

Hi there!
Here's my question. When I do a printf() on a variable of the pthread_t type I expect to get a TID. But I'm getting a negative very long integer. is that normal? What is that negative integer? How do I get the correct thread ID?

[thumper]

pthread_t is an opaque type. While it is often represented by an int or long, you cannot guarantee the value. Solaris seems to use incrementing integer values using 1 for the main thread and increasing values there after. Linux however does not use a method like that. You can be guaranteed that the value is unique for your current process, but that is about it.