pthread.h

The pthread.h header file contains function declarations and mappings for threading interfaces and defines a number of constants used by those functions. The header includes the sched.h header. When _UNIX03_THREADS is defined, pthread.h also includes the time.h header. For _OPEN_THREADS applications, pthread.h defines the timespec structure.

There is a lot of overlap in the namespaces identified by the _OPEN_THREADS and _UNIX03_THREADS feature test macros. There are, however, behavioral differences between functions of the same name exposed by _OPEN_THREADS (POSIX.4a Draft 6) and by _UNIX03_THREADS (Single UNIX Specification, Version 3). See the individual function descriptions for specific details.

_OPEN_THREADS 1
_OPEN_THREADS 2
_OPEN_THREADS 3
_UNIX03_THREADS
_OPEN_SYS
_OPEN_SYS_MUTEX_EXT
The pthread.h header defines the following constants:
Furthermore, pthread.h defines these macros:
_OPEN_THREADS 2