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+PRThreadScope
+=============
+
+The scope of an NSPR thread, specified as a parameter to
+:ref:`PR_CreateThread` or returned by :ref:`PR_GetThreadScope`.
+
+
+Syntax
+------
+
+.. code::
+
+   #include <prthread.h>
+
+   typedef enum PRThreadScope {
+      PR_LOCAL_THREAD,
+      PR_GLOBAL_THREAD
+      PR_GLOBAL_BOUND_THREAD
+   } PRThreadScope;
+
+
+Enumerators
+~~~~~~~~~~~
+
+``PR_LOCAL_THREAD``
+   A local thread, scheduled locally by NSPR within the process.
+``PR_GLOBAL_THREAD``
+   A global thread, scheduled by the host OS.
+``PR_GLOBAL_BOUND_THREAD``
+   A global bound (kernel) thread, scheduled by the host OS
+
+
+Description
+-----------
+
+An enumerator of type :ref:`PRThreadScope` specifies how a thread is
+scheduled: either locally by NSPR within the process (a local thread) or
+globally by the host (a global thread).
+
+Global threads are scheduled by the host OS and compete with all other
+threads on the host OS for resources. They are subject to fairly
+sophisticated scheduling techniques.
+
+Local threads are scheduled by NSPR within the process. The process is
+assumed to be globally scheduled, but NSPR can manipulate local threads
+without system intervention. In most cases, this leads to a significant
+performance benefit.
+
+However, on systems that require NSPR to make a distinction between
+global and local threads, global threads are invariably required to do
+any form of I/O. If a thread is likely to do a lot of I/O, making it a
+global thread early is probably warranted.
+
+On systems that don't make a distinction between local and global
+threads, NSPR silently ignores the scheduling request. To find the scope
+of the thread, call :ref:`PR_GetThreadScope`.