Adding upstream version 1:115.7.0.upstream/1%115.7.0upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 42 insertions, 0 deletions

diff --git a/docs/nspr/reference/pr_setconcurrency.rst b/docs/nspr/reference/pr_setconcurrency.rst
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+PR_SetConcurrency
+=================
+
+Creates extra virtual processor threads. Generally used with MP systems.
+
+
+Syntax
+------
+
+.. code::
+
+   #include <prinit.h>
+
+   void PR_SetConcurrency(PRUintn numCPUs);
+
+
+Parameter
+~~~~~~~~~
+
+:ref:`PR_SetConcurrency` has one parameter:
+
+``numCPUs``
+   The number of extra virtual processor threads to be created.
+
+
+Description
+-----------
+
+Setting concurrency controls the number of virtual processors that NSPR
+uses to implement its ``M x N`` threading model. The ``M x N`` model is
+not available on all host systems. On those where it is not available,
+:ref:`PR_SetConcurrency` is ignored.
+
+Virtual processors are actually\ *global* threads, each of which is
+designed to support an arbitrary number of\ *local* threads. Since
+global threads are scheduled by the host operating system, this model is
+particularly applicable to multiprocessor architectures, where true
+parallelism is possible. However, it may also prove advantageous on
+uniprocessor systems to reduce the impact of having a locally scheduled
+thread calling incidental blocking functions. In such cases, all the
+threads being supported by the virtual processor will block, but those
+assigned to another virtual processor will be unaffected.