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In Newlib, the stdio streams are defined to thread-specific pointers _reent::_stdin, _reent::_stdout and _reent::_stderr. In case _REENT_SMALL is not defined, then these pointers are initialized via _REENT_INIT_PTR() or _REENT_INIT_PTR_ZEROED() to thread-specific FILE objects provided via _reent::__sf[3]. There are two problems with this (at least in case of RTEMS). (1) The thread-specific FILE objects are closed by _reclaim_reent(). This leads to problems with language run-time libraries that provide wrappers to the C/POSIX stdio streams (e.g. C++ and Ada), since they use the thread-specific FILE objects of the initialization thread. In case the initialization thread is deleted, then they use freed memory. (2) Since thread-specific FILE objects are used with a common output device via file descriptors 0, 1 and 2, the locking at FILE object level cannot ensure atomicity of the output, e.g. a call to printf(). Introduce a new Newlib configuration option _REENT_GLOBAL_STDIO_STREAMS to enable the use of global stdio FILE objects. As a side-effect this reduces the size of struct _reent by more than 50%. The _REENT_GLOBAL_STDIO_STREAMS should not be used without _STDIO_CLOSE_PER_REENT_STD_STREAMS. Signed-off-by: Sebastian Huber <sebastian.huber@embedded-brains.de>