[PATCH v2 5/5] Add --enable-newlib-global-stdio-streams

[PATCH v2 5/5] Add --enable-newlib-global-stdio-streams

[Sebastian Huber]

Signed-off-by: Sebastian Huber <sebastian.huber@embedded-brains.de>
---
 newlib/README                    |  6 ++++++
 newlib/configure                 | 24 ++++++++++++++++++++++--
 newlib/configure.in              | 13 +++++++++++++
 newlib/libc/include/sys/config.h |  6 ++++++
 newlib/newlib.hin                |  5 +++++
 5 files changed, 52 insertions(+), 2 deletions(-)

diff --git a/newlib/README b/newlib/README
index ed8fb3540..78f4de846 100644
--- a/newlib/README
+++ b/newlib/README
@@ -297,6 +297,12 @@ One feature can be enabled by specifying `--enable-FEATURE=yes' or
      is not referenced.
      Disabled by default.
 
+`--enable-newlib-global-stdio-streams'
+     Enable to move the stdio stream FILE objects out of struct _reent and make
+     them global.  The stdio stream pointers of struct _reent are initialized
+     to point to the global stdio FILE stream objects.
+     Disabled by default.
+
 `--enable-newlib-reent-small'
      Enable small reentrant struct support.
      Disabled by default.
diff --git a/newlib/configure b/newlib/configure
index de28c25b3..b2f0b3340 100755
--- a/newlib/configure
+++ b/newlib/configure
@@ -795,6 +795,7 @@ enable_newlib_iconv_external_ccs
 enable_newlib_atexit_dynamic_alloc
 enable_newlib_global_atexit
 enable_newlib_reent_small
+enable_newlib_global_stdio_streams
 enable_newlib_fvwrite_in_streamio
 enable_newlib_fseek_optimization
 enable_newlib_wide_orient
@@ -1467,6 +1468,7 @@ Optional Features:
   --disable-newlib-atexit-dynamic-alloc    disable dynamic allocation of atexit entries
   --enable-newlib-global-atexit	enable atexit data structure as global
   --enable-newlib-reent-small   enable small reentrant struct support
+  --enable-newlib-global-stdio-streams   enable global stdio streams
   --disable-newlib-fvwrite-in-streamio    disable iov in streamio
   --disable-newlib-fseek-optimization    disable fseek optimization
   --disable-newlib-wide-orient    Turn off wide orientation in streamio
@@ -2387,6 +2389,17 @@ else
   newlib_reent_small=
 fi
 
+# Check whether --enable-newlib-global-stdio-streams was given.
+if test "${enable_newlib_global_stdio_streams+set}" = set; then :
+  enableval=$enable_newlib_global_stdio_streams; case "${enableval}" in
+  yes) newlib_global_stdio_streams=yes;;
+  no)  newlib_global_stdio_streams=no ;;
+  *)   as_fn_error $? "bad value ${enableval} for newlib-global-stdio-streams option" "$LINENO" 5 ;;
+ esac
+else
+  newlib_global_stdio_streams=
+fi
+
 # Check whether --enable-newlib-fvwrite-in-streamio was given.
 if test "${enable_newlib_fvwrite_in_streamio+set}" = set; then :
   enableval=$enable_newlib_fvwrite_in_streamio; if test "${newlib_fvwrite_in_streamio+set}" != set; then
@@ -11794,7 +11807,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 11797 "configure"
+#line 11810 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -11900,7 +11913,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 11903 "configure"
+#line 11916 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -12347,6 +12360,13 @@ _ACEOF
 
 fi
 
+if test "${newlib_global_stdio_streams}" = "yes"; then
+cat >>confdefs.h <<_ACEOF
+#define _WANT_REENT_GLOBAL_STDIO_STREAMS 1
+_ACEOF
+
+fi
+
 if test "${newlib_mb}" = "yes"; then
 cat >>confdefs.h <<_ACEOF
 #define _MB_CAPABLE 1
diff --git a/newlib/configure.in b/newlib/configure.in
index 354c07ca5..5b86ee800 100644
--- a/newlib/configure.in
+++ b/newlib/configure.in
@@ -136,6 +136,15 @@ AC_ARG_ENABLE(newlib-reent-small,
   no)  newlib_reent_small=no ;;
   *)   AC_MSG_ERROR(bad value ${enableval} for newlib-reent-small option) ;;
  esac], [newlib_reent_small=])dnl
+
+dnl Support --enable-newlib-global-stdio-streams
+AC_ARG_ENABLE(newlib-global-stdio-streams,
+[  --enable-newlib-global-stdio-streams   enable global stdio streams],
+[case "${enableval}" in
+  yes) newlib_global_stdio_streams=yes;;
+  no)  newlib_global_stdio_streams=no ;;
+  *)   AC_MSG_ERROR(bad value ${enableval} for newlib-global-stdio-streams option) ;;
+ esac], [newlib_global_stdio_streams=])dnl
  
 dnl Support --disable-newlib-fvwrite-in-streamio
 AC_ARG_ENABLE(newlib-fvwrite-in-streamio,
@@ -400,6 +409,10 @@ if test "${newlib_reent_small}" = "yes"; then
 AC_DEFINE_UNQUOTED(_WANT_REENT_SMALL)
 fi
 
+if test "${newlib_global_stdio_streams}" = "yes"; then
+AC_DEFINE_UNQUOTED(_WANT_REENT_GLOBAL_STDIO_STREAMS)
+fi
+
 if test "${newlib_mb}" = "yes"; then
 AC_DEFINE_UNQUOTED(_MB_CAPABLE)
 AC_DEFINE_UNQUOTED(_MB_LEN_MAX,8)
diff --git a/newlib/libc/include/sys/config.h b/newlib/libc/include/sys/config.h
index ae8caff7b..e45aa5417 100644
--- a/newlib/libc/include/sys/config.h
+++ b/newlib/libc/include/sys/config.h
@@ -276,6 +276,12 @@
 #endif
 #endif
 
+#ifdef _WANT_REENT_GLOBAL_STDIO_STREAMS
+#ifndef _REENT_GLOBAL_STDIO_STREAMS
+#define _REENT_GLOBAL_STDIO_STREAMS
+#endif
+#endif
+
 /* If _MB_EXTENDED_CHARSETS_ALL is set, we want all of the extended
    charsets.  The extended charsets add a few functions and a couple
    of tables of a few K each. */
diff --git a/newlib/newlib.hin b/newlib/newlib.hin
index 397bc9b96..45c683187 100644
--- a/newlib/newlib.hin
+++ b/newlib/newlib.hin
@@ -79,6 +79,11 @@
 /* Define if declare atexit data as global.  */
 #undef _REENT_GLOBAL_ATEXIT
 
+/* Define to move the stdio stream FILE objects out of struct _reent and make
+   them global.  The stdio stream pointers of struct _reent are initialized to
+   point to the global stdio FILE stream objects. */
+#undef _WANT_REENT_GLOBAL_STDIO_STREAMS
+
 /* Define if small footprint nano-formatted-IO implementation used.  */
 #undef _NANO_FORMATTED_IO
 
-- 
2.12.3

[PATCH v2 3/5] Introduce _REENT_GLOBAL_STDIO_STREAMS

[Sebastian Huber]

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>
---
 newlib/libc/include/sys/reent.h | 21 +++++++++++++++------
 newlib/libc/stdio/findfp.c      | 24 ++++++++++++++++++++++++
 2 files changed, 39 insertions(+), 6 deletions(-)

diff --git a/newlib/libc/include/sys/reent.h b/newlib/libc/include/sys/reent.h
index 8b67889ac..7cfe3937d 100644
--- a/newlib/libc/include/sys/reent.h
+++ b/newlib/libc/include/sys/reent.h
@@ -644,14 +644,23 @@ struct _reent
      of the above members (on the off chance that future binary compatibility
      would be broken otherwise).  */
   struct _glue __sglue;		/* root of glue chain */
+# ifndef _REENT_GLOBAL_STDIO_STREAMS
   __FILE __sf[3];  		/* first three file descriptors */
+# endif
 };
 
+#ifdef _REENT_GLOBAL_STDIO_STREAMS
+extern __FILE __sf[3];
+#define _REENT_STDIO_STREAM(var, index) &__sf[index]
+#else
+#define _REENT_STDIO_STREAM(var, index) &(var)->__sf[index]
+#endif
+
 #define _REENT_INIT(var) \
   { 0, \
-    &(var).__sf[0], \
-    &(var).__sf[1], \
-    &(var).__sf[2], \
+    _REENT_STDIO_STREAM(var, 0), \
+    _REENT_STDIO_STREAM(var, 1), \
+    _REENT_STDIO_STREAM(var, 2), \
     0, \
     "", \
     0, \
@@ -696,9 +705,9 @@ struct _reent
   }
 
 #define _REENT_INIT_PTR_ZEROED(var) \
-  { (var)->_stdin = &(var)->__sf[0]; \
-    (var)->_stdout = &(var)->__sf[1]; \
-    (var)->_stderr = &(var)->__sf[2]; \
+  { (var)->_stdin = _REENT_STDIO_STREAM(var, 0); \
+    (var)->_stdout = _REENT_STDIO_STREAM(var, 1); \
+    (var)->_stderr = _REENT_STDIO_STREAM(var, 2); \
     (var)->_new._reent._rand_next = 1; \
     (var)->_new._reent._r48._seed[0] = _RAND48_SEED_0; \
     (var)->_new._reent._r48._seed[1] = _RAND48_SEED_1; \
diff --git a/newlib/libc/stdio/findfp.c b/newlib/libc/stdio/findfp.c
index b40aa9240..737bde102 100644
--- a/newlib/libc/stdio/findfp.c
+++ b/newlib/libc/stdio/findfp.c
@@ -35,6 +35,10 @@ const struct __sFILE_fake __sf_fake_stderr =
     {_NULL, 0, 0, 0, 0, {_NULL, 0}, 0, _NULL};
 #endif
 
+#ifdef _REENT_GLOBAL_STDIO_STREAMS
+__FILE __sf[3];
+#endif
+
 #if (defined (__OPTIMIZE_SIZE__) || defined (PREFER_SIZE_OVER_SPEED))
 _NOINLINE_STATIC _VOID
 #else
@@ -218,6 +222,14 @@ _DEFUN(_cleanup_r, (ptr),
   cleanup_func = _fclose_r;
 #endif
 #endif
+#ifdef _REENT_GLOBAL_STDIO_STREAMS
+  if (ptr->_stdin != &__sf[0])
+    (*cleanup_func) (ptr, ptr->_stdin);
+  if (ptr->_stdout != &__sf[1])
+    (*cleanup_func) (ptr, ptr->_stdout);
+  if (ptr->_stderr != &__sf[2])
+    (*cleanup_func) (ptr, ptr->_stderr);
+#endif
   _CAST_VOID _fwalk_reent (ptr, cleanup_func);
 }
 
@@ -250,8 +262,10 @@ _DEFUN(__sinit, (s),
 
   s->__sglue._next = NULL;
 #ifndef _REENT_SMALL
+# ifndef _REENT_GLOBAL_STDIO_STREAMS
   s->__sglue._niobs = 3;
   s->__sglue._iobs = &s->__sf[0];
+# endif
 #else
   s->__sglue._niobs = 0;
   s->__sglue._iobs = NULL;
@@ -265,9 +279,19 @@ _DEFUN(__sinit, (s),
   s->_stderr = __sfp(s);
 #endif
 
+#ifdef _REENT_GLOBAL_STDIO_STREAMS
+  if (__sf[0]._cookie == NULL) {
+    _GLOBAL_REENT->__sglue._niobs = 3;
+    _GLOBAL_REENT->__sglue._iobs = &__sf[0];
+    stdin_init (&__sf[0]);
+    stdout_init (&__sf[1]);
+    stderr_init (&__sf[2]);
+  }
+#else
   stdin_init (s->_stdin);
   stdout_init (s->_stdout);
   stderr_init (s->_stderr);
+#endif
 
   s->__sdidinit = 1;
 
-- 
2.12.3

[PATCH v2 1/5] Remove superfluous parameter from std()

[Sebastian Huber]

Signed-off-by: Sebastian Huber <sebastian.huber@embedded-brains.de>
---
 newlib/libc/stdio/findfp.c | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/newlib/libc/stdio/findfp.c b/newlib/libc/stdio/findfp.c
index 83d3dc558..ecc65d6d3 100644
--- a/newlib/libc/stdio/findfp.c
+++ b/newlib/libc/stdio/findfp.c
@@ -40,11 +40,10 @@ _NOINLINE_STATIC _VOID
 #else
 static _VOID
 #endif
-_DEFUN(std, (ptr, flags, file, data),
+_DEFUN(std, (ptr, flags, file),
             FILE *ptr _AND
             int flags _AND
-            int file  _AND
-            struct _reent *data)
+            int file)
 {
   ptr->_p = 0;
   ptr->_r = 0;
@@ -236,7 +235,7 @@ _DEFUN(__sinit, (s),
   s->_stderr = __sfp(s);
 #endif
 
-  std (s->_stdin,  __SRD, 0, s);
+  std (s->_stdin,  __SRD, 0);
 
   /* On platforms that have true file system I/O, we can verify
      whether stdout is an interactive terminal or not, as part of
@@ -245,14 +244,14 @@ _DEFUN(__sinit, (s),
      requires both stdin and stdout to be line-buffered, but tradition
      leaves stdin alone on systems without fcntl.  */
 #ifdef HAVE_FCNTL
-  std (s->_stdout, __SWR, 1, s);
+  std (s->_stdout, __SWR, 1);
 #else
-  std (s->_stdout, __SWR | __SLBF, 1, s);
+  std (s->_stdout, __SWR | __SLBF, 1);
 #endif
 
   /* POSIX requires stderr to be opened for reading and writing, even
      when the underlying fd 2 is write-only.  */
-  std (s->_stderr, __SRW | __SNBF, 2, s);
+  std (s->_stderr, __SRW | __SNBF, 2);
 
   s->__sdidinit = 1;
 
-- 
2.12.3

[PATCH v2 4/5] Enable _REENT_GLOBAL_STDIO_STREAMS for RTEMS

[Sebastian Huber]

Signed-off-by: Sebastian Huber <sebastian.huber@embedded-brains.de>
---
 newlib/libc/include/sys/config.h | 1 +
 newlib/libc/stdio/local.h        | 2 +-
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/newlib/libc/include/sys/config.h b/newlib/libc/include/sys/config.h
index 555239f8b..ae8caff7b 100644
--- a/newlib/libc/include/sys/config.h
+++ b/newlib/libc/include/sys/config.h
@@ -238,6 +238,7 @@
 #define _READ_WRITE_RETURN_TYPE _ssize_t
 #define __DYNAMIC_REENT__
 #define _REENT_GLOBAL_ATEXIT
+#define _REENT_GLOBAL_STDIO_STREAMS
 #endif
 
 #ifndef __EXPORT
diff --git a/newlib/libc/stdio/local.h b/newlib/libc/stdio/local.h
index 5f6995501..511e5e35f 100644
--- a/newlib/libc/stdio/local.h
+++ b/newlib/libc/stdio/local.h
@@ -38,7 +38,7 @@
    case _STDIO_CLOSE_PER_REENT_STD_STREAMS is defined these file descriptors
    will be closed via close() provided the owner of the reent structure
    triggerd the on demand reent initilization, see CHECK_INIT(). */
-#if !defined(__rtems__) && !defined(__tirtos__)
+#if !defined(__tirtos__)
 #define _STDIO_CLOSE_PER_REENT_STD_STREAMS
 #endif
 
-- 
2.12.3

[PATCH v2 2/5] Add stdin_init(), stdout_init() and stderr_init()

[Sebastian Huber]

This simplifies further changes in this area.

Signed-off-by: Sebastian Huber <sebastian.huber@embedded-brains.de>
---
 newlib/libc/stdio/findfp.c | 50 ++++++++++++++++++++++++++++++----------------
 1 file changed, 33 insertions(+), 17 deletions(-)

diff --git a/newlib/libc/stdio/findfp.c b/newlib/libc/stdio/findfp.c
index ecc65d6d3..b40aa9240 100644
--- a/newlib/libc/stdio/findfp.c
+++ b/newlib/libc/stdio/findfp.c
@@ -84,6 +84,36 @@ _DEFUN(std, (ptr, flags, file),
 #endif
 }
 
+static inline void
+stdin_init(FILE *ptr)
+{
+  std (ptr,  __SRD, 0);
+}
+
+static inline void
+stdout_init(FILE *ptr)
+{
+  /* On platforms that have true file system I/O, we can verify
+     whether stdout is an interactive terminal or not, as part of
+     __smakebuf on first use of the stream.  For all other platforms,
+     we will default to line buffered mode here.  Technically, POSIX
+     requires both stdin and stdout to be line-buffered, but tradition
+     leaves stdin alone on systems without fcntl.  */
+#ifdef HAVE_FCNTL
+  std (ptr, __SWR, 1);
+#else
+  std (ptr, __SWR | __SLBF, 1);
+#endif
+}
+
+static inline void
+stderr_init(FILE *ptr)
+{
+  /* POSIX requires stderr to be opened for reading and writing, even
+     when the underlying fd 2 is write-only.  */
+  std (ptr, __SRW | __SNBF, 2);
+}
+
 struct glue_with_file {
   struct _glue glue;
   FILE file;
@@ -235,23 +265,9 @@ _DEFUN(__sinit, (s),
   s->_stderr = __sfp(s);
 #endif
 
-  std (s->_stdin,  __SRD, 0);
-
-  /* On platforms that have true file system I/O, we can verify
-     whether stdout is an interactive terminal or not, as part of
-     __smakebuf on first use of the stream.  For all other platforms,
-     we will default to line buffered mode here.  Technically, POSIX
-     requires both stdin and stdout to be line-buffered, but tradition
-     leaves stdin alone on systems without fcntl.  */
-#ifdef HAVE_FCNTL
-  std (s->_stdout, __SWR, 1);
-#else
-  std (s->_stdout, __SWR | __SLBF, 1);
-#endif
-
-  /* POSIX requires stderr to be opened for reading and writing, even
-     when the underlying fd 2 is write-only.  */
-  std (s->_stderr, __SRW | __SNBF, 2);
+  stdin_init (s->_stdin);
+  stdout_init (s->_stdout);
+  stderr_init (s->_stderr);
 
   s->__sdidinit = 1;
 
-- 
2.12.3

Re: [PATCH v2 3/5] Introduce _REENT_GLOBAL_STDIO_STREAMS

[Sebastian Huber]

Sorry, this patch is still broken. I got confused by the var parameter 
which is in one place a pointer and in another the variable directly. I 
need a v3 of the patch set.

-- 
Sebastian Huber, embedded brains GmbH

Address : Dornierstr. 4, D-82178 Puchheim, Germany
Phone   : +49 89 189 47 41-16
Fax     : +49 89 189 47 41-09
E-Mail  : sebastian.huber@embedded-brains.de
PGP     : Public key available on request.

Diese Nachricht ist keine geschäftliche Mitteilung im Sinne des EHUG.