drivers/serial/serial.c open, read, write, and poll methods will not return a short transfer or an EINTR error if a signal is received while waiting (only)

git-svn-id: https://nuttx.svn.sourceforge.net/svnroot/nuttx/trunk@5022 7fd9a85b-ad96-42d3-883c-3090e2eb8679

nuttx/lib/stdio/lib_libfwrite.c

@@ -2,7 +2,7 @@
  * lib/stdio/lib_libfwrite.c
  *
  *   Copyright (C) 2007-2009, 2011 Gregory Nutt. All rights reserved.
- *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions

nuttx/lib/stdio/lib_lowinstream.c

@@ -1,8 +1,8 @@
 /****************************************************************************
  * lib/stdio/lib_lowinstream.c
  *
- *   Copyright (C) 2007-2009, 2011 Gregory Nutt. All rights reserved.
- *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *   Copyright (C) 2007-2009, 2011-2012 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -42,7 +42,9 @@
 #ifdef CONFIG_ARCH_LOWGETC
 
 #include <stdio.h>
+#include <assert.h>
 #include <errno.h>
+
 #include <nuttx/arch.h>
 
 #include "lib_internal.h"
@@ -57,10 +59,19 @@
 
 static int lowinstream_getc(FAR struct lib_instream_s *this)
 {
-  if (this && up_getc(ch) != EOF)
+  int ret;
+
+  DEBUGASSERT(this);
+
+  /* Get the next character from the incoming stream */
+
+  ret = up_getc(ch)
+  if (ret != EOF)
     {
       this->nget++;
     }
+
+  return ret;
 }
 
 /****************************************************************************

nuttx/lib/stdio/lib_lowoutstream.c

@@ -42,6 +42,7 @@
 #ifdef CONFIG_ARCH_LOWPUTC
 
 #include <stdio.h>
+#include <assert.h>
 #include <errno.h>
 #include <nuttx/arch.h>
 
@@ -57,7 +58,9 @@
 
 static void lowoutstream_putc(FAR struct lib_outstream_s *this, int ch)
 {
-  if (this && up_putc(ch) != EOF)
+  DEBUGASSERT(this);
+
+  if (up_putc(ch) != EOF)
     {
       this->nput++;
     }

nuttx/lib/stdio/lib_meminstream.c

@@ -1,8 +1,8 @@
 /****************************************************************************
  * lib/stdio/lib_meminstream.c
  *
- *   Copyright (C) 2007-2009, 2011 Gregory Nutt. All rights reserved.
- *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *   Copyright (C) 2007-2009, 2011-2012 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -37,6 +37,8 @@
  * Included Files
  ****************************************************************************/
 
+#include <assert.h>
+
 #include "lib_internal.h"
 
 /****************************************************************************
@@ -52,7 +54,11 @@ static int meminstream_getc(FAR struct lib_instream_s *this)
   FAR struct lib_meminstream_s *mthis = (FAR struct lib_meminstream_s *)this;
   int ret;
 
-  if (this && this->nget < mthis->buflen)
+  DEBUGASSERT(this);
+
+  /* Get the next character (if any) from the buffer */
+
+  if (this->nget < mthis->buflen)
     {
       ret = mthis->buffer[this->nget];
       this->nget++;
@@ -61,6 +67,7 @@ static int meminstream_getc(FAR struct lib_instream_s *this)
     {
       ret = EOF;
     }
+
   return ret;
 }
 

nuttx/lib/stdio/lib_memoutstream.c

@@ -37,6 +37,8 @@
  * Included Files
  ****************************************************************************/
 
+#include <assert.h>
+
 #include "lib_internal.h"
 
 /****************************************************************************
@@ -51,12 +53,14 @@ static void memoutstream_putc(FAR struct lib_outstream_s *this, int ch)
 {
   FAR struct lib_memoutstream_s *mthis = (FAR struct lib_memoutstream_s *)this;
 
+  DEBUGASSERT(this);
+
   /* If this will not overrun the buffer, then write the character to the
    * buffer.  Not that buflen was pre-decremented when the stream was
    * created so it is okay to write past the end of the buflen by one.
    */
 
-  if (this && this->nput < mthis->buflen)
+  if (this->nput < mthis->buflen)
     {
       mthis->buffer[this->nput] = ch;
       this->nput++;

nuttx/lib/stdio/lib_nullinstream.c

@@ -1,8 +1,8 @@
 /****************************************************************************
  * lib/stdio/lib_nullinstream.c
  *
- *   Copyright (C) 2007-2009, 2011 Gregory Nutt. All rights reserved.
- *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *   Copyright (C) 2007-2009, 2011-2012 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -39,6 +39,7 @@
 
 #include <stdio.h>
 #include <errno.h>
+
 #include "lib_internal.h"
 
 /****************************************************************************

nuttx/lib/stdio/lib_nulloutstream.c

@@ -38,7 +38,9 @@
  ****************************************************************************/
 
 #include <stdio.h>
+#include <assert.h>
 #include <errno.h>
+
 #include "lib_internal.h"
 
 /****************************************************************************
@@ -47,6 +49,7 @@
 
 static void nulloutstream_putc(FAR struct lib_outstream_s *this, int ch)
 {
+  DEBUGASSERT(this);
   this->nput++;
 }
 

nuttx/lib/stdio/lib_rawinstream.c

@@ -1,8 +1,8 @@
 /****************************************************************************
  * lib/stdio/lib_rawinstream.c
  *
- *   Copyright (C) 2007-2009, 2011 Gregory Nutt. All rights reserved.
- *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *   Copyright (C) 2007-2009, 2011-2012 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -38,7 +38,9 @@
  ****************************************************************************/
 
 #include <unistd.h>
+#include <assert.h>
 #include <errno.h>
+
 #include "lib_internal.h"
 
 /****************************************************************************
@@ -52,23 +54,27 @@
 static int rawinstream_getc(FAR struct lib_instream_s *this)
 {
   FAR struct lib_rawinstream_s *rthis = (FAR struct lib_rawinstream_s *)this;
+  int nwritten;
   char ch;
 
-  if (this && rthis->fd >= 0)
+  DEBUGASSERT(this && rthis->fd >= 0);
+
+  /* Attempt to read one character */
+
+  nwritten = read(rthis->fd, &ch, 1);
+  if (nwritten == 1)
     {
-      int nwritten;
-      do
-        {
-          nwritten = read(rthis->fd, &ch, 1);
-          if (nwritten == 1)
-            {
-              this->nget++;
-              return ch;
-            }
-        }
-      while (nwritten < 0 && get_errno() == EINTR);
+      this->nget++;
+      return ch;
     }
 
+  /* Return EOF on any failure to read from the incoming byte stream. The
+   * only expected error is EINTER meaning that the read was interrupted
+   * by a signal.  A Zero return value would indicated an end-of-file
+   * confition.
+   */
+
+  DEBUGASSERT(nwritten == 0 || get_errno() == EINTR);
   return EOF;
 }
 

nuttx/lib/stdio/lib_rawoutstream.c

@@ -38,7 +38,9 @@
  ****************************************************************************/
 
 #include <unistd.h>
+#include <assert.h>
 #include <errno.h>
+
 #include "lib_internal.h"
 
 /****************************************************************************
@@ -52,19 +54,28 @@
 static void rawoutstream_putc(FAR struct lib_outstream_s *this, int ch)
 {
   FAR struct lib_rawoutstream_s *rthis = (FAR struct lib_rawoutstream_s *)this;
+  int nwritten;
   char buffer = ch;
-  if (this && rthis->fd >= 0)
+
+  DEBUGASSERT(this && rthis->fd >= 0);
+
+  /* Loop until the character is successfully transferred  */
+
+  for (;;)
     {
-      int nwritten;
-      do
+      nwritten = write(rthis->fd, &buffer, 1);
+      if (nwritten == 1)
         {
-          nwritten = write(rthis->fd, &buffer, 1);
-          if (nwritten == 1)
-            {
-              this->nput++;
-            }
+          this->nput++;
+          return;
         }
-      while (nwritten < 0 && get_errno() == EINTR);
+
+      /* The only expected error is EINTR, meaning that the write operation
+       * was awakened by a signal.  Zero would not be a valid return value
+       * either.
+       */
+
+      DEBUGASSERT(nwritten < 0 && get_errno() == EINTR);
     }
 }
 

nuttx/lib/stdio/lib_stdinstream.c

@@ -1,8 +1,8 @@
 /****************************************************************************
  * lib/stdio/lib_stdinstream.c
  *
- *   Copyright (C) 2007-2009, 2011 Gregory Nutt. All rights reserved.
- *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *   Copyright (C) 2007-2009, 2011-2012 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -37,6 +37,8 @@
  * Included Files
  ****************************************************************************/
 
+#include <assert.h>
+
 #include "lib_internal.h"
 
 /****************************************************************************
@@ -50,16 +52,19 @@
 static int stdinstream_getc(FAR struct lib_instream_s *this)
 {
   FAR struct lib_stdinstream_s *sthis = (FAR struct lib_stdinstream_s *)this;
-  if (this)
+  int ret;
+
+  DEBUGASSERT(this);
+
+  /* Get the next character from the incoming stream */
+
+  ret = getc(sthis->stream);
+  if (ret != EOF)
     {
-      int ret = getc(sthis->stream);
-      if (ret != EOF)
-        {
-          this->nget++;
-        }
-      return ret;
+      this->nget++;
     }
-  return EOF;
+ 
+ return ret;
 }
 
 /****************************************************************************

nuttx/lib/stdio/lib_stdoutstream.c

@@ -1,8 +1,8 @@
 /****************************************************************************
  * lib/stdio/lib_stdoutstream.c
  *
- *   Copyright (C) 2007-2009, 2011 Gregory Nutt. All rights reserved.
- *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *   Copyright (C) 2007-2009, 2011-2012 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -38,6 +38,8 @@
  ****************************************************************************/
 
 #include <fcntl.h>
+#include <assert.h>
+#include <errno.h>
 
 #include "lib_internal.h"
 
@@ -52,12 +54,26 @@
 static void stdoutstream_putc(FAR struct lib_outstream_s *this, int ch)
 {
   FAR struct lib_stdoutstream_s *sthis = (FAR struct lib_stdoutstream_s *)this;
-  if (this)
+  int result;
+
+  DEBUGASSERT(this && sthis->stream);
+
+  /* Loop until the character is successfully transferred  */
+
+  for (;;)
     {
-      if (putc(ch, sthis->stream) != EOF)
+      result = fputc(ch, sthis->stream);
+      if (result != EOF)
         {
           this->nput++;
+          return;
         }
+
+      /* EINTR (meaning that fputc was interrupted by a signal) is the only
+       * expected error.
+       */
+
+      DEBUGASSERT(get_errno() == EINTR);
     }
 }
 

nuttx/lib/stdio/lib_syslogstream.c

@@ -40,6 +40,7 @@
 #include <nuttx/config.h>
 
 #include <unistd.h>
+#include <assert.h>
 #include <errno.h>
 
 #include <nuttx/syslog.h>
@@ -62,10 +63,31 @@
 
 static void syslogstream_putc(FAR struct lib_outstream_s *this, int ch)
 {
-  /* Write the character to the supported logging device */
+  int ret;
 
-  (void)syslog_putc(ch);
-  this->nput++;
+  /* Try writing until the write was successful or until an irrecoverable
+   * error occurs.
+   */
+
+  for (;;)
+    {
+      /* Write the character to the supported logging device */
+
+      ret = syslog_putc(ch);
+      if (ret == OK)
+        {
+          this->nput++;
+          return;
+        }
+
+      /* On failure syslog_putc will return a negated errno value.  The
+       * errno variable will not be set.  The special value -EINTR means that
+       * syslog_putc() was awakened by a signal.  This is not a real error and
+       * must be ignored in this context.
+       */
+
+      DEBUGASSERT(ret == -EINTR);
+    }
 }
 
 /****************************************************************************