libs/libc: remove unnecessary flockfile to improve performance

modify lib_wrflush/lib_rdflush/lib_ffulsh to unlocked version

Signed-off-by: dongjiuzhu1 <dongjiuzhu1@xiaomi.com>

libs/libc/libc.h

@@ -235,14 +235,15 @@ FAR char *lib_fgets(FAR char *buf, size_t buflen, FILE *stream,
 /* Defined in lib_libfflush.c */
 
 ssize_t lib_fflush(FAR FILE *stream, bool bforce);
+ssize_t lib_fflush_unlocked(FAR FILE *stream, bool bforce);
 
-/* Defined in lib_rdflush.c */
+/* Defined in lib_rdflush_unlocked.c */
 
-int lib_rdflush(FAR FILE *stream);
+int lib_rdflush_unlocked(FAR FILE *stream);
 
-/* Defined in lib_wrflush.c */
+/* Defined in lib_wrflush_unlocked.c */
 
-int lib_wrflush(FAR FILE *stream);
+int lib_wrflush_unlocked(FAR FILE *stream);
 
 /* Defined in lib_libgetbase.c */
 

libs/libc/stdio/CMakeLists.txt

@@ -79,8 +79,8 @@ if(CONFIG_FILE_STREAM)
     lib_fflush.c
     lib_libflushall.c
     lib_libfflush.c
-    lib_rdflush.c
-    lib_wrflush.c
+    lib_rdflush_unlocked.c
+    lib_wrflush_unlocked.c
     lib_putc.c
     lib_fputc.c
     lib_fputs.c

libs/libc/stdio/Make.defs

@@ -42,7 +42,7 @@ CSRCS += lib_fseek.c lib_fseeko.c lib_ftell.c lib_ftello.c lib_fsetpos.c
 CSRCS += lib_getdelim.c lib_fgetpos.c lib_getc.c lib_fgetc.c
 CSRCS += lib_fgets.c lib_libfgets.c lib_fwrite.c
 CSRCS += lib_libfwrite.c lib_fflush.c lib_libflushall.c lib_libfflush.c
-CSRCS += lib_rdflush.c lib_wrflush.c lib_putc.c lib_fputc.c
+CSRCS += lib_rdflush_unlocked.c lib_wrflush_unlocked.c lib_putc.c lib_fputc.c
 CSRCS += lib_fputs.c lib_ungetc.c lib_fprintf.c lib_vfprintf.c
 CSRCS += lib_feof.c lib_ferror.c lib_rewind.c lib_clearerr.c
 CSRCS += lib_scanf.c lib_vscanf.c lib_fscanf.c lib_vfscanf.c lib_tmpfile.c

libs/libc/stdio/lib_freopen.c

@@ -100,14 +100,20 @@ FAR FILE *freopen(FAR const char *path, FAR const char *mode,
           return NULL;
         }
 
+      /* Make sure that we have exclusive access to the stream */
+
+      flockfile(stream);
+
       /* Flush the stream and invalidate the read buffer. */
 
-      fflush(stream);
+      lib_fflush_unlocked(stream, true);
 
 #ifndef CONFIG_STDIO_DISABLE_BUFFERING
-      lib_rdflush(stream);
+      lib_rdflush_unlocked(stream);
 #endif
 
+      funlockfile(stream);
+
       /* Duplicate the new fd to the stream. */
 
       ret = dup2(fd, fileno(stream));

libs/libc/stdio/lib_fseeko.c

@@ -69,10 +69,14 @@ int fseeko(FAR FILE *stream, off_t offset, int whence)
 #ifndef CONFIG_STDIO_DISABLE_BUFFERING
   /* Flush any valid read/write data in the buffer (also verifies stream) */
 
-  if (lib_rdflush(stream) < 0 || lib_wrflush(stream) < 0)
+  flockfile(stream);
+  if (lib_rdflush_unlocked(stream) < 0 || lib_wrflush_unlocked(stream) < 0)
     {
+      funlockfile(stream);
       return ERROR;
     }
+
+  funlockfile(stream);
 #endif
 
   /* On success or failure, discard any characters saved by ungetc() */

libs/libc/stdio/lib_libfflush.c

@@ -56,13 +56,12 @@
  *
  ****************************************************************************/
 
-ssize_t lib_fflush(FAR FILE *stream, bool bforce)
+ssize_t lib_fflush_unlocked(FAR FILE *stream, bool bforce)
 {
 #ifndef CONFIG_STDIO_DISABLE_BUFFERING
   FAR const unsigned char *src;
   ssize_t bytes_written;
   ssize_t nbuffer;
-  int ret;
 
   /* Return EBADF if the file is not opened for writing */
 
@@ -71,18 +70,13 @@ ssize_t lib_fflush(FAR FILE *stream, bool bforce)
       return -EBADF;
     }
 
-  /* Make sure that we have exclusive access to the stream */
-
-  flockfile(stream);
-
   /* Check if there is an allocated I/O buffer */
 
   if (stream->fs_bufstart == NULL)
     {
       /* No, then there can be nothing remaining in the buffer. */
 
-      ret = 0;
-      goto errout_with_lock;
+      return 0;
     }
 
   /* Make sure that the buffer holds valid data */
@@ -99,8 +93,7 @@ ssize_t lib_fflush(FAR FILE *stream, bool bforce)
            * remaining in the buffer."
            */
 
-          ret = 0;
-          goto errout_with_lock;
+          return 0;
         }
 
       /* How many bytes of write data are used in the buffer now */
@@ -122,8 +115,7 @@ ssize_t lib_fflush(FAR FILE *stream, bool bforce)
                */
 
               stream->fs_flags |= __FS_FLAG_ERROR;
-              ret = _NX_GETERRVAL(bytes_written);
-              goto errout_with_lock;
+              return _NX_GETERRVAL(bytes_written);
             }
 
           /* Handle partial writes.  fflush() must either return with
@@ -156,16 +148,23 @@ ssize_t lib_fflush(FAR FILE *stream, bool bforce)
    * remaining in the buffer.
    */
 
-  funlockfile(stream);
   return stream->fs_bufpos - stream->fs_bufstart;
 
-errout_with_lock:
-  funlockfile(stream);
-  return ret;
-
 #else
   /* Return no bytes remaining in the buffer */
 
   return 0;
 #endif
 }
+
+ssize_t lib_fflush(FAR FILE *stream, bool bforce)
+{
+  ssize_t ret;
+
+  /* Make sure that we have exclusive access to the stream */
+
+  flockfile(stream);
+  ret = lib_fflush_unlocked(stream, bforce);
+  funlockfile(stream);
+  return ret;
+}

libs/libc/stdio/lib_libfwrite.c

@@ -90,7 +90,7 @@ ssize_t lib_fwrite(FAR const void *ptr, size_t count, FAR FILE *stream)
    * buffered read/write access.
    */
 
-  if (lib_rdflush(stream) < 0)
+  if (lib_rdflush_unlocked(stream) < 0)
     {
       goto errout_with_lock;
     }
@@ -125,7 +125,7 @@ ssize_t lib_fwrite(FAR const void *ptr, size_t count, FAR FILE *stream)
         {
           /* Flush the buffered data to the IO stream */
 
-          int bytes_buffered = lib_fflush(stream, false);
+          int bytes_buffered = lib_fflush_unlocked(stream, false);
           if (bytes_buffered < 0)
             {
               goto errout_with_lock;

libs/libc/stdio/lib_puts.c

@@ -71,7 +71,7 @@ int puts(FAR const IPTR char *s)
 
           if ((stream->fs_flags & __FS_FLAG_LBF) != 0)
             {
-              ret = lib_fflush(stream, true);
+              ret = lib_fflush_unlocked(stream, true);
               if (ret < 0)
                 {
                   nput = EOF;

libs/libc/stdio/lib_rdflush_unlocked.c

@@ -1,5 +1,5 @@
 /****************************************************************************
- * libs/libc/stdio/lib_rdflush.c
+ * libs/libc/stdio/lib_rdflush_unlocked.c
  *
  * Licensed to the Apache Software Foundation (ASF) under one or more
  * contributor license agreements.  See the NOTICE file distributed with
@@ -38,7 +38,7 @@
  ****************************************************************************/
 
 /****************************************************************************
- * Name: lib_rdflush
+ * Name: lib_rdflush_unlocked
  *
  * Description:
  *   Flush read data from the I/O buffer and adjust the file pointer to
@@ -46,7 +46,7 @@
  *
  ****************************************************************************/
 
-int lib_rdflush(FAR FILE *stream)
+int lib_rdflush_unlocked(FAR FILE *stream)
 {
   /* Sanity checking */
 
@@ -63,10 +63,6 @@ int lib_rdflush(FAR FILE *stream)
       return OK;
     }
 
-  /* Get exclusive access to the stream */
-
-  flockfile(stream);
-
   /* If the buffer is currently being used for read access, then discard all
    * of the read-ahead data. We do not support concurrent buffered read/write
    * access.
@@ -98,12 +94,10 @@ int lib_rdflush(FAR FILE *stream)
 
       if (fseek(stream, -rdoffset, SEEK_CUR) < 0)
         {
-          funlockfile(stream);
           return ERROR;
         }
     }
 
-  funlockfile(stream);
   return OK;
 }
 

libs/libc/stdio/lib_wrflush_unlocked.c

@@ -1,5 +1,5 @@
 /****************************************************************************
- * libs/libc/stdio/lib_wrflush.c
+ * libs/libc/stdio/lib_wrflush_unlocked.c
  *
  * Licensed to the Apache Software Foundation (ASF) under one or more
  * contributor license agreements.  See the NOTICE file distributed with
@@ -35,7 +35,7 @@
  ****************************************************************************/
 
 /****************************************************************************
- * Name: lib_wrflush
+ * Name: lib_wrflush_unlocked
  *
  * Description:
  *   This is simply a version of fflush that does not report an error if
@@ -43,7 +43,7 @@
  *
  ****************************************************************************/
 
-int lib_wrflush(FAR FILE *stream)
+int lib_wrflush_unlocked(FAR FILE *stream)
 {
 #ifndef CONFIG_STDIO_DISABLE_BUFFERING
   /* Verify that we were passed a valid (i.e., non-NULL) stream */
@@ -82,7 +82,7 @@ int lib_wrflush(FAR FILE *stream)
    * buffered write data was successfully flushed by lib_fflush().
    */
 
-  return lib_fflush(stream, true);
+  return lib_fflush_unlocked(stream, true);
 
 #else
   /* Verify that we were passed a valid (i.e., non-NULL) stream */