* libio/fileops.c (_IO_file_sync_mmap): New function.

	(_IO_file_jumps_mmap): Use it.
	(_IO_file_underflow_mmap): Rewritten.  If after EOF or fflush,
	repeat the stat check and resize the mapped buffer as necessary.

2002-07-31  Roland McGrath  <roland@frob.com>

	* libio/fileops.c (decide_maybe_mmap): New static function.
	Code taken from libio/iofopen.c:__fopen_maybe_mmap to try to
	mmap the file contents.  Then switch the jump tables to the mmap
	tables if it worked, or the vanilla file tables if not.
	(_IO_file_underflow_maybe_mmap): New function.
	(_IO_file_seekoff_maybe_mmap): New function.
	(_IO_file_xsgetn_maybe_mmap): New function.
	(_IO_file_jumps_maybe_mmap): New variable, jump table using those.
	* libio/libioP.h: Declare those.
	* libio/wfileops.c (_IO_wfile_underflow_maybe_mmap): New function.
	(_IO_wfile_jumps_maybe_mmap): New variable, jump table using that.
	* libio/iofopen.c (__fopen_maybe_mmap): Don't try to mmap here.
	If the stream is read-only, set its jump tables to those new ones.
	* libio/iofdopen.c (_IO_new_fdopen) [_G_HAVE_MMAP]: Set the initial
	jump tables to the maybe_mmap ones, and don't call __fopen_maybe_mmap.
	We need the tables set before _IO_file_attach.

	* libio/tst-mmap-eofsync.c: New file.
	* libio/tst-mmap-fflushsync.c: New file.
	* libio/bug-mmap-fflush.c: New file.
	* libio/tst-mmap2-eofsync.c: New file.
	* libio/Makefile (tests): Add them.

	* libio/wfileops.c (_IO_wfile_underflow_mmap): Don't set EOF bit when
	_IO_file_underflow_mmap fails, it already set the appropriate bit.

1 files changed, 27 insertions, 0 deletions

diff --git a/libio/bug-mmap-fflush.c b/libio/bug-mmap-fflush.c
new file mode 100644
index 0000000000..984acb496b
--- /dev/null
+++ b/libio/bug-mmap-fflush.c
@@ -0,0 +1,27 @@
+/* Test for bug in fflush synchronization behavior.  */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+int main (void)
+{
+  FILE *f;
+  off_t o;
+  char buffer [1024];
+
+  system ("echo 'From foo@bar.com' > test");
+  f = fopen ("test", "r");
+  fseek (f, 0, SEEK_END);
+  o = ftello (f);
+  fseek (f, 0, SEEK_SET);
+  fflush (f);
+  system ("echo 'From bar@baz.edu' >> test");
+  fseek (f, o, SEEK_SET);
+  if (fgets (buffer, 1024, f) == NULL)
+    abort ();
+  if (strncmp (buffer, "From ", 5) != 0)
+    abort ();
+  fclose (f);
+  exit (0);
+}