File fix-locking-in-_IO_cleanup.patch of Package glibc
Always do locking when accessing streams
[BZ #15142]
* libio/genops.c (_IO_list_all_stamp): Delete. All uses removed.
(_IO_flush_all_all_lockp): Delete.
(_IO_flush_all): Replace with body of _IO_flush_all_all_lockp.
Always do locking.
(_IO_unbuffer_all): Always do locking.
(_IO_cleanup): Call _IO_flush_all instead of _IO_flush_all_lockp.
* libio/libioP.h (_IO_flush_all_all_lockp): Remove declaration.
diff --git a/libio/genops.c b/libio/genops.c
index e0ce8cc..9def1d4 100644
--- a/libio/genops.c
+++ b/libio/genops.c
@@ -38,10 +38,6 @@
static _IO_lock_t list_all_lock = _IO_lock_initializer;
#endif
-/* Used to signal modifications to the list of FILE decriptors. */
-static int _IO_list_all_stamp;
-
-
static _IO_FILE *run_fp;
#ifdef _IO_MTSAFE_IO
@@ -70,16 +66,12 @@ _IO_un_link (fp)
if (_IO_list_all == NULL)
;
else if (fp == _IO_list_all)
- {
- _IO_list_all = (struct _IO_FILE_plus *) _IO_list_all->file._chain;
- ++_IO_list_all_stamp;
- }
+ _IO_list_all = (struct _IO_FILE_plus *) _IO_list_all->file._chain;
else
for (f = &_IO_list_all->file._chain; *f; f = &(*f)->_chain)
if (*f == (_IO_FILE *) fp)
{
*f = fp->file._chain;
- ++_IO_list_all_stamp;
break;
}
fp->file._flags &= ~_IO_LINKED;
@@ -108,7 +100,6 @@ _IO_link_in (fp)
#endif
fp->file._chain = (_IO_FILE *) _IO_list_all;
_IO_list_all = fp;
- ++_IO_list_all_stamp;
#ifdef _IO_MTSAFE_IO
_IO_funlockfile ((_IO_FILE *) fp);
run_fp = NULL;
@@ -818,25 +809,20 @@ _IO_get_column (fp)
int
-_IO_flush_all_lockp (int do_lock)
+_IO_flush_all (void)
{
int result = 0;
struct _IO_FILE *fp;
- int last_stamp;
#ifdef _IO_MTSAFE_IO
- __libc_cleanup_region_start (do_lock, flush_cleanup, NULL);
- if (do_lock)
- _IO_lock_lock (list_all_lock);
+ _IO_cleanup_region_start_noarg (flush_cleanup);
+ _IO_lock_lock (list_all_lock);
#endif
- last_stamp = _IO_list_all_stamp;
- fp = (_IO_FILE *) _IO_list_all;
- while (fp != NULL)
+ for (fp = (_IO_FILE *) _IO_list_all; fp != NULL; fp = fp->_chain)
{
run_fp = fp;
- if (do_lock)
- _IO_flockfile (fp);
+ _IO_flockfile (fp);
if (((fp->_mode <= 0 && fp->_IO_write_ptr > fp->_IO_write_base)
#if defined _LIBC || defined _GLIBCPP_USE_WCHAR_T
@@ -848,52 +834,30 @@ _IO_flush_all_lockp (int do_lock)
&& _IO_OVERFLOW (fp, EOF) == EOF)
result = EOF;
- if (do_lock)
- _IO_funlockfile (fp);
+ _IO_funlockfile (fp);
run_fp = NULL;
-
- if (last_stamp != _IO_list_all_stamp)
- {
- /* Something was added to the list. Start all over again. */
- fp = (_IO_FILE *) _IO_list_all;
- last_stamp = _IO_list_all_stamp;
- }
- else
- fp = fp->_chain;
}
#ifdef _IO_MTSAFE_IO
- if (do_lock)
- _IO_lock_unlock (list_all_lock);
- __libc_cleanup_region_end (0);
+ _IO_lock_unlock (list_all_lock);
+ _IO_cleanup_region_end (0);
#endif
return result;
}
-
-
-int
-_IO_flush_all (void)
-{
- /* We want locking. */
- return _IO_flush_all_lockp (1);
-}
libc_hidden_def (_IO_flush_all)
void
_IO_flush_all_linebuffered (void)
{
struct _IO_FILE *fp;
- int last_stamp;
#ifdef _IO_MTSAFE_IO
_IO_cleanup_region_start_noarg (flush_cleanup);
_IO_lock_lock (list_all_lock);
#endif
- last_stamp = _IO_list_all_stamp;
- fp = (_IO_FILE *) _IO_list_all;
- while (fp != NULL)
+ for (fp = (_IO_FILE *) _IO_list_all; fp != NULL; fp = fp->_chain)
{
run_fp = fp;
_IO_flockfile (fp);
@@ -903,15 +867,6 @@ _IO_flush_all_linebuffered (void)
_IO_funlockfile (fp);
run_fp = NULL;
-
- if (last_stamp != _IO_list_all_stamp)
- {
- /* Something was added to the list. Start all over again. */
- fp = (_IO_FILE *) _IO_list_all;
- last_stamp = _IO_list_all_stamp;
- }
- else
- fp = fp->_chain;
}
#ifdef _IO_MTSAFE_IO
@@ -947,6 +902,12 @@ static void
_IO_unbuffer_all (void)
{
struct _IO_FILE *fp;
+
+#ifdef _IO_MTSAFE_IO
+ _IO_cleanup_region_start_noarg (flush_cleanup);
+ _IO_lock_lock (list_all_lock);
+#endif
+
for (fp = (_IO_FILE *) _IO_list_all; fp; fp = fp->_chain)
{
if (! (fp->_flags & _IO_UNBUFFERED)
@@ -956,15 +917,8 @@ _IO_unbuffer_write (void)
&& fp->_mode != 0)
{
#ifdef _IO_MTSAFE_IO
- int cnt;
-#define MAXTRIES 2
- for (cnt = 0; cnt < MAXTRIES; ++cnt)
- if (fp->_lock == NULL || _IO_lock_trylock (*fp->_lock) == 0)
- break;
- else
- /* Give the other thread time to finish up its use of the
- stream. */
- __sched_yield ();
+ run_fp = fp;
+ _IO_flockfile (fp);
#endif
if (! dealloc_buffers && !(fp->_flags & _IO_USER_BUF))
@@ -980,8 +934,8 @@ _IO_unbuffer_write (void)
_IO_SETBUF (fp, NULL, 0);
#ifdef _IO_MTSAFE_IO
- if (cnt < MAXTRIES && fp->_lock != NULL)
- _IO_lock_unlock (*fp->_lock);
+ _IO_funlockfile (fp);
+ run_fp = NULL;
#endif
}
@@ -989,6 +943,11 @@ _IO_unbuffer_write (void)
used. */
fp->_mode = -1;
}
+
+#ifdef _IO_MTSAFE_IO
+ _IO_lock_unlock (list_all_lock);
+ _IO_cleanup_region_end (0);
+#endif
}
@@ -1008,9 +967,7 @@ libc_freeres_fn (buffer_free)
int
_IO_cleanup (void)
{
- /* We do *not* want locking. Some threads might use streams but
- that is their problem, we flush them underneath them. */
- int result = _IO_flush_all_lockp (0);
+ int result = _IO_flush_all ();
/* We currently don't have a reliable mechanism for making sure that
C++ static destructors are executed in the correct order.
diff --git a/libio/libioP.h b/libio/libioP.h
index 8a7b85b..3e3a724 100644
--- a/libio/libioP.h
+++ b/libio/libioP.h
@@ -488,7 +488,6 @@ extern int _IO_new_do_write (_IO_FILE *, const char *, _IO_size_t);
extern int _IO_old_do_write (_IO_FILE *, const char *, _IO_size_t);
extern int _IO_wdo_write (_IO_FILE *, const wchar_t *, _IO_size_t);
libc_hidden_proto (_IO_wdo_write)
-extern int _IO_flush_all_lockp (int);
extern int _IO_flush_all (void);
libc_hidden_proto (_IO_flush_all)
extern int _IO_cleanup (void);
--
1.9.1
