libc: speed-up flockfile()/funlockfile()
For Honeycomb, we added proper file thread-safety for
all FILE* operations. However, we did implement that by
using an out-of-band hash table to map FILE* pointers
to phtread_mutex_t mutexes, because we couldn't change
the size of 'struct _sFILE' without breaking the ABI.
It turns out that our BSD-derived code already has
some support code to extend FILE* objects, so use it
instead. See libc/stdio/fileext.h
This patch gets rid of the hash table, and put the
mutex directly into the sFILE extension.
Change-Id: If1c3fe0a0a89da49c568e9a7560b7827737ff4d0
diff --git a/libc/stdio/fileext.h b/libc/stdio/fileext.h
index 2d07043..b36a448 100644
--- a/libc/stdio/fileext.h
+++ b/libc/stdio/fileext.h
@@ -29,24 +29,41 @@
* $Citrus$
*/
+#include <pthread.h>
+#include "wcio.h"
+
/*
* file extension
*/
struct __sfileext {
struct __sbuf _ub; /* ungetc buffer */
struct wchar_io_data _wcio; /* wide char io status */
+ pthread_mutex_t _lock; /* file lock */
};
+#define _FILEEXT_INITIALIZER {{NULL,0},{0},PTHREAD_RECURSIVE_MUTEX_INITIALIZER}
+
#define _EXT(fp) ((struct __sfileext *)((fp)->_ext._base))
#define _UB(fp) _EXT(fp)->_ub
+#define _FLOCK(fp) _EXT(fp)->_lock
#define _FILEEXT_INIT(fp) \
do { \
_UB(fp)._base = NULL; \
_UB(fp)._size = 0; \
WCIO_INIT(fp); \
+ _FLOCK_INIT(fp); \
} while (0)
+/* Helper macros to avoid a function call when you know that fp is not NULL.
+ * Notice that we keep _FLOCK_INIT() fast by slightly breaking our pthread
+ * encapsulation.
+ */
+#define _FLOCK_INIT(fp) _FLOCK(fp).value = __PTHREAD_RECURSIVE_MUTEX_INIT_VALUE
+#define _FLOCK_LOCK(fp) pthread_mutex_lock(&_FLOCK(fp))
+#define _FLOCK_TRYLOCK(fp) pthread_mutex_trylock(&_FLOCK(fp))
+#define _FLOCK_UNLOCK(fp) pthread_mutex_unlock(&_FLOCK(fp))
+
#define _FILEEXT_SETUP(f, fext) \
do { \
(f)->_ext._base = (unsigned char *)(fext); \