Hide the definition of struct __sFILEX and add the needed

lock definitions to it.  flockfile state is now allocated
along with the rest of FILE.  This eliminates the need for a
separate allocation of flockfile state as well as eliminating
the mutex/lock used to serialize its allocation.

include/stdio.h

@@ -68,13 +68,8 @@ struct __sbuf {
 	int	_size;
 };
 
-struct __file_lock;
-
 /* hold a buncha junk that would grow the ABI */
-struct __sFILEX {
+struct __sFILEX;
-	struct __file_lock *_mtlock;	/* used for MT-safety */
-	unsigned char *_up;	/* saved _p when _p is doing ungetc data */
-};
 
 /*
  * stdio state variables.

lib/libc/stdio/_flock_stub.c

@@ -47,6 +47,9 @@
 #include <pthread.h>
 #include "un-namespace.h"
 
+#include "local.h"
+
+
 /*
  * Weak symbols for externally visible functions in this file:
  */
@@ -55,18 +58,6 @@
 #pragma weak	ftrylockfile=_ftrylockfile
 #pragma weak	funlockfile=_funlockfile
 
-static int	init_lock(FILE *);
-
-/*
- * The FILE lock structure. The FILE *fp is locked when the mutex
- * is locked.
- */
-struct	__file_lock {
-	pthread_mutex_t	fl_mutex;
-	pthread_t	fl_owner;	/* current owner */
-	int		fl_count;	/* recursive lock count */
-};
-
 /*
  * We need to retain binary compatibility for a while.  So pretend
  * that _lock is part of FILE * even though it is dereferenced off
@@ -75,62 +66,23 @@ struct	__file_lock {
  * code that has to change in the future (just remove this comment
  * and #define).
  */
-#define _lock _extra->_mtlock
+#define _lock _extra
-
-/*
- * Allocate and initialize a file lock.
- */
-static int
-init_lock(FILE *fp)
-{
-	static pthread_mutex_t init_lock_mutex = PTHREAD_MUTEX_INITIALIZER;
-	struct __file_lock *p;
-	int	ret;
-
-	if ((p = malloc(sizeof(struct __file_lock))) == NULL)
-		ret = -1;
-	else {
-		p->fl_mutex = PTHREAD_MUTEX_INITIALIZER;
-		p->fl_owner = NULL;
-		p->fl_count = 0;
-		if (_pthread_mutex_lock(&init_lock_mutex) != 0) {
-			free(p);
-			return (-1);
-		}
-		if (fp->_lock != NULL) {	/* lost the race */
-			free(p);
-			_pthread_mutex_unlock(&init_lock_mutex);
-			return (0);
-		}
-		fp->_lock = p;
-		_pthread_mutex_unlock(&init_lock_mutex);
-		ret = 0;
-	}
-	return (ret);
-}
 
 void
 _flockfile(FILE *fp)
 {
 	pthread_t curthread = _pthread_self();
 
-	/*
+	if (fp->_lock->fl_owner == curthread)
-	 * Check if this is a real file with a valid lock, creating
+		fp->_lock->fl_count++;
-	 * the lock if needed:
+	else {
-	 */
+		/*
-	if ((fp->_file >= 0) &&
+		 * Make sure this mutex is treated as a private
-	    ((fp->_lock != NULL) || (init_lock(fp) == 0))) {
+		 * internal mutex:
-		if (fp->_lock->fl_owner == curthread)
+		 */
-			fp->_lock->fl_count++;
+		_pthread_mutex_lock(&fp->_lock->fl_mutex);
-		else {
+		fp->_lock->fl_owner = curthread;
-			/*
+		fp->_lock->fl_count = 1;
-			 * Make sure this mutex is treated as a private
-			 * internal mutex:
-			 */
-			_pthread_mutex_lock(&fp->_lock->fl_mutex);
-			fp->_lock->fl_owner = curthread;
-			fp->_lock->fl_count = 1;
-		}
 	}
 }
 
@@ -149,23 +101,15 @@ _ftrylockfile(FILE *fp)
 	pthread_t curthread = _pthread_self();
 	int	ret = 0;
 
+	if (fp->_lock->fl_owner == curthread)
+		fp->_lock->fl_count++;
 	/*
-	 * Check if this is a real file with a valid lock, creating
+	 * Make sure this mutex is treated as a private
-	 * the lock if needed:
+	 * internal mutex:
 	 */
-	if (((fp->_lock != NULL) || (init_lock(fp) == 0))) {
+	else if (_pthread_mutex_trylock(&fp->_lock->fl_mutex) == 0) {
-		if (fp->_lock->fl_owner == curthread)
+		fp->_lock->fl_owner = curthread;
-			fp->_lock->fl_count++;
+		fp->_lock->fl_count = 1;
-		/*
-		 * Make sure this mutex is treated as a private
-		 * internal mutex:
-		 */
-		else if (_pthread_mutex_trylock(&fp->_lock->fl_mutex) == 0) {
-			fp->_lock->fl_owner = curthread;
-			fp->_lock->fl_count = 1;
-		}
-		else
-			ret = -1;
 	}
 	else
 		ret = -1;
@@ -178,11 +122,9 @@ _funlockfile(FILE *fp)
 	pthread_t	curthread = _pthread_self();
 
 	/*
-	 * Check if this is a real file with a valid lock owned
+	 * Check if this file is owned by the current thread:
-	 * by the current thread:
 	 */
-	if ((fp->_lock != NULL) &&
+	if (fp->_lock->fl_owner == curthread) {
-	    (fp->_lock->fl_owner == curthread)) {
 		/*
 		 * Check if this thread has locked the FILE
 		 * more than once:

lib/libc/stdio/local.h

@@ -39,6 +39,7 @@
  */
 
 #include <sys/types.h>	/* for off_t */
+#include <pthread.h>
 
 /*
  * Information local to this implementation of stdio,
@@ -67,6 +68,15 @@ extern int	__vfprintf __P((FILE *, const char *, _BSD_VA_LIST_));
 
 extern int	__sdidinit;
 
+
+/* hold a buncha junk that would grow the ABI */
+struct __sFILEX {
+	unsigned char	*_up;	/* saved _p when _p is doing ungetc data */
+	pthread_mutex_t	fl_mutex;	/* used for MT-safety */
+	pthread_t	fl_owner;	/* current owner */
+	int		fl_count;	/* recursive lock count */
+};
+
 /*
  * Return true iff the given FILE cannot be written now.
  */