Module Name: src
Committed By: pgoyette
Date: Mon May 1 21:35:26 UTC 2017
Modified Files:
src/sys/kern: kern_mutex.c subr_lockdebug.c
src/sys/rump/librump/rumpkern: locks.c
src/sys/sys: mutex.h
Log Message:
Introduce mutex_ownable() to determine if it is possible for the current
process to acquire a mutex.
To generate a diff of this commit:
cvs rdiff -u -r1.64 -r1.65 src/sys/kern/kern_mutex.c
cvs rdiff -u -r1.55 -r1.56 src/sys/kern/subr_lockdebug.c
cvs rdiff -u -r1.73 -r1.74 src/sys/rump/librump/rumpkern/locks.c
cvs rdiff -u -r1.20 -r1.21 src/sys/sys/mutex.h
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/kern/kern_mutex.c
diff -u src/sys/kern/kern_mutex.c:1.64 src/sys/kern/kern_mutex.c:1.65
--- src/sys/kern/kern_mutex.c:1.64 Thu Jan 26 04:11:56 2017
+++ src/sys/kern/kern_mutex.c Mon May 1 21:35:25 2017
@@ -1,4 +1,4 @@
-/* $NetBSD: kern_mutex.c,v 1.64 2017/01/26 04:11:56 christos Exp $ */
+/* $NetBSD: kern_mutex.c,v 1.65 2017/05/01 21:35:25 pgoyette Exp $ */
/*-
* Copyright (c) 2002, 2006, 2007, 2008 The NetBSD Foundation, Inc.
@@ -40,7 +40,7 @@
#define __MUTEX_PRIVATE
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: kern_mutex.c,v 1.64 2017/01/26 04:11:56 christos Exp $");
+__KERNEL_RCSID(0, "$NetBSD: kern_mutex.c,v 1.65 2017/05/01 21:35:25 pgoyette Exp $");
#include <sys/param.h>
#include <sys/atomic.h>
@@ -75,6 +75,9 @@ __KERNEL_RCSID(0, "$NetBSD: kern_mutex.c
#define MUTEX_WANTLOCK(mtx) \
LOCKDEBUG_WANTLOCK(MUTEX_DEBUG_P(mtx), (mtx), \
(uintptr_t)__builtin_return_address(0), 0)
+#define MUTEX_TESTLOCK(mtx) \
+ LOCKDEBUG_WANTLOCK(MUTEX_DEBUG_P(mtx), (mtx), \
+ (uintptr_t)__builtin_return_address(0), -1)
#define MUTEX_LOCKED(mtx) \
LOCKDEBUG_LOCKED(MUTEX_DEBUG_P(mtx), (mtx), NULL, \
(uintptr_t)__builtin_return_address(0), 0)
@@ -831,6 +834,23 @@ mutex_owner(kmutex_t *mtx)
}
/*
+ * mutex_ownable:
+ *
+ * When compiled with DEBUG and LOCKDEBUG defined, ensure that
+ * the mutex is available. We cannot use !mutex_owned() since
+ * that won't work correctly for spin mutexes.
+ */
+int
+mutex_ownable(kmutex_t *mtx)
+{
+
+#ifdef LOCKDEBUG
+ MUTEX_TESTLOCK(mtx);
+#endif
+ return 1;
+}
+
+/*
* mutex_tryenter:
*
* Try to acquire the mutex; return non-zero if we did.
Index: src/sys/kern/subr_lockdebug.c
diff -u src/sys/kern/subr_lockdebug.c:1.55 src/sys/kern/subr_lockdebug.c:1.56
--- src/sys/kern/subr_lockdebug.c:1.55 Thu Jan 26 04:11:56 2017
+++ src/sys/kern/subr_lockdebug.c Mon May 1 21:35:26 2017
@@ -1,4 +1,4 @@
-/* $NetBSD: subr_lockdebug.c,v 1.55 2017/01/26 04:11:56 christos Exp $ */
+/* $NetBSD: subr_lockdebug.c,v 1.56 2017/05/01 21:35:26 pgoyette Exp $ */
/*-
* Copyright (c) 2006, 2007, 2008 The NetBSD Foundation, Inc.
@@ -34,7 +34,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: subr_lockdebug.c,v 1.55 2017/01/26 04:11:56 christos Exp $");
+__KERNEL_RCSID(0, "$NetBSD: subr_lockdebug.c,v 1.56 2017/05/01 21:35:26 pgoyette Exp $");
#ifdef _KERNEL_OPT
#include "opt_ddb.h"
@@ -417,7 +417,9 @@ lockdebug_more(int s)
/*
* lockdebug_wantlock:
*
- * Process the preamble to a lock acquire.
+ * Process the preamble to a lock acquire. The "shared"
+ * parameter controls which ld_{ex,sh}want counter is
+ * updated; a negative value of shared updates neither.
*/
void
lockdebug_wantlock(const char *func, size_t line,
@@ -454,9 +456,9 @@ lockdebug_wantlock(const char *func, siz
return;
}
}
- if (shared)
+ if (shared > 0)
ld->ld_shwant++;
- else
+ else if (shared == 0)
ld->ld_exwant++;
if (recurse) {
lockdebug_abort1(func, line, ld, s, "locking against myself",
Index: src/sys/rump/librump/rumpkern/locks.c
diff -u src/sys/rump/librump/rumpkern/locks.c:1.73 src/sys/rump/librump/rumpkern/locks.c:1.74
--- src/sys/rump/librump/rumpkern/locks.c:1.73 Fri Jan 27 09:50:47 2017
+++ src/sys/rump/librump/rumpkern/locks.c Mon May 1 21:35:26 2017
@@ -1,4 +1,4 @@
-/* $NetBSD: locks.c,v 1.73 2017/01/27 09:50:47 ozaki-r Exp $ */
+/* $NetBSD: locks.c,v 1.74 2017/05/01 21:35:26 pgoyette Exp $ */
/*
* Copyright (c) 2007-2011 Antti Kantee. All Rights Reserved.
@@ -26,7 +26,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: locks.c,v 1.73 2017/01/27 09:50:47 ozaki-r Exp $");
+__KERNEL_RCSID(0, "$NetBSD: locks.c,v 1.74 2017/05/01 21:35:26 pgoyette Exp $");
#include <sys/param.h>
#include <sys/kmem.h>
@@ -183,6 +183,16 @@ mutex_exit(kmutex_t *mtx)
__strong_alias(mutex_spin_exit,mutex_exit);
int
+mutex_ownable(kmutex_t *mtx)
+{
+
+#ifdef LOCKDEBUG
+ WANTLOCK(mtx, -1);
+#endif
+ return 1;
+}
+
+int
mutex_owned(kmutex_t *mtx)
{
Index: src/sys/sys/mutex.h
diff -u src/sys/sys/mutex.h:1.20 src/sys/sys/mutex.h:1.21
--- src/sys/sys/mutex.h:1.20 Mon Feb 8 09:54:27 2010
+++ src/sys/sys/mutex.h Mon May 1 21:35:26 2017
@@ -1,4 +1,4 @@
-/* $NetBSD: mutex.h,v 1.20 2010/02/08 09:54:27 skrll Exp $ */
+/* $NetBSD: mutex.h,v 1.21 2017/05/01 21:35:26 pgoyette Exp $ */
/*-
* Copyright (c) 2002, 2006, 2007, 2008, 2009 The NetBSD Foundation, Inc.
@@ -204,6 +204,7 @@ void mutex_spin_exit(kmutex_t *);
int mutex_tryenter(kmutex_t *);
int mutex_owned(kmutex_t *);
+int mutex_ownable(kmutex_t *);
lwp_t *mutex_owner(kmutex_t *);
void mutex_obj_init(void);
