Hang detection additions.

kern/include/hangman.h

@@ -0,0 +1,84 @@
+/*
+ * Copyright (c) 2015
+ *	The President and Fellows of Harvard College.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE UNIVERSITY AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE UNIVERSITY OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#ifndef HANGMAN_H
+#define HANGMAN_H
+
+/*
+ * Simple deadlock detector. Enable with "options hangman" in the
+ * kernel config.
+ */
+
+#include "opt-hangman.h"
+
+#if OPT_HANGMAN
+
+struct hangman_actor {
+	const char *a_name;
+	const struct hangman_lockable *a_waiting;
+};
+
+struct hangman_lockable {
+	const char *l_name;
+	const struct hangman_actor *l_holding;
+};
+
+void hangman_wait(struct hangman_actor *a, struct hangman_lockable *l);
+void hangman_acquire(struct hangman_actor *a, struct hangman_lockable *l);
+void hangman_release(struct hangman_actor *a, struct hangman_lockable *l);
+
+#define HANGMAN_ACTOR(sym)	struct hangman_actor sym
+#define HANGMAN_LOCKABLE(sym)	struct hangman_lockable sym
+
+#define HANGMAN_ACTORINIT(a, n)	    ((a)->a_name = (n), (a)->a_waiting = NULL)
+#define HANGMAN_LOCKABLEINIT(l, n)  ((l)->l_name = (n), (l)->l_holding = NULL)
+
+#define HANGMAN_LOCKABLE_INITIALIZER	{ "spinlock", NULL }
+
+#define HANGMAN_WAIT(a, l)	hangman_wait(a, l)
+#define HANGMAN_ACQUIRE(a, l)	hangman_acquire(a, l)
+#define HANGMAN_RELEASE(a, l)	hangman_release(a, l)
+
+#else
+
+#define HANGMAN_ACTOR(sym)
+#define HANGMAN_LOCKABLE(sym)
+
+#define HANGMAN_ACTORINIT(a, name)
+#define HANGMAN_LOCKABLEINIT(a, name)
+
+#define HANGMAN_LOCKABLE_INITIALIZER
+
+#define HANGMAN_WAIT(a, l)
+#define HANGMAN_ACQUIRE(a, l)
+#define HANGMAN_RELEASE(a, l)
+
+#endif
+
+#endif /* HANGMAN_H */