Initial Spring 2016 commit.

2015-12-23 00:50:04 +00:00
commit cafa9f5690
732 changed files with 92195 additions and 0 deletions
--- a/kern/fs/semfs/semfs.h
+++ b/kern/fs/semfs/semfs.h
@@ -0,0 +1,123 @@
+/*
+ * Copyright (c) 2014
+ *	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 SEMFS_H
+#define SEMFS_H
+
+#include <array.h>
+#include <fs.h>
+#include <vnode.h>
+
+#ifndef SEMFS_INLINE
+#define SEMFS_INLINE INLINE
+#endif
+
+/*
+ * Constants
+ */
+
+#define SEMFS_ROOTDIR	0xffffffffU		/* semnum for root dir */
+
+/*
+ * A user-facing semaphore.
+ *
+ * We don't use the kernel-level semaphore to implement it (although
+ * that would be tidy) because we'd have to violate its abstraction.
+ * XXX: or would we? review once all this is done.
+ */
+struct semfs_sem {
+	struct lock *sems_lock;			/* Lock to protect count */
+	struct cv *sems_cv;			/* CV to wait */
+	unsigned sems_count;			/* Semaphore count */
+	bool sems_hasvnode;			/* The vnode exists */
+	bool sems_linked;			/* In the directory */
+};
+DECLARRAY(semfs_sem, SEMFS_INLINE);
+
+/*
+ * Directory entry; name and reference to a semaphore.
+ */
+struct semfs_direntry {
+	char *semd_name;			/* Name */
+	unsigned semd_semnum;			/* Which semaphore */
+};
+DECLARRAY(semfs_direntry, SEMFS_INLINE);
+
+/*
+ * Vnode. These are separate from the semaphore structures so they can
+ * come and go at the whim of VOP_RECLAIM. (It might seem tidier to
+ * ignore VOP_RECLAIM and destroy vnodes only when the underlying
+ * objects are removed; but it ends up being more complicated in
+ * practice. XXX: review after finishing)
+ */
+struct semfs_vnode {
+	struct vnode semv_absvn;		/* Abstract vnode */
+	struct semfs *semv_semfs;		/* Back-pointer to fs */
+	unsigned semv_semnum;			/* Which semaphore */
+};
+
+/*
+ * The structure for the semaphore file system. Ordinarily there
+ * is only one of these.
+ */
+struct semfs {
+	struct fs semfs_absfs;			/* Abstract fs object */
+
+	struct lock *semfs_tablelock;		/* Lock for following */
+	struct vnodearray *semfs_vnodes;	/* Currently extant vnodes */
+	struct semfs_semarray *semfs_sems;	/* Semaphores */
+
+	struct lock *semfs_dirlock;		/* Lock for following */
+	struct semfs_direntryarray *semfs_dents; /* The root directory */
+};
+
+/*
+ * Arrays
+ */
+
+DEFARRAY(semfs_sem, SEMFS_INLINE);
+DEFARRAY(semfs_direntry, SEMFS_INLINE);
+
+
+/*
+ * Functions.
+ */
+
+/* in semfs_obj.c */
+struct semfs_sem *semfs_sem_create(const char *name);
+int semfs_sem_insert(struct semfs *, struct semfs_sem *, unsigned *);
+void semfs_sem_destroy(struct semfs_sem *);
+struct semfs_direntry *semfs_direntry_create(const char *name, unsigned semno);
+void semfs_direntry_destroy(struct semfs_direntry *);
+
+/* in semfs_vnops.c */
+int semfs_getvnode(struct semfs *, unsigned, struct vnode **ret);
+
+
+#endif /* SEMFS_H */