Initial Spring 2016 commit.

userland/testbin/frack/pool.c

@@ -0,0 +1,70 @@
+/*
+ * Copyright (c) 2013
+ *	The President and Fellows of Harvard College.
+ *      Written by David A. Holland.
+ *
+ * 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.
+ */
+
+#include <stdint.h>
+#include <assert.h>
+#include <err.h>
+
+#include "pool.h"
+
+unsigned
+poolalloc(struct poolctl *pool)
+{
+	uint32_t mask;
+	unsigned j, i;
+
+	assert(pool->max % 32 == 0);
+	for (j=0; j<pool->max/32; j++) {
+		for (mask=1, i=0; i<32; mask<<=1, i++) {
+			if ((pool->inuse[j] & mask) == 0) {
+				pool->inuse[j] |= mask;
+				return j*32 + i;
+			}
+		}
+	}
+	errx(1, "Too many %s -- increase %s in %s",
+	     pool->itemtype, pool->maxname, pool->file);
+	return 0;
+}
+
+void
+poolfree(struct poolctl *pool, unsigned num)
+{
+	uint32_t mask;
+	unsigned pos;
+
+	assert(num < pool->max);
+
+	pos = num / 32;
+	mask = 1 << (num % 32);
+
+	assert(pool->inuse[pos] & mask);
+	pool->inuse[pos] &= ~(uint32_t)mask;
+}