Import Dev86-0.0.4.tar.gzv0.0.4

1 files changed, 104 insertions, 0 deletions

diff --git a/unproto/tok_pool.c b/unproto/tok_pool.c
new file mode 100644
index 0000000..c2a9665
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+++ b/unproto/tok_pool.c
@@ -0,0 +1,104 @@
+/*++
+/* NAME
+/*	tok_pool 3
+/* SUMMARY
+/*	maintain pool of unused token structures
+/* PACKAGE
+/*	unproto
+/* SYNOPSIS
+/*	#include "token.h"
+/*
+/*	struct token *tok_alloc()
+/*
+/*	void tok_free(t)
+/*	struct token *t;
+/* DESCRIPTION
+/*	tok_alloc() and tok_free() maintain a pool of unused token
+/*	structures.
+/*
+/*	tok_alloc() takes the first free token structure from the pool
+/*	or allocates a new one if the pool is empty.
+/*
+/*	tok_free() adds a (possibly composite) token structure to the pool.
+/* BUGS
+/*	The pool never shrinks.
+/* AUTHOR(S)
+/*	Wietse Venema
+/*	Eindhoven University of Technology
+/*	Department of Mathematics and Computer Science
+/*	Den Dolech 2, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
+/* LAST MODIFICATION
+/*	91/09/01 23:08:36
+/* VERSION/RELEASE
+/*	1.1
+/*--*/
+
+static char pool_sccsid[] = "@(#) tok_pool.c 1.1 91/09/01 23:08:36";
+
+/* C library */
+
+extern char *malloc();
+
+/* Application-specific stuff */
+
+#include "token.h"
+#include "vstring.h"
+
+extern void error();
+
+#define	TOKLEN	5			/* initial string buffer length */
+
+struct token *tok_pool = 0;		/* free token pool */
+
+/* tok_alloc - allocate token structure from pool or heap */
+
+struct token *tok_alloc()
+{
+    register struct token *t;
+
+    if (tok_pool) {				/* re-use an old one */
+	t = tok_pool;
+	tok_pool = t->next;
+    } else {					/* create a new one */
+	if ((t = (struct token *) malloc(sizeof(struct token))) == 0
+	    || (t->vstr = vs_alloc(TOKLEN)) == 0)
+	    error(1, "out of memory");
+    }
+    t->next = t->head = t->tail = 0;
+#ifdef	DEBUG
+    strcpy(t->vstr->str, "BUSY");
+#endif
+    return (t);
+}
+
+/* tok_free - return (possibly composite) token to pool of free tokens */
+
+void    tok_free(t)
+register struct token *t;
+{
+#ifdef DEBUG
+    /* Check if we are freeing free token */
+
+    register struct token *p;
+
+    for (p = tok_pool; p; p = p->next)
+	if (p == t)
+	    error(1, "freeing free token");
+#endif
+
+    /* Free neighbours and subordinates first */
+
+    if (t->next)
+	tok_free(t->next);
+    if (t->head)
+	tok_free(t->head);
+
+    /* Free self */
+
+    t->next = tok_pool;
+    t->head = t->tail = 0;
+    tok_pool = t;
+#ifdef	DEBUG
+    strcpy(t->vstr->str, "FREE");
+#endif
+}