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-rw-r--r--hw/xfree86/loader/loadext.c419
1 files changed, 419 insertions, 0 deletions
diff --git a/hw/xfree86/loader/loadext.c b/hw/xfree86/loader/loadext.c
new file mode 100644
index 000000000..206c8296a
--- /dev/null
+++ b/hw/xfree86/loader/loadext.c
@@ -0,0 +1,419 @@
+/* $XFree86: xc/programs/Xserver/hw/xfree86/loader/loadext.c,v 1.6 2000/02/08 17:19:19 dawes Exp $ */
+
+/* Copyright 2000 by The XFree86 Project, Inc */
+
+/* Maybe this file belongs elsewhere? */
+
+#define LOADERDECLARATIONS
+#include "loaderProcs.h"
+#include "misc.h"
+#include "xf86.h"
+
+ExtensionModule *ExtensionModuleList = NULL;
+static int numExtensionModules = 0;
+
+
+static ExtensionModule *
+NewExtensionModule(void)
+{
+ ExtensionModule *save = ExtensionModuleList;
+ int n;
+
+ /* Sanity check */
+ if (!ExtensionModuleList)
+ numExtensionModules = 0;
+
+ n = numExtensionModules + 1;
+ ExtensionModuleList = xrealloc(ExtensionModuleList,
+ (n + 1) * sizeof(ExtensionModule));
+ if (ExtensionModuleList == NULL) {
+ ExtensionModuleList = save;
+ return NULL;
+ } else {
+ numExtensionModules++;
+ ExtensionModuleList[numExtensionModules].name = NULL;
+ return ExtensionModuleList + (numExtensionModules - 1);
+ }
+}
+
+void
+LoadExtension(ExtensionModule *e, Bool builtin)
+{
+ ExtensionModule *newext;
+
+ if (e == NULL || e->name == NULL)
+ return;
+
+ if (!(newext = NewExtensionModule()))
+ return;
+
+ if (builtin)
+ xf86MsgVerb(X_INFO, 2, "Initializing built-in extension %s\n",
+ e->name);
+ else
+ xf86MsgVerb(X_INFO, 2, "Loading extension %s\n", e->name);
+
+ newext->name = e->name;
+ newext->initFunc = e->initFunc;
+ newext->disablePtr = e->disablePtr;
+ newext->setupFunc = e->setupFunc;
+ newext->initDependencies = e->initDependencies;
+
+ if (e->setupFunc != NULL)
+ e->setupFunc();
+}
+
+
+/*
+ * Sort ExtensionModuleList according to the initialisation order
+ * dependencies. The code for this is taken from BSD's tsort,
+ * and carries the following copyright/license:
+ *
+ *
+ * Copyright (c) 1989, 1993, 1994
+ * The Regents of the University of California. All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Michael Rendell of Memorial University of Newfoundland.
+ *
+ * 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. All advertising materials mentioning features or use of this software
+ * must display the following acknowledgement:
+ * This product includes software developed by the University of
+ * California, Berkeley and its contributors.
+ * 4. 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 REGENTS 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 REGENTS 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.
+ */
+
+
+#define NF_MARK 0x1 /* marker for cycle detection */
+#define NF_ACYCLIC 0x2 /* this node is cycle free */
+#define NF_NODEST 0x4 /* Unreachable */
+
+typedef struct node_str NODE;
+struct node_str {
+ NODE **n_prevp; /* pointer to previous node's n_next */
+ NODE *n_next; /* next node in graph */
+ NODE **n_arcs; /* array of arcs to other nodes */
+ int n_narcs; /* number of arcs in n_arcs[] */
+ int n_arcsize; /* size of n_arcs[] array */
+ int n_refcnt; /* # of arcs pointing to this node */
+ int n_flags; /* NF_* */
+ const char *n_name; /* name of this node */
+};
+
+static NODE *graph = NULL, **cycle_buf = NULL, **longest_cycle = NULL;
+static int longest = 0;
+static NODE *sorted = NULL, *last = NULL;
+
+/* Find a node in the graph (insert if not found) and return a pointer to it. */
+static NODE *
+get_node(const char *name)
+{
+ NODE *n;
+
+ for (n = graph; n && n->n_name && strcmp(n->n_name, name); n = n->n_next)
+ ;
+ if (n)
+ return (n);
+
+ n = xnfalloc(sizeof(NODE));
+
+ n->n_narcs = 0;
+ n->n_arcsize = 0;
+ n->n_arcs = NULL;
+ n->n_refcnt = 0;
+ n->n_flags = 0;
+ n->n_name = name;
+
+ /* Add to linked list. */
+ if ((n->n_next = graph) != NULL)
+ graph->n_prevp = &n->n_next;
+ n->n_prevp = &graph;
+ graph = n;
+
+ return (n);
+}
+
+
+/*
+ * add an arc from node s1 to node s2 in the graph. If s1 or s2 are not in
+ * the graph, then add them.
+ */
+static void
+add_arc(const char *s1, const char *s2)
+{
+ NODE *n1;
+ NODE *n2;
+ int bsize, i;
+
+ n1 = get_node(s1);
+
+ if (!strcmp(s1, s2))
+ return;
+
+ n2 = get_node(s2);
+
+ /*
+ * Check if this arc is already here.
+ */
+ for (i = 0; i < n1->n_narcs; i++)
+ if (n1->n_arcs[i] == n2)
+ return;
+ /*
+ * Add it.
+ */
+ if (n1->n_narcs == n1->n_arcsize) {
+ if (!n1->n_arcsize)
+ n1->n_arcsize = 10;
+ bsize = n1->n_arcsize * sizeof(*n1->n_arcs) * 2;
+ n1->n_arcs = xnfrealloc(n1->n_arcs, bsize);
+ n1->n_arcsize = bsize / sizeof(*n1->n_arcs);
+ }
+ n1->n_arcs[n1->n_narcs++] = n2;
+ ++n2->n_refcnt;
+}
+
+/*
+ * Clear the NODEST flag from all nodes.
+ */
+static void
+clear_cycle(void)
+{
+ NODE *n;
+
+ for (n = graph; n != NULL; n = n->n_next)
+ n->n_flags &= ~NF_NODEST;
+}
+
+/* print node and remove from graph (does not actually free node) */
+static void
+remove_node(NODE *n)
+{
+ NODE **np;
+ NODE *newnode;
+ int i;
+
+#ifdef DEBUG
+ ErrorF("%s\n", n->n_name);
+#endif
+ newnode = xnfalloc(sizeof(NODE));
+ memcpy(newnode, n, sizeof(NODE));
+ if (last)
+ last->n_next = newnode;
+ else
+ sorted = newnode;
+ last = newnode;
+ newnode->n_next = NULL;
+
+ for (np = n->n_arcs, i = n->n_narcs; --i >= 0; np++)
+ --(*np)->n_refcnt;
+ n->n_narcs = 0;
+ *n->n_prevp = n->n_next;
+ if (n->n_next)
+ n->n_next->n_prevp = n->n_prevp;
+}
+
+
+static void
+free_nodes(NODE *nodelist)
+{
+ NODE *n, *nextnode;
+
+ for (n = nodelist; n;) {
+ nextnode = n->n_next;
+ xfree(n);
+ n = nextnode;
+ }
+}
+
+
+/* look for the longest? cycle from node from to node to. */
+static int
+find_cycle(NODE *from, NODE *to, int longest_len, int depth)
+{
+ NODE **np;
+ int i, len;
+
+ /*
+ * avoid infinite loops and ignore portions of the graph known
+ * to be acyclic
+ */
+ if (from->n_flags & (NF_NODEST|NF_MARK|NF_ACYCLIC))
+ return (0);
+ from->n_flags |= NF_MARK;
+
+ for (np = from->n_arcs, i = from->n_narcs; --i >= 0; np++) {
+ cycle_buf[depth] = *np;
+ if (*np == to) {
+ if (depth + 1 > longest_len) {
+ longest_len = depth + 1;
+ memcpy((char *)longest_cycle,
+ (char *)cycle_buf,
+ longest_len * sizeof(NODE *));
+ }
+ } else {
+ if ((*np)->n_flags & (NF_MARK|NF_ACYCLIC|NF_NODEST))
+ continue;
+ len = find_cycle(*np, to, longest_len, depth + 1);
+
+#ifdef DEBUG
+ ErrorF("%*s %s->%s %d\n", depth, "",
+ from->n_name, to->n_name, len);
+#endif
+
+ if (len == 0)
+ (*np)->n_flags |= NF_NODEST;
+
+ if (len > longest_len)
+ longest_len = len;
+
+ if (len > 0 && !longest)
+ break;
+ }
+ }
+ from->n_flags &= ~NF_MARK;
+ return (longest_len);
+}
+
+
+/* do topological sort on graph */
+static void
+tsort(void)
+{
+ NODE *n, *next;
+ int cnt, i;
+
+ while (graph != NULL) {
+ /*
+ * Keep getting rid of simple cases until there are none left,
+ * if there are any nodes still in the graph, then there is
+ * a cycle in it.
+ */
+ do {
+ for (cnt = 0, n = graph; n != NULL; n = next) {
+ next = n->n_next;
+ if (n->n_refcnt == 0) {
+ remove_node(n);
+ ++cnt;
+ }
+ }
+ } while (graph != NULL && cnt);
+
+ if (graph == NULL)
+ break;
+
+ if (!cycle_buf) {
+ /*
+ * Allocate space for two cycle logs - one to be used
+ * as scratch space, the other to save the longest
+ * cycle.
+ */
+ for (cnt = 0, n = graph; n != NULL; n = n->n_next)
+ ++cnt;
+ cycle_buf = xnfalloc(sizeof(NODE *) * cnt);
+ longest_cycle = xnfalloc(sizeof(NODE *) * cnt);
+ if (cycle_buf == NULL || longest_cycle == NULL)
+ return;
+ }
+ for (n = graph; n != NULL; n = n->n_next)
+ if (!(n->n_flags & NF_ACYCLIC)) {
+ if ((cnt = find_cycle(n, n, 0, 0))) {
+ ErrorF("tsort: cycle in data");
+ for (i = 0; i < cnt; i++)
+ ErrorF("%s",
+ longest_cycle[i]->n_name);
+ remove_node(n);
+ clear_cycle();
+ break;
+ } else {
+ /* to avoid further checks */
+ n->n_flags |= NF_ACYCLIC;
+ clear_cycle();
+ }
+ }
+
+ if (n == NULL)
+ ErrorF("tsort: internal error -- could not find cycle");
+ }
+ if (cycle_buf)
+ xfree(cycle_buf);
+ if (longest_cycle)
+ xfree(longest_cycle);
+ if (graph)
+ free_nodes(graph);
+}
+
+void
+LoaderSortExtensions()
+{
+ int i, j;
+ ExtensionModule *ext, *newList;
+ NODE *node;
+
+ graph = NULL;
+ longest = 0;
+ sorted = NULL;
+ last = NULL;
+ cycle_buf = NULL;
+ longest_cycle = NULL;
+
+ /*
+ * Parse list and build the graph. Enter them in reverse order
+ * because tsort() will reverse those that have no depedencies.
+ */
+ for (i = numExtensionModules - 1; i >= 0; i--) {
+ ext = &ExtensionModuleList[i];
+ add_arc(ext->name, ext->name);
+#ifdef DEBUG
+ ErrorF("Extension %s:\n", ext->name);
+#endif
+ if (ext->initDependencies)
+ for (j = 0; ext->initDependencies[j]; j++) {
+ add_arc(ext->initDependencies[j], ext->name);
+#ifdef DEBUG
+ ErrorF("\t%s\n", ext->initDependencies[j]);
+#endif
+ }
+ }
+ tsort();
+ newList = xnfalloc((numExtensionModules + 1) * sizeof(ExtensionModule));
+ i = 0;
+ for (node = sorted; node; node = node->n_next) {
+ for (j = 0; j < numExtensionModules; j++)
+ if (!strcmp(node->n_name, ExtensionModuleList[j].name))
+ break;
+ if (j != numExtensionModules)
+ newList[i++] = ExtensionModuleList[j];
+ }
+ if (sorted)
+ free_nodes(sorted);
+ newList[i].name = NULL;
+ xfree(ExtensionModuleList);
+ ExtensionModuleList = newList;
+#ifdef DEBUG
+ for (i = 0; ExtensionModuleList[i].name; i++)
+ ErrorF("Extension %s\n", ExtensionModuleList[i].name);
+#endif
+}
+