diff options
Diffstat (limited to 'xc/programs/Xserver/hw/xfree86/loader/loadext.c')
| -rw-r--r-- | xc/programs/Xserver/hw/xfree86/loader/loadext.c | 419 |
1 files changed, 419 insertions, 0 deletions
diff --git a/xc/programs/Xserver/hw/xfree86/loader/loadext.c b/xc/programs/Xserver/hw/xfree86/loader/loadext.c new file mode 100644 index 000000000..206c8296a --- /dev/null +++ b/xc/programs/Xserver/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 +} + |