+ /* If satisfies is in a transaction, we wait until after commit. */
+ /* FIXME: If transaction is cancelled, don't need dependency. */
+ if (sat_start) {
+ if (op[satisfies_file][sat_start].op
+ == OP_TDB_TRANSACTION_START) {
+ satisfies_opnum = sat_start
+ + op[satisfies_file][sat_start].group_len;
+#ifdef DEBUG_DEPS
+ printf(" -> Depends on %u\n", satisfies_opnum+1);
+ fflush(stdout);
+#endif
+ }
+ }
+
+ assert(op[needs_file][needs_opnum].op != OP_TDB_TRAVERSE);
+ assert(op[satisfies_file][satisfies_opnum].op != OP_TDB_TRAVERSE);
+
+ dep = talloc(ctx, struct depend);
+ dep->needs_file = needs_file;
+ dep->needs_opnum = needs_opnum;
+ dep->satisfies_file = satisfies_file;
+ dep->satisfies_opnum = satisfies_opnum;
+ list_add(&op[satisfies_file][satisfies_opnum].post, &dep->post_list);
+ list_add(&op[needs_file][needs_opnum].pre, &dep->pre_list);
+ talloc_set_destructor(dep, destroy_depend);
+}
+
+#if TRAVERSALS_TAKE_TRANSACTION_LOCK
+struct traverse_dep {
+ unsigned int file;
+ unsigned int op_num;
+};
+
+/* Traversals can deadlock against each other, and transactions. Force
+ * order. */
+static void make_traverse_depends(char *filename[],
+ struct op *op[], unsigned int num_ops[],
+ unsigned int num)
+{
+ unsigned int i, j, num_traversals = 0;
+ struct traverse_dep *dep;
+
+ /* Sort by which one runs first. */
+ int compare_traverse_dep(const void *_a, const void *_b)
+ {
+ const struct traverse_dep *ta = _a, *tb = _b;
+ const struct op *a = &op[ta->file][ta->op_num],
+ *b = &op[tb->file][tb->op_num];
+
+ if (a->serial != b->serial)
+ return a->serial - b->serial;
+
+ /* If they have same serial, it means one didn't make any
+ * changes. Thus sort by end in that case. */
+ return a[a->group_len].serial - b[b->group_len].serial;
+ }
+
+ dep = talloc_array(NULL, struct traverse_dep, 1);
+
+ /* Count them. */
+ for (i = 0; i < num; i++) {
+ for (j = 1; j < num_ops[i]; j++) {
+ /* Transaction or traverse start. */
+ if (op[i][j].group_start == j) {
+ dep = talloc_realloc(NULL, dep,
+ struct traverse_dep,
+ num_traversals+1);
+ dep[num_traversals].file = i;
+ dep[num_traversals].op_num = j;
+ num_traversals++;
+ }
+ }
+ }
+ qsort(dep, num_traversals, sizeof(dep[0]), compare_traverse_dep);
+ for (i = 1; i < num_traversals; i++) {
+ /* i depends on end of traverse i-1. */
+ add_dependency(NULL, op, filename, dep[i].file, dep[i].op_num,
+ dep[i-1].file, dep[i-1].op_num
+ + op[dep[i-1].file][dep[i-1].op_num].group_len);
+ }
+ talloc_free(dep);
+}
+#endif /* TRAVERSALS_TAKE_TRANSACTION_LOCK */
+
+static bool changes_db(const struct op *op)
+{
+ return gives(op, NULL) != NULL;
+}
+
+static void depend_on_previous(struct op *op[],
+ char *filename[],
+ unsigned int num,
+ struct key_user user[],
+ unsigned int i,
+ int prev)
+{
+ bool deps[num];
+ int j;
+
+ if (i == 0)
+ return;
+
+ if (prev == i - 1) {
+ /* Just depend on previous. */
+ add_dependency(NULL, op, filename,
+ user[i].file, user[i].op_num,
+ user[prev].file, user[prev].op_num);
+ return;
+ }
+
+ /* We have to wait for the readers. Find last one in *each* file. */
+ memset(deps, 0, sizeof(deps));
+ deps[user[i].file] = true;
+ for (j = i - 1; j > prev; j--) {
+ if (!deps[user[j].file]) {
+ add_dependency(NULL, op, filename,
+ user[i].file, user[i].op_num,
+ user[j].file, user[j].op_num);
+ deps[user[j].file] = true;
+ }
+ }
+}
+
+/* This is simple, but not complete. We don't take into account
+ * indirect dependencies. */
+static void optimize_dependencies(struct op *op[], unsigned int num_ops[],
+ unsigned int num)
+{
+ unsigned int i, j;
+
+ /* There can only be one real dependency on each file */
+ for (i = 0; i < num; i++) {
+ for (j = 1; j < num_ops[i]; j++) {
+ struct depend *dep, *next;
+ struct depend *prev[num];
+
+ memset(prev, 0, sizeof(prev));
+
+ list_for_each_safe(&op[i][j].pre, dep, next, pre_list) {
+ if (!prev[dep->satisfies_file]) {
+ prev[dep->satisfies_file] = dep;
+ continue;
+ }
+ if (prev[dep->satisfies_file]->satisfies_opnum
+ < dep->satisfies_opnum) {
+ talloc_free(prev[dep->satisfies_file]);
+ prev[dep->satisfies_file] = dep;
+ } else
+ talloc_free(dep);
+ }
+ }
+ }
+
+ for (i = 0; i < num; i++) {
+ int deps[num];
+
+ for (j = 0; j < num; j++)
+ deps[j] = -1;
+
+ for (j = 1; j < num_ops[i]; j++) {
+ struct depend *dep, *next;
+
+ list_for_each_safe(&op[i][j].pre, dep, next, pre_list) {
+ if (deps[dep->satisfies_file]
+ >= (int)dep->satisfies_opnum)
+ talloc_free(dep);
+ else
+ deps[dep->satisfies_file]
+ = dep->satisfies_opnum;
+ }
+ }
+ }