#include <sys/time.h>
#include <errno.h>
#include <signal.h>
+#include <assert.h>
#define STRINGIFY2(x) #x
#define STRINGIFY(x) STRINGIFY2(x)
union {
int flag; /* open and store */
struct traverse *trav; /* traverse start */
- TDB_DATA pre_append; /* append */
+ struct { /* append */
+ TDB_DATA pre;
+ TDB_DATA post;
+ } append;
unsigned int transaction_end; /* transaction start */
};
};
static void op_add_append(const char *filename,
struct op op[], unsigned int op_num, char *words[])
{
- TDB_DATA post_append;
-
if (!words[2] || !words[3] || !words[4] || !words[5] || words[6]
|| !streq(words[4], "="))
fail(filename, op_num+1, "Expect <key> <data> = <rec>");
op[op_num].key = make_tdb_data(op, filename, op_num+1, words[2]);
op[op_num].data = make_tdb_data(op, filename, op_num+1, words[3]);
- post_append = make_tdb_data(op, filename, op_num+1, words[5]);
+ op[op_num].append.post
+ = make_tdb_data(op, filename, op_num+1, words[5]);
/* By subtraction, figure out what previous data was. */
- op[op_num].pre_append.dptr = post_append.dptr;
- op[op_num].pre_append.dsize = post_append.dsize - op[op_num].data.dsize;
+ op[op_num].append.pre.dptr = op[op_num].append.post.dptr;
+ op[op_num].append.pre.dsize
+ = op[op_num].append.post.dsize - op[op_num].data.dsize;
total_keys++;
}
break;
case OP_TDB_STORE:
try(tdb_store(tdb, op[i].key, op[i].data, op[i].flag),
- op[i].ret < 0 ? op[i].ret : 0);
+ op[i].ret);
break;
case OP_TDB_APPEND:
- try(tdb_append(tdb, op[i].key, op[i].data),
- op[i].ret < 0 ? op[i].ret : 0);
+ try(tdb_append(tdb, op[i].key, op[i].data), op[i].ret);
break;
case OP_TDB_GET_SEQNUM:
try(tdb_get_seqnum(tdb), op[i].ret);
return NULL;
case OP_TDB_APPEND:
- if (op->pre_append.dsize == 0)
+ if (op->append.pre.dsize == 0)
return ¬_exists_or_empty;
- return &op->pre_append;
+ return &op->append.pre;
case OP_TDB_STORE:
if (op->flag == TDB_INSERT) {
}
-enum satisfaction {
- /* This op makes the other one possible. */
- SATISFIES,
- /* This op makes the other one impossible. */
- DISSATISFIES,
- /* This op makes no difference. */
- NO_CHANGE
-};
-
-static enum satisfaction satisfies(const struct op *op, const TDB_DATA *need)
+/* What's the data after this op? pre if nothing changed. */
+static const TDB_DATA *gives(const struct op *op, const TDB_DATA *pre)
{
- bool deletes, creates;
-
/* Failed ops don't change state of db. */
if (op->ret < 0)
- return NO_CHANGE;
-
- deletes = (op->op == OP_TDB_DELETE || op->op == OP_TDB_WIPE_ALL);
- /* Append/store is creating the record if ret == 0 (1 means replaced) */
- if (op->op == OP_TDB_APPEND || op->op == OP_TDB_STORE)
- creates = (op->ret == 0);
- else
- creates = false;
-
- if (need == &must_not_exist) {
- if (deletes)
- return SATISFIES;
- if (creates)
- return DISSATISFIES;
- return NO_CHANGE;
- }
+ return pre;
- if (need == &must_exist) {
- if (deletes)
- return DISSATISFIES;
- if (creates)
- return SATISFIES;
- return NO_CHANGE;
- }
+ if (op->op == OP_TDB_DELETE || op->op == OP_TDB_WIPE_ALL)
+ return &tdb_null;
- if (need == ¬_exists_or_empty) {
- if (deletes)
- return SATISFIES;
- if (!creates)
- return NO_CHANGE;
- }
+ if (op->op == OP_TDB_APPEND)
+ return &op->append.post;
- /* OK, we need an exact match. */
- if (deletes)
- return DISSATISFIES;
-
- /* An append which results in the wrong data dissatisfies. */
- if (op->op == OP_TDB_APPEND) {
- if (op->pre_append.dsize + op->data.dsize != need->dsize)
- return DISSATISFIES;
- if (memcmp(op->pre_append.dptr, need->dptr,
- op->pre_append.dsize) != 0)
- return DISSATISFIES;
- if (memcmp(op->data.dptr, need->dptr + op->pre_append.dsize,
- op->data.dsize) != 0)
- return DISSATISFIES;
- return SATISFIES;
- } else if (op->op == OP_TDB_STORE) {
- if (key_eq(op->data, *need))
- return SATISFIES;
- return DISSATISFIES;
- }
- return NO_CHANGE;
+ if (op->op == OP_TDB_STORE)
+ return &op->data;
+
+ return pre;
}
static struct keyinfo *hash_ops(struct op *op[], unsigned int num_ops[],
unsigned int i, j, h;
struct keyinfo *hash;
- /* Gcc nexted function extension. How cool is this? */
- int compare_user_serial(const void *_a, const void *_b)
- {
- const struct key_user *a = _a, *b = _b;
- int ret = op[a->file][a->op_num].serial
- - op[b->file][b->op_num].serial;
-
- /* Serial is not completely reliable. First, fetches don't
- * inc serial, second we don't lock to get seq number.
- * This smooths things a little for simple cases. */
- if (ret == 0) {
- const TDB_DATA *a_needs, *b_needs;
-
- b_needs = needs(&op[b->file][b->op_num]);
- switch (satisfies(&op[a->file][a->op_num], b_needs)) {
- case SATISFIES:
- /* A comes first: it satisfies B. */
- return -1;
- case DISSATISFIES:
- /* A doesn't come first: it messes up B. */
- return 1;
- default:
- break;
- }
-
- a_needs = needs(&op[a->file][a->op_num]);
- switch (satisfies(&op[b->file][b->op_num], a_needs)) {
- case SATISFIES:
- /* B comes first: it satisfies A. */
- return 1;
- case DISSATISFIES:
- /* B doesn't come first: it messes up A. */
- return -1;
- default:
- break;
- }
- }
- return ret;
- }
-
hash = talloc_zero_array(op[0], struct keyinfo, total_keys*2);
for (i = 0; i < num; i++) {
for (j = 1; j < num_ops[i]; j++) {
}
}
+ return hash;
+}
+
+static bool satisfies(const TDB_DATA *data, const TDB_DATA *need)
+{
+ /* Don't need anything? Cool. */
+ if (!need)
+ return true;
+
+ /* This should be tdb_null or a real value. */
+ assert(data != &must_exist);
+ assert(data != &must_not_exist);
+ assert(data != ¬_exists_or_empty);
+
+ /* must_not_exist == must_not_exist, must_exist == must_exist, or
+ not_exists_or_empty == not_exists_or_empty. */
+ if (data->dsize == need->dsize && data->dptr == need->dptr)
+ return true;
+
+ /* Must not exist? data must not exist. */
+ if (need == &must_not_exist)
+ return data->dptr == NULL;
+
+ /* Must exist? */
+ if (need == &must_exist)
+ return data->dptr != NULL;
+
+ /* Either noexist or empty. */
+ if (need == ¬_exists_or_empty)
+ return data->dsize == 0;
+
+ /* Needs something specific. */
+ return key_eq(*data, *need);
+}
+
+static bool sort_deps(char *filename[], struct op *op[],
+ struct key_user res[], unsigned num,
+ const TDB_DATA *data)
+{
+ unsigned int i;
+
+ /* Nothing left? We're sorted. */
+ if (num == 0)
+ return true;
+
+ for (i = 0; i < num; i++) {
+ struct op *this_op = &op[res[i].file][res[i].op_num];
+
+ /* Is what we have good enough for this op? */
+ if (satisfies(data, needs(this_op))) {
+ /* Try this one next. */
+ struct key_user tmp = res[0];
+ res[0] = res[i];
+ res[i] = tmp;
+ if (sort_deps(filename, op, res+1, num-1,
+ gives(this_op, data)))
+ return true;
+ }
+ }
+ /* No combination worked. */
+ return false;
+}
+
+/* All these ops have the same serial number. Which comes first?
+ *
+ * This can happen both because read ops or failed write ops don't
+ * change serial number, and also due to race since we access the
+ * number unlocked (the race can cause less detectable ordering problems,
+ * in which case we'll deadlock and report: fix manually in that case).
+ */
+static void figure_deps(char *filename[], struct op *op[],
+ struct key_user user[], unsigned start, unsigned end)
+{
+ unsigned int i;
+ /* We assume database starts empty. */
+ const struct TDB_DATA *data = &tdb_null;
+
+ /* What do we have to start with? */
+ for (i = 0; i < start; i++)
+ data = gives(&op[user[i].file][user[i].op_num], data);
+
+ if (!sort_deps(filename, op, user + start, end - start, data))
+ fail(filename[user[start].file], user[start].op_num+1,
+ "Could not resolve inter-dependencies");
+}
+
+static void sort_ops(struct keyinfo hash[], char *filename[], struct op *op[])
+{
+ unsigned int h;
+
+ /* Gcc nexted function extension. How cool is this? */
+ int compare_serial(const void *_a, const void *_b)
+ {
+ const struct key_user *a = _a, *b = _b;
+ return op[a->file][a->op_num].serial
+ - op[b->file][b->op_num].serial;
+ }
+
/* Now sort into seqnum order. */
- for (h = 0; h < total_keys * 2; h++)
- qsort(hash[h].user, hash[h].num_users, sizeof(hash[h].user[0]),
- compare_user_serial);
+ for (h = 0; h < total_keys * 2; h++) {
+ unsigned int i, same;
+ struct key_user *user = hash[h].user;
- return hash;
+ qsort(user, hash[h].num_users, sizeof(user[0]), compare_serial);
+
+ /* Try to deal with same serial numbers. */
+ for (i = 1, same = 0; i < hash[h].num_users; i++) {
+ if (op[user[i].file][user[i].op_num].serial
+ == op[user[i-1].file][user[i-1].op_num].serial) {
+ same++;
+ continue;
+ }
+
+ if (same) {
+ figure_deps(filename, op, user, i-same-1, i);
+ same = 0;
+ }
+ }
+ if (same)
+ figure_deps(filename, op, user, i-same-1, i);
+ }
}
static void add_dependency(void *ctx,
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