]> git.ozlabs.org Git - ccan/blobdiff - ccan/tdb/tools/replay_trace.c
YA corner case: help assumption by putting cancelled transactions first.
[ccan] / ccan / tdb / tools / replay_trace.c
index baa56077d65e251caf70d397c972c743e5689c3d..4afe900aa8e8317587e2f4eb0d84572d74fc221b 100644 (file)
@@ -147,7 +147,8 @@ struct op {
                        TDB_DATA pre;
                        TDB_DATA post;
                } append;
-               unsigned int group_len; /* transaction/traverse start */
+               /* transaction/traverse start/chainlock */
+               unsigned int group_len;
        };
 };
 
@@ -320,12 +321,39 @@ static void op_add_transaction(const char *filename, struct op op[],
        op[op_num].group_len = 0;
 }
 
-static int op_transaction_start(struct op op[], unsigned int op_num)
+static void op_add_chainlock(const char *filename,
+                            struct op op[], unsigned int op_num, char *words[])
+{
+       if (words[2] == NULL || words[3])
+               fail(filename, op_num+1, "Expected just a key");
+
+       /* A chainlock key isn't a key in the normal sense; it doesn't
+        * have to be in the db at all.  Also, we don't want to hash this op. */
+       op[op_num].data = make_tdb_data(op, filename, op_num+1, words[2]);
+       op[op_num].key = tdb_null;
+       op[op_num].group_len = 0;
+}
+
+static void op_add_chainlock_ret(const char *filename,
+                                struct op op[], unsigned int op_num,
+                                char *words[])
+{
+       if (!words[2] || !words[3] || !words[4] || words[5]
+           || !streq(words[3], "="))
+               fail(filename, op_num+1, "Expected <key> = <ret>");
+       op[op_num].ret = atoi(words[4]);
+       op[op_num].data = make_tdb_data(op, filename, op_num+1, words[2]);
+       op[op_num].key = tdb_null;
+       op[op_num].group_len = 0;
+       total_keys++;
+}
+
+static int op_find_start(struct op op[], unsigned int op_num, enum op_type type)
 {
        unsigned int i;
 
        for (i = op_num-1; i > 0; i--) {
-               if (op[i].op == OP_TDB_TRANSACTION_START && !op[i].group_len)
+               if (op[i].op == type && !op[i].group_len)
                        return i;
        }
        return 0;
@@ -342,7 +370,7 @@ static void op_analyze_transaction(const char *filename,
        if (words[2])
                fail(filename, op_num+1, "Expect no arguments");
 
-       start = op_transaction_start(op, op_num);
+       start = op_find_start(op, op_num, OP_TDB_TRANSACTION_START);
        if (!start)
                fail(filename, op_num+1, "no transaction start found");
 
@@ -353,10 +381,35 @@ static void op_analyze_transaction(const char *filename,
                op[i].group_start = start;
 }
 
-struct traverse_hash {
-       TDB_DATA key;
-       unsigned int index;
-};
+/* We treat chainlocks a lot like transactions, even though that's overkill */
+static void op_analyze_chainlock(const char *filename,
+                                struct op op[], unsigned int op_num,
+                                char *words[])
+{
+       unsigned int i, start;
+
+       if (words[2] == NULL || words[3])
+               fail(filename, op_num+1, "Expected just a key");
+
+       op[op_num].data = make_tdb_data(op, filename, op_num+1, words[2]);
+       op[op_num].key = tdb_null;
+       total_keys++;
+
+       start = op_find_start(op, op_num, OP_TDB_CHAINLOCK);
+       if (!start)
+               start = op_find_start(op, op_num, OP_TDB_CHAINLOCK_READ);
+       if (!start)
+               fail(filename, op_num+1, "no initial chainlock found");
+
+       /* FIXME: We'd have to do something clever to make this work
+        * vs. deadlock. */
+       if (!key_eq(op[start].data, op[op_num].data))
+               fail(filename, op_num+1, "nested chainlock calls?");
+
+       op[start].group_len = op_num - start;
+       for (i = start; i <= op_num; i++)
+               op[i].group_start = start;
+}
 
 static void op_analyze_traverse(const char *filename,
                                struct op op[], unsigned int op_num,
@@ -374,23 +427,18 @@ static void op_analyze_traverse(const char *filename,
        } else
                op[op_num].ret = 0;
 
-       for (i = op_num-1; i >= 0; i--) {
-               if (op[i].op != OP_TDB_TRAVERSE_READ_START
-                   && op[i].op != OP_TDB_TRAVERSE_START)
-                       continue;
-               if (op[i].group_len)
-                       continue;
-               break;
-       }
-
-       if (i < 0)
+       start = op_find_start(op, op_num, OP_TDB_TRAVERSE_START);
+       if (!start)
+               start = op_find_start(op, op_num, OP_TDB_TRAVERSE_READ_START);
+       if (!start)
                fail(filename, op_num+1, "no traversal start found");
 
-       start = i;
        op[start].group_len = op_num - start;
 
+       /* Don't roll in nested traverse/chainlock */
        for (i = start; i <= op_num; i++)
-               op[i].group_start = start;
+               if (!op[i].group_start)
+                       op[i].group_start = start;
 }
 
 /* Keep -Wmissing-declarations happy: */
@@ -743,7 +791,7 @@ unsigned run_ops(struct tdb_context *tdb,
 static struct op *maybe_cancel_transaction(const char *filename,
                                           struct op *op, unsigned int *num)
 {
-       unsigned int start = op_transaction_start(op, *num);
+       unsigned int start = op_find_start(op, *num, OP_TDB_TRANSACTION_START);
 
        if (start) {
                char *words[] = { "<unknown>", "tdb_close", NULL };
@@ -904,22 +952,56 @@ static const TDB_DATA *needs(const struct op *op)
        
 }
 
-static bool is_transaction(const struct op *op)
+static bool starts_transaction(const struct op *op)
 {
        return op->op == OP_TDB_TRANSACTION_START;
 }
 
+static bool in_transaction(const struct op op[], unsigned int i)
+{
+       return op[i].group_start && starts_transaction(&op[op[i].group_start]);
+}
+
+static bool successful_transaction(const struct op *op)
+{
+       return starts_transaction(op)
+               && op[op->group_len].op == OP_TDB_TRANSACTION_COMMIT;
+}
+
+static bool starts_traverse(const struct op *op)
+{
+       return op->op == OP_TDB_TRAVERSE_START
+               || op->op == OP_TDB_TRAVERSE_READ_START;
+}
+
+static bool in_traverse(const struct op op[], unsigned int i)
+{
+       return op[i].group_start && starts_traverse(&op[op[i].group_start]);
+}
+
+static bool starts_chainlock(const struct op *op)
+{
+       return op->op == OP_TDB_CHAINLOCK_READ || op->op == OP_TDB_CHAINLOCK;
+}
+
+static bool in_chainlock(const struct op op[], unsigned int i)
+{
+       return op[i].group_start && starts_chainlock(&op[op[i].group_start]);
+}
+
 /* What's the data after this op?  pre if nothing changed. */
 static const TDB_DATA *gives(const TDB_DATA *key, const TDB_DATA *pre,
                             const struct op *op)
 {
-       if (is_transaction(op)) {
+       if (starts_transaction(op) || starts_chainlock(op)) {
                unsigned int i;
 
                /* Cancelled transactions don't change anything. */
                if (op[op->group_len].op == OP_TDB_TRANSACTION_CANCEL)
                        return pre;
-               assert(op[op->group_len].op == OP_TDB_TRANSACTION_COMMIT);
+               assert(op[op->group_len].op == OP_TDB_TRANSACTION_COMMIT
+                      || op[op->group_len].op == OP_TDB_CHAINUNLOCK_READ
+                      || op[op->group_len].op == OP_TDB_CHAINUNLOCK);
 
                for (i = 1; i < op->group_len; i++) {
                        /* This skips nested transactions, too */
@@ -945,22 +1027,6 @@ static const TDB_DATA *gives(const TDB_DATA *key, const TDB_DATA *pre,
        return pre;
 }
 
-static bool in_transaction(const struct op op[], unsigned int i)
-{
-       return op[i].group_start && is_transaction(&op[op[i].group_start]);
-}
-
-static bool is_traverse(const struct op *op)
-{
-       return op->op == OP_TDB_TRAVERSE_START
-               || op->op == OP_TDB_TRAVERSE_READ_START;
-}
-
-static bool in_traverse(const struct op op[], unsigned int i)
-{
-       return op[i].group_start && is_traverse(&op[op[i].group_start]);
-}
-
 static struct keyinfo *hash_ops(struct op *op[], unsigned int num_ops[],
                                unsigned int num)
 {
@@ -996,7 +1062,8 @@ static struct keyinfo *hash_ops(struct op *op[], unsigned int num_ops[],
 
                        /* If it's in a transaction, it's the transaction which
                         * matters from an analysis POV. */
-                       if (in_transaction(op[i], j)) {
+                       if (in_transaction(op[i], j)
+                           || in_chainlock(op[i], j)) {
                                unsigned start = op[i][j].group_start;
 
                                /* Don't include twice. */
@@ -1023,7 +1090,7 @@ static bool satisfies(const TDB_DATA *key, const TDB_DATA *data,
 {
        const TDB_DATA *need = NULL;
 
-       if (is_transaction(op)) {
+       if (starts_transaction(op) || starts_chainlock(op)) {
                unsigned int i;
 
                /* Look through for an op in this transaction which
@@ -1204,8 +1271,21 @@ static void sort_ops(struct keyinfo hash[], char *filename[], struct op *op[],
                        return a->op_num - b->op_num;
 
                /* Otherwise, arrange by serial order. */
-               return op[a->file][a->op_num].serial
-                       - op[b->file][b->op_num].serial;
+               if (op[a->file][a->op_num].serial !=
+                   op[b->file][b->op_num].serial)
+                       return op[a->file][a->op_num].serial
+                               - op[b->file][b->op_num].serial;
+
+               /* Cancelled transactions are assumed to happen first. */
+               if (starts_transaction(&op[a->file][a->op_num])
+                   && !successful_transaction(&op[a->file][a->op_num]))
+                       return -1;
+               if (starts_transaction(&op[b->file][b->op_num])
+                   && !successful_transaction(&op[b->file][b->op_num]))
+                       return 1;
+
+               /* No idea. */
+               return 0;
        }
 
        /* Now sort into serial order. */
@@ -1252,9 +1332,11 @@ static void add_dependency(void *ctx,
         * traverse/transaction, it creates a dependency between the
         * two groups. */
        if ((in_traverse(op[satisfies_file], satisfies_opnum)
-            && op[needs_file][needs_opnum].group_start)
+            && (starts_transaction(&op[needs_file][needs_opnum])
+                || starts_traverse(&op[needs_file][needs_opnum])))
            || (in_traverse(op[needs_file], needs_opnum)
-               && op[satisfies_file][satisfies_opnum].group_start)) {
+               && (starts_transaction(&op[satisfies_file][satisfies_opnum])
+                   || starts_traverse(&op[satisfies_file][satisfies_opnum])))){
                unsigned int sat;
 
                /* We are satisfied by end of group. */
@@ -1282,8 +1364,10 @@ static void add_dependency(void *ctx,
        }
 #endif
 
-       /* If you depend on a transaction, you actually depend on it ending. */
-       if (is_transaction(&op[satisfies_file][satisfies_opnum])) {
+       /* If you depend on a transaction or chainlock, you actually
+        * depend on it ending. */
+       if (starts_transaction(&op[satisfies_file][satisfies_opnum])
+           || starts_chainlock(&op[satisfies_file][satisfies_opnum])) {
                satisfies_opnum
                        += op[satisfies_file][satisfies_opnum].group_len;
 #if DEBUG_DEPS
@@ -1440,7 +1524,7 @@ static void make_traverse_depends(char *filename[],
                        /* Traverse start (ignore those in
                         * transactions; they're already covered by
                         * transaction dependencies). */
-                       if (is_traverse(&op[i][j])
+                       if (starts_traverse(&op[i][j])
                            && !in_transaction(op[i], j)) {
                                dep = talloc_realloc(NULL, dep,
                                                     struct traverse_dep,
@@ -1455,6 +1539,12 @@ static void make_traverse_depends(char *filename[],
 
        for (i = 1; i < num_traversals; i++) {
                const struct op *prev = &op[dep[i-1].file][dep[i-1].op_num];
+               const struct op *curr = &op[dep[i].file][dep[i].op_num];
+
+               /* Read traverses don't depend on each other (read lock). */
+               if (prev->op == OP_TDB_TRAVERSE_READ_START
+                   && curr->op == OP_TDB_TRAVERSE_READ_START)
+                       continue;
 
                /* Only make dependency if it's clear. */
                if (compare_traverse_dep(&dep[i], &dep[i-1])) {