DB-832 capture txn start time and make it available to the txn object and live txn iterator

Conflicts:
	ft/txn/txn.cc

buildheader/make_tdb.cc

@@ -587,6 +587,7 @@ static void print_db_txn_struct (void) {
         "uint64_t (*get_client_id)(DB_TXN *)",
         "bool (*is_prepared)(DB_TXN *)",
         "DB_TXN *(*get_child)(DB_TXN *)",
+        "uint64_t (*get_start_time)(DB_TXN *)",
 	NULL};
     sort_and_dump_fields("db_txn", false, extra);
 }
@@ -786,7 +787,7 @@ int main (int argc, char *const argv[] __attribute__((__unused__))) {
 
     printf("typedef void (*lock_timeout_callback)(DB *db, uint64_t requesting_txnid, const DBT *left_key, const DBT *right_key, uint64_t blocking_txnid);\n");
     printf("typedef int (*iterate_row_locks_callback)(DB **db, DBT *left_key, DBT *right_key, void *extra);\n");
-    printf("typedef int (*iterate_transactions_callback)(uint64_t txnid, uint64_t client_id, iterate_row_locks_callback cb, void *locks_extra, void *extra);\n");
+    printf("typedef int (*iterate_transactions_callback)(DB_TXN *dbtxn, iterate_row_locks_callback cb, void *locks_extra, void *extra);\n");
     printf("typedef int (*iterate_requests_callback)(DB *db, uint64_t requesting_txnid, const DBT *left_key, const DBT *right_key, uint64_t blocking_txnid, uint64_t start_time, void *extra);\n");
     print_db_env_struct();
     print_db_key_range_struct();

ft/txn/txn.cc

@@ -342,6 +342,7 @@ static txn_child_manager tcm;
         .state = TOKUTXN_LIVE,
         .num_pin = 0,
         .client_id = 0,
+        .start_time = time(NULL),
     };
 
     TOKUTXN result = NULL;
@@ -785,6 +786,10 @@ void toku_txn_set_client_id(TOKUTXN txn, uint64_t client_id) {
     txn->client_id = client_id;
 }
 
+time_t toku_txn_get_start_time(struct tokutxn *txn) {
+    return txn->start_time;
+}
+
 int toku_txn_reads_txnid(TXNID txnid, TOKUTXN txn) {
     int r = 0;
     TXNID oldest_live_in_snapshot = toku_get_oldest_in_live_root_txn_list(txn);

ft/txn/txn.h

@@ -253,6 +253,7 @@ struct tokutxn {
     uint32_t num_pin; // number of threads (all hot indexes) that want this
                       // txn to not transition to commit or abort
     uint64_t client_id;
+    time_t start_time;
 };
 typedef struct tokutxn *TOKUTXN;
 
@@ -368,6 +369,8 @@ bool toku_txn_has_spilled_rollback(struct tokutxn *txn);
 uint64_t toku_txn_get_client_id(struct tokutxn *txn);
 void toku_txn_set_client_id(struct tokutxn *txn, uint64_t client_id);
 
+time_t toku_txn_get_start_time(struct tokutxn *txn);
+
 //
 // This function is used by the leafentry iterators.
 // returns TOKUDB_ACCEPT if live transaction context is allowed to read a value

src/tests/test_iterate_live_transactions.cc

@@ -104,9 +104,11 @@ struct iterate_extra {
     bool visited_txn[3];
 };
 
-static int iterate_callback(uint64_t txnid, uint64_t client_id,
+static int iterate_callback(DB_TXN *txn,
                             iterate_row_locks_callback iterate_locks,
                             void *locks_extra, void *extra) {
+    uint64_t txnid = txn->id64(txn);
+    uint64_t client_id = txn->get_client_id(txn);
     iterate_extra *info = reinterpret_cast<iterate_extra *>(extra);
     DB *db;
     DBT left_key, right_key;

src/tests/test_stress0.cc

@@ -140,9 +140,11 @@ static int UU() iterate_pending_lock_requests_op(DB_TXN *UU(txn), ARG arg, void
     return r;
 }
 
-static int iterate_txns(uint64_t txnid, uint64_t client_id,
+static int iterate_txns(DB_TXN *txn,
                         iterate_row_locks_callback iterate_locks,
                         void *locks_extra, void *extra) {
+    uint64_t txnid = txn->id64(txn);
+    uint64_t client_id = txn->get_client_id(txn);
     invariant_null(extra);
     invariant(txnid > 0);
     invariant(client_id == 0);

src/ydb.cc

@@ -2500,8 +2500,7 @@ static int iter_txns_callback(TOKUTXN txn, void *extra) {
     toku_pthread_rwlock_rdlock(&info->env->i->open_dbs_rwlock);
 
     iter_txn_row_locks_callback_extra e(info->env, &db_txn_struct_i(dbtxn)->lt_map);
-    const int r = info->callback(toku_txn_get_txnid(txn).parent_id64,
-                                 toku_txn_get_client_id(txn),
+    const int r = info->callback(dbtxn,
                                  iter_txn_row_locks_callback,
                                  &e,
                                  info->extra);

src/ydb_txn.cc

@@ -432,6 +432,11 @@ static DB_TXN *toku_txn_get_child(DB_TXN *txn) {
     return db_txn_struct_i(txn)->child;
 }
 
+static uint64_t toku_txn_get_start_time(DB_TXN *txn) {
+    TOKUTXN ttxn = db_txn_struct_i(txn)->tokutxn;
+    return toku_txn_get_start_time(ttxn);
+}
+
 static inline void txn_func_init(DB_TXN *txn) {
 #define STXN(name) txn->name = locked_txn_ ## name
     STXN(abort);
@@ -450,6 +455,7 @@ static inline void txn_func_init(DB_TXN *txn) {
     txn->id64 = toku_txn_id64;
     txn->is_prepared = toku_txn_is_prepared;
     txn->get_child = toku_txn_get_child;
+    txn->get_start_time = toku_txn_get_start_time;
 }
 
 //