[t:2356], make lock wait on reads user controlled

git-svn-id: file:///svn/mysql/tokudb-engine/tokudb-engine@17986 c7de825b-a66e-492c-adef-691d508d4ae1

storage/tokudb/ha_tokudb.h

@@ -244,6 +244,8 @@ private:
     //
     char write_status_msg[200]; //buffer of 200 should be a good upper bound.
 
+    ulonglong read_lock_wait_time;
+
     bool fix_rec_buff_for_blob(ulong length);
     void fix_mult_rec_buff();
     uchar current_ident[TOKUDB_HIDDEN_PRIMARY_KEY_LENGTH];

storage/tokudb/hatoku_hton.cc

@@ -62,6 +62,18 @@ static MYSQL_THDVAR_ULONGLONG(write_lock_wait,
   1 // blocksize
   );
 
+static MYSQL_THDVAR_ULONGLONG(read_lock_wait,
+  0,
+  "time waiting for read lock",
+  NULL, 
+  NULL, 
+  4000, // default
+  0, // min?
+  ULONGLONG_MAX, // max
+  1 // blocksize
+  );
+
+
 static void tokudb_print_error(const DB_ENV * db_env, const char *db_errpfx, const char *buffer);
 static void tokudb_cleanup_log_files(void);
 static int tokudb_end(handlerton * hton, ha_panic_function type);
@@ -446,6 +458,12 @@ ulonglong get_write_lock_wait_time (THD* thd) {
     return (ret_val == 0) ? ULONGLONG_MAX : ret_val;
 }
 
+
+ulonglong get_read_lock_wait_time (THD* thd) {
+    ulonglong ret_val = THDVAR(thd, read_lock_wait);
+    return (ret_val == 0) ? ULONGLONG_MAX : ret_val;
+}
+
 static int tokudb_commit(handlerton * hton, THD * thd, bool all) {
     TOKUDB_DBUG_ENTER("tokudb_commit");
     DBUG_PRINT("trans", ("ending transaction %s", all ? "all" : "stmt"));
@@ -1032,6 +1050,7 @@ static struct st_mysql_sys_var *tokudb_system_variables[] = {
     MYSQL_SYSVAR(debug),
     MYSQL_SYSVAR(commit_sync),
     MYSQL_SYSVAR(write_lock_wait),
+    MYSQL_SYSVAR(read_lock_wait),
     MYSQL_SYSVAR(version),
     MYSQL_SYSVAR(init_flags),
     MYSQL_SYSVAR(checkpointing_period),

storage/tokudb/hatoku_hton.h

@@ -12,6 +12,7 @@ extern DB *metadata_db;
 
 // thread variables
 ulonglong get_write_lock_wait_time (THD* thd);
+ulonglong get_read_lock_wait_time (THD* thd);
 
 extern HASH tokudb_open_tables;
 extern pthread_mutex_t tokudb_mutex;