Fixed memory leaks in embedded server and mysqltest

This commit fixes the following issues:
- memory leak checking enabled for mysqltest. This cover all cases except
  calls to 'die()' that only happens in case of internal failures in
  mysqltest. die() is not called anymore in the result files differs.
- One can now run mtr --embedded without failures (this crashed or hang
  before)
- cleanup_and_exit() has a new parameter that indicates that it is called
  from die(), in which case we should not do memory leak checks. We now
  always call cleanup_and_exit() instead of exit() to be able to free up
  memory and discover memory leaks.
- Lots of new assert to catch error conditions
- More DBUG statements.
- Fixed that all results are freed in mysqltest (Fixed a memory leak in
  mysqltest when using prepared statements).
- Fixed race condition in do_stmt_close() that caused embedded server
  to not free memory. (Memory leak in mysqltest with embedded server).
- Fixed two memory leaks in embedded server when using prepared statements.
  These memory leaks caused timeout hangs in mtr when server was compiled
  with safemalloc. This issue was not noticed (except as timeouts) as
  memory report checking was done but output of it was disabled.

client/mysqltest.cc

@@ -616,7 +616,7 @@ void replace_strings_append(struct st_replace *rep, DYNAMIC_STRING* ds,
 const char *from);
 
 ATTRIBUTE_NORETURN
-static void cleanup_and_exit(int exit_code);
+static void cleanup_and_exit(int exit_code, bool called_from_die);
 
 ATTRIBUTE_NORETURN
 static void really_die(const char *msg);
@@ -933,6 +933,7 @@ pthread_attr_t cn_thd_attrib;
 pthread_handler_t connection_thread(void *arg)
 {
   struct st_connection *cn= (struct st_connection*)arg;
+  DBUG_ENTER("connection_thread");
 
   mysql_thread_init();
   while (cn->command != EMB_END_CONNECTION)
@@ -944,6 +945,7 @@ pthread_handler_t connection_thread(void *arg)
         pthread_cond_wait(&cn->query_cond, &cn->query_mutex);
       pthread_mutex_unlock(&cn->query_mutex);
     }
+    DBUG_PRINT("info", ("executing command: %d", cn->command));
     switch (cn->command)
     {
       case EMB_END_CONNECTION:
@@ -964,24 +966,26 @@ pthread_handler_t connection_thread(void *arg)
         break;
       case EMB_CLOSE_STMT:
         cn->result= mysql_stmt_close(cn->stmt);
+        cn->stmt= 0;
         break;
       default:
         DBUG_ASSERT(0);
     }
-    cn->command= 0;
     pthread_mutex_lock(&cn->result_mutex);
     cn->query_done= 1;
+    cn->command= 0;
     pthread_cond_signal(&cn->result_cond);
     pthread_mutex_unlock(&cn->result_mutex);
   }
 
 end_thread:
-  cn->query_done= 1;
+  DBUG_ASSERT(cn->stmt == 0);
   mysql_close(cn->mysql);
   cn->mysql= 0;
+  cn->query_done= 1;
   mysql_thread_end();
   pthread_exit(0);
-  return 0;
+  DBUG_RETURN(0);
 }
 
 static void wait_query_thread_done(struct st_connection *con)
@@ -999,12 +1003,16 @@ static void wait_query_thread_done(struct st_connection *con)
 
 static void signal_connection_thd(struct st_connection *cn, int command)
 {
+  DBUG_ENTER("signal_connection_thd");
+  DBUG_PRINT("enter", ("command: %d", command));
+
   DBUG_ASSERT(cn->has_thread);
   cn->query_done= 0;
-  cn->command= command;
   pthread_mutex_lock(&cn->query_mutex);
+  cn->command= command;
   pthread_cond_signal(&cn->query_cond);
   pthread_mutex_unlock(&cn->query_mutex);
+  DBUG_VOID_RETURN;
 }
 
 
@@ -1066,27 +1074,38 @@ static int do_stmt_execute(struct st_connection *cn)
 
 static int do_stmt_close(struct st_connection *cn)
 {
-  /* The cn->stmt is already set. */
+  DBUG_ENTER("do_stmt_close");
   if (!cn->has_thread)
-    return mysql_stmt_close(cn->stmt);
+  {
+    /* The cn->stmt is already set. */
+    int res= mysql_stmt_close(cn->stmt);
+    cn->stmt= 0;
+    DBUG_RETURN(res);
+  }
+  wait_query_thread_done(cn);
   signal_connection_thd(cn, EMB_CLOSE_STMT);
   wait_query_thread_done(cn);
-  return cn->result;
+  DBUG_ASSERT(cn->stmt == 0);
+  DBUG_RETURN(cn->result);
 }
 
 
 static void emb_close_connection(struct st_connection *cn)
 {
+  DBUG_ENTER("emb_close_connection");
   if (!cn->has_thread)
-    return;
+    DBUG_VOID_RETURN;
   wait_query_thread_done(cn);
   signal_connection_thd(cn, EMB_END_CONNECTION);
   pthread_join(cn->tid, NULL);
   cn->has_thread= FALSE;
+  DBUG_ASSERT(cn->mysql == 0);
+  DBUG_ASSERT(cn->stmt == 0);
   pthread_mutex_destroy(&cn->query_mutex);
   pthread_cond_destroy(&cn->query_cond);
   pthread_mutex_destroy(&cn->result_mutex);
   pthread_cond_destroy(&cn->result_cond);
+  DBUG_VOID_RETURN;
 }
 
 
@@ -1110,7 +1129,13 @@ static void init_connection_thd(struct st_connection *cn)
 #define do_read_query_result(cn) mysql_read_query_result(cn->mysql)
 #define do_stmt_prepare(cn, q, q_len) mysql_stmt_prepare(cn->stmt, q, (ulong)q_len)
 #define do_stmt_execute(cn) mysql_stmt_execute(cn->stmt)
-#define do_stmt_close(cn) mysql_stmt_close(cn->stmt)
+
+static int do_stmt_close(struct st_connection *cn)
+{
+  int res= mysql_stmt_close(cn->stmt);
+  cn->stmt= 0;
+  return res;
+}
 
 #endif /*EMBEDDED_LIBRARY*/
 
@@ -1438,7 +1463,6 @@ void close_statements()
   {
     if (con->stmt)
       do_stmt_close(con);
-    con->stmt= 0;
   }
   DBUG_VOID_RETURN;
 }
@@ -1505,7 +1529,8 @@ void free_used_memory()
 }
 
 
-ATTRIBUTE_NORETURN static void cleanup_and_exit(int exit_code)
+ATTRIBUTE_NORETURN static void cleanup_and_exit(int exit_code,
+                                                bool called_from_die)
 {
   free_used_memory();
 
@@ -1513,16 +1538,6 @@ ATTRIBUTE_NORETURN static void cleanup_and_exit(int exit_code)
   if (server_initialized)
     mysql_server_end();
 
-  /*
-    mysqltest is fundamentally written in a way that makes impossible
-    to free all memory before exit (consider memory allocated
-    for frame local DYNAMIC_STRING's and die() invoked down the stack.
-
-    We close stderr here to stop unavoidable safemalloc reports
-    from polluting the output.
-  */
-  fclose(stderr);
-
   my_end(my_end_arg);
 
   if (!silent) {
@@ -1542,6 +1557,11 @@ ATTRIBUTE_NORETURN static void cleanup_and_exit(int exit_code)
     }
   }
 
+  /*
+    Report memory leaks, if not called from 'die()', as die() will not release
+    all memory.
+  */
+  sf_leaking_memory= called_from_die;
   exit(exit_code);
 }
 
@@ -1608,7 +1628,7 @@ static void really_die(const char *msg)
     second time, just exit
   */
   if (dying)
-    cleanup_and_exit(1);
+    cleanup_and_exit(1, 1);
   dying= 1;
 
   log_file.show_tail(opt_tail_lines);
@@ -1620,7 +1640,7 @@ static void really_die(const char *msg)
   if (cur_con && !cur_con->pending)
     show_warnings_before_error(cur_con->mysql);
 
-  cleanup_and_exit(1);
+  cleanup_and_exit(1, 1);
 }
 
 void report_or_die(const char *fmt, ...)
@@ -1674,7 +1694,7 @@ void abort_not_supported_test(const char *fmt, ...)
   }
   va_end(args);
 
-  cleanup_and_exit(62);
+  cleanup_and_exit(62, 0);
 }
 
 
@@ -2220,14 +2240,14 @@ int dyn_string_cmp(DYNAMIC_STRING* ds, const char *fname)
   check_result
 
   RETURN VALUES
-  error - the function will not return
-
+  0  ok
+  1  error
 */
 
-void check_result()
+int check_result()
 {
   const char *mess= 0;
-
+  int error= 1;
   DBUG_ENTER("check_result");
   DBUG_ASSERT(result_file_name);
   DBUG_PRINT("enter", ("result_file_name: %s", result_file_name));
@@ -2235,7 +2255,10 @@ void check_result()
   switch (compare_files(log_file.file_name(), result_file_name)) {
   case RESULT_OK:
     if (!error_count)
+    {
+      error= 0;
       break; /* ok */
+    }
     mess= "Got errors while running test";
     /* Fallthrough */
   case RESULT_LENGTH_MISMATCH:
@@ -2274,14 +2297,13 @@ void check_result()
           log_file.file_name(), reject_file, errno);
 
     show_diff(NULL, result_file_name, reject_file);
-    die("%s", mess);
+    fprintf(stderr, "%s", mess);
     break;
   }
   default: /* impossible */
     die("Unknown error code from dyn_string_cmp()");
   }
-
-  DBUG_VOID_RETURN;
+  DBUG_RETURN(error);
 }
 
 
@@ -5631,7 +5653,6 @@ void do_close_connection(struct st_command *command)
 #endif /*!EMBEDDED_LIBRARY*/
   if (con->stmt)
     do_stmt_close(con);
-  con->stmt= 0;
 #ifdef EMBEDDED_LIBRARY
   /*
     As query could be still executed in a separate thread
@@ -7308,17 +7329,17 @@ get_one_option(const struct my_option *opt, const char *argument, const char *)
     break;
   case 'V':
     print_version();
-    exit(0);
+    cleanup_and_exit(0,0);
   case OPT_MYSQL_PROTOCOL:
 #ifndef EMBEDDED_LIBRARY
     if ((opt_protocol= find_type_with_warning(argument, &sql_protocol_typelib,
                                               opt->name)) <= 0)
-      exit(1);
+      cleanup_and_exit(1,0);
 #endif
     break;
   case '?':
     usage();
-    exit(0);
+    cleanup_and_exit(0,0);
   }
   return 0;
 }
@@ -7330,12 +7351,12 @@ int parse_args(int argc, char **argv)
   default_argv= argv;
 
   if ((handle_options(&argc, &argv, my_long_options, get_one_option)))
-    exit(1);
+    cleanup_and_exit(1, 0);
 
   if (argc > 1)
   {
     usage();
-    exit(1);
+    cleanup_and_exit(1, 0);
   }
   if (argc == 1)
     opt_db= *argv;
@@ -8445,7 +8466,7 @@ void run_query_stmt(struct st_connection *cn, struct st_command *command,
   my_bool ds_res_1st_execution_init = FALSE;
   my_bool compare_2nd_execution = TRUE;
   int query_match_ps2_re;
-
+  MYSQL_RES *res;
   DBUG_ENTER("run_query_stmt");
   DBUG_PRINT("query", ("'%-.60s'", query));
 
@@ -8631,10 +8652,13 @@ void run_query_stmt(struct st_connection *cn, struct st_command *command,
       The --enable_prepare_warnings command can be used to change this so
       that warnings from both the prepare and execute phase are shown.
     */
-    if ((mysql_stmt_result_metadata(stmt) != NULL) &&
-        !disable_warnings &&
-        !prepare_warnings_enabled)
-      dynstr_set(&ds_prepare_warnings, NULL);
+    if ((res= mysql_stmt_result_metadata(stmt)))
+    {
+      if (!disable_warnings &&
+          !prepare_warnings_enabled)
+        dynstr_set(&ds_prepare_warnings, NULL);
+      mysql_free_result(res);
+    }
 
     /*
       Fetch info before fetching warnings, since it will be reset
@@ -9729,6 +9753,7 @@ static sig_handler signal_handler(int sig)
   fflush(stderr);
   my_write_core(sig);
 #ifndef _WIN32
+  sf_leaking_memory= 1;
   exit(1);			// Shouldn't get here but just in case
 #endif
 }
@@ -9802,12 +9827,10 @@ int main(int argc, char **argv)
   uint command_executed= 0, last_command_executed= 0;
   char save_file[FN_REFLEN];
   bool empty_result= FALSE;
+  int error= 0;
   MY_INIT(argv[0]);
   DBUG_ENTER("main");
 
-  /* mysqltest has no way to free all its memory correctly */
-  sf_leaking_memory= 1;
-
   save_file[0]= 0;
   TMPDIR[0]= 0;
 
@@ -10486,7 +10509,7 @@ int main(int argc, char **argv)
     die("Test ended with parsing disabled");
 
   /*
-    The whole test has been executed _successfully_.
+    The whole test has been executed successfully.
     Time to compare result or save it to record file.
     The entire output from test is in the log file
   */
@@ -10509,7 +10532,7 @@ int main(int argc, char **argv)
       else
       {
 	/* Check that the output from test is equal to result file */
-	check_result();
+	error= check_result();
       }
     }
   }
@@ -10519,7 +10542,8 @@ int main(int argc, char **argv)
     if (! result_file_name || record ||
         compare_files (log_file.file_name(), result_file_name))
     {
-      die("The test didn't produce any output");
+      fprintf(stderr, "mysqltest: The test didn't produce any output\n");
+      error= 1;
     }
     else 
     {
@@ -10528,12 +10552,15 @@ int main(int argc, char **argv)
   }
 
   if (!command_executed && result_file_name && !empty_result)
-    die("No queries executed but non-empty result file found!");
+  {
+    fprintf(stderr, "mysqltest: No queries executed but non-empty result file found!\n");
+    error= 1;
+  }
 
-  verbose_msg("Test has succeeded!");
+  if (!error)
+    verbose_msg("Test has succeeded!");
   timer_output();
-  /* Yes, if we got this far the test has succeeded! Sakila smiles */
-  cleanup_and_exit(0);
+  cleanup_and_exit(error, 0);
   return 0; /* Keep compiler happy too */
 }
 

libmysqld/lib_sql.cc

@@ -266,6 +266,7 @@ static my_bool emb_read_prepare_result(MYSQL *mysql, MYSQL_STMT *stmt)
       mysql->server_status|= SERVER_STATUS_IN_TRANS;
 
     stmt->fields= mysql->fields;
+    free_root(&stmt->mem_root, MYF(0));
     stmt->mem_root= res->alloc;
     mysql->fields= NULL;
     my_free(res);
@@ -375,6 +376,7 @@ int emb_read_binary_rows(MYSQL_STMT *stmt)
     set_stmt_errmsg(stmt, &stmt->mysql->net);
     return 1;
   }
+  free_root(&stmt->result.alloc, MYF(0));
   stmt->result= *data;
   my_free(data);
   set_stmt_errmsg(stmt, &stmt->mysql->net);