MXS-1776: Add test case

Added test case that reproduces the problem.

maxscale-system-test/CMakeLists.txt

@@ -633,6 +633,10 @@ add_test_executable(mxs1751_available_when_donor_crash.cpp mxs1751_available_whe
 # https://jira.mariadb.org/browse/MXS-1773
 add_test_executable(mxs1773_failing_ldli.cpp mxs1773_failing_ldli replication LABELS readwritesplit REPL_BACKEND)
 
+# MXS-1776: recursive COM_STMT_EXECUTE execution
+# https://jira.mariadb.org/browse/MXS-1776
+add_test_executable(mxs1776_ps_exec_hang.cpp mxs1776_ps_exec_hang replication LABELS readwritesplit REPL_BACKEND)
+
 # 'namedserverfilter' test
 add_test_executable(namedserverfilter.cpp namedserverfilter namedserverfilter LABELS namedserverfilter LIGHT REPL_BACKEND)
 

maxscale-system-test/mxs1776_ps_exec_hang.cpp

@@ -0,0 +1,193 @@
+#include "testconnections.h"
+#include <iostream>
+#include <functional>
+#include <vector>
+
+using namespace std;
+
+struct Bind
+{
+    Bind()
+    {
+        bind.buffer = buffer;
+        bind.buffer_type = MYSQL_TYPE_LONG;
+        bind.error = &err;
+        bind.is_null = &is_null;
+        bind.length = &length;
+    }
+
+    MYSQL_BIND bind;
+    char err = 0;
+    char is_null = 0;
+    char is_unsigned = 0;
+    uint8_t buffer[1024];
+    unsigned long length = 0;
+};
+
+struct TestCase
+{
+    std::string name;
+    std::function<bool (MYSQL*, MYSQL_STMT*, Bind&)> func;
+};
+
+bool run_test(TestConnections& test, TestCase test_case)
+{
+    test.maxscales->connect();
+
+    MYSQL_STMT* stmt = mysql_stmt_init(test.maxscales->conn_rwsplit[0]);
+    std::string query = "SELECT * FROM test.t1";
+    unsigned long cursor_type = CURSOR_TYPE_READ_ONLY;
+    mysql_stmt_attr_set(stmt, STMT_ATTR_CURSOR_TYPE, &cursor_type);
+
+    Bind bind;
+
+    test.set_timeout(30);
+
+    if (mysql_stmt_prepare(stmt, query.c_str(), query.size()))
+    {
+        test.assert(false, "Prepared statement failure: %s", mysql_stmt_error(stmt));
+    }
+
+    cout << test_case.name << endl;
+    test.assert(test_case.func(test.maxscales->conn_rwsplit[0], stmt, bind), "Test '%s' failed",
+                test_case.name.c_str());
+
+    mysql_stmt_close(stmt);
+
+    test.assert(mysql_query(test.maxscales->conn_rwsplit[0], "SELECT 1") == 0, "Normal queries should work");
+
+    test.maxscales->disconnect();
+}
+
+
+int main(int argc, char* argv[])
+{
+    TestConnections test(argc, argv);
+
+    test.maxscales->connect();
+
+    test.try_query(test.maxscales->conn_rwsplit[0], "CREATE OR REPLACE TABLE test.t1(id INT)");
+    test.try_query(test.maxscales->conn_rwsplit[0], "BEGIN");
+
+    for (int i = 0; i < 100; i++)
+    {
+        execute_query(test.maxscales->conn_rwsplit[0], "INSERT INTO test.t1 VALUES (%d)", i);
+    }
+
+    test.try_query(test.maxscales->conn_rwsplit[0], "COMMIT");
+    test.maxscales->disconnect();
+
+    vector<TestCase> tests =
+    {
+        {
+            "Simple execute and fetch",
+            [](MYSQL * conn, MYSQL_STMT * stmt, Bind & bind)
+            {
+                bool rval = true;
+
+                if (mysql_stmt_execute(stmt) ||
+                    mysql_stmt_bind_result(stmt, &bind.bind))
+                {
+                    rval = false;
+                }
+
+                while (mysql_stmt_fetch(stmt) == 0)
+                {
+                    ;
+                }
+
+                return rval;
+            }
+        },
+        {
+            "Multiple overlapping executions without fetch",
+            [](MYSQL * conn, MYSQL_STMT * stmt, Bind & bind)
+            {
+                bool rval = true;
+
+                if (mysql_stmt_execute(stmt) ||
+                    mysql_stmt_execute(stmt) ||
+                    mysql_stmt_execute(stmt) ||
+                    mysql_stmt_execute(stmt) ||
+                    mysql_stmt_execute(stmt))
+                {
+                    rval = false;
+                }
+
+                return rval;
+            }
+        },
+        {
+            "Multiple overlapping executions with fetch",
+            [](MYSQL * conn, MYSQL_STMT * stmt, Bind & bind)
+            {
+                bool rval = true;
+
+                if (mysql_stmt_execute(stmt) ||
+                    mysql_stmt_execute(stmt) ||
+                    mysql_stmt_execute(stmt) ||
+                    mysql_stmt_execute(stmt) ||
+                    mysql_stmt_bind_result(stmt, &bind.bind))
+                {
+                    rval = false;
+                }
+
+                while (mysql_stmt_fetch(stmt) == 0)
+                {
+                    ;
+                }
+
+                return rval;
+            }
+        },
+        {
+            "Execution of queries while fetching",
+            [](MYSQL * conn, MYSQL_STMT * stmt, Bind & bind)
+            {
+                bool rval = true;
+
+                if (mysql_stmt_execute(stmt) ||
+                    mysql_stmt_execute(stmt) ||
+                    mysql_stmt_execute(stmt) ||
+                    mysql_stmt_execute(stmt) ||
+                    mysql_stmt_bind_result(stmt, &bind.bind))
+                {
+                    rval = false;
+                }
+
+                while (mysql_stmt_fetch(stmt) == 0)
+                {
+                    mysql_query(conn, "SELECT 1");
+                }
+
+                return rval;
+            }
+        },
+        {
+            "Multiple overlapping executions and a query",
+            [](MYSQL * conn, MYSQL_STMT * stmt, Bind & bind)
+            {
+                bool rval = true;
+
+                if (mysql_stmt_execute(stmt) ||
+                    mysql_stmt_execute(stmt) ||
+                    mysql_stmt_execute(stmt) ||
+                    mysql_stmt_execute(stmt) ||
+                    mysql_stmt_execute(stmt) ||
+                    mysql_query(conn, "SET @a = 1"))
+                {
+                    rval = false;
+                }
+
+                return rval;
+            }
+        }
+    };
+
+    for (auto a : tests)
+    {
+        run_test(test, a);
+    }
+
+    return test.global_result;
+}