Add test case for txn try

test/cases.cc

@@ -67,6 +67,7 @@ void testcase_setup(const char *casename, actor_params &params,
     configure_actor(last_space_id, ac_hill, nullptr, params);
     configure_actor(last_space_id, ac_jitter, nullptr, params);
     configure_actor(last_space_id, ac_hill, nullptr, params);
+    configure_actor(last_space_id, ac_try, nullptr, params);
     log_notice("<<< testcase_setup(%s): done", casename);
   } else {
     failure("unknown testcase `%s`", casename);

test/config.h

@@ -20,7 +20,7 @@
 
 #define ACTOR_ID_MAX INT16_MAX
 
-enum actor_testcase { ac_none, ac_hill, ac_deadread, ac_deadwrite, ac_jitter };
+enum actor_testcase { ac_none, ac_hill, ac_deadread, ac_deadwrite, ac_jitter, ac_try };
 
 enum actor_status {
   as_unknown,

test/test.cc

@@ -29,6 +29,8 @@ const char *testcase2str(const actor_testcase testcase) {
     return "deadwrite";
   case ac_jitter:
     return "jitter";
+  case ac_try:
+    return "try";
   }
 }
 
@@ -443,6 +445,9 @@ bool test_execute(const actor_config &config) {
     case ac_jitter:
       test.reset(new testcase_jitter(config, pid));
       break;
+    case ac_try:
+      test.reset(new testcase_try(config, pid));
+      break;
     default:
       test.reset(new testcase(config, pid));
       break;

test/test.h

@@ -190,3 +190,14 @@ public:
   bool run();
   bool teardown();
 };
+
+class testcase_try : public testcase {
+  typedef testcase inherited;
+
+public:
+  testcase_try(const actor_config &config, const mdbx_pid_t pid)
+      : testcase(config, pid) {}
+  bool setup();
+  bool run();
+  bool teardown();
+};

test/try.cc

@@ -0,0 +1,38 @@
+#include "test.h"
+
+bool testcase_try::setup() {
+  log_trace(">> setup");
+  if (!inherited::setup())
+    return false;
+
+  log_trace("<< setup");
+  return true;
+}
+
+bool testcase_try::run() {
+  db_open();
+  assert(!txn_guard);
+
+  MDBX_txn *txn = nullptr;
+  MDBX_txn *txn2 = nullptr;
+  int rc =
+      mdbx_txn_begin(db_guard.get(), nullptr, 0, &txn);
+  if (unlikely(rc != MDBX_SUCCESS))
+    failure_perror("mdbx_txn_begin(MDBX_TRYTXN)", rc);
+  else {
+    rc = mdbx_txn_begin(db_guard.get(), nullptr, MDBX_TRYTXN, &txn2);
+    if (unlikely(rc != MDBX_BUSY))
+      failure_perror("mdbx_txn_begin(MDBX_TRYTXN)", rc);
+  }
+
+  txn_guard.reset(txn);
+  return true;
+}
+
+bool testcase_try::teardown() {
+  log_trace(">> teardown");
+  cursor_guard.release();
+  txn_guard.release();
+  db_guard.release();
+  return inherited::teardown();
+}