[source debug] refine some code in source debugging (#856)

- move the wait_cond from exec_env to debug_instance, so the debug thread can be waken up by any threads
- process more general query message from debugger
- refine debug instance create/destroy mechanism
- avoid creating debug instance during module instantiating
- avoid blocking execution thread during creating debug instance
- update related documents

core/iwasm/common/wasm_exec_env.c

@@ -148,9 +148,6 @@ wasm_exec_env_create(struct WASMModuleInstanceCommon *module_inst,
         wasm_exec_env_destroy_internal(exec_env);
         return NULL;
     }
-#if WASM_ENABLE_DEBUG_INTERP != 0
-    wasm_debug_instance_create(cluster);
-#endif
 #endif /* end of WASM_ENABLE_THREAD_MGR */
 
     return exec_env;
@@ -165,7 +162,6 @@ wasm_exec_env_destroy(WASMExecEnv *exec_env)
     if (cluster) {
 #if WASM_ENABLE_DEBUG_INTERP != 0
         wasm_cluster_thread_exited(exec_env);
-        wasm_debug_instance_destroy(cluster);
 #endif
         wasm_cluster_terminate_all_except_self(cluster, exec_env);
         wasm_cluster_del_exec_env(cluster, exec_env);

core/iwasm/common/wasm_runtime_common.c

@@ -294,6 +294,26 @@ get_package_type(const uint8 *buf, uint32 size)
     return Package_Type_Unknown;
 }
 
+#if (WASM_ENABLE_THREAD_MGR != 0) && (WASM_ENABLE_DEBUG_INTERP != 0)
+uint32
+wasm_runtime_start_debug_instance(WASMExecEnv *exec_env)
+{
+    WASMCluster *cluster = wasm_exec_env_get_cluster(exec_env);
+    bh_assert(cluster);
+
+    if (cluster->debug_inst) {
+        LOG_WARNING("Cluster already bind to a debug instance");
+        return cluster->debug_inst->control_thread->port;
+    }
+
+    if (wasm_debug_instance_create(cluster)) {
+        return cluster->debug_inst->control_thread->port;
+    }
+
+    return 0;
+}
+#endif
+
 #if WASM_ENABLE_MULTI_MODULE != 0
 static module_reader reader;
 static module_destroyer destroyer;
@@ -1431,7 +1451,7 @@ wasm_runtime_create_exec_env_and_call_wasm(
     if (module_inst->module_type == Wasm_Module_Bytecode)
         ret = wasm_create_exec_env_and_call_function(
             (WASMModuleInstance *)module_inst, (WASMFunctionInstance *)function,
-            argc, argv);
+            argc, argv, true);
 #endif
 #if WASM_ENABLE_AOT != 0
     if (module_inst->module_type == Wasm_Module_AoT)

core/iwasm/common/wasm_runtime_common.h

@@ -494,6 +494,12 @@ wasm_runtime_call_wasm_v(WASMExecEnv *exec_env,
                          uint32 num_results, wasm_val_t *results,
                          uint32 num_args, ...);
 
+#if WASM_ENABLE_DEBUG_INTERP != 0
+/* See wasm_export.h for description */
+WASM_RUNTIME_API_EXTERN uint32
+wasm_runtime_start_debug_instance(WASMExecEnv *exec_env);
+#endif
+
 /**
  * Call a function reference of a given WASM runtime instance with
  * arguments.