[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/libraries/thread-mgr/thread_manager.c

@@ -5,6 +5,10 @@
 
 #include "thread_manager.h"
 
+#if WASM_ENABLE_DEBUG_INTERP != 0
+#include "debug_engine.h"
+#endif
+
 typedef struct {
     bh_list_link l;
     void (*destroy_cb)(WASMCluster *);
@@ -227,6 +231,11 @@ wasm_cluster_destroy(WASMCluster *cluster)
         wasm_runtime_free(cluster->stack_tops);
     if (cluster->stack_segment_occupied)
         wasm_runtime_free(cluster->stack_segment_occupied);
+
+#if WASM_ENABLE_DEBUG_INTERP != 0
+    wasm_debug_instance_destroy(cluster);
+#endif
+
     wasm_runtime_free(cluster);
 }
 
@@ -488,31 +497,18 @@ wasm_cluster_create_exenv_status()
     WASMCurrentEnvStatus *status;
 
     if (!(status = wasm_runtime_malloc(sizeof(WASMCurrentEnvStatus)))) {
-        goto fail;
+        return NULL;
     }
-    if (os_mutex_init(&status->wait_lock) != 0)
-        goto fail1;
 
-    if (os_cond_init(&status->wait_cond) != 0)
-        goto fail2;
     status->step_count = 0;
     status->signal_flag = 0;
     status->running_status = 0;
     return status;
-
-fail2:
-    os_mutex_destroy(&status->wait_lock);
-fail1:
-    wasm_runtime_free(status);
-fail:
-    return NULL;
 }
 
 void
 wasm_cluster_destroy_exenv_status(WASMCurrentEnvStatus *status)
 {
-    os_mutex_destroy(&status->wait_lock);
-    os_cond_destroy(&status->wait_cond);
     wasm_runtime_free(status);
 }
 
@@ -529,29 +525,34 @@ wasm_cluster_clear_thread_signal(WASMExecEnv *exec_env)
     exec_env->current_status->signal_flag = 0;
 }
 
-void
-wasm_cluster_wait_thread_status(WASMExecEnv *exec_env, uint32 *status)
-{
-    os_mutex_lock(&exec_env->current_status->wait_lock);
-    while (wasm_cluster_thread_is_running(exec_env)) {
-        os_cond_wait(&exec_env->current_status->wait_cond,
-                     &exec_env->current_status->wait_lock);
-    }
-    *status = exec_env->current_status->signal_flag;
-    os_mutex_unlock(&exec_env->current_status->wait_lock);
-}
-
 void
 wasm_cluster_thread_send_signal(WASMExecEnv *exec_env, uint32 signo)
 {
     exec_env->current_status->signal_flag = signo;
 }
 
+static void
+notify_debug_instance(WASMExecEnv *exec_env)
+{
+    WASMCluster *cluster;
+
+    cluster = wasm_exec_env_get_cluster(exec_env);
+    bh_assert(cluster);
+
+    if (!cluster->debug_inst) {
+        return;
+    }
+
+    os_mutex_lock(&cluster->debug_inst->wait_lock);
+    os_cond_signal(&cluster->debug_inst->wait_cond);
+    os_mutex_unlock(&cluster->debug_inst->wait_lock);
+}
+
 void
 wasm_cluster_thread_stopped(WASMExecEnv *exec_env)
 {
     exec_env->current_status->running_status = STATUS_STOP;
-    os_cond_signal(&exec_env->current_status->wait_cond);
+    notify_debug_instance(exec_env);
 }
 
 void
@@ -578,7 +579,7 @@ void
 wasm_cluster_thread_exited(WASMExecEnv *exec_env)
 {
     exec_env->current_status->running_status = STATUS_EXIT;
-    os_cond_signal(&exec_env->current_status->wait_cond);
+    notify_debug_instance(exec_env);
 }
 
 void
@@ -595,7 +596,14 @@ wasm_cluster_thread_step(WASMExecEnv *exec_env)
     exec_env->current_status->running_status = STATUS_STEP;
     os_cond_signal(&exec_env->wait_cond);
 }
-#endif
+
+void
+wasm_cluster_set_debug_inst(WASMCluster *cluster, WASMDebugInstance *inst)
+{
+    cluster->debug_inst = inst;
+}
+
+#endif /* end of WASM_ENABLE_DEBUG_INTERP */
 
 int32
 wasm_cluster_join_thread(WASMExecEnv *exec_env, void **ret_val)

core/iwasm/libraries/thread-mgr/thread_manager.h

@@ -39,6 +39,8 @@ typedef struct WASMCurrentEnvStatus {
     korp_cond wait_cond;
 } WASMCurrentEnvStatus;
 
+typedef struct WASMDebugInstance WASMDebugInstance;
+
 WASMCurrentEnvStatus *
 wasm_cluster_create_exenv_status();
 
@@ -69,6 +71,9 @@ wasm_cluster_thread_send_signal(WASMExecEnv *exec_env, uint32 signo);
 void
 wasm_cluster_thread_step(WASMExecEnv *exec_env);
 
+void
+wasm_cluster_set_debug_inst(WASMCluster *cluster, WASMDebugInstance *inst);
+
 #endif
 typedef struct WASMCluster {
     struct WASMCluster *next;
@@ -84,6 +89,9 @@ typedef struct WASMCluster {
     uint32 stack_size;
     /* Record which segments are occupied */
     bool *stack_segment_occupied;
+#if WASM_ENABLE_DEBUG_INTERP != 0
+    WASMDebugInstance *debug_inst;
+#endif
 } WASMCluster;
 
 void