watch fields

jbalint · Mar 11, 2017 · e06df27 · e06df27
1 parent d8ae08b
commit e06df27
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Showing 6 changed files with 147 additions and 3 deletions.
diff --git a/Makefile b/Makefile
@@ -12,6 +12,7 @@ LJ_OBJS = lua_java.o lua_jvmti_event.o \
 	lua_java/lj_method.o \
 	lua_java/lj_raw_monitor.o \
 	lua_java/lj_stack_frame.o \
+	lua_java/lj_watch.o \
 	java_bridge/types.o
 
 libyt.so: yt.o lua_interface.o jni_util.o $(LJ_OBJS)

diff --git a/lua_java.c b/lua_java.c
@@ -838,6 +838,7 @@ void lj_force_early_return_register(lua_State *L);
 void lj_method_register(lua_State *L);
 void lj_raw_monitor_register(lua_State *L);
 void lj_stack_frame_register(lua_State *L);
+void lj_watch_register(lua_State *L);
 
 void lj_init(lua_State *L, JavaVM *jvm, jvmtiEnv *jvmti)
 {
@@ -850,6 +851,7 @@ void lj_init(lua_State *L, JavaVM *jvm, jvmtiEnv *jvmti)
   lj_method_register(L);
   lj_raw_monitor_register(L);
   lj_stack_frame_register(L);
+  lj_watch_register(L);
 
   lua_register(L, "lj_set_breakpoint",             lj_set_breakpoint);
   lua_register(L, "lj_clear_breakpoint",           lj_clear_breakpoint);

diff --git a/lua_java/lj_class.c b/lua_java/lj_class.c
@@ -151,7 +151,7 @@ static int lj_get_loaded_classes(lua_State *L)
    incremented for the next iteration. We need to tag all items and
    then retrieve them. There is no reason/method to clear all tags so
    we increment the number so it's different next time. It's
-   *possible* that if you used this method a (max jlong) times that
+   *possible* that if you used this method (max jlong) times that
    there may be objects leftover with an old tag.
  */
 static jlong class_instances_search_tag = 1000;
@@ -186,8 +186,6 @@ static int lj_get_class_instances(lua_State *L) {
   lj_err = (*current_jvmti())->GetObjectsWithTags(current_jvmti(), 1, &class_instances_search_tag, &output_count, &obj_output, &tag_output);
   lj_check_jvmti_error(L);
 
-  fprintf(stderr, "output_count=%d\n", output_count);
-
   /* add it to the result */
   lua_createtable(L, output_count, 0);
   for (i = 0; i < output_count; ++i) {

diff --git a/lua_java/lj_watch.c b/lua_java/lj_watch.c
@@ -0,0 +1,40 @@
+#include "myjni.h"
+#include "jni_util.h"
+#include "lua_interface.h"
+#include "lua_java.h"
+#include "java_bridge.h"
+#include "lj_internal.h"
+
+static int lj_set_field_access_watch(lua_State *L)
+{
+	lj_field_id *field_id;
+
+	field_id = (lj_field_id *)luaL_checkudata(L, 1, "jfield_id");
+	lua_pop(L, 1);
+
+	lj_err = (*current_jvmti())->SetFieldAccessWatch(current_jvmti(), field_id->class, field_id->field_id);
+	lj_check_jvmti_error(L);
+
+	return 0;
+}
+
+static int lj_set_field_modification_watch(lua_State *L)
+{
+	lj_field_id *field_id;
+
+	field_id = (lj_field_id *)luaL_checkudata(L, 1, "jfield_id");
+	lua_pop(L, 1);
+
+	lj_err = (*current_jvmti())->SetFieldModificationWatch(current_jvmti(), field_id->class, field_id->field_id);
+	lj_check_jvmti_error(L);
+
+	return 0;
+}
+
+void lj_watch_register(lua_State *L)
+{
+	lua_register(L, "lj_set_field_access_watch", lj_set_field_access_watch);
+	/* lua_register(L, "lj_clear_field_access_watch", lj_clear_field_access_watch); */
+	lua_register(L, "lj_set_field_modification_watch", lj_set_field_modification_watch);
+	/* lua_register(L, "lj_clear_field_modification_watch", lj_clear_field_modification_watch); */
+}
diff --git a/lua_jvmti_event.c b/lua_jvmti_event.c
@@ -26,6 +26,8 @@ static struct {
   int cb_single_step_ref;
   int cb_exception_throw_ref;
   int cb_exception_catch_ref;
+  int cb_field_access_ref;
+  int cb_field_modification_ref;
 } lj_jvmti_callbacks;
 
 void lj_init_jvmti_event()
@@ -38,6 +40,9 @@ void lj_init_jvmti_event()
 
   lj_jvmti_callbacks.cb_exception_throw_ref = LUA_NOREF;
   lj_jvmti_callbacks.cb_exception_catch_ref = LUA_NOREF;
+
+  lj_jvmti_callbacks.cb_field_access_ref = LUA_NOREF;
+  lj_jvmti_callbacks.cb_field_modification_ref = LUA_NOREF;
 }
 
 static void disable_events_before_callback_handling(lua_State *L)
@@ -204,6 +209,82 @@ static void JNICALL cb_exception_throw(jvmtiEnv *jvmti, JNIEnv *jni, jthread thr
   enable_events_after_callback_handling(lj_L);
 }
 
+static void JNICALL cb_field_access(jvmtiEnv *jvmti,
+                                    JNIEnv* jni,
+                                    jthread thread,
+                                    jmethodID method_id,
+                                    jlocation location,
+                                    jclass field_klass,
+                                    jobject object,
+                                    jfieldID field_id)
+{
+    int ref = lj_jvmti_callbacks.cb_field_access_ref;
+    lua_State *L;
+
+    printf("***** cb_field_access_ref *****\n");
+    if (ref == LUA_NOREF)
+        return;
+
+    L = lua_newthread(lj_L);
+
+    lj_current_thread = (*jni)->NewGlobalRef(jni, thread);
+    assert(lj_current_thread);
+
+    disable_events_before_callback_handling(lj_L);
+
+    lua_pushcfunction(L, lua_print_traceback);
+    lua_rawgeti(L, LUA_REGISTRYINDEX, ref);
+    new_jobject(L, thread);
+    new_jmethod_id(L, method_id);
+    lua_pushinteger(L, location);
+    new_jobject(L, field_klass);
+    new_jobject(L, object);
+    new_jfield_id(L, field_id, field_klass);
+    lua_pcall(L, 6, 0, -8);
+    lua_pop(lj_L, 1); /* the new lua_State, we're done with it */
+
+    enable_events_after_callback_handling(lj_L);
+}
+
+static void JNICALL cb_field_modification(jvmtiEnv *jvmti,
+                                          JNIEnv* jni,
+                                          jthread thread,
+                                          jmethodID method_id,
+                                          jlocation location,
+                                          jclass field_klass,
+                                          jobject object,
+                                          jfieldID field_id,
+                                          char signature_type,
+                                          jvalue new_value)
+{
+    int ref = lj_jvmti_callbacks.cb_field_modification_ref;
+    lua_State *L;
+
+    printf("***** cb_field_modification_ref *****\n");
+    if (ref == LUA_NOREF)
+        return;
+
+    L = lua_newthread(lj_L);
+
+    lj_current_thread = (*jni)->NewGlobalRef(jni, thread);
+    assert(lj_current_thread);
+
+    disable_events_before_callback_handling(lj_L);
+
+    lua_pushcfunction(L, lua_print_traceback);
+    lua_rawgeti(L, LUA_REGISTRYINDEX, ref);
+    new_jobject(L, thread);
+    new_jmethod_id(L, method_id);
+    lua_pushinteger(L, location);
+    new_jobject(L, field_klass);
+    new_jobject(L, object);
+    new_jfield_id(L, field_id, field_klass);
+    lua_pcall(L, 6, 0, -8);
+    lua_pop(lj_L, 1); /* the new lua_State, we're done with it */
+
+    enable_events_after_callback_handling(lj_L);
+}
+
 static void get_jvmti_callback_pointers(const char *callback,
 										void ***jvmti_function_ptr_ptr,
 										void **lj_function_ptr, 
@@ -255,6 +336,18 @@ static void get_jvmti_callback_pointers(const char *callback,
 	*lj_function_ptr = cb_exception_throw;
 	*ref_ptr = &lj_jvmti_callbacks.cb_exception_throw_ref;
   }
+  else if (!strcmp(callback, "field_access"))
+  {
+	*jvmti_function_ptr_ptr = (void **)&evCbs->FieldAccess;
+	*lj_function_ptr = cb_field_access;
+	*ref_ptr = &lj_jvmti_callbacks.cb_field_access_ref;
+  }
+  else if (!strcmp(callback, "field_modification"))
+  {
+    *jvmti_function_ptr_ptr = (void **)&evCbs->FieldModification;
+	*lj_function_ptr = cb_field_modification;
+	*ref_ptr = &lj_jvmti_callbacks.cb_field_modification_ref;
+  }
 }
 
 int lj_set_jvmti_callback(lua_State *L)
@@ -286,6 +379,10 @@ int lj_set_jvmti_callback(lua_State *L)
 	lj_err = EV_ENABLET(METHOD_EXIT, get_current_java_thread());
   else if (!strcmp(callback, "exception_throw"))
 	lj_err = EV_ENABLET(EXCEPTION, get_current_java_thread());
+  else if (!strcmp(callback, "field_access"))
+	lj_err = EV_ENABLET(FIELD_ACCESS, get_current_java_thread());
+  else if (!strcmp(callback, "field_modification"))
+	lj_err = EV_ENABLET(FIELD_MODIFICATION, get_current_java_thread());
   lj_check_jvmti_error(L);
 
   get_jvmti_callback_pointers(callback, &jvmti_callback_ptr, &lj_callback_ptr, &ref_ptr);
@@ -320,6 +417,10 @@ int lj_clear_jvmti_callback(lua_State *L)
 	EV_DISABLET(METHOD_EXIT, get_current_java_thread());
   else if (!strcmp(callback, "exception_throw"))
 	EV_DISABLET(EXCEPTION, get_current_java_thread());
+  else if (!strcmp(callback, "field_access"))
+	EV_DISABLET(FIELD_ACCESS, get_current_java_thread());
+  else if (!strcmp(callback, "field_modification"))
+	EV_DISABLET(FIELD_MODIFICATION, get_current_java_thread());
   lj_check_jvmti_error(L);
 
   get_jvmti_callback_pointers(callback, &jvmti_callback_ptr, NULL, &ref_ptr);

diff --git a/yt.c b/yt.c
@@ -132,6 +132,8 @@ Agent_OnLoad(JavaVM *jvm, char *options, void *reserved)
   caps.can_generate_single_step_events = 1; /* Used for line-oriented stepping */
 /*   caps.can_generate_frame_pop_events = 1; */
   caps.can_force_early_return = 1;
+  caps.can_generate_field_access_events = 1;
+  caps.can_generate_field_modification_events = 1;
 
   rc = (*jvm)->GetEnv(jvm, (void **)&jvmti, JVMTI_VERSION_1_0);
   if(rc < 0)