--- a/src/hotspot/share/jfr/instrumentation/jfrJvmtiAgent.cpp Mon Nov 25 15:21:44 2019 +0000
+++ b/src/hotspot/share/jfr/instrumentation/jfrJvmtiAgent.cpp Mon Nov 25 18:38:01 2019 +0100
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2016, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2016, 2019, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
@@ -32,7 +32,9 @@
#include "jfr/support/jfrEventClass.hpp"
#include "logging/log.hpp"
#include "memory/resourceArea.hpp"
+#include "prims/jvmtiEnvBase.hpp"
#include "prims/jvmtiExport.hpp"
+#include "prims/jvmtiUtil.hpp"
#include "runtime/interfaceSupport.inline.hpp"
#include "runtime/thread.inline.hpp"
#include "utilities/exceptions.hpp"
@@ -52,19 +54,17 @@
}
}
-static jvmtiError set_event_notification_mode(jvmtiEventMode mode,
- jvmtiEvent event,
- jthread event_thread,
- ...) {
- if (jfr_jvmti_env == NULL) {
- return JVMTI_ERROR_NONE;
- }
+static bool set_event_notification_mode(jvmtiEventMode mode,
+ jvmtiEvent event,
+ jthread event_thread,
+ ...) {
+ assert(jfr_jvmti_env != NULL, "invariant");
const jvmtiError jvmti_ret_code = jfr_jvmti_env->SetEventNotificationMode(mode, event, event_thread);
check_jvmti_error(jfr_jvmti_env, jvmti_ret_code, "SetEventNotificationMode");
- return jvmti_ret_code;
+ return jvmti_ret_code == JVMTI_ERROR_NONE;
}
-static jvmtiError update_class_file_load_hook_event(jvmtiEventMode mode) {
+static bool update_class_file_load_hook_event(jvmtiEventMode mode) {
return set_event_notification_mode(mode, JVMTI_EVENT_CLASS_FILE_LOAD_HOOK, NULL);
}
@@ -117,12 +117,23 @@
return classes;
}
-static void log_and_throw(TRAPS) {
+// caller needs ResourceMark
+static void log_and_throw(jvmtiError error, TRAPS) {
if (!HAS_PENDING_EXCEPTION) {
DEBUG_ONLY(JfrJavaSupport::check_java_thread_in_native(THREAD));
ThreadInVMfromNative tvmfn((JavaThread*)THREAD);
- log_error(jfr, system)("JfrJvmtiAgent::retransformClasses failed");
- JfrJavaSupport::throw_class_format_error("JfrJvmtiAgent::retransformClasses failed", THREAD);
+ const char base_error_msg[] = "JfrJvmtiAgent::retransformClasses failed: ";
+ size_t length = sizeof base_error_msg; // includes terminating null
+ const char* const jvmti_error_name = JvmtiUtil::error_name(error);
+ assert(jvmti_error_name != NULL, "invariant");
+ length += strlen(jvmti_error_name);
+ char* error_msg = NEW_RESOURCE_ARRAY(char, length);
+ jio_snprintf(error_msg, length, "%s%s", base_error_msg, jvmti_error_name);
+ if (JVMTI_ERROR_INVALID_CLASS_FORMAT == error) {
+ JfrJavaSupport::throw_class_format_error(error_msg, THREAD);
+ } else {
+ JfrJavaSupport::throw_runtime_exception(error_msg, THREAD);
+ }
}
}
@@ -137,12 +148,15 @@
}
}
+static bool is_valid_jvmti_phase() {
+ return JvmtiEnvBase::get_phase() == JVMTI_PHASE_LIVE;
+}
+
void JfrJvmtiAgent::retransform_classes(JNIEnv* env, jobjectArray classes_array, TRAPS) {
assert(env != NULL, "invariant");
+ assert(classes_array != NULL, "invariant");
+ assert(is_valid_jvmti_phase(), "invariant");
DEBUG_ONLY(JfrJavaSupport::check_java_thread_in_native(THREAD));
- if (classes_array == NULL) {
- return;
- }
const jint classes_count = env->GetArrayLength(classes_array);
if (classes_count <= 0) {
return;
@@ -153,27 +167,27 @@
for (jint i = 0; i < classes_count; i++) {
jclass clz = (jclass)env->GetObjectArrayElement(classes_array, i);
check_exception_and_log(env, THREAD);
-
+ classes[i] = clz;
+ }
+ {
// inspecting the oop/klass requires a thread transition
- {
- ThreadInVMfromNative transition((JavaThread*)THREAD);
- if (JdkJfrEvent::is_a(clz)) {
- // should have been tagged already
- assert(JdkJfrEvent::is_subklass(clz), "invariant");
- } else {
+ ThreadInVMfromNative transition((JavaThread*)THREAD);
+ for (jint i = 0; i < classes_count; ++i) {
+ jclass clz = classes[i];
+ if (!JdkJfrEvent::is_a(clz)) {
// outside the event hierarchy
JdkJfrEvent::tag_as_host(clz);
}
}
-
- classes[i] = clz;
}
- if (jfr_jvmti_env->RetransformClasses(classes_count, classes) != JVMTI_ERROR_NONE) {
- log_and_throw(THREAD);
+ DEBUG_ONLY(JfrJavaSupport::check_java_thread_in_native(THREAD));
+ const jvmtiError result = jfr_jvmti_env->RetransformClasses(classes_count, classes);
+ if (result != JVMTI_ERROR_NONE) {
+ log_and_throw(result, THREAD);
}
}
-static jvmtiError register_callbacks(JavaThread* jt) {
+static bool register_callbacks(JavaThread* jt) {
assert(jfr_jvmti_env != NULL, "invariant");
DEBUG_ONLY(JfrJavaSupport::check_java_thread_in_native(jt));
jvmtiEventCallbacks callbacks;
@@ -182,10 +196,10 @@
callbacks.ClassFileLoadHook = jfr_on_class_file_load_hook;
const jvmtiError jvmti_ret_code = jfr_jvmti_env->SetEventCallbacks(&callbacks, sizeof(callbacks));
check_jvmti_error(jfr_jvmti_env, jvmti_ret_code, "SetEventCallbacks");
- return jvmti_ret_code;
+ return jvmti_ret_code == JVMTI_ERROR_NONE;
}
-static jvmtiError register_capabilities(JavaThread* jt) {
+static bool register_capabilities(JavaThread* jt) {
assert(jfr_jvmti_env != NULL, "invariant");
DEBUG_ONLY(JfrJavaSupport::check_java_thread_in_native(jt));
jvmtiCapabilities capabilities;
@@ -195,7 +209,7 @@
capabilities.can_retransform_any_class = 1;
const jvmtiError jvmti_ret_code = jfr_jvmti_env->AddCapabilities(&capabilities);
check_jvmti_error(jfr_jvmti_env, jvmti_ret_code, "Add Capabilities");
- return jvmti_ret_code;
+ return jvmti_ret_code == JVMTI_ERROR_NONE;
}
static jint create_jvmti_env(JavaThread* jt) {
@@ -206,16 +220,14 @@
return vm->GetEnv((void **)&jfr_jvmti_env, JVMTI_VERSION);
}
-static jvmtiError unregister_callbacks(JavaThread* jt) {
- if (jfr_jvmti_env == NULL) {
- return JVMTI_ERROR_NONE;
- }
+static bool unregister_callbacks(JavaThread* jt) {
+ assert(jfr_jvmti_env != NULL, "invariant");
jvmtiEventCallbacks callbacks;
/* Set empty callbacks */
memset(&callbacks, 0, sizeof(callbacks));
const jvmtiError jvmti_ret_code = jfr_jvmti_env->SetEventCallbacks(&callbacks, sizeof(callbacks));
check_jvmti_error(jfr_jvmti_env, jvmti_ret_code, "SetEventCallbacks");
- return jvmti_ret_code;
+ return jvmti_ret_code == JVMTI_ERROR_NONE;
}
JfrJvmtiAgent::JfrJvmtiAgent() {}
@@ -223,20 +235,17 @@
JfrJvmtiAgent::~JfrJvmtiAgent() {
JavaThread* jt = current_java_thread();
DEBUG_ONLY(JfrJavaSupport::check_java_thread_in_vm(jt));
- ThreadToNativeFromVM transition(jt);
- update_class_file_load_hook_event(JVMTI_DISABLE);
- unregister_callbacks(jt);
if (jfr_jvmti_env != NULL) {
+ ThreadToNativeFromVM transition(jt);
+ update_class_file_load_hook_event(JVMTI_DISABLE);
+ unregister_callbacks(jt);
jfr_jvmti_env->DisposeEnvironment();
jfr_jvmti_env = NULL;
}
- agent = NULL;
}
-static bool initialize() {
- JavaThread* const jt = current_java_thread();
+static bool initialize(JavaThread* jt) {
assert(jt != NULL, "invariant");
- assert(jt->thread_state() == _thread_in_vm, "invariant");
DEBUG_ONLY(JfrJavaSupport::check_java_thread_in_vm(jt));
ThreadToNativeFromVM transition(jt);
if (create_jvmti_env(jt) != JNI_OK) {
@@ -244,25 +253,36 @@
return false;
}
assert(jfr_jvmti_env != NULL, "invariant");
- if (register_capabilities(jt) != JVMTI_ERROR_NONE) {
+ if (!register_capabilities(jt)) {
+ return false;
+ }
+ if (!register_callbacks(jt)) {
return false;
}
- if (register_callbacks(jt) != JVMTI_ERROR_NONE) {
- return false;
- }
- if (update_class_file_load_hook_event(JVMTI_ENABLE) != JVMTI_ERROR_NONE) {
- return false;
- }
- return true;
+ return update_class_file_load_hook_event(JVMTI_ENABLE);
+}
+
+static void log_and_throw_illegal_state_exception(TRAPS) {
+ DEBUG_ONLY(JfrJavaSupport::check_java_thread_in_vm(THREAD));
+ const char* const illegal_state_msg = "An attempt was made to start JFR too early in the VM initialization sequence.";
+ log_error(jfr, system)(illegal_state_msg);
+ log_error(jfr, system)("JFR uses JVMTI RetransformClasses and requires the JVMTI state to have entered JVMTI_PHASE_LIVE.");
+ log_error(jfr, system)("Please initialize JFR in response to event JVMTI_EVENT_VM_INIT instead of JVMTI_EVENT_VM_START.");
+ JfrJavaSupport::throw_illegal_state_exception(illegal_state_msg, THREAD);
}
bool JfrJvmtiAgent::create() {
- assert(jfr_jvmti_env == NULL, "invariant");
+ assert(agent == NULL, "invariant");
+ JavaThread* const jt = current_java_thread();
+ if (!is_valid_jvmti_phase()) {
+ log_and_throw_illegal_state_exception(jt);
+ return false;
+ }
agent = new JfrJvmtiAgent();
if (agent == NULL) {
return false;
}
- if (!initialize()) {
+ if (!initialize(jt)) {
delete agent;
agent = NULL;
return false;
@@ -276,4 +296,3 @@
agent = NULL;
}
}
-