1 files changed, 115 insertions, 0 deletions
diff --git a/tools/dump-jvmti-state/dump-jvmti.cc b/tools/dump-jvmti-state/dump-jvmti.cc
new file mode 100644
index 0000000000..71a0115999
--- /dev/null
+++ b/tools/dump-jvmti-state/dump-jvmti.cc
@@ -0,0 +1,115 @@
+// Copyright (C) 2019 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+#include <android-base/logging.h>
+
+#include <jni.h>
+#include <jvmti.h>
+
+namespace dumpjvmti {
+
+namespace {
+
+// Special art ti-version number. We will use this as a fallback if we cannot get a regular JVMTI
+// env.
+static constexpr jint kArtTiVersion = JVMTI_VERSION_1_2 | 0x40000000;
+
+template <typename T> static void Dealloc(jvmtiEnv* env, T* t) {
+  env->Deallocate(reinterpret_cast<unsigned char*>(t));
+}
+
+template <typename T, typename... Rest> static void Dealloc(jvmtiEnv* env, T* t, Rest... rs) {
+  Dealloc(env, t);
+  Dealloc(env, rs...);
+}
+
+static void DeallocParams(jvmtiEnv* env, jvmtiParamInfo* params, jint n_params) {
+  for (jint i = 0; i < n_params; i++) {
+    Dealloc(env, params[i].name);
+  }
+}
+
+// The extension function to get the internal data
+static jvmtiError (*GetInternalData)(jvmtiEnv* env, unsigned char** data) = nullptr;
+
+static jint SetupJvmtiEnv(JavaVM* vm, jvmtiEnv** jvmti) {
+  jint res = 0;
+  res = vm->GetEnv(reinterpret_cast<void**>(jvmti), JVMTI_VERSION_1_1);
+
+  if (res != JNI_OK || *jvmti == nullptr) {
+    LOG(ERROR) << "Unable to access JVMTI, error code " << res;
+    res = vm->GetEnv(reinterpret_cast<void**>(jvmti), kArtTiVersion);
+    if (res != JNI_OK) {
+      return res;
+    }
+  }
+
+  jvmtiEnv* env = *jvmti;
+
+  // Get the extensions.
+  jint n_ext = 0;
+  jvmtiExtensionFunctionInfo* infos = nullptr;
+  if (env->GetExtensionFunctions(&n_ext, &infos) != JVMTI_ERROR_NONE) {
+    return JNI_ERR;
+  }
+  for (jint i = 0; i < n_ext; i++) {
+    jvmtiExtensionFunctionInfo* cur_info = &infos[i];
+    if (strcmp("com.android.art.misc.get_plugin_internal_state", cur_info->id) == 0) {
+      GetInternalData = reinterpret_cast<decltype(GetInternalData)>(cur_info->func);
+    }
+    // Cleanup the cur_info
+    DeallocParams(env, cur_info->params, cur_info->param_count);
+    Dealloc(env, cur_info->id, cur_info->short_description, cur_info->params, cur_info->errors);
+  }
+  // Cleanup the array.
+  Dealloc(env, infos);
+  return GetInternalData != nullptr ? JNI_OK : JNI_ERR;
+}
+
+static void CbDataDump(jvmtiEnv* jvmti) {
+  unsigned char* data = nullptr;
+  if (JVMTI_ERROR_NONE == GetInternalData(jvmti, &data)) {
+    LOG(INFO) << data;
+    Dealloc(jvmti, data);
+  }
+}
+
+}  // namespace
+
+static jint AgentStart(JavaVM* vm, char* options ATTRIBUTE_UNUSED, void* reserved ATTRIBUTE_UNUSED) {
+  jvmtiEnv* jvmti = nullptr;
+  if (SetupJvmtiEnv(vm, &jvmti) != JNI_OK) {
+    LOG(ERROR) << "Could not get JVMTI env or ArtTiEnv!";
+    return JNI_ERR;
+  }
+  jvmtiEventCallbacks cb{
+    .DataDumpRequest = CbDataDump,
+  };
+  jvmti->SetEventCallbacks(&cb, sizeof(cb));
+  jvmti->SetEventNotificationMode(JVMTI_ENABLE, JVMTI_EVENT_DATA_DUMP_REQUEST, nullptr);
+  return JNI_OK;
+}
+
+// Late attachment (e.g. 'am attach-agent').
+extern "C" JNIEXPORT jint JNICALL Agent_OnAttach(JavaVM* vm, char* options, void* reserved) {
+  return AgentStart(vm, options, reserved);
+}
+
+// Early attachment
+extern "C" JNIEXPORT jint JNICALL Agent_OnLoad(JavaVM* jvm, char* options, void* reserved) {
+  return AgentStart(jvm, options, reserved);
+}
+
+}  // namespace dumpjvmti