Merge "AndroidRuntime: Expose javaAttachThread / javaDetachThread."
diff --git a/core/jni/Android.bp b/core/jni/Android.bp
index b236385..aae727d 100644
--- a/core/jni/Android.bp
+++ b/core/jni/Android.bp
@@ -297,6 +297,7 @@
header_libs: [
"bionic_libc_platform_headers",
"dnsproxyd_protocol_headers",
+ "libandroid_runtime_threads_headers",
],
},
host: {
@@ -338,3 +339,18 @@
never: true,
},
}
+
+cc_library_headers {
+ name: "libandroid_runtime_threads_headers",
+ host_supported: true,
+ vendor_available: true,
+ // TODO(b/153609531): remove when libbinder is not native_bridge_supported
+ native_bridge_supported: true,
+ // Allow only modules from the following list to create threads that can be
+ // attached to the JVM. This list should be a subset of the dependencies of
+ // libandroid_runtime.
+ visibility: [
+ "//frameworks/native/libs/binder",
+ ],
+ export_include_dirs: ["include_threads"],
+}
diff --git a/core/jni/AndroidRuntime.cpp b/core/jni/AndroidRuntime.cpp
index f4a10ef..79038b0 100644
--- a/core/jni/AndroidRuntime.cpp
+++ b/core/jni/AndroidRuntime.cpp
@@ -22,6 +22,7 @@
#include <android-base/properties.h>
#include <android/graphics/jni_runtime.h>
#include <android_runtime/AndroidRuntime.h>
+#include <android_runtime/threads.h>
#include <assert.h>
#include <binder/IBinder.h>
#include <binder/IPCThreadState.h>
@@ -1338,14 +1339,15 @@
return env;
}
+extern "C" {
+
/*
* Makes the current thread visible to the VM.
*
* The JNIEnv pointer returned is only valid for the current thread, and
* thus must be tucked into thread-local storage.
*/
-static int javaAttachThread(const char* threadName, JNIEnv** pEnv)
-{
+bool androidJavaAttachThread(const char* threadName) {
JavaVMAttachArgs args;
JavaVM* vm;
jint result;
@@ -1357,18 +1359,17 @@
args.name = (char*) threadName;
args.group = NULL;
- result = vm->AttachCurrentThread(pEnv, (void*) &args);
- if (result != JNI_OK)
- ALOGI("NOTE: attach of thread '%s' failed\n", threadName);
+ JNIEnv* env;
+ result = vm->AttachCurrentThread(&env, (void*)&args);
+ if (result != JNI_OK) ALOGI("NOTE: attach of thread '%s' failed\n", threadName);
- return result;
+ return result == JNI_OK;
}
/*
* Detach the current thread from the set visible to the VM.
*/
-static int javaDetachThread(void)
-{
+bool androidJavaDetachThread(void) {
JavaVM* vm;
jint result;
@@ -1376,11 +1377,12 @@
assert(vm != NULL);
result = vm->DetachCurrentThread();
- if (result != JNI_OK)
- ALOGE("ERROR: thread detach failed\n");
- return result;
+ if (result != JNI_OK) ALOGE("ERROR: thread detach failed\n");
+ return result == JNI_OK;
}
+} // extern "C"
+
/*
* When starting a native thread that will be visible from the VM, we
* bounce through this to get the right attach/detach action.
@@ -1391,18 +1393,16 @@
void* userData = ((void **)args)[1];
char* name = (char*) ((void **)args)[2]; // we own this storage
free(args);
- JNIEnv* env;
int result;
/* hook us into the VM */
- if (javaAttachThread(name, &env) != JNI_OK)
- return -1;
+ if (!androidJavaAttachThread(name)) return -1;
/* start the thread running */
result = (*(android_thread_func_t)start)(userData);
/* unhook us */
- javaDetachThread();
+ (void)androidJavaDetachThread();
free(name);
return result;
diff --git a/core/jni/include_threads/android_runtime/threads.h b/core/jni/include_threads/android_runtime/threads.h
new file mode 100644
index 0000000..a410529
--- /dev/null
+++ b/core/jni/include_threads/android_runtime/threads.h
@@ -0,0 +1,30 @@
+/*
+ * Copyright (C) 2021 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.
+ */
+
+// Manages the interaction between threads and the Android Runtime. If these symbols do not exist
+// at runtime, it means the current process does not link to libandroid_runtime.
+
+#pragma once
+
+extern "C" {
+
+// Attach current thread to JVM. Return true if successful, false otherwise.
+bool androidJavaAttachThread(const char* threadName);
+
+// Detach current thread to JVM. Return true if successful, false otherwise.
+bool androidJavaDetachThread();
+
+} // extern "C"