IPCThreadState: Add a public method to probe if a binder call is being served.
This can be useful when common code can be executed by both hwbinder and
binder threads, and, they want to access (hardware::)IPCThreadState
specific information. Eg: cameraserver.
This commit adds a vndk private library 'libbinderthreadstate' which
serves as common ground for both libbinder and libhwbinder to inform
them about the nature of the IPC call being served (if at all) on the current
thread.
Bug: 110364143
Test: Boot device, use GCA
Change-Id: Ifefb273c9a1f545417a82e9511a45bda00f701aa
Signed-off-by: Jayant Chowdhary <jchowdhary@google.com>
diff --git a/libs/binderthreadstate/Android.bp b/libs/binderthreadstate/Android.bp
new file mode 100644
index 0000000..7106cbb
--- /dev/null
+++ b/libs/binderthreadstate/Android.bp
@@ -0,0 +1,44 @@
+// Copyright (C) 2018 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.
+
+cc_library {
+ name: "libbinderthreadstate",
+ recovery_available: true,
+ vendor_available: false,
+ vndk: {
+ enabled: true,
+ support_system_process: true,
+ },
+ srcs: [
+ "IPCThreadStateBase.cpp",
+ ],
+
+ shared_libs: [
+ "libbase",
+ "liblog",
+ "libcutils",
+ "libutils",
+ ],
+
+ export_include_dirs: ["include"],
+
+ sanitize: {
+ misc_undefined: ["integer"],
+ },
+
+ cflags: [
+ "-Wall",
+ "-Werror",
+ ],
+}
diff --git a/libs/binderthreadstate/IPCThreadStateBase.cpp b/libs/binderthreadstate/IPCThreadStateBase.cpp
new file mode 100644
index 0000000..fede151
--- /dev/null
+++ b/libs/binderthreadstate/IPCThreadStateBase.cpp
@@ -0,0 +1,89 @@
+/*
+ * Copyright (C) 2018 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.
+ */
+
+#define LOG_TAG "IPCThreadStateBase"
+
+#include <binderthreadstate/IPCThreadStateBase.h>
+#include <android-base/macros.h>
+
+#include <utils/Log.h>
+
+#include <errno.h>
+#include <inttypes.h>
+#include <pthread.h>
+
+namespace android {
+
+static pthread_mutex_t gTLSMutex = PTHREAD_MUTEX_INITIALIZER;
+static bool gHaveTLS = false;
+static pthread_key_t gTLS = 0;
+
+IPCThreadStateBase::IPCThreadStateBase() {
+ pthread_setspecific(gTLS, this);
+}
+
+IPCThreadStateBase* IPCThreadStateBase::self()
+{
+ if (gHaveTLS) {
+restart:
+ const pthread_key_t k = gTLS;
+ IPCThreadStateBase* st = (IPCThreadStateBase*)pthread_getspecific(k);
+ if (st) return st;
+ return new IPCThreadStateBase;
+ }
+
+ pthread_mutex_lock(&gTLSMutex);
+ if (!gHaveTLS) {
+ int key_create_value = pthread_key_create(&gTLS, threadDestructor);
+ if (key_create_value != 0) {
+ pthread_mutex_unlock(&gTLSMutex);
+ ALOGW("IPCThreadStateBase::self() unable to create TLS key, expect a crash: %s\n",
+ strerror(key_create_value));
+ return nullptr;
+ }
+ gHaveTLS = true;
+ }
+ pthread_mutex_unlock(&gTLSMutex);
+ goto restart;
+}
+
+void IPCThreadStateBase::pushCurrentState(CallState callState) {
+ mCallStateStack.emplace(callState);
+}
+
+IPCThreadStateBase::CallState IPCThreadStateBase::popCurrentState() {
+ ALOG_ASSERT(mCallStateStack.size > 0);
+ CallState val = mCallStateStack.top();
+ mCallStateStack.pop();
+ return val;
+}
+
+IPCThreadStateBase::CallState IPCThreadStateBase::getCurrentBinderCallState() {
+ if (mCallStateStack.size() > 0) {
+ return mCallStateStack.top();
+ }
+ return CallState::NONE;
+}
+
+void IPCThreadStateBase::threadDestructor(void *st)
+{
+ IPCThreadStateBase* const self = static_cast<IPCThreadStateBase*>(st);
+ if (self) {
+ delete self;
+ }
+}
+
+}; // namespace android
diff --git a/libs/binderthreadstate/include/binderthreadstate/IPCThreadStateBase.h b/libs/binderthreadstate/include/binderthreadstate/IPCThreadStateBase.h
new file mode 100644
index 0000000..6fdcc84
--- /dev/null
+++ b/libs/binderthreadstate/include/binderthreadstate/IPCThreadStateBase.h
@@ -0,0 +1,44 @@
+/*
+ * Copyright (C) 2018 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.
+ */
+
+#ifndef BINDER_THREADSTATE_IPC_THREADSTATE_BASE_H
+#define BINDER_THREADSTATE_IPC_THREADSTATE_BASE_H
+
+#include <stack>
+namespace android {
+
+class IPCThreadStateBase {
+public:
+ enum CallState {
+ HWBINDER,
+ BINDER,
+ NONE,
+ };
+ static IPCThreadStateBase* self();
+ void pushCurrentState(CallState callState);
+ CallState popCurrentState();
+ CallState getCurrentBinderCallState();
+
+private:
+ IPCThreadStateBase();
+ static void threadDestructor(void *st);
+
+ std::stack<CallState> mCallStateStack;
+};
+
+}; // namespace android
+
+#endif // BINDER_THREADSTATE_IPC_THREADSTATE_BASE_H