Add utility methods to support hidl instrumentation.
* Add method registerInstrumentationCallback which looks up and
dynamically loads the hidl instrumentation libraries and registers
the instrumentation callbacks.
* The method looks up interumentation libraries under directories:
/system/lib(64)/hw, /vender/lib(64)/hw, /odm/lib(64)/hw.
* The method only loads libraries with a particualr name pattern, e.g.
android.hardware.nfc@1.0.*.profiler.so
* The method is a no-op for user builds.
Bug: 31266145
Test: test pass with hidl_test.
Change-Id: Id11486e36081d75481a45836219f84ddf5b112d7
diff --git a/Android.mk b/Android.mk
index 3b15645..c4f7bd3 100644
--- a/Android.mk
+++ b/Android.mk
@@ -29,6 +29,10 @@
Static.cpp \
Status.cpp
+ifeq ($(TARGET_BUILD_VARIANT),user)
+ LOCAL_CFLAGS += -DLIBHIDL_TARGET_BUILD_VARIANT_USER
+endif
+
LOCAL_C_INCLUDES := $(LOCAL_PATH)/include
LOCAL_MULTILIB := both
include $(BUILD_SHARED_LIBRARY)
diff --git a/HidlSupport.cpp b/HidlSupport.cpp
index 27daa94..37d4b9f 100644
--- a/HidlSupport.cpp
+++ b/HidlSupport.cpp
@@ -16,6 +16,12 @@
#include <hidl/HidlSupport.h>
+#ifndef DLIBHIDL_TARGET_BUILD_VARIANT_USER
+#include <android-base/logging.h>
+#include <cutils/properties.h>
+#include <regex>
+#endif
+
namespace android {
namespace hardware {
@@ -116,6 +122,74 @@
// static
const size_t hidl_string::kOffsetOfBuffer = offsetof(hidl_string, mBuffer);
+
+
+void registerInstrumentationCallbacks(
+ const std::string &profilerPrefix,
+ std::vector<InstrumentationCallback> *instrumentationCallbacks) {
+#ifndef DLIBHIDL_TARGET_BUILD_VARIANT_USER
+ std::vector<std::string> instrumentationLibPaths;
+ instrumentationLibPaths.push_back(HAL_LIBRARY_PATH_SYSTEM);
+ instrumentationLibPaths.push_back(HAL_LIBRARY_PATH_VENDOR);
+ instrumentationLibPaths.push_back(HAL_LIBRARY_PATH_ODM);
+ for (auto path : instrumentationLibPaths) {
+ DIR *dir = opendir(path.c_str());
+ if (dir == 0) {
+ LOG(WARNING) << path << " does not exit. ";
+ return;
+ }
+
+ struct dirent *file;
+ while ((file = readdir(dir)) != NULL) {
+ if (!isInstrumentationLib(profilerPrefix, file))
+ continue;
+
+ void *handle = dlopen((path + file->d_name).c_str(), RTLD_NOW);
+ if (handle == nullptr) {
+ LOG(WARNING) << "couldn't load file: " << file->d_name
+ << " error: " << dlerror();
+ continue;
+ }
+ using cb_fun = void (*)(
+ const InstrumentationEvent,
+ const char *,
+ const char *,
+ const char *,
+ const char *,
+ std::vector<void *> *);
+ auto cb = (cb_fun)dlsym(handle, "HIDL_INSTRUMENTATION_FUNCTION");
+ if (cb == nullptr) {
+ LOG(WARNING)
+ << "couldn't find symbol: HIDL_INSTRUMENTATION_FUNCTION, "
+ "error: "
+ << dlerror();
+ continue;
+ }
+ instrumentationCallbacks->push_back(cb);
+ LOG(INFO) << "Register instrumentation callback from "
+ << file->d_name;
+ }
+ closedir(dir);
+ }
+#else
+ // No-op for user builds.
+ return;
+#endif
+}
+
+bool isInstrumentationLib(
+ const std::string &profiler_prefix,
+ const dirent *file) {
+#ifndef DLIBHIDL_TARGET_BUILD_VARIANT_USER
+ if (file->d_type != DT_REG) return false;
+ std::cmatch cm;
+ std::regex e("^" + profiler_prefix + "(.*).profiler.so$");
+ if (std::regex_match(file->d_name, cm, e)) return true;
+#else
+#endif
+ return false;
+}
+
} // namespace hardware
} // namespace android
diff --git a/include/hidl/HidlSupport.h b/include/hidl/HidlSupport.h
index 347d9e4..6b88664 100644
--- a/include/hidl/HidlSupport.h
+++ b/include/hidl/HidlSupport.h
@@ -18,6 +18,7 @@
#define ANDROID_HIDL_SUPPORT_H
#include <algorithm>
+#include <dirent.h>
#include <dlfcn.h>
#include <hwbinder/Parcel.h>
#include <utils/Errors.h>
@@ -286,6 +287,53 @@
I##INTERFACE::version); \
}
+// ----------------------------------------------------------------------
+// Hidl instrumentation utilities.
+
+// Event that triggers the instrumentation. e.g. enter of an API call on
+// the server/client side, exit of an API call on the server/client side etc.
+enum InstrumentationEvent {
+ SERVER_API_ENTRY = 0,
+ SERVER_API_EXIT,
+ CLIENT_API_ENTRY,
+ CLIENT_API_EXIT,
+ SYNC_CALLBACK_ENTRY,
+ SYNC_CALLBACK_EXIT,
+ ASYNC_CALLBACK_ENTRY,
+ ASYNC_CALLBACK_EXIT,
+};
+
+// Signature of the instrumentation callback function.
+using InstrumentationCallback = std::function<void(
+ const InstrumentationEvent event,
+ const char *package,
+ const char *version,
+ const char *interface,
+ const char *method,
+ std::vector<void *> *args)>;
+
+// Function that lookup and dynamically loads the hidl instrumentation libraries
+// and registers the instrumentation callback functions.
+//
+// The instrumentation libraries should be stored under any of the following
+// directories: HAL_LIBRARY_PATH_SYSTEM, HAL_LIBRARY_PATH_VENDOR and
+// HAL_LIBRARY_PATH_ODM. The name of instrumentation libraries should follow
+// pattern: ^profilerPrefix(.*).profiler.so$
+//
+// Each instrumentation library is expected to implement the instrumentation
+// function called HIDL_INSTRUMENTATION_FUNCTION.
+//
+// A no-op for user build.
+void registerInstrumentationCallbacks(
+ const std::string &profilerPrefix,
+ std::vector<InstrumentationCallback> *instrumentationCallbacks);
+
+// Utility function to determine whether a give file is a instrumentation
+// library (i.e. the file name follow the expected pattern).
+bool isInstrumentationLib(
+ const std::string &profilerPrefix,
+ const dirent *file);
+
} // namespace hardware
} // namespace android