1 files changed, 119 insertions, 0 deletions

diff --git a/simpleperf/demo/SimpleperfExampleWithNative/app/src/main/cpp/native-lib.cpp b/simpleperf/demo/SimpleperfExampleWithNative/app/src/main/cpp/native-lib.cpp
new file mode 100644
index 00000000..bd66bcde
--- /dev/null
+++ b/simpleperf/demo/SimpleperfExampleWithNative/app/src/main/cpp/native-lib.cpp
@@ -0,0 +1,119 @@
+#include <jni.h>
+
+#include <pthread.h>
+#include <stdlib.h>
+#include <time.h>
+#include <string>
+
+#define noinline __attribute__((__noinline__))
+
+extern "C"
+JNIEXPORT jstring JNICALL
+Java_com_example_simpleperf_simpleperfexamplewithnative_MainActivity_stringFromJNI(
+        JNIEnv *env,
+        jobject /* this */) {
+    std::string hello = "Hello from C++";
+    return env->NewStringUTF(hello.c_str());
+}
+
+static void ThrowErrnoException(JNIEnv* env, const char* function_name, int err) {
+    jclass cls = env->FindClass("android/system/ErrnoException");
+    if (cls == nullptr) {
+        return;
+    }
+    jmethodID cid = env->GetMethodID(cls, "<init>", "(Ljava/lang/String;I)V");
+    if (cid == nullptr) {
+        return;
+    }
+    jstring msg = env->NewStringUTF(function_name);
+    if (msg == nullptr) {
+        return;
+    }
+    jthrowable obj = (jthrowable)env->NewObject(cls, cid, msg, err);
+    if (obj == nullptr) {
+        return;
+    }
+    env->Throw(obj);
+}
+
+int CallFunction(int a) {
+    return a + atoi("1");
+}
+
+static void* BusyLoopThread(void*) {
+    volatile int i = 0;
+    while (true) {
+        i = CallFunction(i);
+    }
+    return nullptr;
+}
+
+extern "C"
+JNIEXPORT void JNICALL
+Java_com_example_simpleperf_simpleperfexamplewithnative_MainActivity_createBusyThreadFromJNI(
+        JNIEnv *env,
+        jobject /* this */) {
+    pthread_t thread;
+    int ret = pthread_create(&thread, nullptr, BusyLoopThread, nullptr);
+    if (ret) {
+        ThrowErrnoException(env, "pthread_create", ret);
+        return;
+    }
+}
+
+static inline uint64_t GetSystemClock() {
+    timespec ts;
+    clock_gettime(CLOCK_MONOTONIC, &ts);
+    return ts.tv_sec * 1000000000ULL + ts.tv_nsec;
+}
+
+constexpr int LOOP_COUNT = 100000000;
+static uint64_t noinline RunFunction() {
+    uint64_t start_time_in_ns = GetSystemClock();
+    for (volatile int i = 0; i < LOOP_COUNT; ++i) {
+    }
+    return GetSystemClock() - start_time_in_ns;
+}
+
+static uint64_t noinline SleepFunction(unsigned long long sleep_time_in_ns) {
+    uint64_t start_time_in_ns = GetSystemClock();
+    struct timespec req;
+    req.tv_sec = sleep_time_in_ns / 1000000000;
+    req.tv_nsec = sleep_time_in_ns % 1000000000;
+    nanosleep(&req, nullptr);
+    return GetSystemClock() - start_time_in_ns;
+}
+
+static void* SleepThread(void*) {
+    pthread_setname_np(pthread_self(), "SleepThread");
+    uint64_t total_sleep_time_in_ns = 0;
+    uint64_t total_run_time_in_ns = 0;
+    while (true) {
+        total_run_time_in_ns += RunFunction();
+        if (total_sleep_time_in_ns < total_run_time_in_ns) {
+            total_sleep_time_in_ns += SleepFunction(total_run_time_in_ns - total_sleep_time_in_ns);
+        }
+    }
+}
+
+extern "C"
+JNIEXPORT void JNICALL
+Java_com_example_simpleperf_simpleperfexamplewithnative_SleepActivity_createSleepThreadFromJNI(
+        JNIEnv *env,
+        jobject /* this */) {
+    pthread_t thread;
+    int ret = pthread_create(&thread, nullptr, SleepThread, nullptr);
+    if (ret) {
+        ThrowErrnoException(env, "pthread_create", ret);
+        return;
+    }
+}
+
+extern "C"
+JNIEXPORT int JNICALL
+Java_com_example_simpleperf_simpleperfexamplewithnative_MixActivity_callFunction(
+        JNIEnv *env,
+        jobject /* this */,
+        int a) {
+    return CallFunction(a);
+}
\ No newline at end of file