Expanding the C++ demo to make it more useful

src/examples/DemoCpp/demo.cpp

@@ -3,39 +3,122 @@
 #include <unistd.h>
 #include <iostream>
 
-using namespace apex;
 using namespace std;
 
+/* First method for timers: using a scoped timer object.
+ * This is the simplest method for timing C++ */
+
+void scopedTimerExample1(void) {
+    /* This function is timed with a scoped timer using the function name */
+    apex::scoped_timer(__func__);
+    usleep(2000);
+    return;
+}
+
+void scopedTimerExample2(void) {
+    /* This function is timed with a scoped timer using the function address */
+    apex::scoped_timer((apex_function_address)&scopedTimerExample2);
+    usleep(2000);
+    return;
+}
+
+/* Second method for timers: using a task wrapper.
+ * The benefit of this case is that the timer can be yielded and resumed */
+
+void taskWrapperExample1(void) {
+    /* This function is timed with a task_wrapper that is explicitly started/stopped */
+    std::shared_ptr<apex::task_wrapper> wrapper = apex::new_task(__func__);
+    apex::start(wrapper);
+    usleep(2000);
+    apex::yield(wrapper);
+    usleep(2000);
+    apex::start(wrapper);
+    usleep(2000);
+    apex::stop(wrapper);
+    return;
+}
+
+void taskWrapperExample2(void) {
+    /* This function is timed with a task_wrapper that is explicitly started/stopped */
+    std::shared_ptr<apex::task_wrapper> wrapper =
+        apex::new_task((apex_function_address)&taskWrapperExample2);
+    apex::start(wrapper);
+    usleep(2000);
+    apex::yield(wrapper);
+    usleep(2000);
+    apex::start(wrapper);
+    usleep(2000);
+    apex::stop(wrapper);
+    return;
+}
+
+/* Third example, using simple profiler objects */
+
+void profilerExample1(void) {
+    /* This function is timed with a profiler object */
+    auto * profiler = apex::start(__func__);
+    usleep(2000);
+    apex::stop(profiler);
+}
+
+void profilerExample2(void) {
+    /* This function is timed with a profiler object */
+    auto * profiler = apex::start((apex_function_address)&profilerExample2);
+    usleep(2000);
+    apex::stop(profiler);
+}
+
 void* someThread(void* tmp)
 {
-  int* tid = (int*)tmp;
-  char name[32];
-  sprintf(name, "worker-thread#%d", *tid);
-  register_thread(name);
-  profiler* p = start((apex_function_address)someThread);
-  sample_value("/threadqueue{locality#0/total}/length", 2.0);
-  char counter[64];
-  sprintf(counter, "/threadqueue{locality#0/%s}/length", name);
-  sample_value(counter, 2.0);
-  stop(p);
-  exit_thread();
-  return NULL;
+    int* tid = (int*)tmp;
+    char name[32];
+    sprintf(name, "worker-thread#%d", *tid);
+    /* Tell APEX that there is a new thread */
+    apex::register_thread(name);
+    /* Time this thread */
+    apex::profiler* p = apex::start((apex_function_address)someThread);
+    /* Sample a counter */
+    apex::sample_value("test_counter_1", 2.0);
+    char counter[64];
+    /* Sample another counter */
+    sprintf(counter, "test_counter_%s", name);
+    apex::sample_value(counter, 2.0);
+    /* Stop timing the thread */
+    apex::stop(p);
+    apex::exit_thread();
+    return NULL;
 }
 
 int main (int argc, char** argv) {
-  init(argv[0], 0, 1);
-  cout << "APEX Version : " << version() << endl;
-  apex_options::print_options();
-  profiler* p = start((apex_function_address)(main));
-  pthread_t thread[2];
-  int tid = 0;
-  pthread_create(&(thread[0]), NULL, someThread, &tid);
-  int tid2 = 1;
-  pthread_create(&(thread[1]), NULL, someThread, &tid2);
-  pthread_join(thread[0], NULL);
-  pthread_join(thread[1], NULL);
-  stop(p);
-  finalize();
-  return 0;
+    /* Initialize APEX */
+    apex::init(argv[0], 0, 1);
+    /* Get some version and verbose option information */
+    cout << "APEX Version : " << apex::version() << endl;
+    apex::apex_options::print_options();
+    apex::apex_options::use_screen_output(true);
+    /* Start a timer for the main function, using its address (requires binutils) */
+    apex::profiler* p = apex::start((apex_function_address)(main));
+    /* Launch two threads */
+    pthread_t thread[2];
+    int tid = 0;
+    pthread_create(&(thread[0]), NULL, someThread, &tid);
+    int tid2 = 1;
+    pthread_create(&(thread[1]), NULL, someThread, &tid2);
+    /* Join the 2 threads */
+    pthread_join(thread[0], NULL);
+    pthread_join(thread[1], NULL);
+
+    /* test some other timers */
+    scopedTimerExample1();
+    scopedTimerExample2();
+    taskWrapperExample1();
+    taskWrapperExample2();
+    profilerExample1();
+    profilerExample2();
+
+    /* Stop the main timer and exit */
+    apex::stop(p);
+    apex::finalize();
+    return 0;
 }