Support RAII for C++ and ctx manager for Python (#66)

Author: leducp

lib/include/rtm/probe.h

@@ -12,6 +12,23 @@
 
 namespace rtm
 {
+    class Probe;
+
+    class ProbeGuard
+    {
+    public:
+        ProbeGuard(Probe& probe);
+        ~ProbeGuard();
+
+        ProbeGuard(ProbeGuard const&) = delete;
+        ProbeGuard(ProbeGuard&&) = delete;
+        ProbeGuard& operator=(ProbeGuard const&) = delete;
+        ProbeGuard& operator=(ProbeGuard&&) = delete;
+
+    private:
+        Probe* probe_;
+    };
+
     class Probe
     {
     public:

lib/py_bindings/src/lib_py.cc

@@ -89,7 +89,9 @@ namespace rtm
             .def("set_threshold", [](Probe& self, uint64_t threshold_ns)
                 {
                     self.set_threshold(nanoseconds{threshold_ns});
-                }, "threshold_ns"_a);
+                }, "threshold_ns"_a)
+            .def("__enter__", [](Probe& self) -> Probe& { self.log(); return self; })
+            .def("__exit__", [](Probe& self, nb::handle, nb::handle, nb::handle) { self.log(); });
 
         nb::bind_vector<std::vector<float>>(m, "FVector");
         nb::bind_vector<std::vector<nanoseconds>>(m, "nsVector");

lib/src/probe.cc

@@ -8,6 +8,17 @@
 
 namespace rtm
 {
+    ProbeGuard::ProbeGuard(Probe& probe)
+        : probe_(&probe)
+    {
+        probe_->log();
+    }
+
+    ProbeGuard::~ProbeGuard()
+    {
+        probe_->log();
+    }
+
     Probe::Probe()
     {
         samples_.reserve(MAX_SAMPLES);

py_bindings/examples/probe.py

@@ -19,16 +19,15 @@
 TARGET = 0.001  # 1 ms
 
 for i in range(400000):
-    p.log_start()
-    start = time.perf_counter()
+    with p:
+        start = time.perf_counter()
 
-    # ---- dummy computation ----
-    x = i * i
+        # ---- dummy computation ----
+        x = i * i
 
-    # ---- adjust to hit 1 ms ----
-    elapsed = time.perf_counter() - start
-    remaining = TARGET - elapsed
-    p.log_end()
+        # ---- adjust to hit 1 ms ----
+        elapsed = time.perf_counter() - start
+        remaining = TARGET - elapsed
 
     if remaining > 0:
         time.sleep(remaining)