First step in refactoring out the build running from the gui for later thread fiascos.

builder.cpp

@@ -36,29 +36,39 @@ Builder::Builder(GUI &g, GameEngine &engine)
   config["build_cmd"].template get_to<string>(build_cmd);
 }
 
-void Builder::run_build() {
-  std::regex err_re("(.*?):([0-9]+):([0-9]+):\\s*(.*?):\\s*(.*)\n*");
-
-  char buffer[BUF_MAX]; // BUF_MAX is a define already?
-  std::ofstream stats_out;
-
-
-  stats_out.open("stats.csv", std::ios::out | std::ios::app);
-  std::time_t tstamp = std::time(nullptr);
+FILE *start_command(string &build_cmd) {
+  FILE *build_out = popen(build_cmd.c_str(), "r");
+  dbc::check(build_out != nullptr, "Failed to run command.");
 
-  dbc::check(stats_out.good(), "Error opening stats.csv file.");
-  dbc::pre("simple test", [&]() { return stats_out.good(); });
+  return build_out;
+}
 
+string read_line(FILE *build_out, bool &done_out) {
+  char buffer[BUF_MAX];
+  char *res = fgets(buffer, BUF_MAX, build_out);
+  //!!! exception if res == nullptr
+  done_out = res == nullptr;
 
-  // need to catch the error message when the command is bad
-  FILE *build_out = popen(build_cmd.c_str(), "r");
-  dbc::check(build_out != nullptr, "Failed to run command.");
+  if(!done_out) {
+    return string{buffer};  // yeah, that's probably a problem
+  } else {
+    return "";
+  }
+}
 
+void end_build(FILE *build_out, GUI &gui, string &build_cmd) {
+  int rc = pclose(build_out);
 
-  game.start_round();
+  if(rc == 0) {
+    gui.build_works();
+  } else {
+    // BUG: make it not play two sounds
+    gui.build_failed(true, build_cmd);
+  }
+}
 
-  while(fgets(buffer, BUF_MAX, build_out) != nullptr) {
-    string line(buffer);  // yeah, that's probably a problem
+void Builder::run_build(const string &line) {
+  std::regex err_re("(.*?):([0-9]+):([0-9]+):\\s*(.*?):\\s*(.*)\n*");
 
   std::smatch err;
   bool match = std::regex_match(line, err, err_re);
@@ -70,37 +80,16 @@ void Builder::run_build() {
     string type = err[4].str();
     string message = err[5].str();
 
-      string result = format("{:%FT%T},{},{},{},{},{}",
-          fmt::localtime(tstamp), file_name,
-          lnumber, col, type, message);
-
-      stats_out << result;
     gui.output(format("HIT WITH {} @ {}:{}:{} {}", type, file_name, lnumber, col, message));
 
     game.hit(type);
-
-      // refactor this
-      if(game.is_dead()) {
-        gui.you_died();
   }
-    }
-  }
-
-
-  game.end_round();
-
-  int rc = pclose(build_out);
-  if(rc == 0) {
-    gui.build_works();
-  } else {
-    gui.output(format(">>>>>>>> DIED? {}", game.is_dead()));
-    gui.build_failed(!game.is_dead(), build_cmd);
-  }
-
-  stats_out.close();
-  dbc::post("a post test", [&]() { return !stats_out.is_open(); });
 }
 
+enum BuildState {
+  WAITING, BUILDING, DONE
+};
+
 void Builder::run() {
   git_repository* repo = nullptr;
 
@@ -120,22 +109,53 @@ void Builder::run() {
     gui.output(format("Watching directory {} for changes...", git_path));
     efsw::WatchID wid = fileWatcher->addWatch(git_path, listener, true);
 
-    int rc = gui.main_loop(game, [&] {
+    FILE *build_out = NULL;
+    bool build_done = false;
+    BuildState state = WAITING;
+
     fileWatcher->watch();
 
+    int rc = gui.main_loop(game, [&] {
+      switch(state) {
+      case WAITING:
         if(listener->changes) {
+          game.start_round();
           gui.building();
           gui.output(format("CHANGES! Running build {}", build_cmd));
+          build_out = start_command(build_cmd);
+          state = BUILDING;
+        }
+      break;
+
+      case BUILDING: {
+          // check if there's output
+          string line = read_line(build_out, build_done);
+          if(build_done) {
+            end_build(build_out, gui, build_cmd);
+            build_out = NULL;
+            state = DONE;
+          } else {
+            // get the command line
+            // run the build if it's available
+            run_build(line);
+            state = BUILDING;
+          }
+       }
+      break;
 
-        run_build();
+      case DONE: {
+        game.end_round();
 
         if(game.is_dead()) {
-          gui.output("!!!! YOU DIED! !!!! Learn to code luser.");
+          gui.you_died();
           game.reset();
         }
 
         listener->reset_state();
         gui.output("^^^^^^^^^^^ END ^^^^^^^^^^^");
+        state = WAITING;
+       }
+      break;
       }
 
       return 0;

builder.hpp

@@ -1,6 +1,7 @@
 #pragma once
 #include "gui.hpp"
 #include "game_engine.hpp"
+#include <stdio.h>
 
 using std::string;
 
@@ -14,7 +15,7 @@ class Builder {
 
   Builder(GUI &g, GameEngine &engine);
 
-  void run_build();
+  void run_build(const string &line);
 
   void run();
 };

gui.cpp

@@ -85,6 +85,7 @@ void GUI::build_failed(bool play_sound, const string &command) {
 void GUI::you_died() {
   building_sound.stop();
   you_died_sound.play();
+  output("!!!! YOU DIED! !!!! Learn to code luser.");
   output("YOU DIED!");
 }
 

meson.build

@@ -46,6 +46,9 @@ executable('jsontest', 'jsontest.cpp',
 executable('threadtest', 'threadtest.cpp',
   dependencies: dependencies)
 
+executable('badref', 'badref.cpp',
+  dependencies: dependencies)
+
 executable('corotest', [
     'corotest.cpp'
   ],

threadtest.cpp

@@ -1,34 +1,54 @@
-#include <thread>
-#include <fmt/core.h>
-#include <chrono>
-#include <iostream>
-#include <thread>
-#include <utility>
+#include <condition_variable>
 #include <iostream>
 #include <mutex>
+#include <string>
+#include <thread>
 
-using namespace std::chrono_literals;
+std::mutex m;
+std::condition_variable cv;
+std::string data;
+bool ready = false;
+bool processed = false;
 
-std::atomic_int counter = 0;
-std::mutex counter_mutex;
+void worker_thread()
+{
+    // wait until main() sends data
+    std::unique_lock lk(m);
+    cv.wait(lk, []{ return ready; });
 
+    // after the wait, we own the lock
+    std::cout << "Worker thread is processing data\n";
+    data += " after processing";
 
-void locked_counter() {
-  for (int i = 0; i < 5; ++i)
-  {
-    std::lock_guard<std::mutex> lock(counter_mutex);
-    std::this_thread::sleep_for(100ms);
-    std::cout << "Thread 1 executing\n";
-    ++counter;
-  }
+    // send data back to main()
+    processed = true;
+    std::cout << "Worker thread signals data processing completed\n";
+
+    // manual unlocking is done before notifying, to avoid waking up
+    // the waiting thread only to block again (see notify_one for details)
+    lk.unlock();
+    cv.notify_one();
 }
 
 int main()
 {
-  std::jthread t2(locked_counter); // pass by value
+    std::thread worker(worker_thread);
+
+    data = "Example data";
+    // send data to the worker thread
+    {
+        std::lock_guard lk(m);
+        ready = true;
+        std::cout << "main() signals data ready for processing\n";
+    }
+    cv.notify_one();
 
-  for(int i = 0; i < 5; ++i) {
-    std::lock_guard<std::mutex> lock(counter_mutex);
-    std::cout << "counter is " << counter << std::endl;
+    // wait for the worker
+    {
+        std::unique_lock lk(m);
+        cv.wait(lk, []{ return processed; });
     }
+    std::cout << "Back in main(), data = " << data << '\n';
+
+    worker.join();
 }