Sets up application starting and stopping

codexcrawler.nim

@@ -1,5 +1,60 @@
-import
-  ./codexcrawler/todo
+import pkg/chronicles
+import pkg/chronos
+
+import ./codexcrawler/main
+when defined(posix):
+  import system/ansi_c
+
+type
+  ApplicationStatus {.pure.} = enum
+    Stopped,
+    Stopping,
+    Running
+
+  Application = ref object
+    status: ApplicationStatus
+
+proc run(app: Application) =
+  app.status = ApplicationStatus.Running
+
+  waitFor runApplication()
+
+  while app.status == ApplicationStatus.Running:
+    try:
+      chronos.poll()
+    except Exception as exc:
+      error "Unhandled exception", msg = exc.msg
+      quit QuitFailure
+  notice "Done"
 
 when isMainModule:
-  run()
+  let app = Application()
+
+  # Stopping code must be in scope of app declaration.
+  # Else capture of the instance is not allowed due to {.noconv.}.
+  proc onStopSignal() =
+    app.status = ApplicationStatus.Stopping
+    notice "Stopping Crawler..."
+
+  proc controlCHandler() {.noconv.} =
+    when defined(windows):
+      # workaround for https://github.com/nim-lang/Nim/issues/4057
+      try:
+        setupForeignThreadGc()
+      except Exception as exc: raiseAssert exc.msg
+    notice "Shutting down after having received SIGINT"
+    onStopSignal()
+
+  try:
+    setControlCHook(controlCHandler)
+  except Exception as exc:
+    warn "Cannot set ctrl-c handler", msg = exc.msg
+
+  when defined(posix):
+    proc SIGTERMHandler(signal: cint) {.noconv.} =
+      notice "Shutting down after having received SIGTERM"
+      onStopSignal()
+
+    c_signal(ansi_c.SIGTERM, SIGTERMHandler)
+
+  app.run()

codexcrawler/main.nim

@@ -0,0 +1,18 @@
+import pkg/chronicles
+import pkg/chronos
+
+logScope:
+  topics = "main"
+
+proc runApplication*() {.async.} =
+  proc aaa() {.async.} =
+    while true:
+      notice "a"
+      await sleepAsync(1000)
+
+  asyncSpawn aaa()
+  
+  await sleepAsync(1000)
+
+  notice "b"
+

codexcrawler/todo.nim

@@ -1,2 +0,0 @@
-proc run*() =
-  echo "Run!"