moved cpu usage to a grpc call that the gui will listen to, fixed grpc stream typing to be grpc.Future, fixed pygui issue for start callback when a start fails, but there are no exceptions

daemon/core/gui/coreclient.py

@@ -16,6 +16,7 @@ from core.api.grpc import client
 from core.api.grpc.common_pb2 import ConfigOption
 from core.api.grpc.configservices_pb2 import ConfigService, ConfigServiceConfig
 from core.api.grpc.core_pb2 import (
+    CpuUsageEvent,
     Event,
     ExceptionEvent,
     Hook,
@@ -55,6 +56,7 @@ if TYPE_CHECKING:
     from core.gui.app import Application
 
 GUI_SOURCE = "gui"
+CPU_USAGE_DELAY = 3
 
 
 class CoreClient:
@@ -92,8 +94,9 @@ class CoreClient:
         self.hooks: Dict[str, Hook] = {}
         self.emane_config: Dict[str, ConfigOption] = {}
         self.mobility_players: Dict[int, MobilityPlayer] = {}
-        self.handling_throughputs: Optional[grpc.Channel] = None
-        self.handling_events: Optional[grpc.Channel] = None
+        self.handling_throughputs: Optional[grpc.Future] = None
+        self.handling_cpu_usage: Optional[grpc.Future] = None
+        self.handling_events: Optional[grpc.Future] = None
         self.xml_dir: Optional[str] = None
         self.xml_file: Optional[str] = None
 
@@ -111,6 +114,7 @@ class CoreClient:
                 )
                 if throughputs_enabled:
                     self.enable_throughputs()
+            self.setup_cpu_usage()
         return self._client
 
     def reset(self) -> None:
@@ -258,6 +262,20 @@ class CoreClient:
             self.handling_events.cancel()
             self.handling_events = None
 
+    def cancel_cpu_usage(self) -> None:
+        if self.handling_cpu_usage:
+            self.handling_cpu_usage.cancel()
+            self.handling_cpu_usage = None
+
+    def setup_cpu_usage(self) -> None:
+        if self.handling_cpu_usage and self.handling_cpu_usage.running():
+            return
+        if self.handling_cpu_usage:
+            self.handling_cpu_usage.cancel()
+        self.handling_cpu_usage = self._client.cpu_usage(
+            CPU_USAGE_DELAY, self.handle_cpu_event
+        )
+
     def handle_throughputs(self, event: ThroughputsEvent) -> None:
         if event.session_id != self.session_id:
             logging.warning(
@@ -269,6 +287,9 @@ class CoreClient:
         logging.debug("handling throughputs event: %s", event)
         self.app.after(0, self.app.canvas.set_throughputs, event)
 
+    def handle_cpu_event(self, event: CpuUsageEvent) -> None:
+        self.app.after(0, self.app.statusbar.set_cpu, event.usage)
+
     def handle_exception_event(self, event: ExceptionEvent) -> None:
         logging.info("exception event: %s", event)
         self.app.statusbar.add_alert(event)
@@ -479,6 +500,8 @@ class CoreClient:
         """
         try:
             self.client.connect()
+            self.setup_cpu_usage()
+
             # get service information
             response = self.client.get_services()
             for service in response.services:

daemon/core/gui/statusbar.py

@@ -1,10 +1,7 @@
 """
 status bar
 """
-import sched
 import tkinter as tk
-from pathlib import Path
-from threading import Thread
 from tkinter import ttk
 from typing import TYPE_CHECKING, List, Optional
 
@@ -16,41 +13,6 @@ if TYPE_CHECKING:
     from core.gui.app import Application
 
 
-class CpuUsage:
-    def __init__(self, statusbar: "StatusBar") -> None:
-        self.scheduler: sched.scheduler = sched.scheduler()
-        self.running: bool = False
-        self.thread: Optional[Thread] = None
-        self.prev_idle: int = 0
-        self.prev_total: int = 0
-        self.stat_file: Path = Path("/proc/stat")
-        self.statusbar: "StatusBar" = statusbar
-
-    def start(self) -> None:
-        self.running = True
-        self.thread = Thread(target=self._start, daemon=True)
-        self.thread.start()
-
-    def _start(self):
-        self.scheduler.enter(0, 0, self.run)
-        self.scheduler.run()
-
-    def run(self) -> None:
-        lines = self.stat_file.read_text().splitlines()[0]
-        values = [int(x) for x in lines.split()[1:]]
-        idle = sum(values[3:5])
-        non_idle = sum(values[:3] + values[5:8])
-        total = idle + non_idle
-        total_diff = total - self.prev_total
-        idle_diff = idle - self.prev_idle
-        cpu_percent = (total_diff - idle_diff) / total_diff
-        self.statusbar.after(0, self.statusbar.set_cpu, cpu_percent)
-        self.prev_idle = idle
-        self.prev_total = total
-        if self.running:
-            self.scheduler.enter(3, 0, self.run)
-
-
 class StatusBar(ttk.Frame):
     def __init__(self, master: tk.Widget, app: "Application") -> None:
         super().__init__(master)
@@ -64,8 +26,6 @@ class StatusBar(ttk.Frame):
         self.running: bool = False
         self.core_alarms: List[ExceptionEvent] = []
         self.draw()
-        self.cpu_usage: CpuUsage = CpuUsage(self)
-        self.cpu_usage.start()
 
     def draw(self) -> None:
         self.columnconfigure(0, weight=7)

daemon/core/gui/toolbar.py

@@ -305,10 +305,11 @@ class Toolbar(ttk.Frame):
             self.set_runtime()
             self.app.core.set_metadata()
             self.app.core.show_mobility_players()
-        elif response.exceptions:
+        else:
             enable_buttons(self.design_frame, enabled=True)
-            message = "\n".join(response.exceptions)
-            self.app.show_error("Start Session Error", message)
+            if response.exceptions:
+                message = "\n".join(response.exceptions)
+                self.app.show_error("Start Session Error", message)
 
     def set_runtime(self) -> None:
         enable_buttons(self.runtime_frame, enabled=True)