Debugger: Do not waste CPU when using LLDB

Fixes: QTCREATORBUG-23311
Change-Id: I5b1c40663c7977322e806af2e0393a3730e70049
Reviewed-by: hjk <hjk@qt.io>

2 files changed, 10 insertions, 5 deletions

diff --git a/share/qtcreator/debugger/lldbbridge.py b/share/qtcreator/debugger/lldbbridge.py
index 689753a800..bfea3b04c0 100644
--- a/share/qtcreator/debugger/lldbbridge.py
+++ b/share/qtcreator/debugger/lldbbridge.py
@@ -29,6 +29,7 @@ import platform
 import re
 import sys
 import threading
+import time
 import lldb
 
 from contextlib import contextmanager
@@ -953,14 +954,16 @@ class Dumper(DumperBase):
 
     def loop(self):
         event = lldb.SBEvent()
-        broadcaster = self.target.GetBroadcaster()
+        #broadcaster = self.target.GetBroadcaster()
         listener = self.debugger.GetListener()
+
         while True:
-            sys.stdout.flush() # IMPORTANT! to receive process state changes with lldb 1100
             while listener.GetNextEvent(event):
                 self.handleEvent(event)
-            if listener.WaitForEventForBroadcaster(0, broadcaster, event):
-                self.handleEvent(event)
+            time.sleep(0.25)
+
+            #if listener.WaitForEventForBroadcaster(0, broadcaster, event):
+            #    self.handleEvent(event)
 
 
     def describeError(self, error):
diff --git a/src/plugins/debugger/lldb/lldbengine.cpp b/src/plugins/debugger/lldb/lldbengine.cpp
index f75c491d5d..318944f4dc 100644
--- a/src/plugins/debugger/lldb/lldbengine.cpp
+++ b/src/plugins/debugger/lldb/lldbengine.cpp
@@ -203,7 +203,9 @@ void LldbEngine::setupEngine()
     const FilePath lldbCmd = runParameters().debugger.executable;
 
     showMessage("STARTING LLDB: " + lldbCmd.toUserOutput());
-    m_lldbProc.setEnvironment(runParameters().debugger.environment);
+    Environment environment = runParameters().debugger.environment;
+    environment.appendOrSet("PYTHONUNBUFFERED", "1");  // avoid flushing problem on macOS
+    m_lldbProc.setEnvironment(environment);
     if (QFileInfo(runParameters().debugger.workingDirectory).isDir())
         m_lldbProc.setWorkingDirectory(runParameters().debugger.workingDirectory);