scripts: natively scan mtrace file and adjust inactivity timeouts

Refactor the runner to open a concurrent file descriptor against the ace-mtrace file, instantly scanning it for 'halting system' messages instead of relying on delayed filesystem mtime. Timeout is extended to 5 seconds to gracefully account for the initial Zephyr banner loading gap.

Signed-off-by: Liam Girdwood <liam.r.girdwood@linux.intel.com>

Author: lrgirdwo

scripts/sof-qemu-run.py

@@ -18,16 +18,7 @@
 import os
 import time
 
-def check_external_logs_active(rcmd):
-    files_to_check = []
-    if "QEMU_ACE_MTRACE_FILE" in os.environ:
-        files_to_check.append(os.environ["QEMU_ACE_MTRACE_FILE"])
-        
-    for fp in files_to_check:
-        if os.path.isfile(fp):
-            if time.time() - os.path.getmtime(fp) < 2.0:
-                return True
-    return False
+
 
 import re
 
@@ -56,7 +47,8 @@ def check_for_crash(output):
         "Exception",
         "PC=",  # QEMU PC output format
         "EXCCAUSE=",
-        "Backtrace:"
+        "Backtrace:",
+        "halting system"
     ]
     for keyword in crash_keywords:
         if keyword in output:
@@ -229,12 +221,17 @@ def main():
         # Suffix distinct files appropriately if chained
         active_log = args.log_file + (f".{idx}" if len(runs) > 1 else "")
 
+        mtrace_file = os.environ.get("QEMU_ACE_MTRACE_FILE")
+        mtrace_fd = None
+        last_active_time = time.time()
+        
         with open(active_log, "w") as log_file:
             try:
                 while True:
                     try:
-                        index = child.expect([r'\r\n', pexpect.TIMEOUT, pexpect.EOF], timeout=2)
+                        index = child.expect([r'\r\n', pexpect.TIMEOUT, pexpect.EOF], timeout=0.5)
                         if index == 0:
+                            last_active_time = time.time()
                             line = child.before + '\n'
                             clean_line = re.sub(r'\x1B(?:[@-Z\\-_]|\[[0-?]*[ -/]*[@-~])', '', line)
                             log_file.write(clean_line)
@@ -245,23 +242,35 @@ def main():
                             sys.stdout.flush()
 
                             full_output += line
-                        elif index == 1: # TIMEOUT
-                            if check_external_logs_active(rcmd):
-                                continue
-                            print("\n\n[sof-qemu-run] 2 seconds passed since last log event. Checking status...")
-                            break
                         elif index == 2: # EOF
                             print("\n\n[sof-qemu-run] QEMU process terminated.")
                             break
 
                     except pexpect.TIMEOUT:
-                        if check_external_logs_active(rcmd):
-                            continue
-                        print("\n\n[sof-qemu-run] 2 seconds passed since last log event. Checking status...")
-                        break
+                        pass
                     except pexpect.EOF:
                         print("\n\n[sof-qemu-run] QEMU process terminated.")
                         break
+                        
+                    if mtrace_file and os.path.isfile(mtrace_file):
+                        if not mtrace_fd:
+                            try:
+                                mtrace_fd = open(mtrace_file, "r", encoding="utf-8", errors="ignore")
+                            except Exception:
+                                pass
+                        
+                        if mtrace_fd:
+                            new_data = mtrace_fd.read()
+                            if new_data:
+                                last_active_time = time.time()
+                                full_output += new_data
+                                if "halting system" in new_data:
+                                    print("\n\n[sof-qemu-run] Detected 'halting system' in mtrace log! Breaking...")
+                                    break
+                                    
+                    if time.time() - last_active_time >= 5.0:
+                        print("\n\n[sof-qemu-run] 5 seconds passed since last log event. Checking status...")
+                        break
 
             except KeyboardInterrupt:
                 print("\n[sof-qemu-run] Interrupted by user.")