utils: Extract wait_for_file_by_prefix()

gprofiler/python.py

@@ -26,6 +26,7 @@
     run_process,
     start_process,
     wait_event,
+    wait_for_file_by_prefix,
 )
 
 logger = logging.getLogger(__name__)
@@ -217,24 +218,13 @@ def start(self):
         else:
             self.process = process
 
-    def _glob_output(self) -> List[str]:
-        # important to not grab the transient data file
-        return glob.glob(f"{str(self.output_path)}.*")
-
-    def _wait_for_output_file(self, timeout: float) -> Path:
-        wait_event(timeout, self._stop_event, lambda: len(self._glob_output()) > 0)
-
-        output_files = self._glob_output()
-        # All the snapshot samples should be in one file
-        assert len(output_files) == 1
-        return Path(output_files[0])
-
     def _dump(self) -> Path:
         assert self.process is not None, "profiling not started!"
         self.process.send_signal(self.dump_signal)
 
         try:
-            output = self._wait_for_output_file(self.dump_timeout)
+            # important to not grab the transient data file - hence the following '.'
+            output = wait_for_file_by_prefix(f"{self.output_path}.", self.dump_timeout, self._stop_event)
             # PyPerf outputs sampling & error counters every interval (after writing the output file), print them.
             # also, makes sure its output pipe doesn't fill up.
             # using read1() which performs just a single read() call and doesn't read until EOF

gprofiler/utils.py

@@ -6,6 +6,7 @@
 import datetime
 import errno
 import fcntl
+import glob
 import logging
 import os
 import platform
@@ -127,6 +128,16 @@ def poll_process(process, timeout: float, stop_event: Event):
         raise
 
 
+def wait_for_file_by_prefix(prefix: str, timeout: float, stop_event: Event) -> Path:
+    glob_pattern = f"{prefix}*"
+    wait_event(timeout, stop_event, lambda: len(glob.glob(glob_pattern)) > 0)
+
+    output_files = glob.glob(glob_pattern)
+    # All the snapshot samples should be in one file
+    assert len(output_files) == 1
+    return Path(output_files[0])
+
+
 def run_process(
     cmd: Union[str, List[str]],
     stop_event: Event = None,