Enable fd 1,2,3 in child.py (#1013)

Co-authored-by: yuxuan-ms <[email protected]>

testplan/runners/pools/child.py

@@ -92,27 +92,22 @@ def _setup_logfiles(self):
         if not os.path.exists(self.runpath):
             os.makedirs(self.runpath)
 
-        stderr_file = os.path.join(
-            self.runpath, f"{self._metadata['index']}_stderr"
-        )
-        log_file = os.path.join(
+        stdout_file = os.path.join(
             self.runpath, f"{self._metadata['index']}_stdout"
         )
-        self.logger.info(
-            "stdout file = %(file)s (log level = %(lvl)s)",
-            {"file": log_file, "lvl": self.logger.level},
+        stderr_file = os.path.join(
+            self.runpath, f"{self._metadata['index']}_stderr"
         )
+        log_file = os.path.join(self.runpath, f"{self._metadata['index']}_log")
+        self.logger.info("stdout file = %s", stdout_file)
         self.logger.info("stderr file = %s", stderr_file)
         self.logger.info(
-            "Closing stdin, stdout and stderr file descriptors..."
+            "log file = %(file)s (log level = %(lvl)s)",
+            {"file": log_file, "lvl": self.logger.level},
         )
 
-        # This closes stdin, stdout and stderr for this process.
-        for fdesc in range(3):
-            os.close(fdesc)
-        mode = "w" if platform.python_version().startswith("3") else "wb"
-
-        sys.stderr = open(stderr_file, mode)
+        sys.stderr = open(stderr_file, "w")
+        sys.stdout = open(stdout_file, "w")
         fhandler = logging.FileHandler(log_file, encoding="utf-8")
 
         formatter = logging.Formatter(LOGFILE_FORMAT)