[3.8] bpo-36670, regrtest: Fix WindowsLoadTracker() for partial line (GH-16550) by vstinner · Pull Request #16554 · python/cpython

@@ -14,7 +14,7 @@ LOAD_FACTOR_1 = 0.9200444146293232478931553241
# Seconds per measurement SAMPLING_INTERVAL = 5 SAMPLING_INTERVAL = 1 # Windows registry subkey of HKEY_LOCAL_MACHINE where the counter names # of typeperf are registered COUNTER_REGISTRY_KEY = (r"SOFTWARE\Microsoft\Windows NT\CurrentVersion" @@ -32,6 +32,7 @@ class WindowsLoadTracker(): def __init__(self): self.load = 0.0 self.counter_name = '' self._buffer = '' self.popen = None self.start()
@@ -94,42 +95,60 @@ def close(self): def __del__(self): self.close()
def read_output(self): def _parse_line(self, line): # typeperf outputs in a CSV format like this: # "07/19/2018 01:32:26.605","3.000000" # (date, process queue length) tokens = line.split(',') if len(tokens) != 2: raise ValueError
value = tokens[1] if not value.startswith('"') or not value.endswith('"'): raise ValueError value = value[1:-1] return float(value)
def read_lines(self): overlapped, _ = _winapi.ReadFile(self.pipe, BUFSIZE, True) bytes_read, res = overlapped.GetOverlappedResult(False) if res != 0: return return ()
output = overlapped.getbuffer() return output.decode('oem', 'replace') output = output.decode('oem', 'replace') output = self._buffer + output lines = output.splitlines(True)
# bpo-36670: typeperf only writes a newline *before* writing a value, # not after. Sometimes, the written line in incomplete (ex: only # timestamp, without the process queue length). Only pass the last line # to the parser if it's a valid value, otherwise store it in # self._buffer. try: self._parse_line(lines[-1]) except ValueError: self._buffer = lines.pop(-1) else: self._buffer = ''
return lines
def getloadavg(self): typeperf_output = self.read_output() # Nothing to update, just return the current load if not typeperf_output: return self.load for line in self.read_lines(): line = line.rstrip()
# Process the backlog of load values for line in typeperf_output.splitlines(): # Ignore the initial header: # "(PDH-CSV 4.0)","\\\\WIN\\System\\Processor Queue Length" if '\\\\' in line: if 'PDH-CSV' in line: continue
# Ignore blank lines if not line.strip(): if not line: continue
# typeperf outputs in a CSV format like this: # "07/19/2018 01:32:26.605","3.000000" # (date, process queue length) try: tokens = line.split(',') if len(tokens) != 2: raise ValueError
value = tokens[1].replace('"', '') load = float(value) load = self._parse_line(line) except ValueError: print_warning("Failed to parse typeperf output: %a" % line) continue