view tests/killdaemons.py @ 30361:1070df141718

dirstate: change added/modified placeholder hash length to 20 bytes

Previously the added/modified placeholder hash for manifests generated from the
dirstate was a 21byte long string consisting of the p1 file hash plus a single
character to indicate an add or a modify. Normal hashes are only 20 bytes long.
This makes it complicated to implement more efficient manifest implementations
which rely on the hashes being fixed length.

Let's change this hash to just be 20 bytes long, and rely on the astronomical
improbability of an actual hash being these 20 bytes (just like we rely on no
hash every being the nullid).

This changes the possible behavior slightly in that the hash for all
added/modified entries in the dirstate manifest will now be the same (so simple
node comparisons would say they are equal), but we should never be doing simple
node comparisons on these nodes even with the old hashes, because they did not
accurately represent the content (i.e. two files based off the same p1 file
node, with different working copy contents would have the same hash (even with
the appended character) in the old scheme too, so we couldn't depend on the
hashes period).

#!/usr/bin/env python

from __future__ import absolute_import
import errno
import os
import signal
import sys
import time

if os.name =='nt':
    import ctypes

    def _check(ret, expectederr=None):
        if ret == 0:
            winerrno = ctypes.GetLastError()
            if winerrno == expectederr:
                return True
            raise ctypes.WinError(winerrno)

    def kill(pid, logfn, tryhard=True):
        logfn('# Killing daemon process %d' % pid)
        PROCESS_TERMINATE = 1
        PROCESS_QUERY_INFORMATION = 0x400
        SYNCHRONIZE = 0x00100000
        WAIT_OBJECT_0 = 0
        WAIT_TIMEOUT = 258
        handle = ctypes.windll.kernel32.OpenProcess(
                PROCESS_TERMINATE|SYNCHRONIZE|PROCESS_QUERY_INFORMATION,
                False, pid)
        if handle == 0:
            _check(0, 87) # err 87 when process not found
            return # process not found, already finished
        try:
            r = ctypes.windll.kernel32.WaitForSingleObject(handle, 100)
            if r == WAIT_OBJECT_0:
                pass # terminated, but process handle still available
            elif r == WAIT_TIMEOUT:
                _check(ctypes.windll.kernel32.TerminateProcess(handle, -1))
            else:
                _check(r)

            # TODO?: forcefully kill when timeout
            #        and ?shorter waiting time? when tryhard==True
            r = ctypes.windll.kernel32.WaitForSingleObject(handle, 100)
                                                       # timeout = 100 ms
            if r == WAIT_OBJECT_0:
                pass # process is terminated
            elif r == WAIT_TIMEOUT:
                logfn('# Daemon process %d is stuck')
            else:
                _check(r) # any error
        except: #re-raises
            ctypes.windll.kernel32.CloseHandle(handle) # no _check, keep error
            raise
        _check(ctypes.windll.kernel32.CloseHandle(handle))

else:
    def kill(pid, logfn, tryhard=True):
        try:
            os.kill(pid, 0)
            logfn('# Killing daemon process %d' % pid)
            os.kill(pid, signal.SIGTERM)
            if tryhard:
                for i in range(10):
                    time.sleep(0.05)
                    os.kill(pid, 0)
            else:
                time.sleep(0.1)
                os.kill(pid, 0)
            logfn('# Daemon process %d is stuck - really killing it' % pid)
            os.kill(pid, signal.SIGKILL)
        except OSError as err:
            if err.errno != errno.ESRCH:
                raise

def killdaemons(pidfile, tryhard=True, remove=False, logfn=None):
    if not logfn:
        logfn = lambda s: s
    # Kill off any leftover daemon processes
    try:
        fp = open(pidfile)
        for line in fp:
            try:
                pid = int(line)
                if pid <= 0:
                    raise ValueError
            except ValueError:
                logfn('# Not killing daemon process %s - invalid pid'
                      % line.rstrip())
                continue
            kill(pid, logfn, tryhard)
        fp.close()
        if remove:
            os.unlink(pidfile)
    except IOError:
        pass

if __name__ == '__main__':
    if len(sys.argv) > 1:
        path, = sys.argv[1:]
    else:
        path = os.environ["DAEMON_PIDS"]

    killdaemons(path)