tests/killdaemons.py

fncache: move fncache writing to be in a transaction

Previously the fncache was written at lock.release time. This meant it was not
tracked by a transaction, and if an error occurred during the fncache write it
would fail to update the fncache, but would not rollback the transaction,
resulting in an fncache that was not in sync with the files on disk (which
causes verify to fail, and causes streaming clones to not copy all the revlogs).

This uses the new transaction backup mechanism to make the fncache transacted.
It also moves the fncache from being written at lock.release time, to being
written at transaction.close time.

#!/usr/bin/env python

import os, sys, time, errno, signal

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, 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)
            except ValueError:
                continue
            kill(pid, logfn, tryhard)
        fp.close()
        if remove:
            os.unlink(pidfile)
    except IOError:
        pass

if __name__ == '__main__':
    path, = sys.argv[1:]
    killdaemons(path)