view tests/killdaemons.py @ 47072:4c041c71ec01

revlog: introduce an explicit tracking of what the revlog is about

Since the dawn of time, people have been forced to rely to lossy introspection
of the index filename to determine what the purpose and role of the revlog they
encounter is. This is hacky, error prone, inflexible, abstraction-leaky,
<insert-your-own-complaints-here>.

In f63299ee7e4d Raphaël introduced a new attribute to track this information:
`revlog_kind`. However it is initialized in an odd place and various instances
end up not having it set. In addition is only tracking some of the information
we end up having to introspect in various pieces of code.

So we add a new attribute that holds more data and is more strictly enforced.
This work is done in collaboration with Raphaël.

The `revlog_kind` one will be removed/adapted in the next changeset. We expect
to be able to clean up various existing piece of code and to simplify coming
work around the newer revlog format.

Differential Revision: https://phab.mercurial-scm.org/D10352

#!/usr/bin/env python3

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

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

    _BOOL = ctypes.c_long
    _DWORD = ctypes.c_ulong
    _UINT = ctypes.c_uint
    _HANDLE = ctypes.c_void_p

    ctypes.windll.kernel32.CloseHandle.argtypes = [_HANDLE]
    ctypes.windll.kernel32.CloseHandle.restype = _BOOL

    ctypes.windll.kernel32.GetLastError.argtypes = []
    ctypes.windll.kernel32.GetLastError.restype = _DWORD

    ctypes.windll.kernel32.OpenProcess.argtypes = [_DWORD, _BOOL, _DWORD]
    ctypes.windll.kernel32.OpenProcess.restype = _HANDLE

    ctypes.windll.kernel32.TerminateProcess.argtypes = [_HANDLE, _UINT]
    ctypes.windll.kernel32.TerminateProcess.restype = _BOOL

    ctypes.windll.kernel32.WaitForSingleObject.argtypes = [_HANDLE, _DWORD]
    ctypes.windll.kernel32.WaitForSingleObject.restype = _DWORD

    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
        WAIT_FAILED = _DWORD(0xFFFFFFFF).value
        handle = ctypes.windll.kernel32.OpenProcess(
            PROCESS_TERMINATE | SYNCHRONIZE | PROCESS_QUERY_INFORMATION,
            False,
            pid,
        )
        if handle is None:
            _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))
            elif r == WAIT_FAILED:
                _check(0)  # err stored in GetLastError()

            # 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')
            elif r == WAIT_FAILED:
                _check(0)  # err stored in GetLastError()
        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:
        pids = []
        with open(pidfile) as fp:
            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
                pids.append(pid)
        for pid in pids:
            kill(pid, logfn, tryhard)
        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, remove=True)