Mercurial > hg
view mercurial/cffi/osutil.py @ 35460:8652ab4046e4
osutil: add a function to unblock signals
Signals could be blocked by something like:
#include <unistd.h>
#include <signal.h>
int main(int argc, char * const argv[]) {
sigset_t set;
sigfillset(&set);
sigprocmask(SIG_BLOCK, &set, NULL);
execv("/bin/hg", argv);
return 0;
}
One of the problems is if SIGCHLD is blocked, chgserver would not reap
zombie workers since it depends on SIGCHLD handler entirely.
While it's the parent process to blame but it seems a good idea to just
unblock the signal from hg. FWIW git does that for SIGPIPE already [1].
Unfortunately Python 2 does not reset or provide APIs to change signal
masks. Therefore let's add one in osutil. Note: Python 3.3 introduced
`signal.pthread_sigmask` which solves the problem.
`sigprocmask` is part of POSIX [2] so there is no feature testing in
`setup.py`.
[1]: https://github.com/git/git/commit/7559a1be8a0afb10df41d25e4cf4c5285a5faef1
[2]: http://pubs.opengroup.org/onlinepubs/7908799/xsh/sigprocmask.html
Differential Revision: https://phab.mercurial-scm.org/D1736
author | Jun Wu <quark@fb.com> |
---|---|
date | Wed, 20 Dec 2017 02:13:35 -0800 |
parents | dacfcdd8b94e |
children | 2372284d9457 |
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line source
# osutil.py - CFFI version of osutil.c # # Copyright 2016 Maciej Fijalkowski <fijall@gmail.com> # # This software may be used and distributed according to the terms of the # GNU General Public License version 2 or any later version. from __future__ import absolute_import import os import stat as statmod from ..pure.osutil import * from .. import ( pycompat, ) if pycompat.isdarwin: from . import _osutil ffi = _osutil.ffi lib = _osutil.lib listdir_batch_size = 4096 # tweakable number, only affects performance, which chunks # of bytes do we get back from getattrlistbulk attrkinds = [None] * 20 # we need the max no for enum VXXX, 20 is plenty attrkinds[lib.VREG] = statmod.S_IFREG attrkinds[lib.VDIR] = statmod.S_IFDIR attrkinds[lib.VLNK] = statmod.S_IFLNK attrkinds[lib.VBLK] = statmod.S_IFBLK attrkinds[lib.VCHR] = statmod.S_IFCHR attrkinds[lib.VFIFO] = statmod.S_IFIFO attrkinds[lib.VSOCK] = statmod.S_IFSOCK class stat_res(object): def __init__(self, st_mode, st_mtime, st_size): self.st_mode = st_mode self.st_mtime = st_mtime self.st_size = st_size tv_sec_ofs = ffi.offsetof("struct timespec", "tv_sec") buf = ffi.new("char[]", listdir_batch_size) def listdirinternal(dfd, req, stat, skip): ret = [] while True: r = lib.getattrlistbulk(dfd, req, buf, listdir_batch_size, 0) if r == 0: break if r == -1: raise OSError(ffi.errno, os.strerror(ffi.errno)) cur = ffi.cast("val_attrs_t*", buf) for i in range(r): lgt = cur.length assert lgt == ffi.cast('uint32_t*', cur)[0] ofs = cur.name_info.attr_dataoffset str_lgt = cur.name_info.attr_length base_ofs = ffi.offsetof('val_attrs_t', 'name_info') name = str(ffi.buffer(ffi.cast("char*", cur) + base_ofs + ofs, str_lgt - 1)) tp = attrkinds[cur.obj_type] if name == "." or name == "..": continue if skip == name and tp == statmod.S_ISDIR: return [] if stat: mtime = cur.mtime.tv_sec mode = (cur.accessmask & ~lib.S_IFMT)| tp ret.append((name, tp, stat_res(st_mode=mode, st_mtime=mtime, st_size=cur.datalength))) else: ret.append((name, tp)) cur = ffi.cast("val_attrs_t*", int(ffi.cast("intptr_t", cur)) + lgt) return ret def listdir(path, stat=False, skip=None): req = ffi.new("struct attrlist*") req.bitmapcount = lib.ATTR_BIT_MAP_COUNT req.commonattr = (lib.ATTR_CMN_RETURNED_ATTRS | lib.ATTR_CMN_NAME | lib.ATTR_CMN_OBJTYPE | lib.ATTR_CMN_ACCESSMASK | lib.ATTR_CMN_MODTIME) req.fileattr = lib.ATTR_FILE_DATALENGTH dfd = lib.open(path, lib.O_RDONLY, 0) if dfd == -1: raise OSError(ffi.errno, os.strerror(ffi.errno)) try: ret = listdirinternal(dfd, req, stat, skip) finally: try: lib.close(dfd) except BaseException: pass # we ignore all the errors from closing, not # much we can do about that return ret