Mercurial > hg
view mercurial/exewrapper.c @ 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 | 31c6c4d27be7 |
children | aca727359ec5 |
line wrap: on
line source
/* exewrapper.c - wrapper for calling a python script on Windows Copyright 2012 Adrian Buehlmann <adrian@cadifra.com> and others This software may be used and distributed according to the terms of the GNU General Public License version 2 or any later version. */ #include <stdio.h> #include <windows.h> #include "hgpythonlib.h" #ifdef __GNUC__ int strcat_s(char *d, size_t n, const char *s) { return !strncat(d, s, n); } int strcpy_s(char *d, size_t n, const char *s) { return !strncpy(d, s, n); } #endif static char pyscript[MAX_PATH + 10]; static char pyhome[MAX_PATH + 10]; static char envpyhome[MAX_PATH + 10]; static char pydllfile[MAX_PATH + 10]; int main(int argc, char *argv[]) { char *p; int ret; int i; int n; char **pyargv; WIN32_FIND_DATA fdata; HANDLE hfind; const char *err; HMODULE pydll; void(__cdecl * Py_SetPythonHome)(char *home); int(__cdecl * Py_Main)(int argc, char *argv[]); if (GetModuleFileName(NULL, pyscript, sizeof(pyscript)) == 0) { err = "GetModuleFileName failed"; goto bail; } p = strrchr(pyscript, '.'); if (p == NULL) { err = "malformed module filename"; goto bail; } *p = 0; /* cut trailing ".exe" */ strcpy_s(pyhome, sizeof(pyhome), pyscript); hfind = FindFirstFile(pyscript, &fdata); if (hfind != INVALID_HANDLE_VALUE) { /* pyscript exists, close handle */ FindClose(hfind); } else { /* file pyscript isn't there, take <pyscript>exe.py */ strcat_s(pyscript, sizeof(pyscript), "exe.py"); } pydll = NULL; p = strrchr(pyhome, '\\'); if (p == NULL) { err = "can't find backslash in module filename"; goto bail; } *p = 0; /* cut at directory */ /* check for private Python of HackableMercurial */ strcat_s(pyhome, sizeof(pyhome), "\\hg-python"); hfind = FindFirstFile(pyhome, &fdata); if (hfind != INVALID_HANDLE_VALUE) { /* Path .\hg-python exists. We are probably in HackableMercurial scenario, so let's load python dll from this dir. */ FindClose(hfind); strcpy_s(pydllfile, sizeof(pydllfile), pyhome); strcat_s(pydllfile, sizeof(pydllfile), "\\" HGPYTHONLIB ".dll"); pydll = LoadLibrary(pydllfile); if (pydll == NULL) { err = "failed to load private Python DLL " HGPYTHONLIB ".dll"; goto bail; } Py_SetPythonHome = (void *)GetProcAddress(pydll, "Py_SetPythonHome"); if (Py_SetPythonHome == NULL) { err = "failed to get Py_SetPythonHome"; goto bail; } Py_SetPythonHome(pyhome); } if (pydll == NULL) { pydll = LoadLibrary(HGPYTHONLIB ".dll"); if (pydll == NULL) { err = "failed to load Python DLL " HGPYTHONLIB ".dll"; goto bail; } } Py_Main = (void *)GetProcAddress(pydll, "Py_Main"); if (Py_Main == NULL) { err = "failed to get Py_Main"; goto bail; } /* Only add the pyscript to the args, if it's not already there. It may already be there, if the script spawned a child process of itself, in the same way as it got called, that is, with the pyscript already in place. So we optionally accept the pyscript as the first argument (argv[1]), letting our exe taking the role of the python interpreter. */ if (argc >= 2 && strcmp(argv[1], pyscript) == 0) { /* pyscript is already in the args, so there is no need to copy the args and we can directly call the python interpreter with the original args. */ return Py_Main(argc, argv); } /* Start assembling the args for the Python interpreter call. We put the name of our exe (argv[0]) in the position where the python.exe canonically is, and insert the pyscript next. */ pyargv = malloc((argc + 5) * sizeof(char *)); if (pyargv == NULL) { err = "not enough memory"; goto bail; } n = 0; pyargv[n++] = argv[0]; pyargv[n++] = pyscript; /* copy remaining args from the command line */ for (i = 1; i < argc; i++) pyargv[n++] = argv[i]; /* argv[argc] is guaranteed to be NULL, so we forward that guarantee */ pyargv[n] = NULL; ret = Py_Main(n, pyargv); /* The Python interpreter call */ free(pyargv); return ret; bail: fprintf(stderr, "abort: %s\n", err); return 255; }