Mercurial > hg
view mercurial/exewrapper.c @ 49232:4c57ce494a4e
worker: stop relying on garbage collection to release memoryview
On CPython, before resizing the bytearray, all memoryviews referencing it must
be released. Before this change, we ensured that all references to them were
deleted. On CPython, this was enough to set the reference count to zero, which
results in garbage collecting and releasing them.
On PyPy, releasing the memoryviews is not necessary because they are implemented
differently. If it would be necessary however, ensuring that all references are
deleted would not be suffient because PyPy doesn’t use reference counting.
By using with statements that take care of releasing the memoryviews, we ensure
that the bytearray is resizable without relying on implementation details. So
while this doesn’t fix any observable bug, it increases compatiblity with other
and future Python implementations.
author | Manuel Jacob <me@manueljacob.de> |
---|---|
date | Sat, 21 May 2022 23:31:30 +0200 |
parents | 2ec5fbe26659 |
children |
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/* 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 <Python.h> #include <stdio.h> #include <tchar.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); } #define _tcscpy_s strcpy_s #define _tcscat_s strcat_s #define _countof(array) (sizeof(array) / sizeof(array[0])) #endif static TCHAR pyscript[MAX_PATH + 10]; static TCHAR pyhome[MAX_PATH + 10]; static TCHAR pydllfile[MAX_PATH + 10]; int _tmain(int argc, TCHAR *argv[]) { TCHAR *p; int ret; int i; int n; TCHAR **pyargv; WIN32_FIND_DATA fdata; HANDLE hfind; const char *err; HMODULE pydll; void(__cdecl * Py_SetPythonHome)(TCHAR * home); int(__cdecl * Py_Main)(int argc, TCHAR *argv[]); #if PY_MAJOR_VERSION >= 3 _wputenv(L"PYTHONLEGACYWINDOWSSTDIO=1"); #endif if (GetModuleFileName(NULL, pyscript, _countof(pyscript)) == 0) { err = "GetModuleFileName failed"; goto bail; } p = _tcsrchr(pyscript, '.'); if (p == NULL) { err = "malformed module filename"; goto bail; } *p = 0; /* cut trailing ".exe" */ _tcscpy_s(pyhome, _countof(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 */ _tcscat_s(pyscript, _countof(pyscript), _T("exe.py")); } pydll = NULL; p = _tcsrchr(pyhome, _T('\\')); if (p == NULL) { err = "can't find backslash in module filename"; goto bail; } *p = 0; /* cut at directory */ /* check for private Python of HackableMercurial */ _tcscat_s(pyhome, _countof(pyhome), _T("\\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); _tcscpy_s(pydllfile, _countof(pydllfile), pyhome); _tcscat_s(pydllfile, _countof(pydllfile), _T("\\") _T(HGPYTHONLIB) _T(".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(_T(HGPYTHONLIB) _T(".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 && _tcscmp(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(TCHAR *)); 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; }