/PC/VS8.0/kill_python.c

  1/*
  2 * Helper program for killing lingering python[_d].exe processes before
  3 * building, thus attempting to avoid build failures due to files being
  4 * locked.
  5 */
  6
  7#include <windows.h>
  8#include <wchar.h>
  9#include <tlhelp32.h>
 10#include <stdio.h>
 11
 12#pragma comment(lib, "psapi")
 13
 14#ifdef _DEBUG
 15#define PYTHON_EXE          (L"python_d.exe")
 16#define PYTHON_EXE_LEN      (12)
 17#define KILL_PYTHON_EXE     (L"kill_python_d.exe")
 18#define KILL_PYTHON_EXE_LEN (17)
 19#else
 20#define PYTHON_EXE          (L"python.exe")
 21#define PYTHON_EXE_LEN      (10)
 22#define KILL_PYTHON_EXE     (L"kill_python.exe")
 23#define KILL_PYTHON_EXE_LEN (15)
 24#endif
 25
 26int
 27main(int argc, char **argv)
 28{
 29    HANDLE   hp, hsp, hsm; /* process, snapshot processes, snapshot modules */
 30    DWORD    dac, our_pid;
 31    size_t   len;
 32    wchar_t  path[MAX_PATH+1];
 33
 34    MODULEENTRY32W  me;
 35    PROCESSENTRY32W pe;
 36
 37    me.dwSize = sizeof(MODULEENTRY32W);
 38    pe.dwSize = sizeof(PROCESSENTRY32W);
 39
 40    memset(path, 0, MAX_PATH+1);
 41
 42    our_pid = GetCurrentProcessId();
 43
 44    hsm = CreateToolhelp32Snapshot(TH32CS_SNAPMODULE, our_pid);
 45    if (hsm == INVALID_HANDLE_VALUE) {
 46        printf("CreateToolhelp32Snapshot[1] failed: %d\n", GetLastError());
 47        return 1;
 48    }
 49
 50    if (!Module32FirstW(hsm, &me)) {
 51        printf("Module32FirstW[1] failed: %d\n", GetLastError());
 52        CloseHandle(hsm);
 53        return 1;
 54    }
 55
 56    /*
 57     * Enumerate over the modules for the current process in order to find
 58     * kill_process[_d].exe, then take a note of the directory it lives in.
 59     */
 60    do {
 61        if (_wcsnicmp(me.szModule, KILL_PYTHON_EXE, KILL_PYTHON_EXE_LEN))
 62            continue;
 63
 64        len = wcsnlen_s(me.szExePath, MAX_PATH) - KILL_PYTHON_EXE_LEN;
 65        wcsncpy_s(path, MAX_PATH+1, me.szExePath, len); 
 66
 67        break;
 68
 69    } while (Module32NextW(hsm, &me));
 70
 71    CloseHandle(hsm);
 72
 73    if (path == NULL) {
 74        printf("failed to discern directory of running process\n");
 75        return 1;
 76    }
 77
 78    /*
 79     * Take a snapshot of system processes.  Enumerate over the snapshot,
 80     * looking for python processes.  When we find one, verify it lives
 81     * in the same directory we live in.  If it does, kill it.  If we're
 82     * unable to kill it, treat this as a fatal error and return 1.
 83     * 
 84     * The rationale behind this is that we're called at the start of the 
 85     * build process on the basis that we'll take care of killing any
 86     * running instances, such that the build won't encounter permission
 87     * denied errors during linking. If we can't kill one of the processes,
 88     * we can't provide this assurance, and the build shouldn't start.
 89     */
 90
 91    hsp = CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, 0);
 92    if (hsp == INVALID_HANDLE_VALUE) {
 93        printf("CreateToolhelp32Snapshot[2] failed: %d\n", GetLastError());
 94        return 1;
 95    }
 96
 97    if (!Process32FirstW(hsp, &pe)) {
 98        printf("Process32FirstW failed: %d\n", GetLastError());
 99        CloseHandle(hsp);
100        return 1;
101    }
102
103    dac = PROCESS_QUERY_INFORMATION | PROCESS_VM_READ | PROCESS_TERMINATE;
104    do {
105
106        /*
107         * XXX TODO: if we really wanted to be fancy, we could check the 
108         * modules for all processes (not just the python[_d].exe ones)
109         * and see if any of our DLLs are loaded (i.e. python30[_d].dll),
110         * as that would also inhibit our ability to rebuild the solution.
111         * Not worth loosing sleep over though; for now, a simple check 
112         * for just the python executable should be sufficient.
113         */
114
115        if (_wcsnicmp(pe.szExeFile, PYTHON_EXE, PYTHON_EXE_LEN))
116            /* This isn't a python process. */
117            continue;
118
119        /* It's a python process, so figure out which directory it's in... */
120        hsm = CreateToolhelp32Snapshot(TH32CS_SNAPMODULE, pe.th32ProcessID);
121        if (hsm == INVALID_HANDLE_VALUE)
122            /* 
123             * If our module snapshot fails (which will happen if we don't own
124             * the process), just ignore it and continue.  (It seems different
125             * versions of Windows return different values for GetLastError()
126             * in this situation; it's easier to just ignore it and move on vs.
127             * stopping the build for what could be a false positive.)
128             */
129             continue;
130
131        if (!Module32FirstW(hsm, &me)) {
132            printf("Module32FirstW[2] failed: %d\n", GetLastError());
133            CloseHandle(hsp);
134            CloseHandle(hsm);
135            return 1;
136        }
137
138        do {
139            if (_wcsnicmp(me.szModule, PYTHON_EXE, PYTHON_EXE_LEN))
140                /* Wrong module, we're looking for python[_d].exe... */
141                continue;
142
143            if (_wcsnicmp(path, me.szExePath, len))
144                /* Process doesn't live in our directory. */
145                break;
146
147            /* Python process residing in the right directory, kill it!  */
148            hp = OpenProcess(dac, FALSE, pe.th32ProcessID);
149            if (!hp) {
150                printf("OpenProcess failed: %d\n", GetLastError());
151                CloseHandle(hsp);
152                CloseHandle(hsm);
153                return 1;
154            }
155
156            if (!TerminateProcess(hp, 1)) {
157                printf("TerminateProcess failed: %d\n", GetLastError());
158                CloseHandle(hsp);
159                CloseHandle(hsm);
160                CloseHandle(hp);
161                return 1;
162            }
163
164            CloseHandle(hp);
165            break;
166
167        } while (Module32NextW(hsm, &me));
168
169        CloseHandle(hsm);
170
171    } while (Process32NextW(hsp, &pe));
172
173    CloseHandle(hsp);
174
175    return 0;
176}
177
178/* vi: set ts=8 sw=4 sts=4 expandtab */