[PATCH v4 05/15] mingw: use real pid
- From
Erik Faye-Lund <kusmabite@gmail.com>
- Date
- Oct 11, 2010, 21:50 UTC
- Message-ID
- <1286833829-5116-6-git-send-email-kusmabite@gmail.com>
- In-Reply-To
- <1286833829-5116-1-git-send-email-kusmabite@gmail.com>
The Windows port have so far been using process handles in place of PID. However, this is not work consistent with what getpid returns.
PIDs are system-global identifiers, but process handles are local to a process. Using PIDs instead of process handles allows, for instance, a user to kill a hung process with the Task Manager, something that would have been impossible with process handles.
Change the code to use the real PID, and use OpenProcess to get a process-handle. Store the PID and the process handle in a table protected by a critical section, so we can safely close the process handle later.
Signed-off-by: Erik Faye-Lund <kusmabite@gmail.com> --- compat/mingw.c | 70 +++++++++++++++++++++++++++++++++++++++++++++++++++++++- compat/mingw.h | 10 ++----- 2 files changed, 72 insertions(+), 8 deletions(-)
diff --git a/compat/mingw.c b/compat/mingw.c index 701a555..e2e3c54 100644 --- a/compat/mingw.c +++ b/compat/mingw.c @@ -702,6 +702,13 @@ static int env_compare(const void *a, const void *b) return strcasecmp(*ea, *eb); } +struct { + pid_t pid; + HANDLE proc; +} *pinfo; +static int num_pinfo; +CRITICAL_SECTION pinfo_cs; + static pid_t mingw_spawnve_fd(const char *cmd, const char **argv, char **env, const char *dir, int prepend_cmd, int fhin, int fhout, int fherr) @@ -794,7 +801,23 @@ static pid_t mingw_spawnve_fd(const char *cmd, const char **argv, char **env, return -1; } CloseHandle(pi.hThread); - return (pid_t)pi.hProcess; + + /* + * The process ID is the human-readable identifier of the process + * that we want to present in log and error messages. The handle + * is not useful for this purpose. But we cannot close it, either, + * because it is not possible to turn a process ID into a process + * handle after the process terminated. + * Keep the handle in a list for waitpid. + */ + EnterCriticalSection(&pinfo_cs); + num_pinfo++; + pinfo = xrealloc(pinfo, sizeof(*pinfo) * num_pinfo); + pinfo[num_pinfo - 1].pid = pi.dwProcessId; + pinfo[num_pinfo - 1].proc = pi.hProcess; + LeaveCriticalSection(&pinfo_cs); + + return (pid_t)pi.dwProcessId; } static pid_t mingw_spawnve(const char *cmd, const char **argv, char **env, @@ -1518,6 +1541,51 @@ char *getpass(const char *prompt) return strbuf_detach(&buf, NULL); } +pid_t waitpid(pid_t pid, int *status, unsigned options) +{ + HANDLE h = OpenProcess(SYNCHRONIZE | PROCESS_QUERY_INFORMATION, + FALSE, pid); + if (!h) { + errno = ECHILD; + return -1; + } + + if (options == 0) { + int i; + if (WaitForSingleObject(h, INFINITE) != WAIT_OBJECT_0) { + CloseHandle(h); + return 0; + } + + if (status) + GetExitCodeProcess(h, (LPDWORD)status); + + EnterCriticalSection(&pinfo_cs); + + for (i = 0; i < num_pinfo; ++i) + if (pinfo[i].pid == pid) + break; + + if (i < num_pinfo) { + CloseHandle(pinfo[i].proc); + memmove(pinfo + i, pinfo + i + 1, + sizeof(*pinfo) * (num_pinfo - i - 1)); + num_pinfo--; + pinfo = xrealloc(pinfo, + sizeof(*pinfo) * num_pinfo); + } + + LeaveCriticalSection(&pinfo_cs); + + CloseHandle(h); + return pid; + } + CloseHandle(h); + + errno = EINVAL; + return -1; +} + #ifndef NO_MINGW_REPLACE_READDIR /* MinGW readdir implementation to avoid extra lstats for Git */ struct mingw_DIR diff --git a/compat/mingw.h b/compat/mingw.h index a5bde82..7c4eeea 100644 --- a/compat/mingw.h +++ b/compat/mingw.h @@ -140,13 +140,7 @@ static inline int mingw_unlink(const char *pathname) } #define unlink mingw_unlink -static inline pid_t waitpid(pid_t pid, int *status, unsigned options) -{ - if (options == 0) - return _cwait(status, pid, 0); - errno = EINVAL; - return -1; -} +pid_t waitpid(pid_t pid, int *status, unsigned options); #ifndef NO_OPENSSL #include <openssl/ssl.h> @@ -321,11 +315,13 @@ void free_environ(char **env); static int mingw_main(); \ int main(int argc, const char **argv) \ { \ + extern CRITICAL_SECTION pinfo_cs; \ _fmode = _O_BINARY; \ _setmode(_fileno(stdin), _O_BINARY); \ _setmode(_fileno(stdout), _O_BINARY); \ _setmode(_fileno(stderr), _O_BINARY); \ argv[0] = xstrdup(_pgmptr); \ + InitializeCriticalSection(&pinfo_cs); \ return mingw_main(argc, argv); \ } \ static int mingw_main(c,v)
-- 1.7.3.1.199.g72340