mingw: use real pid
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 linked list protected by a critical section, so we can safely close the process handle later. Linked list code written by Pat Thoyts. Signed-off-by: Erik Faye-Lund <kusmabite@gmail.com> Signed-off-by: Pat Thoyts <patthoyts@users.sourceforge.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Erik Faye-Lund committed
Nov 4, 2010 at 02:35 UTC
52de4db57977175c5ad1d6c3922e772d6de08496
2 files changed
+75
-8
compat/mingw.c
+72
-1
@@ -702,6 +702,14 @@ static int env_compare(const void *a, const void *b)
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return strcasecmp(*ea, *eb);
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}
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+struct pinfo_t {
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+ struct pinfo_t *next;
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+ pid_t pid;
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+ HANDLE proc;
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+} pinfo_t;
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+struct pinfo_t *pinfo = NULL;
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+CRITICAL_SECTION pinfo_cs;
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+
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static pid_t mingw_spawnve_fd(const char *cmd, const char **argv, char **env,
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const char *dir,
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int prepend_cmd, int fhin, int fhout, int fherr)
@@ -794,7 +802,26 @@ static pid_t mingw_spawnve_fd(const char *cmd, const char **argv, char **env,
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return -1;
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}
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CloseHandle(pi.hThread);
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- return (pid_t)pi.hProcess;
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+
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+ /*
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+ * The process ID is the human-readable identifier of the process
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+ * that we want to present in log and error messages. The handle
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+ * is not useful for this purpose. But we cannot close it, either,
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+ * because it is not possible to turn a process ID into a process
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+ * handle after the process terminated.
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+ * Keep the handle in a list for waitpid.
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+ */
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+ EnterCriticalSection(&pinfo_cs);
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+ {
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+ struct pinfo_t *info = xmalloc(sizeof(struct pinfo_t));
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+ info->pid = pi.dwProcessId;
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+ info->proc = pi.hProcess;
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+ info->next = pinfo;
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+ pinfo = info;
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+ }
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+ LeaveCriticalSection(&pinfo_cs);
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+
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+ return (pid_t)pi.dwProcessId;
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}
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static pid_t mingw_spawnve(const char *cmd, const char **argv, char **env,
@@ -1518,6 +1545,50 @@ char *getpass(const char *prompt)
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return strbuf_detach(&buf, NULL);
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}
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+pid_t waitpid(pid_t pid, int *status, unsigned options)
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+{
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+ HANDLE h = OpenProcess(SYNCHRONIZE | PROCESS_QUERY_INFORMATION,
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+ FALSE, pid);
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+ if (!h) {
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+ errno = ECHILD;
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+ return -1;
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+ }
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+
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+ if (options == 0) {
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+ struct pinfo_t **ppinfo;
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+ if (WaitForSingleObject(h, INFINITE) != WAIT_OBJECT_0) {
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+ CloseHandle(h);
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+ return 0;
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+ }
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+
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+ if (status)
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+ GetExitCodeProcess(h, (LPDWORD)status);
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+
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+ EnterCriticalSection(&pinfo_cs);
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+
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+ ppinfo = &pinfo;
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+ while (*ppinfo) {
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+ struct pinfo_t *info = *ppinfo;
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+ if (info->pid == pid) {
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+ CloseHandle(info->proc);
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+ *ppinfo = info->next;
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+ free(info);
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+ break;
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+ }
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+ ppinfo = &info->next;
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+ }
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+
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+ LeaveCriticalSection(&pinfo_cs);
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+
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+ CloseHandle(h);
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+ return pid;
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+ }
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+ CloseHandle(h);
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+
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+ errno = EINVAL;
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+ return -1;
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+}
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+
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#ifndef NO_MINGW_REPLACE_READDIR
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/* MinGW readdir implementation to avoid extra lstats for Git */
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struct mingw_DIR
compat/mingw.h
+3
-7
@@ -140,13 +140,7 @@ static inline int mingw_unlink(const char *pathname)
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}
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#define unlink mingw_unlink
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-static inline pid_t waitpid(pid_t pid, int *status, unsigned options)
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-{
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- if (options == 0)
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- return _cwait(status, pid, 0);
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- errno = EINVAL;
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- return -1;
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-}
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+pid_t waitpid(pid_t pid, int *status, unsigned options);
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#ifndef NO_OPENSSL
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#include <openssl/ssl.h>
@@ -321,11 +315,13 @@ void free_environ(char **env);
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static int mingw_main(); \
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int main(int argc, const char **argv) \
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{ \
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+ extern CRITICAL_SECTION pinfo_cs; \
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_fmode = _O_BINARY; \
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_setmode(_fileno(stdin), _O_BINARY); \
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_setmode(_fileno(stdout), _O_BINARY); \
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_setmode(_fileno(stderr), _O_BINARY); \
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argv[0] = xstrdup(_pgmptr); \
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+ InitializeCriticalSection(&pinfo_cs); \
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return mingw_main(argc, argv); \
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} \
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static int mingw_main(c,v)