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[PATCH v3 05/14] mingw: use real pid

From
Erik Faye-Lund <kusmabite@gmail.com>
Date
Oct 10, 2010, 13:20 UTC
Message-ID
<1286716854-5744-6-git-send-email-kusmabite@gmail.com>
In-Reply-To
<1286716854-5744-1-git-send-email-kusmabite@gmail.com>

The Windows port so far used process handles as PID. However, this does not work consistently with getpid.

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 cc5eb2c..4582345 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,
@@ -1577,6 +1600,51 @@ 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 bbfcc0c..96ed931 100644
--- a/compat/mingw.h
+++ b/compat/mingw.h
@@ -153,13 +153,7 @@ 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>
@@ -336,11 +330,13 @@ 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)
-- 
1.7.3.1.51.ge462f.dirty
Previous: Erik Faye-LundNext: Eric Sunshine
Message 19 of 43 in “daemon-win32”
  1. 00/14 daemon-win32Erik Faye-Lund, Oct 10, 2010
  2. 01/14 mingw: add network-wrappers for daemonErik Faye-Lund, Oct 10, 2010
  3. Eric SunshineOct 10, 2010
  4. Erik Faye-LundOct 10, 2010
  5. Eric SunshineOct 10, 2010
  6. 02/14 mingw: implement syslogErik Faye-Lund, Oct 10, 2010
  7. Eric SunshineOct 10, 2010
  8. Erik Faye-LundOct 10, 2010
  9. Johannes SixtOct 10, 2010
  10. Erik Faye-LundOct 10, 2010
  11. Eric SunshineOct 10, 2010
  12. Erik Faye-LundOct 10, 2010
  13. Erik Faye-LundOct 10, 2010
  14. Eric SunshineOct 10, 2010
  15. Erik Faye-LundOct 11, 2010
  16. Erik Faye-LundOct 11, 2010
  17. 03/14 compat: add inet_pton and inet_ntop prototypesErik Faye-Lund, Oct 10, 2010
  18. 04/14 inet_ntop: fix a couple of old-style declsErik Faye-Lund, Oct 10, 2010
  19. 05/14 mingw: use real pidErik Faye-Lund, Oct 10, 2010
  20. Eric SunshineOct 10, 2010
  21. Erik Faye-LundOct 10, 2010
  22. Eric SunshineOct 10, 2010
  23. 06/14 mingw: support waitpid with pid > 0 and WNOHANGErik Faye-Lund, Oct 10, 2010
  24. 07/14 mingw: add kill emulationErik Faye-Lund, Oct 10, 2010
  25. 08/14 daemon: use run-command api for async servingErik Faye-Lund, Oct 10, 2010
  26. Eric SunshineOct 10, 2010
  27. Erik Faye-LundOct 10, 2010
  28. 09/14 daemon: use full buffered mode for stderrErik Faye-Lund, Oct 10, 2010
  29. 10/14 Improve the mingw getaddrinfo stub to handle more use casesErik Faye-Lund, Oct 10, 2010
  30. 11/14 daemon: report connection from root-processErik Faye-Lund, Oct 10, 2010
  31. Johannes SixtOct 10, 2010
  32. Erik Faye-LundOct 10, 2010
  33. Erik Faye-LundOct 10, 2010
  34. Ævar Arnfjörð BjarmasonOct 10, 2010
  35. Erik Faye-LundOct 10, 2010
  36. 12/14 mingw: import poll-emulation from gnulibErik Faye-Lund, Oct 10, 2010
  37. Ævar Arnfjörð BjarmasonOct 10, 2010
  38. Erik Faye-LundOct 10, 2010
  39. Erik Faye-LundOct 10, 2010
  40. Ævar Arnfjörð BjarmasonOct 10, 2010
  41. 13/14 mingw: use poll-emulation from gnulibErik Faye-Lund, Oct 10, 2010
  42. 14/14 daemon: only use posix features on posix systemsErik Faye-Lund, Oct 10, 2010
  43. Ævar Arnfjörð BjarmasonOct 10, 2010

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