win32: fix thread usage for win32

From: Seija Kijin <[email protected]>

Use pthread_exit instead of async_exit.

This means we do not have
to deal with Windows's implementation
requiring an unsigned exit coded
despite the POSIX exit code requiring
a signed exit code.

Use _beginthreadex instead of CreateThread
since we use the Windows CRT.

Finally, check for NULL handles, not "INVALID_HANDLE," as _beginthreadex guarantees a valid handle in most cases

---
win32: fix thread usage for win32

Use pthread_exit instead of async_exit.

This means we do not have to deal with Windows's implementation requiring an unsigned exit coded despite the POSIX exit code requiring a signed exit code.

Use _beginthreadex instead of CreateThread since we use the Windows CRT.

Finally, check for NULL handles, not "INVALID_HANDLE," as _beginthreadex guarantees a valid handle in most cases

Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-git-1440%2FAtariDreams%2FCreateThread-v1
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-git-1440/AtariDreams/CreateThread-v1
Pull-Request: https://github.com/git/git/pull/1440

 compat/mingw.c   |  2 +-
 compat/winansi.c |  8 ++++----
 run-command.c    | 33 ++++++++++++++-------------------
 3 files changed, 19 insertions(+), 24 deletions(-)

index af397e68a1d..c41d821b382 100644
@@ -2295,7 +2295,7 @@ static int start_timer_thread(void)
 	timer_event = CreateEvent(NULL, FALSE, FALSE, NULL);
 	if (timer_event) {
 		timer_thread = (HANDLE) _beginthreadex(NULL, 0, ticktack, NULL, 0, NULL);
-		if (!timer_thread )
+		if (!timer_thread)
 			return errno = ENOMEM,
 				error("cannot start timer thread");
 	} else

index 3abe8dd5a27..be65b27bd75 100644
@@ -340,7 +340,7 @@ enum {
 	TEXT = 0, ESCAPE = 033, BRACKET = '['
 };
 
-static DWORD WINAPI console_thread(LPVOID unused)
+static unsigned int WINAPI console_thread(LPVOID unused)
 {
 	unsigned char buffer[BUFFER_SIZE];
 	DWORD bytes;

@@ -643,9 +643,9 @@ void winansi_init(void)
 		die_lasterr("CreateFile for named pipe failed");
 
 	/* start console spool thread on the pipe's read end */
-	hthread = CreateThread(NULL, 0, console_thread, NULL, 0, NULL);
-	if (hthread == INVALID_HANDLE_VALUE)
-		die_lasterr("CreateThread(console_thread) failed");
+	hthread = (HANDLE)_beginthreadex(NULL, 0, console_thread, NULL, 0, NULL);
+	if (!hthread)
+		die_lasterr("_beginthreadex(console_thread) failed");
 
 	/* schedule cleanup routine */
 	if (atexit(winansi_exit))

index 50cc011654e..93fd0d22d4f 100644
@@ -1030,6 +1030,13 @@ static void *run_thread(void *data)
 	return (void *)ret;
 }
 
+int in_async(void)
+{
+	if (!main_thread_set)
+		return 0; /* no asyncs started yet */
+	return !pthread_equal(main_thread, pthread_self());
+}
+
 static NORETURN void die_async(const char *err, va_list params)
 {
 	report_fn die_message_fn = get_die_message_routine();

@@ -1055,18 +1062,6 @@ static int async_die_is_recursing(void)
 	return ret != NULL;
 }
 
-int in_async(void)
-{
-	if (!main_thread_set)
-		return 0; /* no asyncs started yet */
-	return !pthread_equal(main_thread, pthread_self());
-}
-
-static void NORETURN async_exit(int code)
-{
-	pthread_exit((void *)(intptr_t)code);
-}
-
 #else
 
 static struct {

@@ -1112,18 +1107,18 @@ int in_async(void)
 	return process_is_async;
 }
 
-static void NORETURN async_exit(int code)
-{
-	exit(code);
-}
-
 #endif
 
 void check_pipe(int err)
 {
 	if (err == EPIPE) {
-		if (in_async())
-			async_exit(141);
+		if (in_async()) {
+#ifdef NO_PTHREADS
+			exit(141);
+#else
+			pthread_exit((void *)141);
+#endif
+		}
 
 		signal(SIGPIPE, SIG_DFL);
 		raise(SIGPIPE);

base-commit: 904d404274fef6695c78a6b055edd184b72e2f9b

gitgitgadget

Am 21.01.23 um 21:49 schrieb Rose via GitGitGadget:

This explains *what* the patch does, but not *why*. You replace CreateThread() in winansi.c, but what has this to do with async_exit and why must it be changed?

Please take the time to explain this story more thoroughly.

From: Seija Kijin <[email protected]>

Use _beginthreadex instead of CreateThread
since we use the Windows CRT.

Finally, check for NULL handles, not "INVALID_HANDLE," as _beginthreadex guarantees a valid handle in most cases

---
win32: fix thread usage for win32

Use pthread_exit instead of async_exit.

This means we do not have to deal with Windows's implementation requiring an unsigned exit coded despite the POSIX exit code requiring a signed exit code.

Use _beginthreadex instead of CreateThread since we use the Windows CRT.

Finally, check for NULL handles, not "INVALID_HANDLE," as _beginthreadex guarantees a valid handle in most cases

Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-git-1440%2FAtariDreams%2FCreateThread-v2
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-git-1440/AtariDreams/CreateThread-v2
Pull-Request: https://github.com/git/git/pull/1440

Range-diff vs v1:

1: f5de6bfb759 ! 1: 4a2c3da9d4c win32: fix thread usage for win32
@@ Metadata
## Commit message ##
win32: fix thread usage for win32

- Use pthread_exit instead of async_exit.
-
- This means we do not have
- to deal with Windows's implementation
- requiring an unsigned exit coded
- despite the POSIX exit code requiring
- a signed exit code.
-
Use _beginthreadex instead of CreateThread since we use the Windows CRT.

@@ compat/winansi.c: void winansi_init(void)

/* schedule cleanup routine */
if (atexit(winansi_exit))
-
- ## run-command.c ##
-@@ run-command.c: static void *run_thread(void *data)
- return (void *)ret;
- }
-
-+int in_async(void)
-+{
-+ if (!main_thread_set)
-+ return 0; /* no asyncs started yet */
-+ return !pthread_equal(main_thread, pthread_self());
-+}
-+
- static NORETURN void die_async(const char *err, va_list params)
- {
- report_fn die_message_fn = get_die_message_routine();
-@@ run-command.c: static int async_die_is_recursing(void)
- return ret != NULL;
- }
-
--int in_async(void)
--{
-- if (!main_thread_set)
-- return 0; /* no asyncs started yet */
-- return !pthread_equal(main_thread, pthread_self());
--}
--
--static void NORETURN async_exit(int code)
--{
-- pthread_exit((void *)(intptr_t)code);
--}
--
- #else
-
- static struct {
-@@ run-command.c: int in_async(void)
- return process_is_async;
- }
-
--static void NORETURN async_exit(int code)
--{
-- exit(code);
--}
--
- #endif
-
- void check_pipe(int err)
- {
- if (err == EPIPE) {
-- if (in_async())
-- async_exit(141);
-+ if (in_async()) {
-+#ifdef NO_PTHREADS
-+ exit(141);
-+#else
-+ pthread_exit((void *)141);
-+#endif
-+ }
-
- signal(SIGPIPE, SIG_DFL);
- raise(SIGPIPE);

 compat/mingw.c   | 2 +-
 compat/winansi.c | 8 ++++----
 2 files changed, 5 insertions(+), 5 deletions(-)

index e433740381b..715f1c87e11 100644
@@ -2291,7 +2291,7 @@ static int start_timer_thread(void)
 	timer_event = CreateEvent(NULL, FALSE, FALSE, NULL);
 	if (timer_event) {
 		timer_thread = (HANDLE) _beginthreadex(NULL, 0, ticktack, NULL, 0, NULL);
-		if (!timer_thread )
+		if (!timer_thread)
 			return errno = ENOMEM,
 				error("cannot start timer thread");
 	} else

index 3abe8dd5a27..be65b27bd75 100644
@@ -340,7 +340,7 @@ enum {
 	TEXT = 0, ESCAPE = 033, BRACKET = '['
 };
 
-static DWORD WINAPI console_thread(LPVOID unused)
+static unsigned int WINAPI console_thread(LPVOID unused)
 {
 	unsigned char buffer[BUFFER_SIZE];
 	DWORD bytes;

@@ -643,9 +643,9 @@ void winansi_init(void)
 		die_lasterr("CreateFile for named pipe failed");
 
 	/* start console spool thread on the pipe's read end */
-	hthread = CreateThread(NULL, 0, console_thread, NULL, 0, NULL);
-	if (hthread == INVALID_HANDLE_VALUE)
-		die_lasterr("CreateThread(console_thread) failed");
+	hthread = (HANDLE)_beginthreadex(NULL, 0, console_thread, NULL, 0, NULL);
+	if (!hthread)
+		die_lasterr("_beginthreadex(console_thread) failed");
 
 	/* schedule cleanup routine */
 	if (atexit(winansi_exit))

base-commit: 56c8fb1e95377900ec9d53c07886022af0a5d3c2

gitgitgadget

From: Seija Kijin <[email protected]>

Use _beginthreadex instead of CreateThread
since we use the Windows CRT,
as Microsoft recommends _beginthreadex
over CreateThread for these situations.

Finally, check for NULL handles, not "INVALID_HANDLE," as _beginthreadex guarantees a valid handle in most cases

---
win32: fix thread usage for win32

Use pthread_exit instead of async_exit.

This means we do not have to deal with Windows's implementation requiring an unsigned exit coded despite the POSIX exit code requiring a signed exit code.

Use _beginthreadex instead of CreateThread since we use the Windows CRT.

Finally, check for NULL handles, not "INVALID_HANDLE," as _beginthreadex guarantees a valid handle in most cases

Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-git-1440%2FAtariDreams%2FCreateThread-v3
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-git-1440/AtariDreams/CreateThread-v3
Pull-Request: https://github.com/git/git/pull/1440

Range-diff vs v2:

1: 4a2c3da9d4c ! 1: 68baafba2bd win32: fix thread usage for win32
@@ Commit message
win32: fix thread usage for win32

Use _beginthreadex instead of CreateThread
- since we use the Windows CRT.
+ since we use the Windows CRT,
+ as Microsoft recommends _beginthreadex
+ over CreateThread for these situations.

Finally, check for NULL handles, not "INVALID_HANDLE," as _beginthreadex guarantees a valid handle in most cases

 compat/mingw.c   | 2 +-
 compat/winansi.c | 8 ++++----
 2 files changed, 5 insertions(+), 5 deletions(-)

index e433740381b..715f1c87e11 100644
@@ -2291,7 +2291,7 @@ static int start_timer_thread(void)
 	timer_event = CreateEvent(NULL, FALSE, FALSE, NULL);
 	if (timer_event) {
 		timer_thread = (HANDLE) _beginthreadex(NULL, 0, ticktack, NULL, 0, NULL);
-		if (!timer_thread )
+		if (!timer_thread)
 			return errno = ENOMEM,
 				error("cannot start timer thread");
 	} else

index 3abe8dd5a27..be65b27bd75 100644
@@ -340,7 +340,7 @@ enum {
 	TEXT = 0, ESCAPE = 033, BRACKET = '['
 };
 
-static DWORD WINAPI console_thread(LPVOID unused)
+static unsigned int WINAPI console_thread(LPVOID unused)
 {
 	unsigned char buffer[BUFFER_SIZE];
 	DWORD bytes;

@@ -643,9 +643,9 @@ void winansi_init(void)
 		die_lasterr("CreateFile for named pipe failed");
 
 	/* start console spool thread on the pipe's read end */
-	hthread = CreateThread(NULL, 0, console_thread, NULL, 0, NULL);
-	if (hthread == INVALID_HANDLE_VALUE)
-		die_lasterr("CreateThread(console_thread) failed");
+	hthread = (HANDLE)_beginthreadex(NULL, 0, console_thread, NULL, 0, NULL);
+	if (!hthread)
+		die_lasterr("_beginthreadex(console_thread) failed");
 
 	/* schedule cleanup routine */
 	if (atexit(winansi_exit))

base-commit: 56c8fb1e95377900ec9d53c07886022af0a5d3c2

gitgitgadget

From: Seija Kijin <[email protected]>

Use _beginthreadex instead of CreateThread
since we use the Windows CRT,
as Microsoft recommends _beginthreadex
over CreateThread for these situations.

Finally, check for NULL handles, not "INVALID_HANDLE," as _beginthreadex guarantees a valid handle in most cases

---
win32: fix thread usage for win32

Use pthread_exit instead of async_exit.

This means we do not have to deal with Windows's implementation requiring an unsigned exit coded despite the POSIX exit code requiring a signed exit code.

Use _beginthreadex instead of CreateThread since we use the Windows CRT.

Finally, check for NULL handles, not "INVALID_HANDLE," as _beginthreadex guarantees a valid handle in most cases

Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-git-1440%2FAtariDreams%2FCreateThread-v4
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-git-1440/AtariDreams/CreateThread-v4
Pull-Request: https://github.com/git/git/pull/1440

Range-diff vs v3:

1: 68baafba2bd ! 1: 2e2d5ce7745 win32: fix thread usage for win32
@@ Commit message

- ## compat/mingw.c ##
-@@ compat/mingw.c: static int start_timer_thread(void)
- timer_event = CreateEvent(NULL, FALSE, FALSE, NULL);
- if (timer_event) {
- timer_thread = (HANDLE) _beginthreadex(NULL, 0, ticktack, NULL, 0, NULL);
-- if (!timer_thread )
-+ if (!timer_thread)
- return errno = ENOMEM,
- error("cannot start timer thread");
- } else
-
## compat/winansi.c ##
@@ compat/winansi.c: enum {
TEXT = 0, ESCAPE = 033, BRACKET = '['

 compat/winansi.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

index 3abe8dd5a27..be65b27bd75 100644
@@ -340,7 +340,7 @@ enum {
 	TEXT = 0, ESCAPE = 033, BRACKET = '['
 };
 
-static DWORD WINAPI console_thread(LPVOID unused)
+static unsigned int WINAPI console_thread(LPVOID unused)
 {
 	unsigned char buffer[BUFFER_SIZE];
 	DWORD bytes;

@@ -643,9 +643,9 @@ void winansi_init(void)
 		die_lasterr("CreateFile for named pipe failed");
 
 	/* start console spool thread on the pipe's read end */
-	hthread = CreateThread(NULL, 0, console_thread, NULL, 0, NULL);
-	if (hthread == INVALID_HANDLE_VALUE)
-		die_lasterr("CreateThread(console_thread) failed");
+	hthread = (HANDLE)_beginthreadex(NULL, 0, console_thread, NULL, 0, NULL);
+	if (!hthread)
+		die_lasterr("_beginthreadex(console_thread) failed");
 
 	/* schedule cleanup routine */
 	if (atexit(winansi_exit))

base-commit: 56c8fb1e95377900ec9d53c07886022af0a5d3c2

gitgitgadget

This change may or may not be harmless, but it scares me because it is possibly a very subtle change and is being made for an unknown reason -- is there a problem being fixed here? Or is this just churn for the sake of churn to avoid an awkward cast of the return code?

What does _beginthreadex() specifically do that we need it to do for us?

_beginthreadex() does some CRT init and then calls CreateThread(), so what are we missing by calling CreateThread() directly?

The code in question is 11+ years old and it hasn't been a problem (right?), so I have to wonder what value do we get from this change.

The containing function here is setting up a special console thread and named pipe to access the console, so I doubt that any of the tests in the test suite actually would actually exercise this change (since the tests aren't interactive).

The low-level Windows startup code is very tricky and sensitive (and we need to test with both GCC's CRT and MSVC's CRT). As I said earlier, the change may or may not be harmless, but I question the need for it.

Jeff

Am 23.01.23 um 18:43 schrieb Jeff Hostetler:

I also question the value of this change. As long as the thread does not call into any CRT functions, we do not need the services of _beginthreadex(). AFAICS, it only uses WinAPI functions and some uncritical C functions like memmove and memset. Am I missing something?

From: Seija Kijin <[email protected]>

Use _beginthreadex instead of CreateThread
since we use the Windows CRT,
as Microsoft recommends _beginthreadex
over CreateThread for these situations.

Finally, check for NULL handles, not "INVALID_HANDLE," as _beginthreadex guarantees a valid handle in most cases

---
win32: fix thread usage for win32

Use pthread_exit instead of async_exit.

This means we do not have to deal with Windows's implementation requiring an unsigned exit coded despite the POSIX exit code requiring a signed exit code.

Use _beginthreadex instead of CreateThread since we use the Windows CRT.

Finally, check for NULL handles, not "INVALID_HANDLE," as _beginthreadex guarantees a valid handle in most cases

Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-git-1440%2FAtariDreams%2FCreateThread-v5
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-git-1440/AtariDreams/CreateThread-v5
Pull-Request: https://github.com/git/git/pull/1440

Range-diff vs v4:

1: 2e2d5ce7745 = 1: 6ab79d9275d win32: fix thread usage for win32

 compat/winansi.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

index 3abe8dd5a27..be65b27bd75 100644
@@ -340,7 +340,7 @@ enum {
 	TEXT = 0, ESCAPE = 033, BRACKET = '['
 };
 
-static DWORD WINAPI console_thread(LPVOID unused)
+static unsigned int WINAPI console_thread(LPVOID unused)
 {
 	unsigned char buffer[BUFFER_SIZE];
 	DWORD bytes;

@@ -643,9 +643,9 @@ void winansi_init(void)
 		die_lasterr("CreateFile for named pipe failed");
 
 	/* start console spool thread on the pipe's read end */
-	hthread = CreateThread(NULL, 0, console_thread, NULL, 0, NULL);
-	if (hthread == INVALID_HANDLE_VALUE)
-		die_lasterr("CreateThread(console_thread) failed");
+	hthread = (HANDLE)_beginthreadex(NULL, 0, console_thread, NULL, 0, NULL);
+	if (!hthread)
+		die_lasterr("_beginthreadex(console_thread) failed");
 
 	/* schedule cleanup routine */
 	if (atexit(winansi_exit))

base-commit: 2fc9e9ca3c7505bc60069f11e7ef09b1aeeee473

gitgitgadget

Am 31.01.23 um 15:47 schrieb Rose via GitGitGadget:

If you do not agree with review comments, it would be more polite to express your thinking than to just resend a patch unchanged and silently.

-- Hannes

From: Seija Kijin <[email protected]>

Use _beginthreadex instead of CreateThread
since we use the Windows CRT,
as Microsoft recommends _beginthreadex
over CreateThread for these situations.

Finally, check for NULL handles, not "INVALID_HANDLE," as _beginthreadex guarantees a valid handle in most cases

---
win32: fix thread usage for win32

Use pthread_exit instead of async_exit.

This means we do not have to deal with Windows's implementation requiring an unsigned exit coded despite the POSIX exit code requiring a signed exit code.

Use _beginthreadex instead of CreateThread since we use the Windows CRT.

Finally, check for NULL handles, not "INVALID_HANDLE," as _beginthreadex guarantees a valid handle in most cases

Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-git-1440%2FAtariDreams%2FCreateThread-v6
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-git-1440/AtariDreams/CreateThread-v6
Pull-Request: https://github.com/git/git/pull/1440

Range-diff vs v5:

1: 6ab79d9275d ! 1: 67cef4bd8c9 win32: fix thread usage for win32

     @@ compat/winansi.c: void winansi_init(void)
       
       	/* start console spool thread on the pipe's read end */
      -	hthread = CreateThread(NULL, 0, console_thread, NULL, 0, NULL);
     --	if (hthread == INVALID_HANDLE_VALUE)
     --		die_lasterr("CreateThread(console_thread) failed");
      +	hthread = (HANDLE)_beginthreadex(NULL, 0, console_thread, NULL, 0, NULL);
     -+	if (!hthread)
     + 	if (!hthread)
     +-		die_lasterr("CreateThread(console_thread) failed");
      +		die_lasterr("_beginthreadex(console_thread) failed");
       
       	/* schedule cleanup routine */

 compat/winansi.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

index f83610f684d..be65b27bd75 100644
@@ -340,7 +340,7 @@ enum {
 	TEXT = 0, ESCAPE = 033, BRACKET = '['
 };
 
-static DWORD WINAPI console_thread(LPVOID unused)
+static unsigned int WINAPI console_thread(LPVOID unused)
 {
 	unsigned char buffer[BUFFER_SIZE];
 	DWORD bytes;

@@ -643,9 +643,9 @@ void winansi_init(void)
 		die_lasterr("CreateFile for named pipe failed");
 
 	/* start console spool thread on the pipe's read end */
-	hthread = CreateThread(NULL, 0, console_thread, NULL, 0, NULL);
+	hthread = (HANDLE)_beginthreadex(NULL, 0, console_thread, NULL, 0, NULL);
 	if (!hthread)
-		die_lasterr("CreateThread(console_thread) failed");
+		die_lasterr("_beginthreadex(console_thread) failed");
 
 	/* schedule cleanup routine */
 	if (atexit(winansi_exit))

base-commit: 23c56f7bd5f1667f8b793d796bf30e39545920f6

gitgitgadget

From: Seija Kijin <[email protected]>

Use _beginthreadex instead of CreateThread
since we use the Windows CRT,
as Microsoft recommends _beginthreadex
over CreateThread for these situations.

Finally, check for NULL handles, not "INVALID_HANDLE," as _beginthreadex guarantees a valid handle in most cases

---
win32: prefer beginthreadex over CreateThread

Use pthread_exit instead of async_exit.

This means we do not have to deal with Windows's implementation requiring an unsigned exit coded despite the POSIX exit code requiring a signed exit code.

Use _beginthreadex instead of CreateThread since we use the Windows CRT.

Finally, check for NULL handles, not "INVALID_HANDLE," as _beginthreadex guarantees a valid handle in most cases

Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-git-1440%2FAtariDreams%2FCreateThread-v7
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-git-1440/AtariDreams/CreateThread-v7
Pull-Request: https://github.com/git/git/pull/1440

Range-diff vs v6:

1: 67cef4bd8c9 ! 1: edee5e78c67 win32: fix thread usage for win32
@@ Metadata
Author: Seija Kijin <[email protected]>

## Commit message ##
- win32: fix thread usage for win32
+ win32: prefer beginthreadex over CreateThread

Use _beginthreadex instead of CreateThread since we use the Windows CRT,

 compat/winansi.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

index f83610f684d..be65b27bd75 100644
@@ -340,7 +340,7 @@ enum {
 	TEXT = 0, ESCAPE = 033, BRACKET = '['
 };
 
-static DWORD WINAPI console_thread(LPVOID unused)
+static unsigned int WINAPI console_thread(LPVOID unused)
 {
 	unsigned char buffer[BUFFER_SIZE];
 	DWORD bytes;

@@ -643,9 +643,9 @@ void winansi_init(void)
 		die_lasterr("CreateFile for named pipe failed");
 
 	/* start console spool thread on the pipe's read end */
-	hthread = CreateThread(NULL, 0, console_thread, NULL, 0, NULL);
+	hthread = (HANDLE)_beginthreadex(NULL, 0, console_thread, NULL, 0, NULL);
 	if (!hthread)
-		die_lasterr("CreateThread(console_thread) failed");
+		die_lasterr("_beginthreadex(console_thread) failed");
 
 	/* schedule cleanup routine */
 	if (atexit(winansi_exit))

base-commit: 23c56f7bd5f1667f8b793d796bf30e39545920f6

gitgitgadget