On 1/23/23 11:48 AM, Rose via GitGitGadget wrote:
From: Seija Kijin <doremylover123@xxxxxxxxx>
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
Signed-off-by: Seija Kijin <doremylover123@xxxxxxxxx>
---
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
Signed-off-by: Seija Kijin doremylover123@xxxxxxxxx
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
Signed-off-by: Seija Kijin <doremylover123@xxxxxxxxx>
- ## 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(-)
diff --git a/compat/winansi.c b/compat/winansi.c
index 3abe8dd5a27..be65b27bd75 100644
--- a/compat/winansi.c
+++ b/compat/winansi.c
@@ -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
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
