Hello,
Could your review the fix for the issue:
Bug: https://bugs.openjdk.java.net/browse/JDK-8252248
Fix: http://cr.openjdk.java.net/~alexsch/8252248/webrev.00/
Building JDK on Alpine Linux with musl libc gives the error:
src/java.base/linux/native/libnet/linux_close.c:63:25: error:
'__SIGRTMAX' undeclared here (not in a function); did you mean 'SIGRTMAX'?
63 | static int sigWakeup = (__SIGRTMAX - 2);
musl libc does not contain __SIGRTMAX definition. It defines only
SIGRTMAX as a function call [1].
__SIGRTMAX is used in JDK in two files NativeThread.c and linux_close.c .
The first idea of the fix was simply to substitute __SIGRTMAX to
SIGRTMAX in NativeThread.c and use the same definition
#define INTERRUPT_SIGNAL (__SIGRTMAX - 2)
in linux_close.c.
"static int sigWakeup = (SIGRTMAX - 2)" does not work because the
SIGRTMAX is defined as a function and leads to "initializer element is
not constant" error.
The fix has been discussed on the portola-dev alias [2] where it was
pointed out that the fix can be reviewed in the mainline and it was
suggested to rename the INTERRUPT_SIGNAL and move its definition to
net_util_md.h.
[1] https://git.musl-libc.org/cgit/musl/tree/include/signal.h#n196
[2]
https://mail.openjdk.java.net/pipermail/portola-dev/2020-August/000471.html
Thanks,
Alexander.
