not save (restore) the global pointer (GP) in the jmpbuf in setjmp
(longjmp) because it's not needed in general. GP is considered a
scratch register at callsites and hence is always restored after a
call (when it's possible that the call resolves to a symbol in a
different loadmodule; otherwise GP does not have to be saved and
restored at all), including calls to setjmp/longjmp. There's just
one problem with this now that we use setjmp/longjmp for context
switching: A new context must have GP defined properly for the
thread's entry point. This means that we need to put GP in the
jmpbuf and consequently that we have to restore is in longjmp.
This automaticly requires us to save it as well.
When setjmp/longjmp isn't used for context switching, this can be
reverted again.
integral type to the size of a pointer type when it's known that the
cast is valid. On ia64 such casts are generally bad news and has led
us (=peter :-) to make such casts fatal. By casting to intptr_t
before casting to a pointer type, this now compiles cleanly in LP64
architectures. Note that the final cast has been changed to void*
(instead of siginfo_t*) to make it explicit that we're not trying to
pass a siginfo_t pointer but rather trying to pass an int when the
prototype says it should be a pointer.
because we have 2 stacks per thread: the regular downward
memory stack and the irregular upward register stack. This
implementation lets both stacks grow toward each other. An
alternative scheme is to have them grow away from each other.
The alternate scheme has the advantage that both stack grow
toward guard pages. Since libc_r is virtually dead and we
really want the *context stuff for thread switching, we don't
try to be perfect, just functional.
Both are atomic, but the cmpxchg has memory ordering hints. We
give this acquire semantics.
NOTE: The unlock in libc_r is implemented by a "normal" assign
statement. This is not correct on ia64 due to the memory ordering
characteristics of the architecture. We need release semantics
for an unlock.
descriptors that have the close-on-exec flag set, as that will have no
effect anyway and might screw something else up if the file descriptor
happens to be shared with another process.
PR: standards/43335
MFC after: 1 week
by filling in the jump table.
Convert uses of pthread routines within libc_r to use the internal
versions (_pthread_foo instead of pthread_foo).
Remove a couple of globals from application namespace.
extenston function. It supposed to provide facility to get already created
thread's attributes. Looks like it's last thing we need to make JDK's Hotspot
building without requirement to have source tree.
Reviewed by: deischen
MFC after: 3 days
of a file descriptor has NULL entries, so don't dereference the table entries
to get the owners ever -- don't print the owners when processing a thread_dump
request as a result of SIGINFO.
Reviewed by: deischen
the FPU state on receiving and returning from a signal.
The FPU save and restore macros are no longer needed, but
remain defined in case we need to use them again (something
else breaks). They'll be removed permanently once new
syscalls are added to handle the new i386 ucontext size.
`sigprocmask', `sigaltstack', and `sigwait' as well as to the
prototypes of the apparantly unimplemented functions `sigtimedwait'
and `sigwaitinfo'. This complies with IEEE Std 1003.1-2001.
