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/* Copyright (C) 2009, 2011 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@redhat.com>, 2009.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <sysdep.h>
#include <tcb-offsets.h>
#include <kernel-features.h>
#include "lowlevellock.h"
#if IS_IN (libpthread)
# ifdef SHARED
# define __pthread_unwind __GI___pthread_unwind
# endif
#else
# ifndef SHARED
.weak __pthread_unwind
# endif
#endif
/* It is crucial that the functions in this file don't modify registers
other than %rax and %r11. The syscall wrapper code depends on this
because it doesn't explicitly save the other registers which hold
relevant values. */
.text
.hidden __pthread_enable_asynccancel
ENTRY(__pthread_enable_asynccancel)
movl %fs:CANCELHANDLING, %eax
2: movl %eax, %r11d
orl $TCB_CANCELTYPE_BITMASK, %r11d
cmpl %eax, %r11d
je 1f
lock
cmpxchgl %r11d, %fs:CANCELHANDLING
jnz 2b
andl $(TCB_CANCELSTATE_BITMASK|TCB_CANCELTYPE_BITMASK|TCB_CANCELED_BITMASK|TCB_EXITING_BITMASK|TCB_CANCEL_RESTMASK|TCB_TERMINATED_BITMASK), %r11d
cmpl $(TCB_CANCELTYPE_BITMASK|TCB_CANCELED_BITMASK), %r11d
je 3f
1: ret
3: subq $8, %rsp
cfi_adjust_cfa_offset(8)
LP_OP(mov) $TCB_PTHREAD_CANCELED, %fs:RESULT
lock
orl $TCB_EXITING_BITMASK, %fs:CANCELHANDLING
mov %fs:CLEANUP_JMP_BUF, %RDI_LP
#ifdef SHARED
call __pthread_unwind@PLT
#else
call __pthread_unwind
#endif
hlt
END(__pthread_enable_asynccancel)
.hidden __pthread_disable_asynccancel
ENTRY(__pthread_disable_asynccancel)
testl $TCB_CANCELTYPE_BITMASK, %edi
jnz 1f
movl %fs:CANCELHANDLING, %eax
2: movl %eax, %r11d
andl $~TCB_CANCELTYPE_BITMASK, %r11d
lock
cmpxchgl %r11d, %fs:CANCELHANDLING
jnz 2b
movl %r11d, %eax
3: andl $(TCB_CANCELING_BITMASK|TCB_CANCELED_BITMASK), %eax
cmpl $TCB_CANCELING_BITMASK, %eax
je 4f
1: ret
# define UMTX_OP_WAIT_UINT_PRIVATE 15
# define LOAD_PRIVATE_FUTEX_WAIT(reg) \
movl $UMTX_OP_WAIT_UINT_PRIVATE, reg
/* Performance doesn't matter in this loop. We will
delay until the thread is canceled. And we will unlikely
enter the loop twice. */
# warning check this:
/*
The C-code repeatedy does:
lll_futex_wait (&self->cancelhandling, newval, LLL_PRIVATE);
newval = THREAD_GETMEM (self, cancelhandling);
but the original NPTL code does not fill rdx
with the old value ...
*/
4: mov %fs:0, %RDI_LP
movl $SYS__umtx_op, %eax
xorq %r8, %r8
xorq %r10, %r10
addq $CANCELHANDLING, %rdi
LOAD_PRIVATE_FUTEX_WAIT (%esi)
syscall
movl %fs:CANCELHANDLING, %eax
jmp 3b
END(__pthread_disable_asynccancel)
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