/* Copyright (C) 2009-2018 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"

#define PTHREAD_UNWIND JUMPTARGET(__pthread_unwind)

#if IS_IN (libpthread)

# if defined SHARED && !defined NO_HIDDEN

#  undef PTHREAD_UNWIND

#  define PTHREAD_UNWIND __GI___pthread_unwind

# endif

#else

# ifndef SHARED

	.weak __pthread_unwind

# endif

#endif

#define LOAD_PRIVATE_FUTEX_WAIT(reg) \

	movl	$(FUTEX_WAIT | FUTEX_PRIVATE_FLAG), reg

/* 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

	call	PTHREAD_UNWIND

	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

	/* Performance doesn't matter in this loop.  We will

	   delay until the thread is canceled.  And we will unlikely

	   enter the loop twice.  */

4:	mov	%fs:0, %RDI_LP

	movl	$__NR_futex, %eax

	xorq	%r10, %r10

	addq	$CANCELHANDLING, %rdi

	LOAD_PRIVATE_FUTEX_WAIT (%esi)

	syscall

	movl	%fs:CANCELHANDLING, %eax

	jmp	3b

END(__pthread_disable_asynccancel)