diff options
Diffstat (limited to 'nptl/sysdeps/unix/sysv/linux/x86_64/pthread_rwlock_rdlock.S')
| -rw-r--r-- | nptl/sysdeps/unix/sysv/linux/x86_64/pthread_rwlock_rdlock.S | 175 |
1 files changed, 175 insertions, 0 deletions
diff --git a/nptl/sysdeps/unix/sysv/linux/x86_64/pthread_rwlock_rdlock.S b/nptl/sysdeps/unix/sysv/linux/x86_64/pthread_rwlock_rdlock.S new file mode 100644 index 0000000000..6ef605cde1 --- /dev/null +++ b/nptl/sysdeps/unix/sysv/linux/x86_64/pthread_rwlock_rdlock.S @@ -0,0 +1,175 @@ +/* Copyright (C) 2002, 2003 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Ulrich Drepper <drepper@redhat.com>, 2002. + + 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, write to the Free + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + 02111-1307 USA. */ + +#include <sysdep.h> +#include <lowlevelrwlock.h> + + +#define SYS_futex 202 +#define FUTEX_WAIT 0 +#define FUTEX_WAKE 1 + +#define EAGAIN 11 +#define EDEADLK 35 + +#ifndef UP +# define LOCK lock +#else +# define LOCK +#endif + + + .text + + .globl __pthread_rwlock_rdlock + .type __pthread_rwlock_rdlock,@function + .align 16 +__pthread_rwlock_rdlock: + xorq %r10, %r10 + + /* Get the lock. */ + movl $1, %esi + LOCK +#if MUTEX == 0 + xaddl %esi, (%rdi) +#else + xaddl %esi, MUTEX(%rdi) +#endif + testl %esi, %esi + jne 1f + +2: movq WRITER(%rdi), %rax + testq %rax, %rax + jne 14f + cmpl $0, WRITERS_QUEUED(%rdi) + je 5f + cmpl $0, FLAGS(%rdi) + je 5f + +3: incl READERS_QUEUED(%rdi) + je 4f + + movl READERS_WAKEUP(%rdi), %edx + + LOCK +#if MUTEX == 0 + incl (%rdi) +#else + incl MUTEX(%rdi) +#endif + jne 10f + +11: addq $READERS_WAKEUP-MUTEX, %rdi + movq %r10, %rsi /* movl $FUTEX_WAIT, %ecx */ + movq $SYS_futex, %rax + syscall + + subq $READERS_WAKEUP-MUTEX, %rdi + + /* Reget the lock. */ + movl $1, %esi + LOCK +#if MUTEX == 0 + xaddl %esi, (%rdi) +#else + xaddl %esi, MUTEX(%rdi) +#endif + testl %esi, %esi + jne 12f + +13: decl READERS_QUEUED(%rdi) + jmp 2b + +5: xorq %rcx, %rcx + incl NR_READERS(%rdi) + je 8f +9: LOCK +#if MUTEX == 0 + decl (%rdi) +#else + decl MUTEX(%rdi) +#endif + jne 6f +7: + + movq %rcx, %rax + retq + +1: +#if MUTEX != 0 + addq $MUTEX, %rdi +#endif + call __lll_mutex_lock_wait +#if MUTEX != 0 + subq $MUTEX, %rdi +#endif + jmp 2b + +14: cmpq %gs:16, %rax + jne 3b + /* Deadlock detected. */ + movq $EDEADLK, %rcx + jmp 9b + +6: +#if MUTEX != 0 + addq $MUTEX, %rdi +#endif + call __lll_mutex_unlock_wake +#if MUTEX != 0 + subq $MUTEX, %rdi +#endif + jmp 7b + + /* Overflow. */ +8: decl NR_READERS(%rdi) + movq $EAGAIN, %rcx + jmp 9b + + /* Overflow. */ +4: decl READERS_QUEUED(%rdi) + movq $EAGAIN, %rcx + jmp 9b + +10: +#if MUTEX != 0 + addq $MUTEX, %rdi +#endif + call __lll_mutex_unlock_wake +#if MUTEX != 0 + subq $MUTEX, %rdi +#endif + jmp 11b + +12: +#if MUTEX == 0 + addq $MUTEX, %rdi +#endif + call __lll_mutex_lock_wait +#if MUTEX != 0 + subq $MUTEX, %rdi +#endif + jmp 13b + .size __pthread_rwlock_rdlock,.-__pthread_rwlock_rdlock + + .globl pthread_rwlock_rdlock +pthread_rwlock_rdlock = __pthread_rwlock_rdlock + + .globl __pthread_rwlock_rdlock_internal +__pthread_rwlock_rdlock_internal = __pthread_rwlock_rdlock |