From c68d0fa2d88fc2134a38d99e7e944828384a7671 Mon Sep 17 00:00:00 2001 From: Austin Foxley Date: Sat, 17 Oct 2009 12:26:24 -0700 Subject: libpthread/nptl: core of the "Native Posix Threading Library" for uClibc targetting arm,sh,i386,mips,sparc for now Signed-off-by: Austin Foxley --- .../sysv/linux/i386/i486/pthread_rwlock_rdlock.S | 175 +++++++++++++++++++++ 1 file changed, 175 insertions(+) create mode 100644 libpthread/nptl/sysdeps/unix/sysv/linux/i386/i486/pthread_rwlock_rdlock.S (limited to 'libpthread/nptl/sysdeps/unix/sysv/linux/i386/i486/pthread_rwlock_rdlock.S') diff --git a/libpthread/nptl/sysdeps/unix/sysv/linux/i386/i486/pthread_rwlock_rdlock.S b/libpthread/nptl/sysdeps/unix/sysv/linux/i386/i486/pthread_rwlock_rdlock.S new file mode 100644 index 000000000..aec79f07e --- /dev/null +++ b/libpthread/nptl/sysdeps/unix/sysv/linux/i386/i486/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 , 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 +#include +#include +#include + + +#define FUTEX_WAIT 0 +#define FUTEX_WAKE 1 + +#ifndef UP +# define LOCK lock +#else +# define LOCK +#endif + + + .text + + .globl __pthread_rwlock_rdlock + .type __pthread_rwlock_rdlock,@function + .align 16 +__pthread_rwlock_rdlock: + pushl %esi + pushl %ebx + + xorl %esi, %esi + movl 12(%esp), %ebx + + /* Get the lock. */ + movl $1, %edx + xorl %eax, %eax + LOCK +#if MUTEX == 0 + cmpxchgl %edx, (%ebx) +#else + cmpxchgl %edx, MUTEX(%ebx) +#endif + jnz 1f + +2: movl WRITER(%ebx), %eax + testl %eax, %eax + jne 14f + cmpl $0, WRITERS_QUEUED(%ebx) + je 5f + cmpl $0, FLAGS(%ebx) + je 5f + +3: addl $1, READERS_QUEUED(%ebx) + je 4f + + movl READERS_WAKEUP(%ebx), %edx + + LOCK +#if MUTEX == 0 + subl $1, (%ebx) +#else + subl $1, MUTEX(%ebx) +#endif + jne 10f + +11: addl $READERS_WAKEUP, %ebx + movl %esi, %ecx /* movl $FUTEX_WAIT, %ecx */ + movl $SYS_futex, %eax + ENTER_KERNEL + + subl $READERS_WAKEUP, %ebx + + /* Reget the lock. */ + movl $1, %edx + xorl %eax, %eax + LOCK +#if MUTEX == 0 + cmpxchgl %edx, (%ebx) +#else + cmpxchgl %edx, MUTEX(%ebx) +#endif + jnz 12f + +13: subl $1, READERS_QUEUED(%ebx) + jmp 2b + +5: xorl %ecx, %ecx + addl $1, NR_READERS(%ebx) + je 8f +9: LOCK +#if MUTEX == 0 + subl $1, (%ebx) +#else + subl $1, MUTEX(%ebx) +#endif + jne 6f +7: + + movl %ecx, %eax + popl %ebx + popl %esi + ret + +1: +#if MUTEX == 0 + movl %ebx, %ecx +#else + leal MUTEX(%ebx), %ecx +#endif + call __lll_mutex_lock_wait + jmp 2b + +14: cmpl %gs:TID, %eax + jne 3b + /* Deadlock detected. */ + movl $EDEADLK, %ecx + jmp 9b + +6: +#if MUTEX == 0 + movl %ebx, %eax +#else + leal MUTEX(%ebx), %eax +#endif + call __lll_mutex_unlock_wake + jmp 7b + + /* Overflow. */ +8: subl $1, NR_READERS(%ebx) + movl $EAGAIN, %ecx + jmp 9b + + /* Overflow. */ +4: subl $1, READERS_QUEUED(%ebx) + movl $EAGAIN, %ecx + jmp 9b + +10: +#if MUTEX == 0 + movl %ebx, %eax +#else + leal MUTEX(%ebx), %eax +#endif + call __lll_mutex_unlock_wake + jmp 11b + +12: +#if MUTEX == 0 + movl %ebx, %ecx +#else + leal MUTEX(%ebx), %ecx +#endif + call __lll_mutex_lock_wait + 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 -- cgit v1.2.3