diff options
Diffstat (limited to 'sysdeps/unix/sysv/linux/x86_64/pthread_rwlock_rdlock.S')
| -rw-r--r-- | sysdeps/unix/sysv/linux/x86_64/pthread_rwlock_rdlock.S | 177 |
1 files changed, 177 insertions, 0 deletions
diff --git a/sysdeps/unix/sysv/linux/x86_64/pthread_rwlock_rdlock.S b/sysdeps/unix/sysv/linux/x86_64/pthread_rwlock_rdlock.S new file mode 100644 index 0000000000..3bbb4c7f62 --- /dev/null +++ b/sysdeps/unix/sysv/linux/x86_64/pthread_rwlock_rdlock.S @@ -0,0 +1,177 @@ +/* Copyright (C) 2002-2014 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, see + <http://www.gnu.org/licenses/>. */ + +#include <sysdep.h> +#include <lowlevellock.h> +#include <lowlevelrwlock.h> +#include <pthread-errnos.h> +#include <kernel-features.h> +#include <stap-probe.h> + + .text + + .globl __pthread_rwlock_rdlock + .type __pthread_rwlock_rdlock,@function + .align 16 +__pthread_rwlock_rdlock: + cfi_startproc + + LIBC_PROBE (rdlock_entry, 1, %rdi) + + xorq %r10, %r10 + + /* Get the lock. */ + movl $1, %esi + xorl %eax, %eax + LOCK +#if MUTEX == 0 + cmpxchgl %esi, (%rdi) +#else + cmpxchgl %esi, MUTEX(%rdi) +#endif + jnz 1f + +2: movl WRITER(%rdi), %eax + testl %eax, %eax + 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 + decl (%rdi) +#else + decl MUTEX(%rdi) +#endif + jne 10f + +11: +#ifdef __ASSUME_PRIVATE_FUTEX + movl $FUTEX_PRIVATE_FLAG|FUTEX_WAIT, %esi + xorl PSHARED(%rdi), %esi +#else +# if FUTEX_WAIT == 0 + movl PSHARED(%rdi), %esi +# else + movl $FUTEX_WAIT, %esi + orl PSHARED(%rdi), %esi +# endif + xorl %fs:PRIVATE_FUTEX, %esi +#endif + addq $READERS_WAKEUP, %rdi + movl $SYS_futex, %eax + syscall + + subq $READERS_WAKEUP, %rdi + + /* Reget the lock. */ + movl $1, %esi + xorl %eax, %eax + LOCK +#if MUTEX == 0 + cmpxchgl %esi, (%rdi) +#else + cmpxchgl %esi, MUTEX(%rdi) +#endif + jnz 12f + +13: decl READERS_QUEUED(%rdi) + jmp 2b + +5: xorl %edx, %edx + incl NR_READERS(%rdi) + je 8f +9: LOCK +#if MUTEX == 0 + decl (%rdi) +#else + decl MUTEX(%rdi) +#endif + jne 6f +7: + + movq %rdx, %rax + retq + +1: movl PSHARED(%rdi), %esi +#if MUTEX != 0 + addq $MUTEX, %rdi +#endif + callq __lll_lock_wait +#if MUTEX != 0 + subq $MUTEX, %rdi +#endif + jmp 2b + +14: cmpl %fs:TID, %eax + jne 3b + /* Deadlock detected. */ + movl $EDEADLK, %edx + jmp 9b + +6: movl PSHARED(%rdi), %esi +#if MUTEX != 0 + addq $MUTEX, %rdi +#endif + callq __lll_unlock_wake +#if MUTEX != 0 + subq $MUTEX, %rdi +#endif + jmp 7b + + /* Overflow. */ +8: decl NR_READERS(%rdi) + movl $EAGAIN, %edx + jmp 9b + + /* Overflow. */ +4: decl READERS_QUEUED(%rdi) + movl $EAGAIN, %edx + jmp 9b + +10: movl PSHARED(%rdi), %esi +#if MUTEX != 0 + addq $MUTEX, %rdi +#endif + callq __lll_unlock_wake +#if MUTEX != 0 + subq $MUTEX, %rdi +#endif + jmp 11b + +12: movl PSHARED(%rdi), %esi +#if MUTEX == 0 + addq $MUTEX, %rdi +#endif + callq __lll_lock_wait +#if MUTEX != 0 + subq $MUTEX, %rdi +#endif + jmp 13b + cfi_endproc + .size __pthread_rwlock_rdlock,.-__pthread_rwlock_rdlock + +strong_alias (__pthread_rwlock_rdlock, pthread_rwlock_rdlock) +hidden_def (__pthread_rwlock_rdlock) |