diff options
Diffstat (limited to 'nptl/sysdeps/unix/sysv/linux/i386/pthread_once.S')
| -rw-r--r-- | nptl/sysdeps/unix/sysv/linux/i386/pthread_once.S | 171 |
1 files changed, 171 insertions, 0 deletions
diff --git a/nptl/sysdeps/unix/sysv/linux/i386/pthread_once.S b/nptl/sysdeps/unix/sysv/linux/i386/pthread_once.S new file mode 100644 index 0000000000..747c8ec2d2 --- /dev/null +++ b/nptl/sysdeps/unix/sysv/linux/i386/pthread_once.S @@ -0,0 +1,171 @@ +/* Copyright (C) 2002 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> + +#ifndef UP +# define LOCK lock +#else +# define LOCK +#endif + +#define SYS_futex 240 +#define FUTEX_WAKE 1 + + .comm __fork_generation, 4, 4 + + .text + + + .globl __pthread_once + .type __pthread_once,@function + .align 16 +__pthread_once: + movl 4(%esp), %ecx + testl $2, (%ecx) + jz 1f + xorl %eax, %eax + ret + +1: pushl %ebx + pushl %esi + movl %ecx, %ebx + xorl %esi, %esi + + /* Not yet initialized or initialization in progress. + Get the fork generation counter now. */ +6: movl (%ebx), %eax +#ifdef PIC + call __i686.get_pc_thunk.cx + addl $_GLOBAL_OFFSET_TABLE_, %ecx +#endif + +5: movl %eax, %edx + + testl $2, %eax + jnz 4f + + andl $3, %edx +#ifdef PIC + orl __fork_generation@GOTOFF(%ecx), %edx +#else + orl __fork_generation, %edx +#endif + orl $1, %edx + + LOCK + cmpxchgl %edx, (%ebx) + jnz 5b + + /* Check whether another thread already runs the initializer. */ + testl $1, %eax + jz 3f /* No -> do it. */ + + /* Check whether the initializer execution was interrupted + by a fork. */ + xorl %edx, %eax + testl $0xfffffffc, %eax + jnz 3f /* Different for generation -> run initializer. */ + + /* Somebody else got here first. Wait. */ + movl %esi, %ecx /* movl $FUTEX_WAIT, %ecx */ + movl $SYS_futex, %eax + int $0x80 + jmp 6b + +3: /* Call the initializer function after setting up the + cancellation handler. */ + subl $16, %esp + + /* Push the cleanup handler. */ +#ifdef PIC + leal clear_once_control@GOTOFF(%ecx), %eax +#else + leal clear_once_control, %eax +#endif + movl %esp, %edx + pushl %ebx + pushl %eax + pushl %edx + call _GI_pthread_cleanup_push /* Note: no @PLT. */ + + movl 44(%esp), %eax + call *%eax + + /* Pop the cleanup handler. This code depends on the once + handler and _pthread_cleanup_push not touch the content + of the stack. Otherwise the first parameter would have + to be reloaded. */ + movl $0, 4(%esp) + call _GI_pthread_cleanup_pop /* Note: no @PLT. */ + + addl $28, %esp + + /* Sucessful run of the initializer. Signal that we are done. */ + LOCK + incl (%ebx) + + /* Wake up all other threads. */ + movl $0x7fffffff, %edx + movl $FUTEX_WAKE, %ecx + movl $SYS_futex, %eax + int $0x80 + +4: popl %esi + popl %ebx + xorl %eax, %eax + ret + + .size __pthread_once,.-__pthread_once + + .globl pthread_once +pthread_once = __pthread_once + + + .type clear_once_control,@function + .align 16 +clear_once_control: + pushl %esi + pushl %ebx + + movl 4(%esp), %eax + movl $0, (%eax) + + xorl %esi, %esi + movl $0x7fffffff, %edx + movl $FUTEX_WAKE, %ecx + movl $SYS_futex, %eax + int $0x80 + + popl %ebx + popl %esi + ret + .size clear_once_control,.-clear_once_control + + +#ifdef PIC + .section .gnu.linkonce.t.__i686.get_pc_thunk.cx,"ax",@progbits + .globl __i686.get_pc_thunk.cx + .hidden __i686.get_pc_thunk.cx + .type __i686.get_pc_thunk.cx,@function +__i686.get_pc_thunk.cx: + movl (%esp), %ecx; + ret + .size __i686.get_pc_thunk.cx,.-__i686.get_pc_thunk.cx +#endif |