diff options
Diffstat (limited to 'libpthread/nptl/sysdeps/unix/sysv/linux/x86_64/pthread_once.S')
| -rw-r--r-- | libpthread/nptl/sysdeps/unix/sysv/linux/x86_64/pthread_once.S | 189 |
1 files changed, 189 insertions, 0 deletions
diff --git a/libpthread/nptl/sysdeps/unix/sysv/linux/x86_64/pthread_once.S b/libpthread/nptl/sysdeps/unix/sysv/linux/x86_64/pthread_once.S new file mode 100644 index 000000000..a808b9d7e --- /dev/null +++ b/libpthread/nptl/sysdeps/unix/sysv/linux/x86_64/pthread_once.S @@ -0,0 +1,189 @@ +/* Copyright (C) 2002, 2003, 2005, 2007, 2009 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 <bits/kernel-features.h> +#include <tcb-offsets.h> +#include <lowlevellock.h> + + + .comm __fork_generation, 4, 4 + + .text + + + .globl __pthread_once + .type __pthread_once,@function + .align 16 +__pthread_once: +.LSTARTCODE: + cfi_startproc + testl $2, (%rdi) + jz 1f + xorl %eax, %eax + retq + + /* Preserve the function pointer. */ +1: pushq %rsi + cfi_adjust_cfa_offset(8) + xorq %r10, %r10 + + /* Not yet initialized or initialization in progress. + Get the fork generation counter now. */ +6: movl (%rdi), %eax + +5: movl %eax, %edx + + testl $2, %eax + jnz 4f + + andl $3, %edx + orl __fork_generation(%rip), %edx + orl $1, %edx + + LOCK + cmpxchgl %edx, (%rdi) + 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. */ +#ifdef __ASSUME_PRIVATE_FUTEX + movl $FUTEX_WAIT|FUTEX_PRIVATE_FLAG, %esi +#else +# if FUTEX_WAIT == 0 + movl %fs:PRIVATE_FUTEX, %esi +# else + movl $FUTEX_WAIT, %esi + orl %fs:PRIVATE_FUTEX, %esi +# endif +#endif + movl $SYS_futex, %eax + syscall + jmp 6b + + /* Preserve the pointer to the control variable. */ +3: pushq %rdi + cfi_adjust_cfa_offset(8) + pushq %rdi + cfi_adjust_cfa_offset(8) + +.LcleanupSTART: + callq *16(%rsp) +.LcleanupEND: + + /* Get the control variable address back. */ + popq %rdi + cfi_adjust_cfa_offset(-8) + + /* Sucessful run of the initializer. Signal that we are done. */ + LOCK + incl (%rdi) + + addq $8, %rsp + cfi_adjust_cfa_offset(-8) + + /* Wake up all other threads. */ + movl $0x7fffffff, %edx +#ifdef __ASSUME_PRIVATE_FUTEX + movl $FUTEX_WAKE|FUTEX_PRIVATE_FLAG, %esi +#else + movl $FUTEX_WAKE, %esi + orl %fs:PRIVATE_FUTEX, %esi +#endif + movl $SYS_futex, %eax + syscall + +4: addq $8, %rsp + cfi_adjust_cfa_offset(-8) + xorl %eax, %eax + retq + .size __pthread_once,.-__pthread_once + + + .globl __pthread_once_internal +__pthread_once_internal = __pthread_once + + .globl pthread_once +pthread_once = __pthread_once + + + .type clear_once_control,@function + .align 16 +clear_once_control: + cfi_adjust_cfa_offset(3 * 8) + movq (%rsp), %rdi + movq %rax, %r8 + movl $0, (%rdi) + + movl $0x7fffffff, %edx +#ifdef __ASSUME_PRIVATE_FUTEX + movl $FUTEX_WAKE|FUTEX_PRIVATE_FLAG, %esi +#else + movl $FUTEX_WAKE, %esi + orl %fs:PRIVATE_FUTEX, %esi +#endif + movl $SYS_futex, %eax + syscall + + movq %r8, %rdi +.LcallUR: + call _Unwind_Resume@PLT + hlt +.LENDCODE: + cfi_endproc + .size clear_once_control,.-clear_once_control + + + .section .gcc_except_table,"a",@progbits +.LexceptSTART: + .byte DW_EH_PE_omit # @LPStart format + .byte DW_EH_PE_omit # @TType format + .byte DW_EH_PE_uleb128 # call-site format + .uleb128 .Lcstend-.Lcstbegin +.Lcstbegin: + .uleb128 .LcleanupSTART-.LSTARTCODE + .uleb128 .LcleanupEND-.LcleanupSTART + .uleb128 clear_once_control-.LSTARTCODE + .uleb128 0 + .uleb128 .LcallUR-.LSTARTCODE + .uleb128 .LENDCODE-.LcallUR + .uleb128 0 + .uleb128 0 +.Lcstend: + + +#ifdef SHARED + .hidden DW.ref.__gcc_personality_v0 + .weak DW.ref.__gcc_personality_v0 + .section .gnu.linkonce.d.DW.ref.__gcc_personality_v0,"aw",@progbits + .align 8 + .type DW.ref.__gcc_personality_v0, @object + .size DW.ref.__gcc_personality_v0, 8 +DW.ref.__gcc_personality_v0: + .quad __gcc_personality_v0 +#endif |