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 | 257 |
1 files changed, 257 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..3fb89e419 --- /dev/null +++ b/libpthread/nptl/sysdeps/unix/sysv/linux/x86_64/pthread_once.S @@ -0,0 +1,257 @@ +/* Copyright (C) 2002, 2003, 2005 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. */ + +#ifndef UP +# define LOCK lock +#else +# define LOCK +#endif + +#define FUTEX_WAIT 0 +#define FUTEX_WAKE 1 + + .comm __fork_generation, 4, 4 + + .text + + + .globl __pthread_once + .type __pthread_once,@function + .align 16 +__pthread_once: +.LSTARTCODE: + testl $2, (%rdi) + jz 1f + xorl %eax, %eax + retq + + /* Preserve the function pointer. */ +1: pushq %rsi +.Lpush_rsi: + 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. */ +#if FUTEX_WAIT == 0 + xorl %esi, %esi +#else + movl $FUTEX_WAIT, %esi +#endif + movl $SYS_futex, %eax + syscall + jmp 6b + + /* Preserve the pointer to the control variable. */ +3: pushq %rdi +.Lpush_rdi: + +.LcleanupSTART: + callq *8(%rsp) +.LcleanupEND: + + /* Get the control variable address back. */ + popq %rdi +.Lpop_rdi: + + /* Sucessful run of the initializer. Signal that we are done. */ + LOCK + incl (%rdi) + + /* Wake up all other threads. */ + movl $0x7fffffff, %edx + movl $FUTEX_WAKE, %esi + movl $SYS_futex, %eax + syscall + +4: addq $8, %rsp +.Ladd: + 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: + movq (%rsp), %rdi + movq %rax, %r8 + movl $0, (%rdi) + + movl $0x7fffffff, %edx + movl $FUTEX_WAKE, %esi + movl $SYS_futex, %eax + syscall + + movq %r8, %rdi +.LcallUR: + call _Unwind_Resume@PLT + hlt +.LENDCODE: + .size clear_once_control,.-clear_once_control + + + .section .gcc_except_table,"a",@progbits +.LexceptSTART: + .byte 0xff # @LPStart format (omit) + .byte 0xff # @TType format (omit) + .byte 0x01 # call-site format + # DW_EH_PE_uleb128 + .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: + + + .section .eh_frame,"a",@progbits +.LSTARTFRAME: + .long .LENDCIE-.LSTARTCIE # Length of the CIE. +.LSTARTCIE: + .long 0 # CIE ID. + .byte 1 # Version number. +#ifdef SHARED + .string "zPLR" # NUL-terminated augmentation + # string. +#else + .string "zPL" # NUL-terminated augmentation + # string. +#endif + .uleb128 1 # Code alignment factor. + .sleb128 -8 # Data alignment factor. + .byte 16 # Return address register + # column. +#ifdef SHARED + .uleb128 7 # Augmentation value length. + .byte 0x9b # Personality: DW_EH_PE_pcrel + # + DW_EH_PE_sdata4 + # + DW_EH_PE_indirect + .long DW.ref.__gcc_personality_v0-. + .byte 0x1b # LSDA Encoding: DW_EH_PE_pcrel + # + DW_EH_PE_sdata4. + .byte 0x1b # FDE Encoding: DW_EH_PE_pcrel + # + DW_EH_PE_sdata4. +#else + .uleb128 10 # Augmentation value length. + .byte 0x0 # Personality: absolute + .quad __gcc_personality_v0 + .byte 0x0 # LSDA Encoding: absolute +#endif + .byte 0x0c # DW_CFA_def_cfa + .uleb128 7 + .uleb128 8 + .byte 0x90 # DW_CFA_offset, column 0x10 + .uleb128 1 + .align 8 +.LENDCIE: + + .long .LENDFDE-.LSTARTFDE # Length of the FDE. +.LSTARTFDE: + .long .LSTARTFDE-.LSTARTFRAME # CIE pointer. +#ifdef SHARED + .long .LSTARTCODE-. # PC-relative start address + # of the code. + .long .LENDCODE-.LSTARTCODE # Length of the code. + .uleb128 4 # Augmentation size + .long .LexceptSTART-. +#else + .quad .LSTARTCODE # Start address of the code. + .quad .LENDCODE-.LSTARTCODE # Length of the code. + .uleb128 8 # Augmentation size + .quad .LexceptSTART +#endif + .byte 4 # DW_CFA_advance_loc4 + .long .Lpush_rsi-.LSTARTCODE + .byte 14 # DW_CFA_def_cfa_offset + .uleb128 16 + .byte 4 # DW_CFA_advance_loc4 + .long .Lpush_rdi-.Lpush_rsi + .byte 14 # DW_CFA_def_cfa_offset + .uleb128 24 + .byte 4 # DW_CFA_advance_loc4 + .long .Lpop_rdi-.Lpush_rdi + .byte 14 # DW_CFA_def_cfa_offset + .uleb128 16 + .byte 4 # DW_CFA_advance_loc4 + .long .Ladd-.Lpop_rdi + .byte 14 # DW_CFA_def_cfa_offset + .uleb128 8 + .byte 4 # DW_CFA_advance_loc4 + .long clear_once_control-.Ladd + .byte 14 # DW_CFA_def_cfa_offset + .uleb128 24 +#if 0 + .byte 4 # DW_CFA_advance_loc4 + .long .Lpop_rdi2-clear_once_control + .byte 14 # DW_CFA_def_cfa_offset + .uleb128 16 +#endif + .align 8 +.LENDFDE: + + +#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 |