Mercurial > hg > nginx-quic
view src/os/unix/rfork_thread.S @ 4311:45272aab5eea
Unlock of shared memory zones on process crash.
If process exited abnormally while holding lock on some shared memory zone -
unlock it. It may be not safe thing to do (as crash with lock held may
result in corrupted shared memory structure, and other processes will
subsequently crash while trying to access shared data), therefore complain
loudly if unlock succeeds.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Wed, 23 Nov 2011 14:09:19 +0000 |
parents | 621229427cba |
children | d620f497c50f |
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/* * Copyright (C) Igor Sysoev */ #include <sys/syscall.h> #include <machine/asm.h> /* * rfork_thread(3) - rfork_thread(flags, stack, func, arg); */ #define KERNCALL int $0x80 ENTRY(rfork_thread) push %ebp mov %esp, %ebp push %esi mov 12(%ebp), %esi # the thread stack address sub $4, %esi mov 20(%ebp), %eax # the thread argument mov %eax, (%esi) sub $4, %esi mov 16(%ebp), %eax # the thread start address mov %eax, (%esi) push 8(%ebp) # rfork(2) flags push $0 mov $SYS_rfork, %eax KERNCALL jc error cmp $0, %edx jne child parent: add $8, %esp pop %esi leave ret child: mov %esi, %esp pop %eax call *%eax # call a thread start address ... add $4, %esp push %eax push $0 mov $SYS_exit, %eax # ... and exit(2) after a thread would return KERNCALL error: add $8, %esp pop %esi leave PIC_PROLOGUE /* libc's cerror: jmp PIC_PLT(HIDENAME(cerror)) */ push %eax call PIC_PLT(CNAME(__error)) pop %ecx PIC_EPILOGUE mov %ecx, (%eax) mov $-1, %eax mov $-1, %edx ret