projects / apple / libc.git / blame
| Commit | Line | Data |
|---|---|---|
| e9ce8d39 | 1 | /* |
| 9385eb3d | 2 | * Copyright (c) 1999-2003 Apple Computer, Inc. All rights reserved. |
| e9ce8d39 A |
3 | * |
| 4 | * @APPLE_LICENSE_HEADER_START@ | |
| 5 | * | |
| 734aad71 A |
6 | * This file contains Original Code and/or Modifications of Original Code |
| 7 | * as defined in and that are subject to the Apple Public Source License | |
| 8 | * Version 2.0 (the 'License'). You may not use this file except in | |
| 9 | * compliance with the License. Please obtain a copy of the License at | |
| 10 | * http://www.opensource.apple.com/apsl/ and read it before using this | |
| 11 | * file. | |
| 12 | * | |
| 13 | * The Original Code and all software distributed under the License are | |
| 14 | * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER | |
| e9ce8d39 A |
15 | * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, |
| 16 | * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, | |
| 734aad71 A |
17 | * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. |
| 18 | * Please see the License for the specific language governing rights and | |
| 19 | * limitations under the License. | |
| e9ce8d39 A |
20 | * |
| 21 | * @APPLE_LICENSE_HEADER_END@ | |
| 22 | */ | |
| 23 | /* | |
| 24 | * Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved | |
| 25 | */ | |
| 8e029c65 | 26 | #include <SYS.h> |
| e9ce8d39 | 27 | |
| e9ce8d39 | 28 | #if defined(__DYNAMIC__) |
| 9385eb3d | 29 | #define GET_CURRENT_PID PICIFY(__current_pid) |
| e9ce8d39 | 30 | |
| 9385eb3d A |
31 | NON_LAZY_STUB(__current_pid) |
| 32 | #define __current_pid (%edx) | |
| 33 | #else | |
| 34 | #define GET_CURRENT_PID | |
| e9ce8d39 | 35 | #endif |
| e9ce8d39 | 36 | |
| 9385eb3d A |
37 | /* |
| 38 | * If __current_pid >= 0, we want to put a -1 in there | |
| 39 | * otherwise we just decrement it | |
| 40 | */ | |
| 3b2a1fe8 A |
41 | |
| 42 | LEAF(_vfork, 0) | |
| 9385eb3d A |
43 | GET_CURRENT_PID |
| 44 | movl __current_pid, %eax | |
| 45 | 0: | |
| 46 | xorl %ecx, %ecx | |
| 47 | testl %eax, %eax | |
| 48 | cmovs %eax, %ecx | |
| 49 | decl %ecx | |
| 50 | lock | |
| 51 | cmpxchgl %ecx, __current_pid | |
| 52 | jne 0b | |
| 53 | popl %ecx | |
| 54 | movl $(SYS_vfork), %eax // code for vfork -> eax | |
| 55 | UNIX_SYSCALL_TRAP // do the system call | |
| 56 | jnb L1 // jump if CF==0 | |
| 57 | GET_CURRENT_PID | |
| 58 | lock | |
| 59 | incl __current_pid | |
| 60 | pushl %ecx | |
| 61 | BRANCH_EXTERN(cerror) | |
| 3b2a1fe8 A |
62 | |
| 63 | L1: | |
| 9385eb3d A |
64 | testl %edx, %edx // CF=OF=0, ZF set if zero result |
| 65 | jz L2 // parent, since r1 == 0 in parent, 1 in child | |
| 66 | xorl %eax, %eax // zero eax | |
| 67 | jmp *%ecx | |
| 3b2a1fe8 A |
68 | |
| 69 | L2: | |
| 9385eb3d A |
70 | GET_CURRENT_PID |
| 71 | lock | |
| 72 | incl __current_pid | |
| 73 | jmp *%ecx |