/* * Copyright (c) 1999 Apple Computer, Inc. All rights reserved. * * @APPLE_LICENSE_HEADER_START@ * * The contents of this file constitute Original Code as defined in and * are subject to the Apple Public Source License Version 1.1 (the * "License"). You may not use this file except in compliance with the * License. Please obtain a copy of the License at * http://www.apple.com/publicsource and read it before using this file. * * This Original Code and all software distributed under the License are * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the * License for the specific language governing rights and limitations * under the License. * * @APPLE_LICENSE_HEADER_END@ */ /* Copyright (c) 1998 Apple Computer, Inc. All rights reserved. * * File: libc/ppc/sys/vfork.s * * HISTORY * 23-Jun-1998 Umesh Vaishampayan (umeshv@apple.com) * Created from fork.s * */ #if 0 #import <sys/syscall.h> #import <architecture/ppc/asm_help.h> #import <architecture/ppc/pseudo_inst.h> #import <mach/ppc/syscall_sw.h> /* We use 8 bytes for LOCAL_VAR(1) and LOCAL_VAR(2) */ NESTED(_vfork, 8, 0, 0, 0) CALL_EXTERN(__cthread_fork_prepare) #if defined(__DYNAMIC__) .cstring LC1: .ascii "__dyld_fork_prepare\0" .text .align 2 mflr r0 bl 1f 1: mflr r3 mtlr r0 addis r3,r3,ha16(LC1-1b) addi r3,r3,lo16(LC1-1b) addi r4,r1,LOCAL_VAR(1) bl __dyld_func_lookup lwz r3,LOCAL_VAR(1)(r1) mtspr ctr,r3 bctrl #endif li r0,SYS_vfork sc b Lbotch // error return cmpwi r4,0 beq Lparent // parent, since a1 == 0 in parent, // 1 in child #if defined(__DYNAMIC__) .cstring LC3: .ascii "__dyld_fork_child\0" .text .align 2 mflr r0 bl 1f 1: mflr r3 mtlr r0 addis r3,r3,ha16(LC3-1b) addi r3,r3,lo16(LC3-1b) addi r4,r1,LOCAL_VAR(1) bl __dyld_func_lookup lwz r3,LOCAL_VAR(1)(r1) mtspr ctr,r3 bctrl #endif li r3,0 REG_TO_EXTERN(r3, EXT(_current_pid)) CALL_EXTERN(_fork_mach_init) CALL_EXTERN(__cthread_fork_child) #if defined(__DYNAMIC__) .cstring LC4: .ascii "__dyld_fork_child_final\0" .text .align 2 mflr r0 bl 1f 1: mflr r3 mtlr r0 addis r3,r3,ha16(LC4-1b) addi r3,r3,lo16(LC4-1b) addi r4,r1,LOCAL_VAR(1) bl __dyld_func_lookup lwz r3,LOCAL_VAR(1)(r1) mtspr ctr,r3 bctrl #endif li r3,0 b Lreturn Lparent: #if defined(__DYNAMIC__) stw r3,LOCAL_VAR(2)(r1) // save child pid mflr r0 bl 1f 1: mflr r3 mtlr r0 addis r3,r3,ha16(LC2-1b) addi r3,r3,lo16(LC2-1b) addi r4,r1,LOCAL_VAR(1) bl __dyld_func_lookup lwz r3,LOCAL_VAR(1)(r1) mtspr ctr,r3 bctrl #endif CALL_EXTERN(__cthread_fork_parent) #if defined(__DYNAMIC__) lwz r3,LOCAL_VAR(2)(r1) #endif b Lreturn Lbotch: #if defined(__DYNAMIC__) .cstring LC2: .ascii "__dyld_fork_parent\0" .text .align 2 stw r3,LOCAL_VAR(2)(r1) // save error value mflr r0 bl 1f 1: mflr r3 mtlr r0 addis r3,r3,ha16(LC2-1b) addi r3,r3,lo16(LC2-1b) addi r4,r1,LOCAL_VAR(1) bl __dyld_func_lookup lwz r3,LOCAL_VAR(1)(r1) mtspr ctr,r3 bctrl lwz r3,LOCAL_VAR(2)(r1) // restore error value for cerror #endif CALL_EXTERN(cerror) /* * We use cthread_fork_parent() to clean up after a fork error * (unlock cthreads and mailloc packages) so the parent * process can Malloc() after fork() errors without * deadlocking. */ CALL_EXTERN_AGAIN(__cthread_fork_parent) li32 r3,-1 // error return Lreturn: RETURN END(_vfork) #else #include "SYS.h" LEAF(_vfork) #if defined(__DYNAMIC__) PICIFY(__current_pid) mr r5,PICIFY_REG NON_LAZY_STUB(__current_pid) #else lis r5,ha16(__current_pid) ori r5,r5,lo16(__current_pid) #endif 2: lwarx r6,0,r5 // dont cache pid across vfork cmpwi r6,0 ble- 3f // is another vfork in progress li r6,0 // if not, erase the stored pid 3: addi r6,r6,-1 // count the parallel vforks in stwcx. r6,0,r5 // negative cached pid values bne- 2b li r0,SYS_vfork sc b Lbotch // error return cmpwi r4,0 beq Lparent // parent, since a1 == 0 in parent, li r3,0 // child blr Lparent: lwarx r6,0,r5 // were back, decrement vfork count addi r6,r6,1 stwcx. r6,0,r5 bne- Lparent blr Lbotch: lwarx r6,0,r5 // never went, decrement vfork count addi r6,r6,1 stwcx. r6,0,r5 bne- Lbotch BRANCH_EXTERN(cerror) END(_vfork) #endif