[apple/libc.git] / sys.subproj / i386.subproj / fork.s

/*
 * 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) 1995 NeXT Computer, Inc. All Rights Reserved
 */
#include "SYS.h"

LEAF(_fork, 0) 
	CALL_EXTERN(__cthread_fork_prepare)
#if defined(__DYNAMIC__)
// Just like __cthread_fork_prepare we need to prevent threads on the child's
// side from doing a mach call in the dynamic linker until __dyld_fork_child
// is run (see below).  So we call __dyld_fork_prepare which takes out the dyld
// lock to prevent all other threads but this one from entering dyld.
.cstring
LC1:
	.ascii "__dyld_fork_prepare\0"
.text
	subl	$4,%esp		// allocate space for the address parameter
	leal	0(%esp),%eax	// get the address of the allocated space
	pushl	%eax		// push the address of the allocated space
	call	1f
1:	popl	%eax
	leal	LC1-1b(%eax),%eax
	pushl 	%eax		// push the name of the function to look up
	call 	__dyld_func_lookup
	addl	$8,%esp		// remove parameters to __dyld_func_lookup
	movl	0(%esp),%eax	// move the value returned in address parameter
	addl	$4,%esp		// deallocate the space for the address param
	call	*%eax		// call __dyld_fork_prepare indirectly
#endif

	movl 	$SYS_fork,%eax; 	// code for fork -> eax
	UNIX_SYSCALL_TRAP; 		// do the system call
	jnc	L1			// jump if CF==0

#if defined(__DYNAMIC__)
// __dyld_fork_parent() is called by the parent process after a fork syscall.
// This releases the dyld lock acquired by __dyld_fork_prepare().  In this case
// we just use it to clean up after a fork error so the parent process can 
// dyld after fork() errors without deadlocking.
.cstring
LC2:
	.ascii "__dyld_fork_parent\0"
.text
	pushl	%eax		// save the return value (errno)
	subl	$4,%esp		// allocate space for the address parameter
	leal	0(%esp),%eax	// get the address of the allocated space
	pushl	%eax		// push the address of the allocated space
	call	1f
1:	popl	%eax
	leal	LC2-1b(%eax),%eax
	pushl 	%eax		// push the name of the function to look up
	call 	__dyld_func_lookup
	addl	$8,%esp		// remove parameters to __dyld_func_lookup
	movl	0(%esp),%eax	// move the value returned in address parameter
	addl	$4,%esp		// deallocate the space for the address param
	call	*%eax		// call __dyld_fork_parent indirectly
	popl	%eax		// restore the return value (errno)
#endif
	CALL_EXTERN(cerror)
	CALL_EXTERN(__cthread_fork_parent)
	movl	$-1,%eax
	ret
	
L1:
	orl	%edx,%edx	// CF=OF=0,  ZF set if zero result	
	jz	L2		// parent, since r1 == 0 in parent, 1 in child
	
	//child here...
#if defined(__DYNAMIC__)
// Here on the child side of the fork we need to tell the dynamic linker that
// we have forked.  To do this we call __dyld_fork_child in the dyanmic
// linker.  But since we can't dynamicly bind anything until this is done we
// do this by using the private extern __dyld_func_lookup() function to get the
// address of __dyld_fork_child (the 'C' code equivlent):
//
//	_dyld_func_lookup("__dyld_fork_child", &address);
//	address();
//
.cstring
LC0:
	.ascii "__dyld_fork_child\0"

.text
	subl	$4,%esp		// allocate space for the address parameter
	leal	0(%esp),%eax	// get the address of the allocated space
	pushl	%eax		// push the address of the allocated space
	call	1f
1:	popl	%eax
	leal	LC0-1b(%eax),%eax
	pushl 	%eax		// push the name of the function to look up
	call 	__dyld_func_lookup
	addl	$8,%esp		// remove parameters to __dyld_func_lookup
	movl	0(%esp),%eax	// move the value returned in address parameter
	addl	$4,%esp		// deallocate the space for the address param
	call	*%eax		// call __dyld_fork_child indirectly
#endif
	CALL_EXTERN(_fork_mach_init)
	CALL_EXTERN(__cthread_fork_child)
#if	defined(__DYNAMIC__)
.cstring
LC10:
	.ascii "__dyld_fork_child_final\0"

.text
	subl	$4,%esp		// allocate space for the address parameter
	leal	0(%esp),%eax	// get the address of the allocated space
	pushl	%eax		// push the address of the allocated space
	call	1f
1:	popl	%eax
	leal	LC10-1b(%eax),%eax
	pushl 	%eax		// push the name of the function to look up
	call 	__dyld_func_lookup
	addl	$8,%esp		// remove parameters to __dyld_func_lookup
	movl	0(%esp),%eax	// move the value returned in address parameter
	addl	$4,%esp		// deallocate the space for the address param
	call	*%eax		// call __dyld_fork_child_final indirectly
#endif
	xorl	%eax,%eax	// zero eax
	ret

	//parent here...
L2:
	push	%eax		// save pid
#if	defined(__DYNAMIC__)
// __dyld_fork_parent() is called by the parent process after a fork syscall.
// This releases the dyld lock acquired by __dyld_fork_prepare().
	subl	$4,%esp		// allocate space for the address parameter
	leal	0(%esp),%eax	// get the address of the allocated space
	pushl	%eax		// push the address of the allocated space
	call	1f
1:	popl	%eax
	leal	LC2-1b(%eax),%eax
	pushl 	%eax		// push the name of the function to look up
	call 	__dyld_func_lookup
	addl	$8,%esp		// remove parameters to __dyld_func_lookup
	movl	0(%esp),%eax	// move the value returned in address parameter
	addl	$4,%esp		// deallocate the space for the address param
	call	*%eax		// call __dyld_fork_parent indirectly
#endif
	CALL_EXTERN_AGAIN(__cthread_fork_parent)
	pop	%eax
	ret
Commit	Line	Data
e9ce8d39 A	1	/*
	2	* Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
	3	*
	4	* @APPLE_LICENSE_HEADER_START@
	5	*
	6	* The contents of this file constitute Original Code as defined in and
	7	* are subject to the Apple Public Source License Version 1.1 (the
	8	* "License"). You may not use this file except in compliance with the
	9	* License. Please obtain a copy of the License at
	10	* http://www.apple.com/publicsource and read it before using this file.
	11	*
	12	* This Original Code and all software distributed under the License are
	13	* distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
	14	* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
	15	* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
	16	* FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the
	17	* License for the specific language governing rights and limitations
	18	* under the License.
	19	*
	20	* @APPLE_LICENSE_HEADER_END@
	21	*/
	22	/*
	23	* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved
	24	*/
	25	#include "SYS.h"
	26
	27	LEAF(_fork, 0)
	28	CALL_EXTERN(__cthread_fork_prepare)
	29	#if defined(__DYNAMIC__)
	30	// Just like __cthread_fork_prepare we need to prevent threads on the child's
	31	// side from doing a mach call in the dynamic linker until __dyld_fork_child
	32	// is run (see below). So we call __dyld_fork_prepare which takes out the dyld
	33	// lock to prevent all other threads but this one from entering dyld.
	34	.cstring
	35	LC1:
	36	.ascii "__dyld_fork_prepare\0"
	37	.text
	38	subl $4,%esp // allocate space for the address parameter
	39	leal 0(%esp),%eax // get the address of the allocated space
	40	pushl %eax // push the address of the allocated space
	41	call 1f
	42	1: popl %eax
	43	leal LC1-1b(%eax),%eax
	44	pushl %eax // push the name of the function to look up
	45	call __dyld_func_lookup
	46	addl $8,%esp // remove parameters to __dyld_func_lookup
	47	movl 0(%esp),%eax // move the value returned in address parameter
	48	addl $4,%esp // deallocate the space for the address param
	49	call *%eax // call __dyld_fork_prepare indirectly
	50	#endif
	51
	52	movl $SYS_fork,%eax; // code for fork -> eax
	53	UNIX_SYSCALL_TRAP; // do the system call
	54	jnc L1 // jump if CF==0
	55
	56	#if defined(__DYNAMIC__)
	57	// __dyld_fork_parent() is called by the parent process after a fork syscall.
	58	// This releases the dyld lock acquired by __dyld_fork_prepare(). In this case
	59	// we just use it to clean up after a fork error so the parent process can
	60	// dyld after fork() errors without deadlocking.
	61	.cstring
	62	LC2:
	63	.ascii "__dyld_fork_parent\0"
	64	.text
65	pushl %eax // save the return value (errno)
66	subl $4,%esp // allocate space for the address parameter
67	leal 0(%esp),%eax // get the address of the allocated space
68	pushl %eax // push the address of the allocated space
69	call 1f
70	1: popl %eax
71	leal LC2-1b(%eax),%eax
72	pushl %eax // push the name of the function to look up
73	call __dyld_func_lookup
74	addl $8,%esp // remove parameters to __dyld_func_lookup
75	movl 0(%esp),%eax // move the value returned in address parameter
76	addl $4,%esp // deallocate the space for the address param
77	call *%eax // call __dyld_fork_parent indirectly
78	popl %eax // restore the return value (errno)
79	#endif
80	CALL_EXTERN(cerror)
81	CALL_EXTERN(__cthread_fork_parent)
82	movl $-1,%eax
83	ret
84
85	L1:
86	orl %edx,%edx // CF=OF=0, ZF set if zero result
87	jz L2 // parent, since r1 == 0 in parent, 1 in child
88
89	//child here...
90	#if defined(__DYNAMIC__)
91	// Here on the child side of the fork we need to tell the dynamic linker that
92	// we have forked. To do this we call __dyld_fork_child in the dyanmic
93	// linker. But since we can't dynamicly bind anything until this is done we
94	// do this by using the private extern __dyld_func_lookup() function to get the
95	// address of __dyld_fork_child (the 'C' code equivlent):
96	//
97	// _dyld_func_lookup("__dyld_fork_child", &address);
98	// address();
99	//
100	.cstring
101	LC0:
102	.ascii "__dyld_fork_child\0"
103
104	.text
105	subl $4,%esp // allocate space for the address parameter
106	leal 0(%esp),%eax // get the address of the allocated space
107	pushl %eax // push the address of the allocated space
108	call 1f
109	1: popl %eax
110	leal LC0-1b(%eax),%eax
111	pushl %eax // push the name of the function to look up
112	call __dyld_func_lookup
113	addl $8,%esp // remove parameters to __dyld_func_lookup
114	movl 0(%esp),%eax // move the value returned in address parameter
115	addl $4,%esp // deallocate the space for the address param
116	call *%eax // call __dyld_fork_child indirectly
117	#endif
118	CALL_EXTERN(_fork_mach_init)
119	CALL_EXTERN(__cthread_fork_child)
120	#if defined(__DYNAMIC__)
121	.cstring
122	LC10:
123	.ascii "__dyld_fork_child_final\0"
124
125	.text
126	subl $4,%esp // allocate space for the address parameter
127	leal 0(%esp),%eax // get the address of the allocated space
128	pushl %eax // push the address of the allocated space
129	call 1f
130	1: popl %eax
131	leal LC10-1b(%eax),%eax
132	pushl %eax // push the name of the function to look up
133	call __dyld_func_lookup
134	addl $8,%esp // remove parameters to __dyld_func_lookup
135	movl 0(%esp),%eax // move the value returned in address parameter
136	addl $4,%esp // deallocate the space for the address param
137	call *%eax // call __dyld_fork_child_final indirectly
138	#endif
139	xorl %eax,%eax // zero eax
140	ret
141
142	//parent here...
143	L2:
144	push %eax // save pid
145	#if defined(__DYNAMIC__)
146	// __dyld_fork_parent() is called by the parent process after a fork syscall.
147	// This releases the dyld lock acquired by __dyld_fork_prepare().
148	subl $4,%esp // allocate space for the address parameter
149	leal 0(%esp),%eax // get the address of the allocated space
150	pushl %eax // push the address of the allocated space
151	call 1f
152	1: popl %eax
153	leal LC2-1b(%eax),%eax
154	pushl %eax // push the name of the function to look up
155	call __dyld_func_lookup
156	addl $8,%esp // remove parameters to __dyld_func_lookup
157	movl 0(%esp),%eax // move the value returned in address parameter
158	addl $4,%esp // deallocate the space for the address param
159	call *%eax // call __dyld_fork_parent indirectly
160	#endif
161	CALL_EXTERN_AGAIN(__cthread_fork_parent)
162	pop %eax
163	ret
164