Index: head/lib/libc/sys/fork.2 =================================================================== --- head/lib/libc/sys/fork.2 (revision 100906) +++ head/lib/libc/sys/fork.2 (revision 100907) @@ -1,135 +1,135 @@ .\" Copyright (c) 1980, 1991, 1993 .\" The Regents of the University of California. All rights reserved. .\" .\" Redistribution and use in source and binary forms, with or without .\" modification, are permitted provided that the following conditions .\" are met: .\" 1. Redistributions of source code must retain the above copyright .\" notice, this list of conditions and the following disclaimer. .\" 2. Redistributions in binary form must reproduce the above copyright .\" notice, this list of conditions and the following disclaimer in the .\" documentation and/or other materials provided with the distribution. .\" 3. All advertising materials mentioning features or use of this software .\" must display the following acknowledgement: .\" This product includes software developed by the University of .\" California, Berkeley and its contributors. .\" 4. Neither the name of the University nor the names of its contributors .\" may be used to endorse or promote products derived from this software .\" without specific prior written permission. .\" .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE .\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF .\" SUCH DAMAGE. .\" .\" @(#)fork.2 8.1 (Berkeley) 6/4/93 .\" $FreeBSD$ .\" .Dd June 4, 1993 .Dt FORK 2 .Os .Sh NAME .Nm fork .Nd create a new process .Sh LIBRARY .Lb libc .Sh SYNOPSIS .In sys/types.h .In unistd.h .Ft pid_t .Fn fork void .Sh DESCRIPTION The .Fn fork function causes creation of a new process. The new process (child process) is an exact copy of the calling process (parent process) except for the following: .Bl -bullet -offset indent .It The child process has a unique process ID. .It The child process has a different parent process ID (i.e., the process ID of the parent process). .It The child process has its own copy of the parent's descriptors. These descriptors reference the same underlying objects, so that, for instance, file pointers in file objects are shared between the child and the parent, so that an .Xr lseek 2 on a descriptor in the child process can affect a subsequent .Xr read 2 or .Xr write 2 by the parent. This descriptor copying is also used by the shell to establish standard input and output for newly created processes as well as to set up pipes. .It The child process' resource utilizations are set to 0; see .Xr setrlimit 2 . .It All interval timers are cleared; see .Xr setitimer 2 . .El .Sh RETURN VALUES Upon successful completion, .Fn fork returns a value of 0 to the child process and returns the process ID of the child process to the parent process. Otherwise, a value of -1 is returned to the parent process, no child process is created, and the global variable .Va errno is set to indicate the error. .Sh ERRORS The .Fn fork function will fail and no child process will be created if: .Bl -tag -width Er .It Bq Er EAGAIN The system-imposed limit on the total number of processes under execution would be exceeded. The limit is given by the .Xr sysctl 3 MIB variable .Dv KERN_MAXPROC . -(The limit is actually one less than this +(The limit is actually ten less than this except for the super user). .It Bq Er EAGAIN The user is not the super user, and the system-imposed limit on the total number of processes under execution by a single user would be exceeded. The limit is given by the .Xr sysctl 3 MIB variable .Dv KERN_MAXPROCPERUID . .It Bq Er EAGAIN The user is not the super user, and the soft resource limit corresponding to the resource parameter .Dv RLIMIT_NPROC would be exceeded (see .Xr getrlimit 2 ) . .It Bq Er ENOMEM There is insufficient swap space for the new process. .El .Sh SEE ALSO .Xr execve 2 , .Xr rfork 2 , .Xr setitimer 2 , .Xr setrlimit 2 , .Xr vfork 2 , .Xr wait 2 .Sh HISTORY A .Fn fork function call appeared in .At v6 . Index: head/lib/libc/sys/rfork.2 =================================================================== --- head/lib/libc/sys/rfork.2 (revision 100906) +++ head/lib/libc/sys/rfork.2 (revision 100907) @@ -1,174 +1,174 @@ .\" .\" This manual page is taken directly from Plan9, and modified to .\" describe the actual BSD implementation. Permission for .\" use of this page comes from Rob Pike . .\" .\" $FreeBSD$ .\" .Dd January 12, 1996 .Dt RFORK 2 .Os .Sh NAME .Nm rfork .Nd manipulate process resources .Sh LIBRARY .Lb libc .Sh SYNOPSIS .In unistd.h .Ft int .Fn rfork "int flags" .Sh DESCRIPTION Forking, vforking or rforking are the only ways new processes are created. The .Fa flags argument to .Fn rfork selects which resources of the invoking process (parent) are shared by the new process (child) or initialized to their default values. The resources include the open file descriptor table (which, when shared, permits processes to open and close files for other processes), and open files. .Fa Flags is the logical OR of some subset of: .Bl -tag -width "RFCNAMEG" -compact -offset indent .It RFPROC If set a new process is created; otherwise changes affect the current process. The current implementation requires this flag to always be set. .It RFNOWAIT If set, the child process will be dissociated from the parent. Upon exit the child will not leave a status for the parent to collect. See .Xr wait 2 . .It RFFDG If set, the invoker's file descriptor table (see .Xr intro 2 ) is copied; otherwise the two processes share a single table. .It RFCFDG If set, the new process starts with a clean file descriptor table. Is mutually exclusive with .Dv RFFDG . .It RFMEM If set, the kernel will force sharing of the entire address space, typically by sharing the hardware page table directly. The child will thus inherit and share all the segments the parent process owns, whether they are normally shareable or not. The stack segment is not split (both the parent and child return on the same stack) and thus .Fn rfork with the RFMEM flag may not generally be called directly from high level languages including C. May be set only with .Dv RFPROC . A helper function is provided to assist with this problem and will cause the new process to run on the provided stack. See .Fn rfork_thread 3 for information. .It RFSIGSHARE If set, the kernel will force sharing the sigacts structure between the child and the parent. .It RFLINUXTHPN If set, the kernel will return SIGUSR1 instead of SIGCHILD upon thread exit for the child. This is intended to mimic certain Linux clone behaviour. .El .Pp File descriptors in a shared file descriptor table are kept open until either they are explicitly closed or all processes sharing the table exit. .Pp If .Dv RFPROC is set, the value returned in the parent process is the process id of the child process; the value returned in the child is zero. Without .Dv RFPROC , the return value is zero. Process id's range from 1 to the maximum integer .Ft ( int ) value. .Fn Rfork will sleep, if necessary, until required process resources are available. .Pp .Fn Fork can be implemented as a call to .Fn rfork "RFFDG | RFPROC" but isn't for backwards compatibility. .Sh RETURN VALUES Upon successful completion, .Fn rfork returns a value of 0 to the child process and returns the process ID of the child process to the parent process. Otherwise, a value of -1 is returned to the parent process, no child process is created, and the global variable .Va errno is set to indicate the error. .Sh ERRORS .Fn Rfork will fail and no child process will be created if: .Bl -tag -width Er .It Bq Er EAGAIN The system-imposed limit on the total number of processes under execution would be exceeded. The limit is given by the .Xr sysctl 3 MIB variable .Dv KERN_MAXPROC . -(The limit is actually one less than this +(The limit is actually ten less than this except for the super user). .It Bq Er EAGAIN The user is not the super user, and the system-imposed limit on the total number of processes under execution by a single user would be exceeded. The limit is given by the .Xr sysctl 3 MIB variable .Dv KERN_MAXPROCPERUID . .It Bq Er EAGAIN The user is not the super user, and the soft resource limit corresponding to the resource parameter .Dv RLIMIT_NOFILE would be exceeded (see .Xr getrlimit 2 ) . .It Bq Er EINVAL The RFPROC flag was not specified. .It Bq Er EINVAL Both the RFFDG and the RFCFDG flags were specified. .It Bq Er EINVAL Any flags not listed above were specified. .It Bq Er ENOMEM There is insufficient swap space for the new process. .El .Sh SEE ALSO .Xr fork 2 , .Xr intro 2 , .Xr minherit 2 , .Xr vfork 2 , .Xr rfork_thread 3 .Sh BUGS .Fx does not yet implement a native .Fn clone library call, and the current pthreads implementation does not use .Fn rfork with RFMEM. A native port of the linux threads library, .Pa /usr/ports/devel/linuxthreads , contains a working .Fn clone call that utilizes RFMEM. The .Fn rfork_thread library call can often be used instead of .Fn clone . .Sh HISTORY The .Fn rfork function call first appeared in Plan9.