diff options
Diffstat (limited to 'lib/libc/gen')
| -rw-r--r-- | lib/libc/gen/Makefile.inc | 2 | ||||
| -rw-r--r-- | lib/libc/gen/ftok.3 | 6 | ||||
| -rw-r--r-- | lib/libc/gen/msgctl.3 | 210 | ||||
| -rw-r--r-- | lib/libc/gen/msgget.3 | 141 | ||||
| -rw-r--r-- | lib/libc/gen/msgrcv.3 | 222 | ||||
| -rw-r--r-- | lib/libc/gen/msgsnd.3 | 184 |
6 files changed, 4 insertions, 761 deletions
diff --git a/lib/libc/gen/Makefile.inc b/lib/libc/gen/Makefile.inc index a4badb9..8837038 100644 --- a/lib/libc/gen/Makefile.inc +++ b/lib/libc/gen/Makefile.inc @@ -55,7 +55,7 @@ MAN+= alarm.3 arc4random.3 \ getpagesize.3 getpass.3 getpeereid.3 getprogname.3 getpwent.3 \ getttyent.3 getusershell.3 getvfsbyname.3 \ glob.3 initgroups.3 isgreater.3 ldexp.3 lockf.3 makecontext.3 \ - modf.3 msgctl.3 msgget.3 msgrcv.3 msgsnd.3 \ + modf.3 \ nice.3 nlist.3 pause.3 popen.3 \ posix_spawn.3 posix_spawn_file_actions_addopen.3 \ posix_spawn_file_actions_init.3 posix_spawnattr_getflags.3 \ diff --git a/lib/libc/gen/ftok.3 b/lib/libc/gen/ftok.3 index a1c7dde..78bfe45 100644 --- a/lib/libc/gen/ftok.3 +++ b/lib/libc/gen/ftok.3 @@ -24,7 +24,7 @@ .\" ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. .\" .\" $FreeBSD$ -.Dd June 24, 1994 +.Dd July 9, 2009 .Os .Dt FTOK 3 .Sh NAME @@ -41,7 +41,7 @@ The .Fn ftok function attempts to create a unique key suitable for use with the -.Xr msgget 3 , +.Xr msgget 2 , .Xr semget 2 and .Xr shmget 2 @@ -66,7 +66,7 @@ does not exist or if it cannot be accessed by the calling process. .Sh SEE ALSO .Xr semget 2 , .Xr shmget 2 , -.Xr msgget 3 +.Xr msgget 2 .Sh HISTORY The .Fn ftok diff --git a/lib/libc/gen/msgctl.3 b/lib/libc/gen/msgctl.3 deleted file mode 100644 index 7d4ec0d..0000000 --- a/lib/libc/gen/msgctl.3 +++ /dev/null @@ -1,210 +0,0 @@ -.\" $NetBSD: msgctl.2,v 1.1 1995/10/16 23:49:15 jtc Exp $ -.\" -.\" Copyright (c) 1995 Frank van der Linden -.\" 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 for the NetBSD Project -.\" by Frank van der Linden -.\" 4. The name of the author may not be used to endorse or promote products -.\" derived from this software without specific prior written permission -.\" -.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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. -.\" -.\" $FreeBSD$ -.\"/ -.Dd April 3, 2008 -.Dt MSGCTL 3 -.Os -.Sh NAME -.Nm msgctl -.Nd message control operations -.Sh LIBRARY -.Lb libc -.Sh SYNOPSIS -.In sys/types.h -.In sys/ipc.h -.In sys/msg.h -.Ft int -.Fn msgctl "int msqid" "int cmd" "struct msqid_ds *buf" -.Sh DESCRIPTION -The -.Fn msgctl -system call performs some control operations on the message queue specified -by -.Fa msqid . -.Pp -Each message queue has a data structure associated with it, parts of which -may be altered by -.Fn msgctl -and parts of which determine the actions of -.Fn msgctl . -The data structure is defined in -.In sys/msg.h -and contains (amongst others) the following members: -.Bd -literal -struct msqid_ds { - struct ipc_perm msg_perm; /* msg queue permission bits */ - struct msg *msg_first; /* first message in the queue */ - struct msg *msg_last; /* last message in the queue */ - msglen_t msg_cbytes; /* number of bytes in use on the queue */ - msgqnum_t msg_qnum; /* number of msgs in the queue */ - msglen_t msg_qbytes; /* max # of bytes on the queue */ - pid_t msg_lspid; /* pid of last msgsnd() */ - pid_t msg_lrpid; /* pid of last msgrcv() */ - time_t msg_stime; /* time of last msgsnd() */ - time_t msg_rtime; /* time of last msgrcv() */ - time_t msg_ctime; /* time of last msgctl() */ -}; -.Ed -.Pp -The -.Vt ipc_perm -structure used inside the -.Vt msqid_ds -structure is defined in -.In sys/ipc.h -and looks like this: -.Bd -literal -struct ipc_perm { - uid_t cuid; /* creator user id */ - gid_t cgid; /* creator group id */ - uid_t uid; /* user id */ - gid_t gid; /* group id */ - mode_t mode; /* r/w permission */ - unsigned short seq; /* sequence # (to generate unique ipcid) */ - key_t key; /* user specified msg/sem/shm key */ -}; -.Ed -.Pp -The operation to be performed by -.Fn msgctl -is specified in -.Fa cmd -and is one of: -.Bl -tag -width IPC_RMIDX -.It Dv IPC_STAT -Gather information about the message queue and place it in the -structure pointed to by -.Fa buf . -.It Dv IPC_SET -Set the value of the -.Va msg_perm.uid , -.Va msg_perm.gid , -.Va msg_perm.mode -and -.Va msg_qbytes -fields in the structure associated with -.Fa msqid . -The values are taken from the corresponding fields in the structure -pointed to by -.Fa buf . -This operation can only be executed by the super-user, or a process that -has an effective user id equal to either -.Va msg_perm.cuid -or -.Va msg_perm.uid -in the data structure associated with the message queue. -The value of -.Va msg_qbytes -can only be increased by the super-user. -Values for -.Va msg_qbytes -that exceed the system limit (MSGMNB from -.In sys/msg.h ) -are silently truncated to that limit. -.It Dv IPC_RMID -Remove the message queue specified by -.Fa msqid -and destroy the data associated with it. -Only the super-user or a process -with an effective uid equal to the -.Va msg_perm.cuid -or -.Va msg_perm.uid -values in the data structure associated with the queue can do this. -.El -.Pp -The permission to read from or write to a message queue (see -.Xr msgsnd 3 -and -.Xr msgrcv 3 ) -is determined by the -.Va msg_perm.mode -field in the same way as is -done with files (see -.Xr chmod 2 ) , -but the effective uid can match either the -.Va msg_perm.cuid -field or the -.Va msg_perm.uid -field, and the -effective gid can match either -.Va msg_perm.cgid -or -.Va msg_perm.gid . -.Sh RETURN VALUES -.Rv -std msgctl -.Sh ERRORS -The -.Fn msgctl -function -will fail if: -.Bl -tag -width Er -.It Bq Er EPERM -The -.Fa cmd -argument -is equal to IPC_SET or IPC_RMID and the caller is not the super-user, nor does -the effective uid match either the -.Va msg_perm.uid -or -.Va msg_perm.cuid -fields of the data structure associated with the message queue. -.Pp -An attempt is made to increase the value of -.Va msg_qbytes -through IPC_SET -but the caller is not the super-user. -.It Bq Er EACCES -The command is IPC_STAT -and the caller has no read permission for this message queue. -.It Bq Er EINVAL -The -.Fa msqid -argument -is not a valid message queue identifier. -.Pp -.Va cmd -is not a valid command. -.It Bq Er EFAULT -The -.Fa buf -argument -specifies an invalid address. -.El -.Sh SEE ALSO -.Xr msgget 3 , -.Xr msgrcv 3 , -.Xr msgsnd 3 -.Sh HISTORY -Message queues appeared in the first release of -.At V . diff --git a/lib/libc/gen/msgget.3 b/lib/libc/gen/msgget.3 deleted file mode 100644 index e257c60..0000000 --- a/lib/libc/gen/msgget.3 +++ /dev/null @@ -1,141 +0,0 @@ -.\" $NetBSD: msgget.2,v 1.1 1995/10/16 23:49:19 jtc Exp $ -.\" -.\" Copyright (c) 1995 Frank van der Linden -.\" 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 for the NetBSD Project -.\" by Frank van der Linden -.\" 4. The name of the author may not be used to endorse or promote products -.\" derived from this software without specific prior written permission -.\" -.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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. -.\" $FreeBSD$ -.\" -.\"/ -.Dd August 17, 1995 -.Dt MSGGET 3 -.Os -.Sh NAME -.Nm msgget -.Nd get message queue -.Sh LIBRARY -.Lb libc -.Sh SYNOPSIS -.In sys/types.h -.In sys/ipc.h -.In sys/msg.h -.Ft int -.Fn msgget "key_t key" "int msgflg" -.Sh DESCRIPTION -The -.Fn msgget -function -returns the message queue identifier associated with -.Fa key . -A message queue identifier is a unique integer greater than zero. -.Pp -A message queue is created if either -.Fa key -is equal to -.Dv IPC_PRIVATE , -or -.Fa key -does not have a message queue identifier associated with it, and the -.Dv IPC_CREAT -bit is set in -.Fa msgflg . -.Pp -If a new message queue is created, the data structure associated with it (the -.Va msqid_ds -structure, see -.Xr msgctl 3 ) -is initialized as follows: -.Bl -bullet -.It -.Va msg_perm.cuid -and -.Va msg_perm.uid -are set to the effective uid of the calling process. -.It -.Va msg_perm.gid -and -.Va msg_perm.cgid -are set to the effective gid of the calling process. -.It -.Va msg_perm.mode -is set to the lower 9 bits of -.Fa msgflg . -.It -.Va msg_cbytes , -.Va msg_qnum , -.Va msg_lspid , -.Va msg_lrpid , -.Va msg_rtime , -and -.Va msg_stime -are set to 0. -.It -.Va msg_qbytes -is set to the system wide maximum value for the number of bytes in a queue -.Pf ( Dv MSGMNB ) . -.It -.Va msg_ctime -is set to the current time. -.El -.Sh RETURN VALUES -Upon successful completion a positive message queue identifier is returned. -Otherwise, -1 is returned and the global variable -.Va errno -is set to indicate the error. -.Sh ERRORS -.Bl -tag -width Er -.It Bq Er EACCES -A message queue is already associated with -.Fa key -and the caller has no permission to access it. -.It Bq Er EEXIST -Both -.Dv IPC_CREAT -and -.Dv IPC_EXCL -are set in -.Fa msgflg , -and a message queue is already associated with -.Fa key . -.It Bq Er ENOSPC -A new message queue could not be created because the system limit for -the number of message queues has been reached. -.It Bq Er ENOENT -.Dv IPC_CREAT -was not set in -.Fa msgflg -and no message queue associated with -.Fa key -was found. -.El -.Sh SEE ALSO -.Xr msgctl 3 , -.Xr msgrcv 3 , -.Xr msgsnd 3 -.Sh HISTORY -Message queues appeared in the first release of -.At V . diff --git a/lib/libc/gen/msgrcv.3 b/lib/libc/gen/msgrcv.3 deleted file mode 100644 index e554dcd..0000000 --- a/lib/libc/gen/msgrcv.3 +++ /dev/null @@ -1,222 +0,0 @@ -.\" $NetBSD: msgrcv.2,v 1.1 1995/10/16 23:49:20 jtc Exp $ -.\" -.\" Copyright (c) 1995 Frank van der Linden -.\" 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 for the NetBSD Project -.\" by Frank van der Linden -.\" 4. The name of the author may not be used to endorse or promote products -.\" derived from this software without specific prior written permission -.\" -.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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. -.\" $FreeBSD$ -.\" -.\"/ -.Dd June 15, 2005 -.Dt MSGRCV 3 -.Os -.Sh NAME -.Nm msgrcv -.Nd receive a message from a message queue -.Sh LIBRARY -.Lb libc -.Sh SYNOPSIS -.In sys/types.h -.In sys/ipc.h -.In sys/msg.h -.Ft int -.Fn msgrcv "int msqid" "void *msgp" "size_t msgsz" "long msgtyp" "int msgflg" -.Sh DESCRIPTION -The -.Fn msgrcv -function receives a message from the message queue specified in -.Fa msqid , -and places it into the structure pointed to by -.Fa msgp . -This structure should consist of the following members: -.Bd -literal - long mtype; /* message type */ - char mtext[1]; /* body of message */ -.Ed -.Pp -.Va mtype -is an integer greater than 0 that can be used for selecting messages, -.Va mtext -is an array of bytes, with a size up to that of the system limit -.Pf ( Dv MSGMAX ) . -.Pp -The value of -.Fa msgtyp -has one of the following meanings: -.Bl -bullet -.It -The -.Fa msgtyp -argument -is greater than 0. -The first message of type -.Fa msgtyp -will be received. -.It -The -.Fa msgtyp -argument -is equal to 0. -The first message on the queue will be received. -.It -The -.Fa msgtyp -argument -is less than 0. -The first message of the lowest message type that is -less than or equal to the absolute value of -.Fa msgtyp -will be received. -.El -.Pp -The -.Fa msgsz -argument -specifies the maximum length of the requested message. -If the received -message has a length greater than -.Fa msgsz -it will be silently truncated if the -.Dv MSG_NOERROR -flag is set in -.Fa msgflg , -otherwise an error will be returned. -.Pp -If no matching message is present on the message queue specified by -.Fa msqid , -the behavior of -.Fn msgrcv -depends on whether the -.Dv IPC_NOWAIT -flag is set in -.Fa msgflg -or not. -If -.Dv IPC_NOWAIT -is set, -.Fn msgrcv -will immediately return a value of -1, and set -.Va errno -to -.Er ENOMSG . -If -.Dv IPC_NOWAIT -is not set, the calling process will be blocked -until: -.Bl -bullet -.It -A message of the requested type becomes available on the message queue. -.It -The message queue is removed, in which case -1 will be returned, and -.Va errno -set to -.Er EINVAL . -.It -A signal is received and caught. --1 is returned, and -.Va errno -set to -.Er EINTR . -.El -.Pp -If a message is successfully received, the data structure associated with -.Fa msqid -is updated as follows: -.Bl -bullet -.It -.Va msg_cbytes -is decremented by the size of the message. -.It -.Va msg_lrpid -is set to the pid of the caller. -.It -.Va msg_lrtime -is set to the current time. -.It -.Va msg_qnum -is decremented by 1. -.El -.Sh RETURN VALUES -Upon successful completion, -.Fn msgrcv -returns the number of bytes received into the -.Va mtext -field of the structure pointed to by -.Fa msgp . -Otherwise, -1 is returned, and -.Va errno -set to indicate the error. -.Sh ERRORS -The -.Fn msgrcv -function -will fail if: -.Bl -tag -width Er -.It Bq Er EINVAL -The -.Fa msqid -argument -is not a valid message queue identifier. -.Pp -The message queue was removed while -.Fn msgrcv -was waiting for a message of the requested type to become available on it. -.Pp -The -.Fa msgsz -argument -is less than 0. -.It Bq Er E2BIG -A matching message was received, but its size was greater than -.Fa msgsz -and the -.Dv MSG_NOERROR -flag was not set in -.Fa msgflg . -.It Bq Er EACCES -The calling process does not have read access to the message queue. -.It Bq Er EFAULT -The -.Fa msgp -argument -points to an invalid address. -.It Bq Er EINTR -The system call was interrupted by the delivery of a signal. -.It Bq Er ENOMSG -There is no message of the requested type available on the message queue, -and -.Dv IPC_NOWAIT -is set in -.Fa msgflg . -.El -.Sh SEE ALSO -.Xr msgctl 3 , -.Xr msgget 3 , -.Xr msgsnd 3 -.Sh HISTORY -Message queues appeared in the first release of -.At V . diff --git a/lib/libc/gen/msgsnd.3 b/lib/libc/gen/msgsnd.3 deleted file mode 100644 index fc802b3..0000000 --- a/lib/libc/gen/msgsnd.3 +++ /dev/null @@ -1,184 +0,0 @@ -.\" $NetBSD: msgsnd.2,v 1.1 1995/10/16 23:49:24 jtc Exp $ -.\" -.\" Copyright (c) 1995 Frank van der Linden -.\" 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 for the NetBSD Project -.\" by Frank van der Linden -.\" 4. The name of the author may not be used to endorse or promote products -.\" derived from this software without specific prior written permission -.\" -.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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. -.\" -.\" $FreeBSD$ -.\" -.Dd October 12, 2006 -.Dt MSGSND 3 -.Os -.Sh NAME -.Nm msgsnd -.Nd send a message to a message queue -.Sh LIBRARY -.Lb libc -.Sh SYNOPSIS -.In sys/types.h -.In sys/ipc.h -.In sys/msg.h -.Ft int -.Fn msgsnd "int msqid" "const void *msgp" "size_t msgsz" "int msgflg" -.Sh DESCRIPTION -The -.Fn msgsnd -function sends a message to the message queue specified in -.Fa msqid . -The -.Fa msgp -argument -points to a structure containing the message. -This structure should -consist of the following members: -.Bd -literal - long mtype; /* message type */ - char mtext[1]; /* body of message */ -.Ed -.Pp -.Va mtype -is an integer greater than 0 that can be used for selecting messages (see -.Xr msgrcv 3 ) , -.Va mtext -is an array of -.Fa msgsz -bytes. -The argument -.Fa msgsz -can range from 0 to a system-imposed maximum, -.Dv MSGMAX . -.Pp -If the number of bytes already on the message queue plus -.Fa msgsz -is bigger than the maximum number of bytes on the message queue -.Pf ( Va msg_qbytes , -see -.Xr msgctl 3 ) , -or the number of messages on all queues system-wide is already equal to -the system limit, -.Fa msgflg -determines the action of -.Fn msgsnd . -If -.Fa msgflg -has -.Dv IPC_NOWAIT -mask set in it, the call will return immediately. -If -.Fa msgflg -does not have -.Dv IPC_NOWAIT -set in it, the call will block until: -.Bl -bullet -.It -The condition which caused the call to block does no longer exist. -The message will be sent. -.It -The message queue is removed, in which case -1 will be returned, and -.Va errno -is set to -.Er EINVAL . -.It -The caller catches a signal. -The call returns with -.Va errno -set to -.Er EINTR . -.El -.Pp -After a successful call, the data structure associated with the message -queue is updated in the following way: -.Bl -bullet -.It -.Va msg_cbytes -is incremented by the size of the message. -.It -.Va msg_qnum -is incremented by 1. -.It -.Va msg_lspid -is set to the pid of the calling process. -.It -.Va msg_stime -is set to the current time. -.El -.Sh RETURN VALUES -.Rv -std msgsnd -.Sh ERRORS -The -.Fn msgsnd -function -will fail if: -.Bl -tag -width Er -.It Bq Er EINVAL -The -.Fa msqid -argument -is not a valid message queue identifier -.Pp -The message queue was removed while -.Fn msgsnd -was waiting for a resource to become available in order to deliver the -message. -.Pp -The -.Fa msgsz -argument -is greater than -.Va msg_qbytes . -.Pp -The -.Fa mtype -argument -is not greater than 0. -.It Bq Er EACCES -The calling process does not have write access to the message queue. -.It Bq Er EAGAIN -There was no space for this message either on the queue, or in the whole -system, and -.Dv IPC_NOWAIT -was set in -.Fa msgflg . -.It Bq Er EFAULT -The -.Fa msgp -argument -points to an invalid address. -.It Bq Er EINTR -The system call was interrupted by the delivery of a signal. -.El -.Sh HISTORY -Message queues appeared in the first release of AT&T Unix System V. -.Sh BUGS -.Nx -and -.Fx -do not define the -.Er EIDRM -error value, which should be used -in the case of a removed message queue. |
