Thanks corona 4 ur suggestions. I am little bit confused abt thread creation.
For ur reference I am pasting my daemon template code. Pls embed the new code to establish a TCP connection to vendor server so that I can simulate the same.
Sorry to bother abt my code.
Last edited by blowtorch; 10-05-2006 at 02:53 PM..
Reason: add code tags
Hi,
I have been trying to create a sharef object on my HP UX 11 machine
(HP-UX <myhostname> B.11.00 A 9000/879 ...... two-user license)
to create the shared object first I am creating the object file using
cc -Aa -c +z dyn.c
(I use -Aa and +z as per HP's manual on linkers ) to create the... (0 Replies)
Hi All,
I created the share object file using
gcc -shared -fpic mypp.cpp -o myp.so
but, pls tell me how to link this .so file to my client program.
Thanks (0 Replies)
Hi,
When using shared objects on AIX 4.3 i am getting runtime problems.
I have a small sample program which links to a shared object libray, oracle and system related libraries.
At runtime it fails (gives segmentation fault and coredump ) in one proc file when executing login statement.
But... (0 Replies)
Hi All,
I have a problem with the shared objects setup in AIX. We have a customized shell written by the developers over here. When i issue a MQ Series command (mqsilist) it is giving the error as . All the commands making use of this libImbCmdLib.a.so is failing. But when executed in normal... (1 Reply)
Hi,
I have created a shared object (abc.so) which has a function sum(int a, int b).
Is there any way to load the "abc.so" and use the sum function using shell script..
thanks in advance (2 Replies)
Hi all,
I am developing an application with two components. One "c" binary and one "C++" shared object.
While execution, the shared object crashes out and core dump is created whenever "new" is executed. But if i use malloc this will work perfectly.
I tried to use dbx. Below given was... (1 Reply)
Hello,
While running a c++ shared object on AIX I am facing below error -
rtld: 0712-001 Symbol __ct__3ETDFv was referenced
from module /bancs/aml/lib/libmonitor.so(), but a runtime definition
of the symbol was not found.
rtld: 0712-001 Symbol etd_insert__3ETDFv was... (3 Replies)
Hi,
I would like to create a shared object ( .so).
This shared object
1. uses the functions from a library.
2. Also it should be able to use the global variable in an app
To achieve this what should I do ? 1) To use the functions in the library should I give the -ld option while... (1 Reply)
Hello,
I am new to programming shared objects and I was hoping someone could tell me if what I want to do is possible, or else lead me in the right direction.
I have a main program that contains an abstract base class. I also have a subclass that I'm compiling as a shared object. The subclass... (13 Replies)
Hello,
I am not that experienced with Linux, and I am currently facing some issues.
The application I'm working on uses hundreds of threads. To optimize the memory usage, I am putting all my data inside a shared object (so).
The steps for this are as follows:
1. a C file (generated... (17 Replies)
Discussion started by: Maelstrom
17 Replies
LEARN ABOUT POSIX
sendmmsg
SENDMMSG(2) Linux Programmer's Manual SENDMMSG(2)NAME
sendmmsg - send multiple messages on a socket
SYNOPSIS
#define _GNU_SOURCE /* See feature_test_macros(7) */
#include <sys/socket.h>
int sendmmsg(int sockfd, struct mmsghdr *msgvec, unsigned int vlen,
int flags);
DESCRIPTION
The sendmmsg() system call is an extension of sendmsg(2) that allows the caller to transmit multiple messages on a socket using a single
system call. (This has performance benefits for some applications.)
The sockfd argument is the file descriptor of the socket on which data is to be transmitted.
The msgvec argument is a pointer to an array of mmsghdr structures. The size of this array is specified in vlen.
The mmsghdr structure is defined in <sys/socket.h> as:
struct mmsghdr {
struct msghdr msg_hdr; /* Message header */
unsigned int msg_len; /* Number of bytes transmitted */
};
The msg_hdr field is a msghdr structure, as described in sendmsg(2). The msg_len field is used to return the number of bytes sent from the
message in msg_hdr (i.e., the same as the return value from a single sendmsg(2) call).
The flags argument contains flags ORed together. The flags are the same as for sendmsg(2).
A blocking sendmmsg() call blocks until vlen messages have been sent. A nonblocking call sends as many messages as possible (up to the
limit specified by vlen) and returns immediately.
On return from sendmmsg(), the msg_len fields of successive elements of msgvec are updated to contain the number of bytes transmitted from
the corresponding msg_hdr. The return value of the call indicates the number of elements of msgvec that have been updated.
RETURN VALUE
On success, sendmmsg() returns the number of messages sent from msgvec; if this is less than vlen, the caller can retry with a further
sendmmsg() call to send the remaining messages.
On error, -1 is returned, and errno is set to indicate the error.
ERRORS
Errors are as for sendmsg(2). An error is returned only if no datagrams could be sent. See also BUGS.
VERSIONS
The sendmmsg() system call was added in Linux 3.0. Support in glibc was added in version 2.14.
CONFORMING TO
sendmmsg() is Linux-specific.
NOTES
The value specified in vlen is capped to UIO_MAXIOV(1024).
BUGS
If an error occurs after at least one message has been sent, the call succeeds, and returns the number of messages sent. The error code is
lost. The caller can retry the transmission, starting at the first failed message, but there is no guarantee that, if an error is
returned, it will be the same as the one that was lost on the previous call.
EXAMPLE
The example below uses sendmmsg() to send onetwo and three in two distinct UDP datagrams using one system call. The contents of the first
datagram originates from a pair of buffers.
#define _GNU_SOURCE
#include <netinet/ip.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
int
main(void)
{
int sockfd;
struct sockaddr_in addr;
struct mmsghdr msg[2];
struct iovec msg1[2], msg2;
int retval;
sockfd = socket(AF_INET, SOCK_DGRAM, 0);
if (sockfd == -1) {
perror("socket()");
exit(EXIT_FAILURE);
}
addr.sin_family = AF_INET;
addr.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
addr.sin_port = htons(1234);
if (connect(sockfd, (struct sockaddr *) &addr, sizeof(addr)) == -1) {
perror("connect()");
exit(EXIT_FAILURE);
}
memset(msg1, 0, sizeof(msg1));
msg1[0].iov_base = "one";
msg1[0].iov_len = 3;
msg1[1].iov_base = "two";
msg1[1].iov_len = 3;
memset(&msg2, 0, sizeof(msg2));
msg2.iov_base = "three";
msg2.iov_len = 5;
memset(msg, 0, sizeof(msg));
msg[0].msg_hdr.msg_iov = msg1;
msg[0].msg_hdr.msg_iovlen = 2;
msg[1].msg_hdr.msg_iov = &msg2;
msg[1].msg_hdr.msg_iovlen = 1;
retval = sendmmsg(sockfd, msg, 2, 0);
if (retval == -1)
perror("sendmmsg()");
else
printf("%d messages sent
", retval);
exit(0);
}
SEE ALSO recvmmsg(2), sendmsg(2), socket(2), socket(7)COLOPHON
This page is part of release 4.15 of the Linux man-pages project. A description of the project, information about reporting bugs, and the
latest version of this page, can be found at https://www.kernel.org/doc/man-pages/.
Linux 2018-02-02 SENDMMSG(2)