When I have the following C source code, which is running on an IBM i Midrange, then I get a non-zero result from pthread_create, specifically 3025, which is ENOENT (No such path or directory), which doesn't make any sense to me. Anyone have any thoughts on what the error actually means in this context.
#define _MULTI_THREADED
#define _XOPEN_SOURCE 520
#include <pthread.h>
#include <stdio.h>
#include <errno.h>
void* workerThread(void* parm) {
// Do some work here
pthread_exit(NULL);
}
int main(int argc, char* argv[]) {
pthread_t t;
int rc;
rc = pthread_create(&t, NULL, workerThread, NULL);
if (rc != 0) {
char *msg = strerror(errno);
perror("pthread_create failed");
}
// Other code here
return 0;
}
pthread_create doesn't set errno. You should be checking strerror of rc.
http://pubs.opengroup.org/onlinepubs/7908799/xsh/pthread_create.html
char *msg = strerror(rc);
Related
I have installed Imlib2 on my computer, however doing the example program as below (having changed the line for loading files to include the error code) I keep getting the error code 4.
/* standard headers */
#include <X11/Xlib.h>
#include <Imlib2.h>
#include <stdio.h>
#include <string.h>
/* main program */
int main(int argc, char **argv)
{
/* an image handle */
Imlib_Image image;
Imlib_Load_Error err;
/* if we provided < 2 arguments after the command - exit */
if (argc != 3) exit(1);
/* load the image */
image = imlib_load_image_with_error_return(argv[1],&err);
if(err) printf("load error:%d",err);
/* if the load was successful */
if (image)
{
char *tmp;
imlib_context_set_image(image);
tmp = strrchr(argv[2], '.');
if(tmp)
imlib_image_set_format(tmp + 1);
imlib_save_image(argv[2]);
}
}
When i set the position and velocities of the joints in the trajectory msgs i got an error: \
[state_publisher-2] process has died [pid 13362, exit code -11, cmd /home/rob/catkin_ws/devel/lib/r2d2/state_publisher __name:=state_publisher __log:=/home/rob/.ros/log/9980f352-cf74-11e6-8644-d4c9efe8bd37/state_publisher-2.log].
log file: /home/rob/.ros/log/9980f352-cf74-11e6-8644-d4c9efe8bd37/state_publisher-2*.log
My ros node to send geometry_msgs is:
#include <string>
#include <ros/ros.h>
#include <sensor_msgs/JointState.h>
#include <tf/transform_broadcaster.h>
#include <trajectory_msgs/JointTrajectory.h>
#include <vector>
int main(int argc, char** argv) {
ros::init(argc, argv, "state_publisher");
ros::NodeHandle n;
ros::Publisher joint_pub = n.advertise<trajectory_ms
gs::JointTrajectory>("set_joint_trajectory", 1);
ros::Rate loop_rate(30);
const double degree = M_PI/180;
// robot state
double tilt = 0, tinc = degree, swivel=0, angle=0, height=0, hinc=0.005;
// message declarations
trajectory_msgs::JointTrajectory joint_state;
std::vector<trajectory_msgs::JointTrajectoryPoint> points_n(3);
points_n[0].positions[0] = 1; points_n[0].velocities[0]=10;
while (ros::ok()) {
//update joint_state
joint_state.header.stamp = ros::Time::now();
joint_state.joint_names.resize(3);
joint_state.points.resize(3);
joint_state.joint_names[0] ="swivel";
joint_state.points[0] = points_n[0];
joint_state.joint_names[1] ="tilt";
joint_state.points[1] = points_n[1];
joint_state.joint_names[2] ="periscope";
joint_state.points[2] = points_n[2];
joint_pub.publish(joint_state);
// This will adjust as needed per iteration
loop_rate.sleep();
}
return 0;
}
Here when i donot set the position and velocity value it runs without error and when i run rostopic echo /set_joint_trajectory i can clearly see the outputs as all the parameters of points is 0. I also tried below program but it published nothing:
#include <string>
#include <ros/ros.h>
#include <sensor_msgs/JointState.h>
#include <tf/transform_broadcaster.h>
#include <trajectory_msgs/JointTrajectory.h>
#include <vector>
int main(int argc, char** argv) {
ros::init(argc, argv, "state_publisher");
ros::NodeHandle n;
ros::Publisher joint_pub = n.advertise<trajectory_msgs::JointTrajectory>("set_joint_trajectory", 1);
trajectory_msgs::JointTrajectory joint_state;
joint_state.header.stamp = ros::Time::now();
joint_state.header.frame_id = "camera_link";
joint_state.joint_names.resize(3);
joint_state.points.resize(3);
joint_state.joint_names[0] ="swivel";
joint_state.joint_names[1] ="tilt";
joint_state.joint_names[2] ="periscope";
size_t size = 2;
for(size_t i=0;i<=size;i++) {
trajectory_msgs::JointTrajectoryPoint points_n;
int j = i%3;
points_n.positions.push_back(j);
points_n.positions.push_back(j+1);
points_n.positions.push_back(j*2);
joint_state.points.push_back(points_n);
joint_state.points[i].time_from_start = ros::Duration(0.01);
}
joint_pub.publish(joint_state);
ros::spinOnce();
return 0;
}
You are accessing points_n[0].positions[0] and points_n[0].velocities[0] without allocating the memory for positions and velocities. Use
...
// message declarations
trajectory_msgs::JointTrajectory joint_state;
std::vector<trajectory_msgs::JointTrajectoryPoint> points_n(3);
points_n[0].positions.resize(1);
points_n[0].velocities.resize(1);
...
then set the values or use points_n[0].positions.push_back(...) instead. The same applies to points_n[1] and points_n[2].
In your second example it looks like your program terminates before anything is sent. Try to publish repeatedly in a while-loop with
while(ros::ok()){
...
ros::spinOnce();
}
I got the D-Bus server.c and client.c code, and made some modification.
I want the result that when type for example "hi" from client.c
server will print "receive message hi", and reply "reply_content!!!!!!" to client.c
But it seems that now client.c cannot get the reply message.
Anyone have the idea?
Thanks in advance.
"server.c"
/* server.c */
#include <dbus/dbus.h>
#include <stdbool.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
static DBusHandlerResult
filter_func(DBusConnection *connection, DBusMessage *message, void *usr_data)
{
DBusMessage *reply;
dbus_bool_t handled = false;
char *word = NULL;
DBusError dberr;
dbus_error_init(&dberr);
dbus_message_get_args(message, &dberr, DBUS_TYPE_STRING, &word, DBUS_TYPE_INVALID);
printf("receive message: %s\n", word);
handled = true;
reply = dbus_message_new_method_return(message);
char * reply_content = "reply_content!!!!!!";
dbus_message_append_args(reply, DBUS_TYPE_STRING, &reply_content, DBUS_TYPE_INVALID);
dbus_connection_send(connection, reply, NULL);
dbus_connection_flush(connection);
dbus_message_unref(reply);
return (handled ? DBUS_HANDLER_RESULT_HANDLED : DBUS_HANDLER_RESULT_NOT_YET_HANDLED);
}
int main(int argc, char *argv[])
{
DBusError dberr;
DBusConnection *dbconn;
dbus_error_init(&dberr);
dbconn = dbus_bus_get(DBUS_BUS_SESSION, &dberr);
if (!dbus_connection_add_filter(dbconn, filter_func, NULL, NULL)) {
return -1;
}
dbus_bus_add_match(dbconn, "type='signal',interface='client.signal.Type'", &dberr);
while(dbus_connection_read_write_dispatch(dbconn, -1)) {
/* loop */
}
return 0;
}
Here is client.c
#include <dbus/dbus.h>
#include <stdbool.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
static DBusHandlerResult
filter_func(DBusConnection *connection, DBusMessage *message, void *usr_data)
{
dbus_bool_t handled = false;
char *word = NULL;
DBusError dberr;
dbus_error_init(&dberr);
dbus_message_get_args(message, &dberr, DBUS_TYPE_STRING, &word, DBUS_TYPE_INVALID);
printf("receive message %s\n", word);
handled = true;
return (handled ? DBUS_HANDLER_RESULT_HANDLED : DBUS_HANDLER_RESULT_NOT_YET_HANDLED);
}
int db_send(DBusConnection *dbconn)
{
DBusMessage *dbmsg;
char *word = (char *)malloc(sizeof(char));
int i;
dbmsg = dbus_message_new_signal("/client/signal/Object", "client.signal.Type", "Test");
scanf("%s", word);
if (!dbus_message_append_args(dbmsg, DBUS_TYPE_STRING, &word, DBUS_TYPE_INVALID)) {
return -1;
}
if (!dbus_connection_send(dbconn, dbmsg, NULL)) {
return -1;
}
dbus_connection_flush(dbconn);
printf("send message %s\n", word);
dbus_message_unref(dbmsg);
return 0;
}
int main(int argc, char *argv[])
{
DBusError dberr;
DBusConnection *dbconn;
dbus_error_init(&dberr);
dbconn = dbus_bus_get(DBUS_BUS_SESSION, &dberr);
if (!dbus_connection_add_filter(dbconn, filter_func, NULL, NULL)) {
return -1;
}
db_send(dbconn);
while(dbus_connection_read_write_dispatch(dbconn, -1)) {
db_send(dbconn);
}
dbus_connection_unref(dbconn);
return 0;
}
You're communicating only with signals at the moment, which don't have a return value.
In client.c, use dbus_message_new_method_call instead of dbus_message_new_signal, and in server.c you probably have to change type='signal' to type='method_call'.
So I am getting started with SCTP and have written the basics of the SCTP server application(which I intend to modify to make it a peer-to-peer app). The code is incomplete but I compiled and ran it to test the socket options and the first setsockopt returns error 10042(protocol not supported). I have determined that it's the first call of setsockopt() that returns an error. So here is the incomplete code:
#include "stdafx.h"
#include <iostream>
#include <iostream>
#include <string.h>
#include <stdlib.h>
#ifndef UNICODE
#define UNICODE
#endif
#define WIN32_LEAN_AND_MEAN
#include <WinSock2.h>
#include <WS2tcpip.h>
#include <WS2spi.h>
#include <ws2sctp.h>
#include <wsipv6ok.h>
#include <if.h>
#include "ws2isatap.h"
#include "if_tunnel.h"
#pragma comment(lib, "ws2_32.lib")
#pragma comment(lib, "sctpsp.lib")
using namespace std;
using namespace System;
static int LISTENQ = 5;
void isatap_enable(void);
int main(int argc, char* argv[]){
WSADATA wsaData;
int iResult;
int optv = 10;
u_long imode = 1;
bool connected = false;
char *optval = (char*)&optv;
int optlen = sizeof(optval);
sockaddr_in6 servAddr;
sctp_sndrcvinfo sr;
sctp_event_subscribe evnts;
sctp_initmsg init;
memset(&sr,0,sizeof(sr));
memset(&evnts,0,sizeof(evnts));
memset(&init,0,sizeof(init));
memset(&servAddr,0,sizeof(servAddr));
iResult = WSAStartup(MAKEWORD(2, 2), &wsaData);
if (iResult != NO_ERROR) {
wprintf(L"WSAStartup function failed with error: %d\n", iResult);
return 1;
}
SOCKET servSock = socket(AF_INET6,SOCK_STREAM,IPPROTO_SCTP);
if(servSock==INVALID_SOCKET){
printf("Socket function failed with error: %d\n",GetLastError());
return 1;
}
if(setsockopt(servSock,IPPROTO_IPV6,IPV6_PROTECTION_LEVEL,optval,sizeof(optval))<0){
printf("setsockopt function failed with error: %d\n", GetLastError());
return 1;
}
u_int servPort = 5000;
servAddr.sin6_family = AF_INET6;
servAddr.sin6_addr = in6addr_any;
servAddr.sin6_port = htons(servPort);
if(setsockopt(servSock,IPPROTO_SCTP,SCTP_EVENTS,(const char*)&evnts,sizeof(evnts)) < 0){
printf("setsockopt function failed with error: %d\n", GetLastError());
return 1;
}
ioctlsocket(servSock,FIONBIO, &imode);
if(bind(servSock,(struct sockaddr*)&servAddr,sizeof(servAddr))<0){
printf("Bind function failed with error: %d\n", GetLastError());
return 1;
}
evnts.sctp_data_io_event = 1;
evnts.sctp_association_event = *(u_char*)optval;
for(;;){
if(listen(servSock,LISTENQ) < 0){
printf("Listen function failed with error: %d/n",GetLastError());
return 1;
}else{
printf("Listening on port %d\n",servPort);
}
}
}
If it's related to python packages nameko/kombu/amqp, then it's reported here Issue with 2.1.4 version.
Temporary soln: Roll-back the version to 2.1.3 till it's fixed.
OK guys, I fixed it(for now lol). What I did is substitute the IPPROTO_IPV6 with IPPROTO_SCTP and it seems to work.
I am trying to compile glib in ios, i have got an error in gio/tests/appinfo-test.h
#include <stdlib.h>
#include <gio/gio.h>
int
main (int argc, char *argv[])
{
const gchar *envvar;
gint pid_from_env;
envvar = g_getenv ("GIO_LAUNCHED_DESKTOP_FILE_PID");
g_assert (envvar != NULL);
pid_from_env = atoi (envvar);
g_assert_cmpint (pid_from_env, ==, getpid ());
envvar = g_getenv ("GIO_LAUNCHED_DESKTOP_FILE");
g_assert_cmpstr (envvar, ==, SRCDIR "/appinfo-test.desktop"); //got the error here that "Use of undefined identifier 'SRCDIR' "
return 0;
}
please help me out...Thank you
I can not figure out with given information how you tried to compile the sample code in your ios, but you can add
#define SRCDIR
before main().
The sample code seems to be glib/gio/tests/appinfo-test.c in the source repository. SRCDIR is defined as -DSRCDIR=\""$(srcdir)"\" in the Makefile.am.