Hallo,
I have a problem using pipes. Inside user-space I'm using
the function fCliOnOff to start selected tasks. If I use:
msg.task = ((1<<TASK1) | (1<<TASK2));
all things are going on. If I use:
msg.task = ((1<<TASK1) | (1<<TASK2) | (1<<TASK3));
I will get a segmentation fault. The values of msg.task
are the right one (3 for the first case and 7 for the
second). The problem is the "write" function - this will
crash. I never got the COMMAND_TASK_START inside the
rt-process for the last case. Why is this and how can
I correct my code to going on working?
The structure MY_COMMAND I'm using for shared-memory
commands as well but, this should not be the reason.
----------------- common.h ------------------------
#define COMMAND_TASK_START (1<<0)
#define COMMAND_TASK_ON (1<<1)
...
#define TASK1 0x00
#define TASK2 0x01
#define TASK3 0x02
#define TASKS 3
#define CTRL_FIFO 0
#define CTRL_FIFO_SIZE 1024
#define RT_TASK_STACK_SIZE 1024
#define RT_TASK_PRIORITY 1
static RT_TASK tasks[TASKS];
...
---------------- commands.c -----------------------
...
typedef struct
{
unsigned int inuse;
unsigned int task;
unsigned int command;
unsigned int command_number;
int arg1;
int arg2;
} MY_COMMAND;
extern int ctrlfd; /* fd from Ctrl FIFO, opened in app.c
... ctrlfd = open("/dev/rtf0", O_WRONLY)... */
...
int fCliTaskOnOff()
{
/* Ctrl-Pipe */
MY_COMMAND msg;
msg.command = COMMAND_TASK_START;
msg.task = ((1<<TASK1) | (1<<TASK2) | (1<<TASK3));
if (write(ctrlfd, &msg, sizeof(msg)) < 0) {
fprintf(stderr, "Can't send a command to Control-FIFO (%s)",
strerror(errno));
exit(errno);
}
return(0);
}
...
----------------- rt_process.c ----------------
static void fController(int task_no)
{
...
}
int fTaskHandler(unsigned int fifo)
{
MY_COMMAND msg;
int err;
register int task_no;
RTIME now;
while ((err=rtf_get(fifo, &msg, sizeof(msg))) > 0) {
switch (msg.command) {
case COMMAND_TASK_START:
for(task_no=TASK1; task_no<TASKS; task_no++) {
if((1 << task_no) & msg.task) {
rt_task_make_periodic(&tasks[task_no], /* RT_TASK */
rt_get_time(), /* Now! */
MUSECS_TO_RTIME(RT_TASK_CYCLE_TIME));
}
}
break;
case COMMAND_TASK_ON:
...
rt_task_wakeup(&tasks[task_no]);
...
break;
case COMMAND_TASK_OFF:
...
rt_task_suspend(&tasks[task_no);
...
break;
case COMMAND_TASK_PERIOD:
...
now = rt_get_time();
rt_task_make_periodic(&tasks[task_no] now, msg.arg1);
...
break;
default:
return -EINVAL;
}
}
...
}
int init_module(void)
{
register int task_no;
...
for(task_no=TASK1; task_no<TASKS; task_no++) {
...
/* initialize task code */
rt_task_init(&tasks[task_no], /* RT_TASK */
fController, /* task code function */
task_no, /* startup arg to task code */
RT_TASK_STACK_SIZE, /* task stack size */
RT_TASK_PRIORITY); /* priority */
/* use fp */
rt_task_use_fp(&tasks[task_no], 1);
}
...
rtf_create(CTRL_FIFO, CTRL_FIFO_SIZE);
rtf_create_handler(CTRL_FIFO, &fTaskHandler);
return 0;
}
void cleanup_module(void)
{
...
}
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