You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
137 lines
2.6 KiB
137 lines
2.6 KiB
/*
|
|
* Controller of read/write threads for virtio-trace
|
|
*
|
|
* Copyright (C) 2012 Hitachi, Ltd.
|
|
* Created by Yoshihiro Yunomae <yoshihiro.yunomae.ez@hitachi.com>
|
|
* Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
|
|
*
|
|
* Licensed under GPL version 2 only.
|
|
*
|
|
*/
|
|
|
|
#define _GNU_SOURCE
|
|
#include <fcntl.h>
|
|
#include <poll.h>
|
|
#include <signal.h>
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <unistd.h>
|
|
#include "trace-agent.h"
|
|
|
|
#define HOST_MSG_SIZE 256
|
|
#define EVENT_WAIT_MSEC 100
|
|
|
|
static volatile sig_atomic_t global_signal_val;
|
|
bool global_sig_receive; /* default false */
|
|
bool global_run_operation; /* default false*/
|
|
|
|
/* Handle SIGTERM/SIGINT/SIGQUIT to exit */
|
|
static void signal_handler(int sig)
|
|
{
|
|
global_signal_val = sig;
|
|
}
|
|
|
|
int rw_ctl_init(const char *ctl_path)
|
|
{
|
|
int ctl_fd;
|
|
|
|
ctl_fd = open(ctl_path, O_RDONLY);
|
|
if (ctl_fd == -1) {
|
|
pr_err("Cannot open ctl_fd\n");
|
|
goto error;
|
|
}
|
|
|
|
return ctl_fd;
|
|
|
|
error:
|
|
exit(EXIT_FAILURE);
|
|
}
|
|
|
|
static int wait_order(int ctl_fd)
|
|
{
|
|
struct pollfd poll_fd;
|
|
int ret = 0;
|
|
|
|
while (!global_sig_receive) {
|
|
poll_fd.fd = ctl_fd;
|
|
poll_fd.events = POLLIN;
|
|
|
|
ret = poll(&poll_fd, 1, EVENT_WAIT_MSEC);
|
|
|
|
if (global_signal_val) {
|
|
global_sig_receive = true;
|
|
pr_info("Receive interrupt %d\n", global_signal_val);
|
|
|
|
/* Wakes rw-threads when they are sleeping */
|
|
if (!global_run_operation)
|
|
pthread_cond_broadcast(&cond_wakeup);
|
|
|
|
ret = -1;
|
|
break;
|
|
}
|
|
|
|
if (ret < 0) {
|
|
pr_err("Polling error\n");
|
|
goto error;
|
|
}
|
|
|
|
if (ret)
|
|
break;
|
|
};
|
|
|
|
return ret;
|
|
|
|
error:
|
|
exit(EXIT_FAILURE);
|
|
}
|
|
|
|
/*
|
|
* contol read/write threads by handling global_run_operation
|
|
*/
|
|
void *rw_ctl_loop(int ctl_fd)
|
|
{
|
|
ssize_t rlen;
|
|
char buf[HOST_MSG_SIZE];
|
|
int ret;
|
|
|
|
/* Setup signal handlers */
|
|
signal(SIGTERM, signal_handler);
|
|
signal(SIGINT, signal_handler);
|
|
signal(SIGQUIT, signal_handler);
|
|
|
|
while (!global_sig_receive) {
|
|
|
|
ret = wait_order(ctl_fd);
|
|
if (ret < 0)
|
|
break;
|
|
|
|
rlen = read(ctl_fd, buf, sizeof(buf));
|
|
if (rlen < 0) {
|
|
pr_err("read data error in ctl thread\n");
|
|
goto error;
|
|
}
|
|
|
|
if (rlen == 2 && buf[0] == '1') {
|
|
/*
|
|
* If host writes '1' to a control path,
|
|
* this controller wakes all read/write threads.
|
|
*/
|
|
global_run_operation = true;
|
|
pthread_cond_broadcast(&cond_wakeup);
|
|
pr_debug("Wake up all read/write threads\n");
|
|
} else if (rlen == 2 && buf[0] == '0') {
|
|
/*
|
|
* If host writes '0' to a control path, read/write
|
|
* threads will wait for notification from Host.
|
|
*/
|
|
global_run_operation = false;
|
|
pr_debug("Stop all read/write threads\n");
|
|
} else
|
|
pr_info("Invalid host notification: %s\n", buf);
|
|
}
|
|
|
|
return NULL;
|
|
|
|
error:
|
|
exit(EXIT_FAILURE);
|
|
}
|
|
|