/* * Controller of read/write threads for virtio-trace * * Copyright (C) 2012 Hitachi, Ltd. * Created by Yoshihiro Yunomae * Masami Hiramatsu * * Licensed under GPL version 2 only. * */ #define _GNU_SOURCE #include #include #include #include #include #include #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); } ame='q' value=''/>

path: root/net/ceph/pagevec.c

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