/*

 * Copyright (c) 2001-2020 Mellanox Technologies, Ltd. All rights reserved.

 *

 * This software is available to you under a choice of one of two

 * licenses.  You may choose to be licensed under the terms of the GNU

 * General Public License (GPL) Version 2, available from the file

 * COPYING in the main directory of this source tree, or the

 * BSD license below:

 *

 *     Redistribution and use in source and binary forms, with or

 *     without modification, are permitted provided that the following

 *     conditions are met:

 *

 *      - Redistributions of source code must retain the above

 *        copyright notice, this list of conditions and the following

 *        disclaimer.

 *

 *      - Redistributions in binary form must reproduce the above

 *        copyright notice, this list of conditions and the following

 *        disclaimer in the documentation and/or other materials

 *        provided with the distribution.

 *

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,

 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF

 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND

 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS

 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN

 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN

 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE

 * SOFTWARE.

 */

#include "utils/bullseye.h"

#include "vlogger/vlogger.h"

#include "wakeup_pipe.h"

#include "vma/sock/sock-redirect.h"

#define MODULE_NAME "wakeup_pipe"

#define wkup_logpanic             __log_info_panic

#define wkup_logerr               __log_info_err

#define wkup_logwarn              __log_info_warn

#define wkup_loginfo              __log_info_info

#define wkup_logdbg               __log_info_dbg

#define wkup_logfunc              __log_info_func

#define wkup_logfuncall           __log_info_funcall

#define wkup_entry_dbg		  __log_entry_dbg

#undef  MODULE_HDR_INFO

#define MODULE_HDR_INFO 	MODULE_NAME "[epfd=%d]:%d:%s() "

#undef	__INFO__

#define __INFO__	m_epfd

#define UNINIT_PIPE_FD (-1)

int wakeup_pipe::g_wakeup_pipes[2] = {UNINIT_PIPE_FD, UNINIT_PIPE_FD};

atomic_t wakeup_pipe::ref_count = ATOMIC_INIT(0);

wakeup_pipe::wakeup_pipe()

{

	int ref = atomic_fetch_and_inc(&ref_count);

	if (ref == 0) {

		BULLSEYE_EXCLUDE_BLOCK_START

		if (orig_os_api.pipe(g_wakeup_pipes)) {

			wkup_logpanic("wakeup pipe create failed (errno=%d %m)", errno);

		}

		if (orig_os_api.write(g_wakeup_pipes[1], "^", 1) != 1) {

			wkup_logpanic("wakeup pipe write failed(errno=%d %m)", errno);

		}

		BULLSEYE_EXCLUDE_BLOCK_END

		wkup_logdbg("created wakeup pipe [RD=%d, WR=%d]", g_wakeup_pipes[0], g_wakeup_pipes[1]);

		// ToDo - these pipe should be closed at some point

		// orig_os_api.close(g_si_wakeup_pipes[1]);

		// orig_os_api.close(g_si_wakeup_pipes[0]);

	}

	m_ev.events = EPOLLIN;

	m_ev.data.fd = g_wakeup_pipes[0];

}

void wakeup_pipe::do_wakeup()

{

	wkup_logfuncall("");

	//m_wakeup_lock.lock();

	//This func should be called under socket / epoll lock

	//Call to wakeup only in case there is some thread that is sleeping on epoll

	if (!m_is_sleeping)

	{

		wkup_logfunc("There is no thread in epoll_wait, therefore not calling for wakeup");

		//m_wakeup_lock.unlock();

		return;

	}

	wkup_entry_dbg("");

	int errno_tmp = errno; //don't let wakeup affect errno, as this can fail with EEXIST

	BULLSEYE_EXCLUDE_BLOCK_START

	if ((orig_os_api.epoll_ctl(m_epfd, EPOLL_CTL_ADD, g_wakeup_pipes[0], &m_ev)) && (errno != EEXIST)) {

		wkup_logerr("Failed to add wakeup fd to internal epfd (errno=%d %m)", errno);

	}

	BULLSEYE_EXCLUDE_BLOCK_END

	errno = errno_tmp;

	//m_wakeup_lock.unlock();

	//sched_yield();

}

void wakeup_pipe::remove_wakeup_fd()

{

	if (m_is_sleeping) return;

	wkup_entry_dbg("");

	int tmp_errno = errno;

	if (orig_os_api.epoll_ctl(m_epfd, EPOLL_CTL_DEL, g_wakeup_pipes[0], NULL))

	{

		BULLSEYE_EXCLUDE_BLOCK_START

		if (errno == ENOENT) {

			wkup_logdbg("Failed to delete global pipe from internal epfd it was already deleted");

		} else {

			wkup_logerr("failed to delete global pipe from internal epfd (errno=%d %m)", errno);

		}

		BULLSEYE_EXCLUDE_BLOCK_END

	}

	errno = tmp_errno;

}

wakeup_pipe::~wakeup_pipe()

{

	int ref = atomic_fetch_and_dec(&ref_count);

	if (ref == 1) {

		close(g_wakeup_pipes[0]);

		close(g_wakeup_pipes[1]);

		g_wakeup_pipes[0] = UNINIT_PIPE_FD;

		g_wakeup_pipes[1] = UNINIT_PIPE_FD;

	}

}