// Copyright(c) 2018-2019, Intel Corporation

//

// 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.

// * Neither the name  of Intel Corporation  nor the names of its contributors

//   may be used to  endorse or promote  products derived  from this  software

//   without specific prior written permission.

//

// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"

// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING,  BUT NOT LIMITED TO,  THE

// IMPLIED WARRANTIES OF  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

// ARE DISCLAIMED.  IN NO EVENT  SHALL THE COPYRIGHT OWNER  OR CONTRIBUTORS BE

// LIABLE  FOR  ANY  DIRECT,  INDIRECT,  INCIDENTAL,  SPECIAL,  EXEMPLARY,  OR

// CONSEQUENTIAL  DAMAGES  (INCLUDING,  BUT  NOT LIMITED  TO,  PROCUREMENT  OF

// SUBSTITUTE GOODS OR SERVICES;  LOSS OF USE,  DATA, OR PROFITS;  OR BUSINESS

// INTERRUPTION)  HOWEVER CAUSED  AND ON ANY THEORY  OF LIABILITY,  WHETHER IN

// CONTRACT,  STRICT LIABILITY,  OR TORT  (INCLUDING NEGLIGENCE  OR OTHERWISE)

// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,  EVEN IF ADVISED OF THE

// POSSIBILITY OF SUCH DAMAGE.

#ifdef HAVE_CONFIG_H

#include <config.h>

#endif // HAVE_CONFIG_H

#include <dlfcn.h>

#include "monitored_device.h"

#include "monitor_thread.h"

#include "event_dispatcher_thread.h"

#ifdef LOG

#undef LOG

#endif

#define LOG(format, ...) \

log_printf("monitor_thread: " format, ##__VA_ARGS__)

monitor_thread_config monitor_config = {

	.global = &global_config,

	.sched_policy = SCHED_RR,

	.sched_priority = 20,

};

STATIC pthread_mutex_t mon_list_lock = PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP;

STATIC fpgad_monitored_device *monitored_device_list;

STATIC void mon_queue_response(fpgad_detection_status status,

			       fpgad_respond_event_t response,

			       fpgad_monitored_device *d,

			       void *response_context)

{

	if (status == FPGAD_STATUS_DETECTED_HIGH) {

		if (evt_queue_response_high(response,

					    d,

					    response_context)) {

			pthread_yield();

		} else {

			LOG("high priority event queue is full. Dropping!\n");

		}

	} else if (status == FPGAD_STATUS_DETECTED) {

		if (evt_queue_response(response,

				       d,

				       response_context)) {

			pthread_yield();

		} else {

			LOG("event queue is full. Dropping!\n");

		}

	}

}

STATIC void mon_monitor(fpgad_monitored_device *d)

{

	unsigned i;

	if (!d->detections)

		return;

	for (i = 0 ; d->detections[i] ; ++i) {

		fpgad_detection_status result;

		fpgad_detect_event_t detect =

			d->detections[i];

		void *detect_context =

			d->detection_contexts ?

			d->detection_contexts[i] : NULL;

		result = detect(d, detect_context);

		if (result != FPGAD_STATUS_NOT_DETECTED && d->responses) {

			fpgad_respond_event_t response =

				d->responses[i];

			void *response_context =

				d->response_contexts ?

				d->response_contexts[i] : NULL;

			if (response) {

				mon_queue_response(result,

						   response,

						   d,

						   response_context);

			}

		}

	}

}

STATIC volatile bool mon_is_ready = false;

bool monitor_is_ready(void)

{

	return mon_is_ready;

}

void *monitor_thread(void *thread_context)

{

	monitor_thread_config *c = (monitor_thread_config *)thread_context;

	struct sched_param sched_param;

	int policy = 0;

	int res;

	int err;

	fpgad_monitored_device *d;

	LOG("starting\n");

	res = pthread_getschedparam(pthread_self(), &policy, &sched_param);

	if (res) {

		LOG("error getting scheduler params: %s\n", strerror(res));

	} else {

		policy = c->sched_policy;

		sched_param.sched_priority = c->sched_priority;

		res = pthread_setschedparam(pthread_self(),

					    policy,

					    &sched_param);

		if (res) {

			LOG("error setting scheduler params"

			    " (got root?): %s\n", strerror(res));

		}

	}

	mon_is_ready = true;

	while (c->global->running) {

		fpgad_mutex_lock(err, &mon_list_lock);

		for (d = monitored_device_list ; d ; d = d->next) {

			mon_monitor(d);

		}

		fpgad_mutex_unlock(err, &mon_list_lock);

		usleep(c->global->poll_interval_usec);

	}

	while (evt_dispatcher_is_ready()) {

		// Wait for the event dispatcher to complete

		// before we destroy the monitored devices.

		usleep(c->global->poll_interval_usec);

	}

	mon_destroy(c->global);

	mon_is_ready = false;

	LOG("exiting\n");

	return NULL;

}

void mon_monitor_device(fpgad_monitored_device *d)

{

	int err;

	fpgad_monitored_device *trav;

	fpgad_mutex_lock(err, &mon_list_lock);

	d->next = NULL;

	if (!monitored_device_list) {

		monitored_device_list = d;

		goto out_unlock;

	}

	for (trav = monitored_device_list ;

		trav->next ;

			trav = trav->next)

		/* find the end of the list */ ;

	trav->next = d;

out_unlock:

	fpgad_mutex_unlock(err, &mon_list_lock);

}

void mon_destroy(struct fpgad_config *c)

{

	unsigned i;

	int err;

	fpgad_monitored_device *d;

	fpgad_mutex_lock(err, &mon_list_lock);

	for (d = monitored_device_list ; d ; ) {

		fpgad_monitored_device *trash = d;

		fpgad_plugin_destroy_t destroy;

		d = d->next;

		if (trash->type == FPGAD_PLUGIN_TYPE_THREAD) {

			if (trash->thread_stop_fn) {

				trash->thread_stop_fn();

			} else {

				LOG("Thread plugin \"%s\" has"

				    " no thread_stop_fn\n",

				    trash->supported->library_path);

				pthread_cancel(trash->thread);

			}

			pthread_join(trash->thread, NULL);

		}

		destroy = (fpgad_plugin_destroy_t)

			dlsym(trash->supported->dl_handle,

				FPGAD_PLUGIN_DESTROY);

		if (destroy) {

			destroy(trash);

		} else {

			LOG("warning - no destructor for \"%s\"\n",

				trash->supported->library_path);

		}

		if (trash->token)

			fpgaDestroyToken(&trash->token);

		free(trash);

	}

	monitored_device_list = NULL;

	if (c->supported_devices) {

		for (i = 0 ; c->supported_devices[i].library_path ; ++i) {

			fpgad_supported_device *d = &c->supported_devices[i];

			if (d->flags & FPGAD_DEV_LOADED) {

				dlclose(d->dl_handle);

			}

			d->flags = 0;

			d->dl_handle = NULL;

		}

	}

	fpgad_mutex_unlock(err, &mon_list_lock);

}