/* StarPU --- Runtime system for heterogeneous multicore architectures.
 *
 * Copyright (C) 2010, 2012-2014  Université de Bordeaux 1
 * Copyright (C) 2010, 2011, 2012, 2013, 2014  Centre National de la Recherche Scientifique
 *
 * StarPU is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation; either version 2.1 of the License, or (at
 * your option) any later version.
 *
 * StarPU is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 *
 * See the GNU Lesser General Public License in COPYING.LGPL for more details.
 */

#include <starpu.h>
#include <common/config.h>
#include <common/utils.h>
#include <libgen.h>
#include <errno.h>
#include <unistd.h>
#include <fcntl.h>

#if defined(_WIN32) && !defined(__CYGWIN__)
#include <io.h>
#include <sys/locking.h>
#define mkdir(path, mode) mkdir(path)
#endif

/* Function with behaviour like `mkdir -p'. This function was adapted from
 * http://niallohiggins.com/2009/01/08/mkpath-mkdir-p-alike-in-c-for-unix/ */

int _starpu_mkpath(const char *s, mode_t mode)
{
	int olderrno;
	char *q, *r = NULL, *path = NULL, *up = NULL;
	int rv;

	rv = -1;
	if (strcmp(s, ".") == 0 || strcmp(s, "/") == 0
#if defined(_WIN32)
		/* C:/ or C:\ */
		|| (s[0] && s[1] == ':' && (s[2] == '/' || s[2] == '\\') && !s[3])
#endif
		)
		return 0;

	if ((path = strdup(s)) == NULL)
		STARPU_ABORT();

	if ((q = strdup(s)) == NULL)
		STARPU_ABORT();

	if ((r = dirname(q)) == NULL)
		goto out;

	if ((up = strdup(r)) == NULL)
		STARPU_ABORT();

	if ((_starpu_mkpath(up, mode) == -1) && (errno != EEXIST))
		goto out;

	if ((mkdir(path, mode) == -1) && (errno != EEXIST))
		rv = -1;
	else
		rv = 0;

out:
	olderrno = errno;
	if (up)
		free(up);

	free(q);
	free(path);
	errno = olderrno;
	return rv;
}

void _starpu_mkpath_and_check(const char *path, mode_t mode)
{
	int ret;

	ret = _starpu_mkpath(path, mode);

	if (ret == -1)
	{
		if (errno != EEXIST)
		{
			fprintf(stderr,"Error making StarPU directory %s:\n", path);
			perror("mkdir");
			STARPU_ABORT();
		}

		/* make sure that it is actually a directory */
		struct stat sb;
		stat(path, &sb);
		if (!S_ISDIR(sb.st_mode))
		{
			fprintf(stderr,"Error: %s is not a directory:\n", path);
			STARPU_ABORT();
		}
	}
}

int _starpu_ftruncate(FILE *file)
{
	return ftruncate(fileno(file), 0);
}

int _starpu_frdlock(FILE *file)
{
#if defined(_WIN32) && !defined(__CYGWIN__)
	int ret;
	do {
		ret = _locking(fileno(file), _LK_RLCK, 10);
	} while (ret == EDEADLOCK);
	return ret;
#else
	struct flock lock = {
		.l_type = F_RDLCK,
		.l_whence = SEEK_SET,
		.l_start = 0,
		.l_len = 0
	};
	return fcntl(fileno(file), F_SETLKW, &lock);
#endif
}

int _starpu_frdunlock(FILE *file)
{
#if defined(_WIN32) && !defined(__CYGWIN__)
#  ifndef _LK_UNLCK
#    define _LK_UNLCK _LK_UNLOCK
#  endif
	return _locking(fileno(file), _LK_UNLCK, 10);
#else
	struct flock lock = {
		.l_type = F_UNLCK,
		.l_whence = SEEK_SET,
		.l_start = 0,
		.l_len = 0
	};
	return fcntl(fileno(file), F_SETLKW, &lock);
#endif
}

int _starpu_fwrlock(FILE *file)
{
#if defined(_WIN32) && !defined(__CYGWIN__)
	int ret;
	do {
		ret = _locking(fileno(file), _LK_LOCK, 10);
	} while (ret == EDEADLOCK);
	return ret;
#else
	struct flock lock = {
		.l_type = F_WRLCK,
		.l_whence = SEEK_SET,
		.l_start = 0,
		.l_len = 0
	};
	return fcntl(fileno(file), F_SETLKW, &lock);
#endif
}

int _starpu_fwrunlock(FILE *file)
{
	return _starpu_frdunlock(file);
}

int _starpu_check_mutex_deadlock(starpu_pthread_mutex_t *mutex)
{
	int ret;
	ret = starpu_pthread_mutex_trylock(mutex);
	if (!ret)
	{
		STARPU_PTHREAD_MUTEX_UNLOCK(mutex);
		return 0;
	}

	if (ret == EBUSY)
		return 0;

	STARPU_ASSERT (ret != EDEADLK);

	return 1;
}

char *_starpu_get_home_path(void)
{
	char *path = getenv("XDG_CACHE_HOME");
	if (!path)
		path = getenv("STARPU_HOME");
	if (!path)
		path = getenv("HOME");
	if (!path)
		path = getenv("USERPROFILE");
	if (!path) {
		static int warn;
		if (!warn) {
			warn = 1;
			_STARPU_DISP("couldn't find a $STARPU_HOME place to put .starpu data, using /tmp\n");
		}
		path = "/tmp";
	}
	return path;
}

void _starpu_gethostname(char *hostname, size_t size)
{
	char *forced_hostname = getenv("STARPU_HOSTNAME");
	if (forced_hostname && forced_hostname[0])
	{
		snprintf(hostname, size-1, "%s", forced_hostname);
		hostname[size-1] = 0;
	}
	else
	{
		char *c;
		gethostname(hostname, size-1);
		hostname[size-1] = 0;
		c = strchr(hostname, '.');
		if (c)
			*c = 0;
	}
}

void _starpu_sleep(struct timespec ts)
{
#ifdef STARPU_SIMGRID
	MSG_process_sleep(ts.tv_sec + ts.tv_nsec / 1000000000.);
#elif defined(STARPU_HAVE_WINDOWS)
	Sleep((ts.tv_sec * 1000) + (ts.tv_nsec / 1000000));
#else
	struct timespec req, rem;

	req = ts;
	while (nanosleep(&req, &rem))
		req = rem;
#endif
}