/********************************************************/

/*  ntapi: Native API core library                      */

/*  Copyright (C) 2013--2016  Z. Gilboa                 */

/*  Released under GPLv2 and GPLv3; see COPYING.NTAPI.  */

/********************************************************/

#include <psxtypes/psxtypes.h>

#include <ntapi/nt_object.h>

#include <ntapi/nt_sync.h>

#include <ntapi/nt_atomic.h>

#include <ntapi/ntapi.h>

#include "ntapi_impl.h"

void __stdcall __ntapi_tt_sync_block_init(

	__in	nt_sync_block *	sync_block,

	__in	uint32_t	flags			__optional,

	__in	int32_t		srvtid			__optional,

	__in	int32_t		default_lock_tries	__optional,

	__in	int64_t		default_lock_wait	__optional,

	__in	void *		hsignal			__optional)

{

	__ntapi->tt_aligned_block_memset(

		sync_block,

		0,sizeof(*sync_block));

	sync_block->lock_tries = default_lock_tries

		? default_lock_tries

		: __NT_SYNC_BLOCK_LOCK_TRIES;

	sync_block->lock_wait.quad = default_lock_wait

		? default_lock_wait

		: (-1);

	sync_block->flags   = flags;

	sync_block->srvtid  = srvtid;

	sync_block->hsignal = hsignal;

	return;

}

int32_t __stdcall __ntapi_tt_sync_block_lock(

	__in	nt_sync_block *	sync_block,

	__in	int32_t		lock_tries	__optional,

	__in	int64_t		lock_wait	__optional,

	__in	uint32_t *	sig_flag	__optional)

{

	int32_t		status;

	int32_t		tid;

	intptr_t	lock;

	void *		hwait[2];

	nt_timeout	timeout;

	/* validation */

	if (sync_block->invalid)

		return NT_STATUS_INVALID_HANDLE;

	/* already owned? */

	tid = pe_get_current_thread_id();

	if (sync_block->tid == tid) return NT_STATUS_SUCCESS;

	/* yield to server? */

	if ((sync_block->flags & NT_SYNC_BLOCK_YIELD_TO_SERVER) && (tid != sync_block->srvtid)) {

		hwait[0] = sync_block->hserver;

		hwait[1] = sync_block->hsignal;

		/* signal support */

		if (sig_flag && *sig_flag)

			return NT_STATUS_ALERTED;

		/* wait */

		status = __ntapi->zw_wait_for_multiple_objects(

			2,

			hwait,

			NT_WAIT_ANY,

			NT_SYNC_NON_ALERTABLE,

			(nt_timeout *)0);

		/* signal support */

		if (sig_flag && *sig_flag)

			return NT_STATUS_ALERTED;

	}

	/* first try */

	lock = at_locked_cas_32(&sync_block->tid,0,tid);

	if (lock && !--lock_tries) return NT_STATUS_NOT_LOCKED;

	/* first-time contended case? */

	if (lock && !sync_block->hwait) {

		status = __ntapi->tt_create_inheritable_event(

			&hwait[0],

			NT_NOTIFICATION_EVENT,

			NT_EVENT_NOT_SIGNALED);

		if (status) return status;

		lock = at_locked_cas(

			(intptr_t *)&sync_block->hwait,

			0,(intptr_t)hwait);

		if (lock)

			__ntapi->zw_close(hwait);

		/* try again without a wait */

		lock = at_locked_cas_32(&sync_block->tid,0,tid);

	}

	/* contended case? */

	if (lock) {

		hwait[0] = sync_block->hwait;

		hwait[1] = sync_block->hsignal;

		lock_tries = lock_tries

			? lock_tries

			: sync_block->lock_tries;

		timeout.quad = lock_wait

			? lock_wait

			: sync_block->lock_wait.quad;

		for (; lock && lock_tries; lock_tries--) {

			/* signal support */

			if (sig_flag && *sig_flag)

				return NT_STATUS_ALERTED;

			/* wait */

			status = __ntapi->zw_wait_for_multiple_objects(

				2,

				&sync_block->hwait,

				NT_WAIT_ANY,

				NT_SYNC_NON_ALERTABLE,

				&timeout);

			/* check status */

			if ((status != NT_STATUS_TIMEOUT) && ((uint32_t)status >= NT_STATUS_WAIT_CAP))

				return status;

			/* signal support */

			if (sig_flag && *sig_flag)

				return NT_STATUS_ALERTED;

			/* try again */

			lock = at_locked_cas_32(&sync_block->tid,0,tid);

		};

	}

	if (lock) return NT_STATUS_NOT_LOCKED;

	/* shared section support */

	sync_block->pid = pe_get_current_process_id();

	return NT_STATUS_SUCCESS;

}

int32_t __stdcall __ntapi_tt_sync_block_server_lock(

	__in	nt_sync_block *	sync_block,

	__in	int32_t		lock_tries	__optional,

	__in	int64_t		lock_wait	__optional,

	__in	uint32_t *	sig_flag	__optional)

{

	int32_t status;

	/* validation */

	 if (sync_block->invalid)

		return NT_STATUS_INVALID_HANDLE;

	else if (sync_block->srvtid != pe_get_current_thread_id())

		return NT_STATUS_RESOURCE_NOT_OWNED;

	/* try once without yield request */

	status = __ntapi_tt_sync_block_lock(

		sync_block,

		1,

		lock_wait,

		sig_flag);

	if (status == NT_STATUS_SUCCESS)

		return status;

	/* hserver */

	if (!sync_block->hserver) {

		status = __ntapi->tt_create_inheritable_event(

			&sync_block->hserver,

			NT_NOTIFICATION_EVENT,

			NT_EVENT_NOT_SIGNALED);

		if (status) return status;

	} else {

		status = __ntapi->zw_reset_event(

			&sync_block->hserver,

			(int32_t *)0);

		if (status) return status;

	}

	/* yield request: set */

	sync_block->flags |= NT_SYNC_BLOCK_YIELD_TO_SERVER;

	/* try again */

	status = __ntapi_tt_sync_block_lock(

		sync_block,

		lock_tries,

		lock_wait,

		sig_flag);

	/* yield request: unset */

	sync_block->flags ^= NT_SYNC_BLOCK_YIELD_TO_SERVER;

	__ntapi->zw_set_event(

		sync_block->hserver,

		(int32_t *)0);

	/* (locking not guaranteed) */

	return status;

}

int32_t __stdcall __ntapi_tt_sync_block_unlock(

	__in	nt_sync_block *	sync_block)

{

	union {

		int64_t			i64;

		nt_large_integer	nti64;

	} cmp;

	if (sync_block->invalid)

		return NT_STATUS_INVALID_HANDLE;

	cmp.nti64.ihigh = pe_get_current_process_id();

	cmp.nti64.ulow  = pe_get_current_thread_id();

	if (cmp.i64 != at_locked_cas_64(

			(int64_t *)&sync_block->tid,

			cmp.i64,0))

		return NT_STATUS_RESOURCE_NOT_OWNED;

	return NT_STATUS_SUCCESS;

}

void __stdcall __ntapi_tt_sync_block_validate(

	__in	nt_sync_block *	sync_block)

{

	at_store_32(&sync_block->invalid,0);

	return;

}

int32_t __stdcall __ntapi_tt_sync_block_invalidate(

	__in	nt_sync_block *	sync_block)

{

	int32_t invalid;

	if (!sync_block)

		return NT_STATUS_INVALID_PARAMETER;

	invalid = at_locked_cas_32(

		&sync_block->invalid,

		0,

		1);

	if (invalid)

		return NT_STATUS_INVALID_HANDLE;

	return NT_STATUS_SUCCESS;

}

int32_t __stdcall __ntapi_tt_sync_block_discard(

	__in	nt_sync_block *	sync_block)

{

	if (!sync_block)

		return NT_STATUS_INVALID_PARAMETER;

	if (sync_block->hwait)

		__ntapi->zw_close(sync_block->hwait);

	if (sync_block->hserver)

		__ntapi->zw_close(sync_block->hserver);

	__ntapi->tt_aligned_block_memset(sync_block,-1,sizeof(*sync_block));

	return NT_STATUS_SUCCESS;

}