//
// Cforall Version 1.0.0 Copyright (C) 2016 University of Waterloo
//
// The contents of this file are covered under the licence agreement in the
// file "LICENCE" distributed with Cforall.
//
// exception.cfa -- Exceptions in a concurrent environment.
//
// Author           : Andrew Beach
// Created On       : Mon Aug 17 10:41:00 2020
// Last Modified By : Andrew Beach
// Last Modified On : Wed Oct 28 14:34:00 2020
// Update Count     : 1
//

#define __cforall_thread__

#include "exception.hfa"

#include "coroutine.hfa"

extern struct thread$ * mainThread;
extern "C" {
extern void __cfactx_thrd_leave();
}

// Common pattern for all the stop functions, wait until the end then act.
#define STOP_AT_END_FUNCTION(NAME, ...) \
static _Unwind_Reason_Code NAME( \
		int version, \
		_Unwind_Action actions, \
		_Unwind_Exception_Class exception_class, \
		struct _Unwind_Exception * unwind_exception, \
		struct _Unwind_Context * unwind_context, \
		void * stop_param) { \
	verify(actions & _UA_CLEANUP_PHASE); \
	verify(actions & _UA_FORCE_UNWIND); \
	verify(!(actions & _UA_SEARCH_PHASE)); \
	verify(!(actions & _UA_HANDLER_FRAME)); \
	if ( actions & _UA_END_OF_STACK ) { \
		__VA_ARGS__ \
	} else { \
		return _URC_NO_REASON; \
	} \
}

STOP_AT_END_FUNCTION(main_cancelstop,
	abort();
)

STOP_AT_END_FUNCTION(thread_cancelstop,
	__cfactx_thrd_leave();
	__cabi_abort( "Resumed cancelled thread" );
)

STOP_AT_END_FUNCTION(coroutine_cancelstop,
	struct coroutine$ * src = (coroutine$ *)stop_param;
	struct coroutine$ * dst = src->last;

	$ctx_switch( src, dst );
	abort();
)

extern "C" {

struct exception_context_t * this_exception_context(void) {
	return &__get_stack( active_coroutine() )->exception_context;
}

_Unwind_Reason_Code __cfaehm_cancellation_unwind( struct _Unwind_Exception * unwind_exception ) {
	_Unwind_Stop_Fn stop_func;
	void * stop_param;

	struct thread$ * this_thread = active_thread();
	if ( &this_thread->self_cor != this_thread->curr_cor ) {
		struct coroutine$ * cor = this_thread->curr_cor;
		cor->cancellation = unwind_exception;

		stop_func = coroutine_cancelstop;
		stop_param = cor;
	} else if ( mainThread == this_thread ) {
		stop_func = main_cancelstop;
		stop_param = (void *)0x22;
	} else {
		this_thread->self_cor.cancellation = unwind_exception;

		stop_func = thread_cancelstop;
		stop_param = this_thread;
	}

	return _Unwind_ForcedUnwind( unwind_exception, stop_func, stop_param );
}

}