ult.c File Reference

User-Level Threads. More...

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdbool.h>
#include <arch/ult.h>
#include <core/core.h>
#include <scheduler/process.h>
#include <mm/dymelor.h>

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Functions
void *	get_ult_stack (size_t size)

Variables
__thread kernel_context_t	kernel_context
	This is the execution context of the simulation kernel.

Detailed Description

User-Level Threads.

The User-Level Thread module allows the creation/scheduling of multiple co-routines which can yield the CPU to a different one, or that can be preëmpted by some asynchronous event.

Due to the possibility of external preëmption, ULTs store the whole CPU context in an ad-hoc buffer. This is a significant difference with respect standard facilities such as setjmp/longjmp which only store callee-save registers.

ULTs are used to implement both runtime-level routines (each worker thread has its own execution context) and model-level routines (each LP has its own execution context).

Copyright

Copyright (C) 2008-2019 HPDCS Group https://hpdcs.github.io

This file is part of ROOT-Sim (ROme OpTimistic Simulator).

ROOT-Sim is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; only version 3 of the License applies.

ROOT-Sim 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 General Public License for more details.

You should have received a copy of the GNU General Public License along with ROOT-Sim; if not, write to the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA

Author

Alessandro Pellegrini

Definition in file ult.c.

Function Documentation

void* get_ult_stack

(

size_t

size

)

When this function is called, a zeroed page-aligned stack for the ULT is created and returned. The size of the stack can be specified by using the parameter. It's suggested to give a stack size which is a multiple of the page size. Nevertheless, no check is done by this function.

Author

Alessandro Pellegrini

Parameters

size	The size of the requested stack

Returns

A pointer to the allocated and zeroed page-aligned stack

Definition at line 65 of file ult.c.

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