6d85de3419
This replaces SDL threads with real cooperative threads, which are less cpu intensive and allow priority scheduling. The backend for context switching is dependant on the host (sigaltstack/longjmp on Unix, Fibers on Windows). configure has options to force or disallow SDL threads. git-svn-id: svn://svn.rockbox.org/rockbox/trunk@29327 a1c6a512-1295-4272-9138-f99709370657
85 lines
2.5 KiB
C
85 lines
2.5 KiB
C
/***************************************************************************
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* __________ __ ___.
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* Open \______ \ ____ ____ | | _\_ |__ _______ ___
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* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
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* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
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* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
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* \/ \/ \/ \/ \/
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* $Id$
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*
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* Copyright (C) 2010 by Thomas Martitz
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*
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* Generic ARM threading support
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2
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* of the License, or (at your option) any later version.
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*
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* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
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* KIND, either express or implied.
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*
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****************************************************************************/
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#include <windows.h>
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#include "system.h"
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#define INIT_MAIN_THREAD
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#define THREAD_STARTUP_INIT(core, thread, function) \
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({ (thread)->context.stack_size = (thread)->stack_size, \
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(thread)->context.stack = (uintptr_t)(thread)->stack; \
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(thread)->context.start = function; })
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static void init_main_thread(void *addr)
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{
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struct regs *context = (struct regs*)addr;
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/* we must convert the current main thread to a fiber to be able to
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* schedule other fibers */
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context->uc = ConvertThreadToFiber(NULL);
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context->stack_size = 0;
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}
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static inline void store_context(void* addr)
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{
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(void)addr;
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/* nothing to do here, Fibers continue after the SwitchToFiber call */
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}
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static void start_thread(void)
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{
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void (*func)(void) = GetFiberData();
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func();
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/* go out if thread function returns */
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thread_exit();
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}
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/*
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* Load context and run it
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*
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* Resume execution from the last load_context call for the thread
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*/
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static inline void load_context(const void* addr)
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{
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struct regs *context = (struct regs*)addr;
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if (UNLIKELY(context->start))
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{ /* need setup before switching to it */
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context->uc = CreateFiber(context->stack_size,
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(LPFIBER_START_ROUTINE)start_thread, context->start);
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/* can't assign stack pointer, only stack size */
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context->stack_size = 0;
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context->start = NULL;
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}
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SwitchToFiber(context->uc);
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}
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/*
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* play nice with the host and sleep while waiting for the tick */
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static inline void core_sleep(void)
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{
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enable_irq();
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wait_for_interrupt();
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}
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