From 6d85de341928aef8178465c60122f3cbe76f5dd6 Mon Sep 17 00:00:00 2001 From: Thomas Martitz Date: Fri, 18 Feb 2011 22:46:01 +0000 Subject: Implement cooperative threads on hosted platforms using C code. 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 --- .../target/hosted/android/thread-android-arm.c | 98 ------- firmware/target/hosted/sdl/kernel-sdl.c | 62 ++++- firmware/target/hosted/sdl/system-sdl.c | 21 +- firmware/target/hosted/sdl/system-sdl.h | 3 + firmware/target/hosted/sdl/thread-sdl.h | 2 + firmware/target/hosted/thread-arm.c | 98 +++++++ firmware/target/hosted/thread-unix.c | 294 +++++++++++++++++++++ firmware/target/hosted/thread-win32.c | 85 ++++++ 8 files changed, 555 insertions(+), 108 deletions(-) delete mode 100644 firmware/target/hosted/android/thread-android-arm.c create mode 100644 firmware/target/hosted/thread-arm.c create mode 100644 firmware/target/hosted/thread-unix.c create mode 100644 firmware/target/hosted/thread-win32.c (limited to 'firmware/target') diff --git a/firmware/target/hosted/android/thread-android-arm.c b/firmware/target/hosted/android/thread-android-arm.c deleted file mode 100644 index 0bfd2b6c44..0000000000 --- a/firmware/target/hosted/android/thread-android-arm.c +++ /dev/null @@ -1,98 +0,0 @@ -/*************************************************************************** - * __________ __ ___. - * Open \______ \ ____ ____ | | _\_ |__ _______ ___ - * Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ / - * Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < < - * Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \ - * \/ \/ \/ \/ \/ - * $Id$ - * - * Copyright (C) 2005 by Thom Johansen - * Copyright (C) 2010 by Thomas Martitz (Android-suitable core_sleep()) - * - * Generic ARM threading support - * - * This program 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; either version 2 - * of the License, or (at your option) any later version. - * - * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY - * KIND, either express or implied. - * - ****************************************************************************/ - -#include -#include -/*--------------------------------------------------------------------------- - * Start the thread running and terminate it if it returns - *--------------------------------------------------------------------------- - */ -static void __attribute__((naked,used)) start_thread(void) -{ - /* r0 = context */ - asm volatile ( - "ldr sp, [r0, #32] \n" /* Load initial sp */ - "ldr r4, [r0, #40] \n" /* start in r4 since it's non-volatile */ - "mov r1, #0 \n" /* Mark thread as running */ - "str r1, [r0, #40] \n" - "mov lr, pc \n" /* Call thread function */ - "bx r4 \n" - ); /* No clobber list - new thread doesn't care */ - thread_exit(); -} - -/* For startup, place context pointer in r4 slot, start_thread pointer in r5 - * slot, and thread function pointer in context.start. See load_context for - * what happens when thread is initially going to run. */ -#define THREAD_STARTUP_INIT(core, thread, function) \ - ({ (thread)->context.r[0] = (uint32_t)&(thread)->context, \ - (thread)->context.r[1] = (uint32_t)start_thread, \ - (thread)->context.start = (uint32_t)function; }) - - -/*--------------------------------------------------------------------------- - * Store non-volatile context. - *--------------------------------------------------------------------------- - */ -static inline void store_context(void* addr) -{ - asm volatile( - "stmia %0, { r4-r11, sp, lr } \n" - : : "r" (addr) - ); -} - -/*--------------------------------------------------------------------------- - * Load non-volatile context. - *--------------------------------------------------------------------------- - */ -static inline void load_context(const void* addr) -{ - asm volatile( - "ldr r0, [%0, #40] \n" /* Load start pointer */ - "cmp r0, #0 \n" /* Check for NULL */ - - /* If not already running, jump to start */ - "ldmneia %0, { r0, pc } \n" - "ldmia %0, { r4-r11, sp, lr } \n" /* Load regs r4 to r14 from context */ - : : "r" (addr) : "r0" /* only! */ - ); -} - -/* - * this core sleep suspends the OS thread rockbox runs under, which greatly - * reduces cpu usage (~100% to <10%) - * - * it returns when the RockboxTimer notified us, i.e. at each tick - * (after it called the tick tasks) - * - * wait_for_interrupt is implemented in kernel-android.c - **/ - -static inline void core_sleep(void) -{ - wait_for_interrupt(); -} - - diff --git a/firmware/target/hosted/sdl/kernel-sdl.c b/firmware/target/hosted/sdl/kernel-sdl.c index d933b9097e..4fb1aede0a 100644 --- a/firmware/target/hosted/sdl/kernel-sdl.c +++ b/firmware/target/hosted/sdl/kernel-sdl.c @@ -34,6 +34,14 @@ static SDL_TimerID tick_timer_id; long start_tick; +#ifndef HAVE_SDL_THREADS +/* for the wait_for_interrupt function */ +static bool do_exit; +static SDL_cond *wfi_cond; +static SDL_mutex *wfi_mutex; +#else +#define do_exit false +#endif /* Condition to signal that "interrupts" may proceed */ static SDL_cond *sim_thread_cond; /* Mutex to serialize changing levels and exclude other threads while @@ -98,6 +106,9 @@ void sim_exit_irq_handler(void) status_reg = 0; SDL_UnlockMutex(sim_irq_mtx); +#ifndef HAVE_SDL_THREADS + SDL_CondSignal(wfi_cond); +#endif } static bool sim_kernel_init(void) @@ -115,15 +126,33 @@ static bool sim_kernel_init(void) panicf("Cannot create sim_thread_cond\n"); return false; } - +#ifndef HAVE_SDL_THREADS + wfi_cond = SDL_CreateCond(); + if (wfi_cond == NULL) + { + panicf("Cannot create wfi\n"); + return false; + } + wfi_mutex = SDL_CreateMutex(); + if (wfi_mutex == NULL) + { + panicf("Cannot create wfi mutex\n"); + return false; + } +#endif return true; } void sim_kernel_shutdown(void) { SDL_RemoveTimer(tick_timer_id); +#ifndef HAVE_SDL_THREADS + do_exit = true; + SDL_CondSignal(wfi_cond); +#endif + disable_irq(); SDL_DestroyMutex(sim_irq_mtx); - SDL_DestroyCond(sim_thread_cond); + SDL_DestroyCond(sim_thread_cond); } Uint32 tick_timer(Uint32 interval, void *param) @@ -135,7 +164,7 @@ Uint32 tick_timer(Uint32 interval, void *param) new_tick = (SDL_GetTicks() - start_tick) / (1000/HZ); - while(new_tick != current_tick) + while(new_tick != current_tick && !do_exit) { sim_enter_irq_handler(); @@ -146,7 +175,7 @@ Uint32 tick_timer(Uint32 interval, void *param) sim_exit_irq_handler(); } - return interval; + return do_exit ? 0 : interval; } void tick_start(unsigned int interval_in_ms) @@ -168,4 +197,29 @@ void tick_start(unsigned int interval_in_ms) } tick_timer_id = SDL_AddTimer(interval_in_ms, tick_timer, NULL); +#ifndef HAVE_SDL_THREADS + SDL_LockMutex(wfi_mutex); +#endif +} + +#ifndef HAVE_SDL_THREADS +static void check_exit(void) +{ + if (UNLIKELY(do_exit)) + { + SDL_DestroyCond(wfi_cond); + SDL_UnlockMutex(wfi_mutex); + SDL_DestroyMutex(wfi_mutex); + sim_do_exit(); + } +} + +void wait_for_interrupt(void) +{ + /* the exit may come at any time, during the CondWait or before, + * so check it twice */ + check_exit(); + SDL_CondWait(wfi_cond, wfi_mutex); + check_exit(); } +#endif diff --git a/firmware/target/hosted/sdl/system-sdl.c b/firmware/target/hosted/sdl/system-sdl.c index 9ea25c1014..1cc9b2c919 100644 --- a/firmware/target/hosted/sdl/system-sdl.c +++ b/firmware/target/hosted/sdl/system-sdl.c @@ -184,7 +184,9 @@ static int sdl_event_thread(void * param) /* Order here is relevent to prevent deadlocks and use of destroyed sync primitives by kernel threads */ - sim_thread_shutdown(); +#ifdef HAVE_SDL_THREADS + sim_thread_shutdown(); /* not needed for native threads */ +#endif sim_kernel_shutdown(); return 0; @@ -199,9 +201,13 @@ void sim_do_exit(void) exit(EXIT_SUCCESS); } +uintptr_t *stackbegin; +uintptr_t *stackend; void system_init(void) { SDL_sem *s; + /* fake stack, OS manages size (and growth) */ + stackbegin = stackend = (uintptr_t*)&s; #if (CONFIG_PLATFORM & PLATFORM_MAEMO) /* Make glib thread safe */ @@ -219,21 +225,24 @@ void system_init(void) /* wait for sdl_event_thread to run so that it can initialize the surfaces * and video subsystem needed for SDL events */ SDL_SemWait(s); - /* cleanup */ SDL_DestroySemaphore(s); } -void system_exception_wait(void) -{ - sim_thread_exception_wait(); -} void system_reboot(void) { +#ifdef HAVE_SDL_THREADS sim_thread_exception_wait(); +#else + sim_do_exit(); +#endif } +void system_exception_wait(void) +{ + system_reboot(); +} void sys_handle_argv(int argc, char *argv[]) { diff --git a/firmware/target/hosted/sdl/system-sdl.h b/firmware/target/hosted/sdl/system-sdl.h index 01952e50a0..bec01ec81d 100644 --- a/firmware/target/hosted/sdl/system-sdl.h +++ b/firmware/target/hosted/sdl/system-sdl.h @@ -46,6 +46,9 @@ void sys_poweroff(void); void sys_handle_argv(int argc, char *argv[]); void gui_message_loop(void); void sim_do_exit(void); +#ifndef HAVE_SDL_THREADS +void wait_for_interrupt(void); +#endif extern bool background; /* True if the background image is enabled */ extern bool showremote; diff --git a/firmware/target/hosted/sdl/thread-sdl.h b/firmware/target/hosted/sdl/thread-sdl.h index 9384e6060d..9edb3ee74e 100644 --- a/firmware/target/hosted/sdl/thread-sdl.h +++ b/firmware/target/hosted/sdl/thread-sdl.h @@ -22,11 +22,13 @@ #ifndef __THREADSDL_H__ #define __THREADSDL_H__ +#ifdef HAVE_SDL_THREADS /* extra thread functions that only apply when running on hosting platforms */ void sim_thread_lock(void *me); void * sim_thread_unlock(void); void sim_thread_exception_wait(void); void sim_thread_shutdown(void); /* Shut down all kernel threads gracefully */ +#endif #endif /* #ifndef __THREADSDL_H__ */ diff --git a/firmware/target/hosted/thread-arm.c b/firmware/target/hosted/thread-arm.c new file mode 100644 index 0000000000..d2fa7d1e5d --- /dev/null +++ b/firmware/target/hosted/thread-arm.c @@ -0,0 +1,98 @@ +/*************************************************************************** + * __________ __ ___. + * Open \______ \ ____ ____ | | _\_ |__ _______ ___ + * Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ / + * Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < < + * Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \ + * \/ \/ \/ \/ \/ + * $Id$ + * + * Copyright (C) 2005 by Thom Johansen + * Copyright (C) 2010 by Thomas Martitz (Android-suitable core_sleep()) + * + * Generic ARM threading support + * + * This program 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; either version 2 + * of the License, or (at your option) any later version. + * + * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY + * KIND, either express or implied. + * + ****************************************************************************/ + +#include +/*--------------------------------------------------------------------------- + * Start the thread running and terminate it if it returns + *--------------------------------------------------------------------------- + */ +static void __attribute__((naked,used)) start_thread(void) +{ + /* r0 = context */ + asm volatile ( + "ldr sp, [r0, #32] \n" /* Load initial sp */ + "ldr r4, [r0, #40] \n" /* start in r4 since it's non-volatile */ + "mov r1, #0 \n" /* Mark thread as running */ + "str r1, [r0, #40] \n" + "mov lr, pc \n" /* Call thread function */ + "bx r4 \n" + ); /* No clobber list - new thread doesn't care */ + thread_exit(); +} + +/* For startup, place context pointer in r4 slot, start_thread pointer in r5 + * slot, and thread function pointer in context.start. See load_context for + * what happens when thread is initially going to run. */ +#define THREAD_STARTUP_INIT(core, thread, function) \ + ({ (thread)->context.r[0] = (uint32_t)&(thread)->context, \ + (thread)->context.r[1] = (uint32_t)start_thread, \ + (thread)->context.start = (uint32_t)function; }) + + +/*--------------------------------------------------------------------------- + * Store non-volatile context. + *--------------------------------------------------------------------------- + */ +static inline void store_context(void* addr) +{ + asm volatile( + "stmia %0, { r4-r11, sp, lr } \n" + : : "r" (addr) + ); +} + +/*--------------------------------------------------------------------------- + * Load non-volatile context. + *--------------------------------------------------------------------------- + */ +static inline void load_context(const void* addr) +{ + asm volatile( + "ldr r0, [%0, #40] \n" /* Load start pointer */ + "cmp r0, #0 \n" /* Check for NULL */ + + /* If not already running, jump to start */ + "ldmneia %0, { r0, pc } \n" + "ldmia %0, { r4-r11, sp, lr } \n" /* Load regs r4 to r14 from context */ + : : "r" (addr) : "r0" /* only! */ + ); +} + +/* + * this core sleep suspends the OS thread rockbox runs under, which greatly + * reduces cpu usage (~100% to <10%) + * + * it returns when when the tick timer is called, other interrupt-like + * events occur + * + * wait_for_interrupt is implemented in kernel-.c + **/ + +static inline void core_sleep(void) +{ + enable_irq(); + wait_for_interrupt(); +} + + diff --git a/firmware/target/hosted/thread-unix.c b/firmware/target/hosted/thread-unix.c new file mode 100644 index 0000000000..a84ac70d56 --- /dev/null +++ b/firmware/target/hosted/thread-unix.c @@ -0,0 +1,294 @@ +#include +#include +#include +#include +#include +#include +#include +#include +#include "debug.h" + +static volatile bool sig_handler_called; +static volatile jmp_buf tramp_buf; +static volatile jmp_buf bootstrap_buf; +static void (*thread_func)(void); +static const int trampoline_sig = SIGUSR1; +static pthread_t main_thread; + +static struct ctx { + jmp_buf thread_buf; +} thread_bufs[MAXTHREADS]; +static struct ctx* thread_context, *target_context; +static int curr_uc; + +static void trampoline(int sig); +static void bootstrap_context(void) __attribute__((noinline)); + +/* The *_context functions are heavily based on Gnu pth + * http://www.gnu.org/software/pth/ + * + * adjusted to work in a multi-thread environment to + * offer a ucontext-like API + */ + +/* + * VARIANT 2: THE SIGNAL STACK TRICK + * + * This uses sigstack/sigaltstack() and friends and is really the + * most tricky part of Pth. When you understand the following + * stuff you're a good Unix hacker and then you've already + * understood the gory ingredients of Pth. So, either welcome to + * the club of hackers, or do yourself a favor and skip this ;) + * + * The ingenious fact is that this variant runs really on _all_ POSIX + * compliant systems without special platform kludges. But be _VERY_ + * carefully when you change something in the following code. The slightest + * change or reordering can lead to horribly broken code. Really every + * function call in the following case is intended to be how it is, doubt + * me... + * + * For more details we strongly recommend you to read the companion + * paper ``Portable Multithreading -- The Signal Stack Trick for + * User-Space Thread Creation'' from Ralf S. Engelschall. A copy of the + * draft of this paper you can find in the file rse-pmt.ps inside the + * GNU Pth distribution. + */ + +static int make_context(struct ctx *ctx, void (*f)(void), char *sp, size_t stack_size) +{ + struct sigaction sa; + struct sigaction osa; + stack_t ss; + stack_t oss; + sigset_t osigs; + sigset_t sigs; + + disable_irq(); + /* + * Preserve the trampoline_sig signal state, block trampoline_sig, + * and establish our signal handler. The signal will + * later transfer control onto the signal stack. + */ + sigemptyset(&sigs); + sigaddset(&sigs, trampoline_sig); + sigprocmask(SIG_BLOCK, &sigs, &osigs); + sa.sa_handler = trampoline; + sigemptyset(&sa.sa_mask); + sa.sa_flags = SA_ONSTACK; + if (sigaction(trampoline_sig, &sa, &osa) != 0) + { + DEBUGF("%s(): %s\n", __func__, strerror(errno)); + return false; + } + /* + * Set the new stack. + * + * For sigaltstack we're lucky [from sigaltstack(2) on + * FreeBSD 3.1]: ``Signal stacks are automatically adjusted + * for the direction of stack growth and alignment + * requirements'' + * + * For sigstack we have to decide ourself [from sigstack(2) + * on Solaris 2.6]: ``The direction of stack growth is not + * indicated in the historical definition of struct sigstack. + * The only way to portably establish a stack pointer is for + * the application to determine stack growth direction.'' + */ + ss.ss_sp = sp; + ss.ss_size = stack_size; + ss.ss_flags = 0; + if (sigaltstack(&ss, &oss) < 0) + { + DEBUGF("%s(): %s\n", __func__, strerror(errno)); + return false; + } + + /* + * Now transfer control onto the signal stack and set it up. + * It will return immediately via "return" after the setjmp() + * was performed. Be careful here with race conditions. The + * signal can be delivered the first time sigsuspend() is + * called. + */ + sig_handler_called = false; + main_thread = pthread_self(); + sigfillset(&sigs); + sigdelset(&sigs, trampoline_sig); + pthread_kill(main_thread, trampoline_sig); + while(!sig_handler_called) + sigsuspend(&sigs); + + /* + * Inform the system that we are back off the signal stack by + * removing the alternative signal stack. Be careful here: It + * first has to be disabled, before it can be removed. + */ + sigaltstack(NULL, &ss); + ss.ss_flags = SS_DISABLE; + if (sigaltstack(&ss, NULL) < 0) + { + DEBUGF("%s(): %s\n", __func__, strerror(errno)); + return false; + } + sigaltstack(NULL, &ss); + if (!(ss.ss_flags & SS_DISABLE)) + { + DEBUGF("%s(): %s\n", __func__, strerror(errno)); + return false; + } + if (!(oss.ss_flags & SS_DISABLE)) + sigaltstack(&oss, NULL); + + /* + * Restore the old trampoline_sig signal handler and mask + */ + sigaction(trampoline_sig, &osa, NULL); + sigprocmask(SIG_SETMASK, &osigs, NULL); + + /* + * Tell the trampoline and bootstrap function where to dump + * the new machine context, and what to do afterwards... + */ + thread_func = f; + thread_context = ctx; + + /* + * Now enter the trampoline again, but this time not as a signal + * handler. Instead we jump into it directly. The functionally + * redundant ping-pong pointer arithmentic is neccessary to avoid + * type-conversion warnings related to the `volatile' qualifier and + * the fact that `jmp_buf' usually is an array type. + */ + if (setjmp(*((jmp_buf *)&bootstrap_buf)) == 0) + longjmp(*((jmp_buf *)&tramp_buf), 1); + + /* + * Ok, we returned again, so now we're finished + */ + enable_irq(); + return true; +} + +static void trampoline(int sig) +{ + (void)sig; + /* sanity check, no other thread should be here */ + if (pthread_self() != main_thread) + return; + + if (setjmp(*((jmp_buf *)&tramp_buf)) == 0) + { + sig_handler_called = true; + return; + } + /* longjump'd back in */ + bootstrap_context(); +} + +void bootstrap_context(void) +{ + /* copy to local storage so we can spawn further threads + * in the meantime */ + void (*thread_entry)(void) = thread_func; + struct ctx *t = thread_context; + + /* + * Save current machine state (on new stack) and + * go back to caller until we're scheduled for real... + */ + if (setjmp(t->thread_buf) == 0) + longjmp(*((jmp_buf *)&bootstrap_buf), 1); + + /* + * The new thread is now running: GREAT! + * Now we just invoke its init function.... + */ + thread_entry(); + DEBUGF("thread left\n"); + thread_exit(); +} + +static inline void set_context(struct ctx *c) +{ + longjmp(c->thread_buf, 1); +} + +static inline void swap_context(struct ctx *old, struct ctx *new) +{ + if (setjmp(old->thread_buf) == 0) + longjmp(new->thread_buf, 1); +} + +static inline void get_context(struct ctx *c) +{ + setjmp(c->thread_buf); +} + + +static void setup_thread(struct regs *context); + +#define INIT_MAIN_THREAD +static void init_main_thread(void *addr) +{ + /* get a context for the main thread so that we can jump to it from + * other threads */ + struct regs *context = (struct regs*)addr; + context->uc = &thread_bufs[curr_uc++]; + get_context(context->uc); +} + +#define THREAD_STARTUP_INIT(core, thread, function) \ + ({ (thread)->context.stack_size = (thread)->stack_size, \ + (thread)->context.stack = (uintptr_t)(thread)->stack; \ + (thread)->context.start = function; }) + + + +/* + * Prepare context to make the thread runnable by calling swapcontext on it + */ +static void setup_thread(struct regs *context) +{ + void (*fn)(void) = context->start; + context->uc = &thread_bufs[curr_uc++]; + while (!make_context(context->uc, fn, (char*)context->stack, context->stack_size)) + DEBUGF("Thread creation failed. Retrying"); +} + + +/* + * Save the ucontext_t pointer for later use in swapcontext() + * + * Cannot do getcontext() here, because jumping back to the context + * resumes after the getcontext call (i.e. store_context), but we need + * to resume from load_context() + */ +static inline void store_context(void* addr) +{ + struct regs *r = (struct regs*)addr; + target_context = r->uc; +} + +/* + * Perform context switch + */ +static inline void load_context(const void* addr) +{ + struct regs *r = (struct regs*)addr; + if (UNLIKELY(r->start)) + { + setup_thread(r); + r->start = NULL; + } + swap_context(target_context, r->uc); +} + +/* + * play nice with the host and sleep while waiting for the tick */ +extern void wait_for_interrupt(void); +static inline void core_sleep(void) +{ + enable_irq(); + wait_for_interrupt(); +} + diff --git a/firmware/target/hosted/thread-win32.c b/firmware/target/hosted/thread-win32.c new file mode 100644 index 0000000000..a60198494a --- /dev/null +++ b/firmware/target/hosted/thread-win32.c @@ -0,0 +1,85 @@ +/*************************************************************************** + * __________ __ ___. + * Open \______ \ ____ ____ | | _\_ |__ _______ ___ + * Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ / + * Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < < + * Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \ + * \/ \/ \/ \/ \/ + * $Id$ + * + * Copyright (C) 2010 by Thomas Martitz + * + * Generic ARM threading support + * + * This program 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; either version 2 + * of the License, or (at your option) any later version. + * + * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY + * KIND, either express or implied. + * + ****************************************************************************/ + + +#include +#include "system.h" + +#define INIT_MAIN_THREAD + +#define THREAD_STARTUP_INIT(core, thread, function) \ + ({ (thread)->context.stack_size = (thread)->stack_size, \ + (thread)->context.stack = (uintptr_t)(thread)->stack; \ + (thread)->context.start = function; }) + +static void init_main_thread(void *addr) +{ + struct regs *context = (struct regs*)addr; + /* we must convert the current main thread to a fiber to be able to + * schedule other fibers */ + context->uc = ConvertThreadToFiber(NULL); + context->stack_size = 0; +} + +static inline void store_context(void* addr) +{ + (void)addr; + /* nothing to do here, Fibers continue after the SwitchToFiber call */ +} + +static void start_thread(void) +{ + void (*func)(void) = GetFiberData(); + func(); + /* go out if thread function returns */ + thread_exit(); +} + +/* + * Load context and run it + * + * Resume execution from the last load_context call for the thread + */ + +static inline void load_context(const void* addr) +{ + struct regs *context = (struct regs*)addr; + if (UNLIKELY(context->start)) + { /* need setup before switching to it */ + context->uc = CreateFiber(context->stack_size, + (LPFIBER_START_ROUTINE)start_thread, context->start); + /* can't assign stack pointer, only stack size */ + context->stack_size = 0; + context->start = NULL; + } + SwitchToFiber(context->uc); +} + +/* + * play nice with the host and sleep while waiting for the tick */ +static inline void core_sleep(void) +{ + enable_irq(); + wait_for_interrupt(); +} + -- cgit v1.2.3