1 files changed, 610 insertions, 0 deletions

diff --git a/firmware/target/hosted/sdl/thread-sdl.c b/firmware/target/hosted/sdl/thread-sdl.c
new file mode 100644
index 0000000000..fbe2621d40
--- /dev/null
+++ b/firmware/target/hosted/sdl/thread-sdl.c
@@ -0,0 +1,610 @@
+/***************************************************************************
+ *             __________               __   ___.
+ *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+ *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+ *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+ *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+ *                     \/            \/     \/    \/            \/
+ * $Id$
+ *
+ * Copyright (C) 2006 Dan Everton
+ *
+ * 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 <stdbool.h>
+#include <time.h>
+#include <SDL.h>
+#include <SDL_thread.h>
+#include <stdlib.h>
+#include <memory.h>
+#include <setjmp.h>
+#include "system-sdl.h"
+#include "thread-sdl.h"
+#include "system.h"
+#include "kernel.h"
+#include "thread.h"
+#include "debug.h"
+
+/* Define this as 1 to show informational messages that are not errors. */
+#define THREAD_SDL_DEBUGF_ENABLED 0
+
+#if THREAD_SDL_DEBUGF_ENABLED
+#define THREAD_SDL_DEBUGF(...) DEBUGF(__VA_ARGS__)
+static char __name[32];
+#define THREAD_SDL_GET_NAME(thread) \
+    ({ thread_get_name(__name, ARRAYLEN(__name), thread); __name; })
+#else
+#define THREAD_SDL_DEBUGF(...)
+#define THREAD_SDL_GET_NAME(thread)
+#endif
+
+#define THREAD_PANICF(str...) \
+    ({ fprintf(stderr, str); exit(-1); })
+
+/* Thread/core entries as in rockbox core */
+static struct core_entry cores[NUM_CORES];
+struct thread_entry threads[MAXTHREADS];
+/* Jump buffers for graceful exit - kernel threads don't stay neatly
+ * in their start routines responding to messages so this is the only
+ * way to get them back in there so they may exit */
+static jmp_buf thread_jmpbufs[MAXTHREADS];
+/* this mutex locks out other Rockbox threads while one runs,
+ * that enables us to simulate a cooperative environment even if
+ * the host is preemptive */
+static SDL_mutex *m;
+static volatile bool threads_exit = false;
+
+extern long start_tick;
+
+void sim_thread_shutdown(void)
+{
+    int i;
+
+    /* Tell all threads jump back to their start routines, unlock and exit
+       gracefully - we'll check each one in turn for it's status. Threads
+       _could_ terminate via remove_thread or multiple threads could exit
+       on each unlock but that is safe. */
+
+    /* Do this before trying to acquire lock */
+    threads_exit = true;
+
+    /* Take control */
+    SDL_LockMutex(m);
+
+    for (i = 0; i < MAXTHREADS; i++)
+    {
+        struct thread_entry *thread = &threads[i];
+        /* exit all current threads, except the main one */
+        if (thread->context.t != NULL)
+        {
+            /* Signal thread on delay or block */
+            SDL_Thread *t = thread->context.t;
+            SDL_SemPost(thread->context.s);
+            SDL_UnlockMutex(m);
+            /* Wait for it to finish */
+            SDL_WaitThread(t, NULL);
+            /* Relock for next thread signal */
+            SDL_LockMutex(m);
+        }        
+    }
+
+    SDL_UnlockMutex(m);
+    SDL_DestroyMutex(m);
+}
+
+static void new_thread_id(unsigned int slot_num,
+                          struct thread_entry *thread)
+{
+    unsigned int version =
+        (thread->id + (1u << THREAD_ID_VERSION_SHIFT))
+            & THREAD_ID_VERSION_MASK;
+
+    if (version == 0)
+        version = 1u << THREAD_ID_VERSION_SHIFT;
+
+    thread->id = version | (slot_num & THREAD_ID_SLOT_MASK);
+}
+
+static struct thread_entry * find_empty_thread_slot(void)
+{
+    struct thread_entry *thread = NULL;
+    int n;
+
+    for (n = 0; n < MAXTHREADS; n++)
+    {
+        int state = threads[n].state;
+
+        if (state == STATE_KILLED)
+        {
+            thread = &threads[n];
+            break;
+        }
+    }
+
+    return thread;
+}
+
+
+/* Initialize SDL threading */
+void init_threads(void)
+{
+    struct thread_entry *thread;
+    int n;
+
+    memset(cores, 0, sizeof(cores));
+    memset(threads, 0, sizeof(threads));
+
+    m = SDL_CreateMutex();
+
+    if (SDL_LockMutex(m) == -1)
+    {
+        fprintf(stderr, "Couldn't lock mutex\n");
+        return;
+    }
+
+    /* Initialize all IDs */
+    for (n = 0; n < MAXTHREADS; n++)
+        threads[n].id = THREAD_ID_INIT(n);
+
+    /* Slot 0 is reserved for the main thread - initialize it here and
+       then create the SDL thread - it is possible to have a quick, early
+       shutdown try to access the structure. */
+    thread = &threads[0];
+    thread->stack = (uintptr_t *)"       ";
+    thread->stack_size = 8;
+    thread->name = "main";
+    thread->state = STATE_RUNNING;
+    thread->context.s = SDL_CreateSemaphore(0);
+    thread->context.t = NULL; /* NULL for the implicit main thread */
+    cores[CURRENT_CORE].running = thread;
+ 
+    if (thread->context.s == NULL)
+    {
+        fprintf(stderr, "Failed to create main semaphore\n");
+        return;
+    }
+
+    THREAD_SDL_DEBUGF("Main thread: %p\n", thread);
+
+    return;
+}
+
+void sim_thread_exception_wait(void)
+{
+    while (1)
+    {
+        SDL_Delay(HZ/10);
+        if (threads_exit)
+            thread_exit();
+    }
+}
+
+/* A way to yield and leave the threading system for extended periods */
+void sim_thread_lock(void *me)
+{
+    SDL_LockMutex(m);
+    cores[CURRENT_CORE].running = (struct thread_entry *)me;
+
+    if (threads_exit)
+        thread_exit();
+}
+
+void * sim_thread_unlock(void)
+{
+    struct thread_entry *current = cores[CURRENT_CORE].running;
+    SDL_UnlockMutex(m);
+    return current;
+}
+
+struct thread_entry * thread_id_entry(unsigned int thread_id)
+{
+    return (thread_id == THREAD_ID_CURRENT) ? 
+        cores[CURRENT_CORE].running :
+        &threads[thread_id & THREAD_ID_SLOT_MASK];
+}
+
+static void add_to_list_l(struct thread_entry **list,
+                          struct thread_entry *thread)
+{
+    if (*list == NULL)
+    {
+        /* Insert into unoccupied list */
+        thread->l.next = thread;
+        thread->l.prev = thread;
+        *list = thread;
+    }
+    else
+    {
+        /* Insert last */
+        thread->l.next = *list;
+        thread->l.prev = (*list)->l.prev;
+        thread->l.prev->l.next = thread;
+        (*list)->l.prev = thread;
+    }
+}
+
+static void remove_from_list_l(struct thread_entry **list,
+                               struct thread_entry *thread)
+{
+    if (thread == thread->l.next)
+    {
+        /* The only item */
+        *list = NULL;
+        return;
+    }
+
+    if (thread == *list)
+    {
+        /* List becomes next item */
+        *list = thread->l.next;
+    }
+
+    /* Fix links to jump over the removed entry. */
+    thread->l.prev->l.next = thread->l.next;
+    thread->l.next->l.prev = thread->l.prev;
+}
+
+unsigned int thread_get_current(void)
+{
+    return cores[CURRENT_CORE].running->id;
+}
+
+void switch_thread(void)
+{
+    struct thread_entry *current = cores[CURRENT_CORE].running;
+
+    enable_irq();
+
+    switch (current->state)
+    {
+    case STATE_RUNNING:
+    {
+        SDL_UnlockMutex(m);
+        /* Any other thread waiting already will get it first */
+        SDL_LockMutex(m);
+        break;
+        } /* STATE_RUNNING: */
+
+    case STATE_BLOCKED:
+    {
+        int oldlevel;
+
+        SDL_UnlockMutex(m);
+        SDL_SemWait(current->context.s);
+        SDL_LockMutex(m);
+
+        oldlevel = disable_irq_save();
+        current->state = STATE_RUNNING;
+        restore_irq(oldlevel);
+        break;
+        } /* STATE_BLOCKED: */
+
+    case STATE_BLOCKED_W_TMO:
+    {
+        int result, oldlevel;
+
+        SDL_UnlockMutex(m);
+        result = SDL_SemWaitTimeout(current->context.s, current->tmo_tick);
+        SDL_LockMutex(m);
+
+        oldlevel = disable_irq_save();
+
+        if (current->state == STATE_BLOCKED_W_TMO)
+        {
+            /* Timed out */
+            remove_from_list_l(current->bqp, current);
+
+#ifdef HAVE_WAKEUP_EXT_CB
+            if (current->wakeup_ext_cb != NULL)
+                current->wakeup_ext_cb(current);
+#endif
+            current->state = STATE_RUNNING;
+        }
+
+        if (result == SDL_MUTEX_TIMEDOUT)
+        {
+            /* Other signals from an explicit wake could have been made before
+             * arriving here if we timed out waiting for the semaphore. Make
+             * sure the count is reset. */
+            while (SDL_SemValue(current->context.s) > 0)
+                SDL_SemTryWait(current->context.s);
+        }
+
+        restore_irq(oldlevel);
+        break;
+        } /* STATE_BLOCKED_W_TMO: */
+
+    case STATE_SLEEPING:
+    {
+        SDL_UnlockMutex(m);
+        SDL_SemWaitTimeout(current->context.s, current->tmo_tick);
+        SDL_LockMutex(m);
+        current->state = STATE_RUNNING;
+        break;
+        } /* STATE_SLEEPING: */
+    }
+
+    cores[CURRENT_CORE].running = current;
+
+    if (threads_exit)
+        thread_exit();
+}
+
+void sleep_thread(int ticks)
+{
+    struct thread_entry *current = cores[CURRENT_CORE].running;
+    int rem;
+
+    current->state = STATE_SLEEPING;
+
+    rem = (SDL_GetTicks() - start_tick) % (1000/HZ);
+    if (rem < 0)
+        rem = 0;
+
+    current->tmo_tick = (1000/HZ) * ticks + ((1000/HZ)-1) - rem;
+}
+
+void block_thread(struct thread_entry *current)
+{
+    current->state = STATE_BLOCKED;
+    add_to_list_l(current->bqp, current);
+}
+
+void block_thread_w_tmo(struct thread_entry *current, int ticks)
+{
+    current->state = STATE_BLOCKED_W_TMO;
+    current->tmo_tick = (1000/HZ)*ticks;
+    add_to_list_l(current->bqp, current);
+}
+
+unsigned int wakeup_thread(struct thread_entry **list)
+{
+    struct thread_entry *thread = *list;
+
+    if (thread != NULL)
+    {
+        switch (thread->state)
+        {
+        case STATE_BLOCKED:
+        case STATE_BLOCKED_W_TMO:
+            remove_from_list_l(list, thread);
+            thread->state = STATE_RUNNING;
+            SDL_SemPost(thread->context.s);
+            return THREAD_OK;
+        }
+    }
+
+    return THREAD_NONE;
+}
+
+unsigned int thread_queue_wake(struct thread_entry **list)
+{
+    unsigned int result = THREAD_NONE;
+
+    for (;;)
+    {
+        unsigned int rc = wakeup_thread(list);
+
+        if (rc == THREAD_NONE)
+            break;
+
+        result |= rc;        
+    }
+
+    return result;
+}
+
+void thread_thaw(unsigned int thread_id)
+{
+    struct thread_entry *thread = thread_id_entry(thread_id);
+
+    if (thread->id == thread_id && thread->state == STATE_FROZEN)
+    {
+        thread->state = STATE_RUNNING;
+        SDL_SemPost(thread->context.s);
+    }
+}
+
+int runthread(void *data)
+{
+    struct thread_entry *current;
+    jmp_buf *current_jmpbuf;
+
+    /* Cannot access thread variables before locking the mutex as the
+       data structures may not be filled-in yet. */
+    SDL_LockMutex(m);
+    cores[CURRENT_CORE].running = (struct thread_entry *)data;
+    current = cores[CURRENT_CORE].running;
+    current_jmpbuf = &thread_jmpbufs[current - threads];
+
+    /* Setup jump for exit */
+    if (setjmp(*current_jmpbuf) == 0)
+    {
+        /* Run the thread routine */
+        if (current->state == STATE_FROZEN)
+        {
+            SDL_UnlockMutex(m);
+            SDL_SemWait(current->context.s);
+            SDL_LockMutex(m);
+            cores[CURRENT_CORE].running = current;
+        }
+
+        if (!threads_exit)
+        {
+            current->context.start();
+            THREAD_SDL_DEBUGF("Thread Done: %d (%s)\n",
+                              current - threads, THREAD_SDL_GET_NAME(current));
+            /* Thread routine returned - suicide */
+        }
+
+        thread_exit();
+    }
+    else
+    {
+        /* Unlock and exit */
+        SDL_UnlockMutex(m);
+    }
+
+    return 0;
+}
+
+unsigned int create_thread(void (*function)(void),
+                           void* stack, size_t stack_size,
+                           unsigned flags, const char *name)
+{
+    struct thread_entry *thread;
+    SDL_Thread* t;
+    SDL_sem *s;
+
+    THREAD_SDL_DEBUGF("Creating thread: (%s)\n", name ? name : "");
+
+    thread = find_empty_thread_slot();
+    if (thread == NULL)
+    {
+        DEBUGF("Failed to find thread slot\n");
+        return 0;
+    }
+
+    s = SDL_CreateSemaphore(0);
+    if (s == NULL)
+    {
+        DEBUGF("Failed to create semaphore\n");
+        return 0;
+    }
+
+    t = SDL_CreateThread(runthread, thread);
+    if (t == NULL)
+    {
+        DEBUGF("Failed to create SDL thread\n");
+        SDL_DestroySemaphore(s);
+        return 0;
+    }
+
+    thread->stack = stack;
+    thread->stack_size = stack_size;
+    thread->name = name;
+    thread->state = (flags & CREATE_THREAD_FROZEN) ?
+        STATE_FROZEN : STATE_RUNNING;
+    thread->context.start = function;
+    thread->context.t = t;
+    thread->context.s = s;
+
+    THREAD_SDL_DEBUGF("New Thread: %d (%s)\n",
+                      thread - threads, THREAD_SDL_GET_NAME(thread));
+
+    return thread->id;
+}
+
+#ifndef ALLOW_REMOVE_THREAD
+static void remove_thread(unsigned int thread_id)
+#else
+void remove_thread(unsigned int thread_id)
+#endif
+{
+    struct thread_entry *current = cores[CURRENT_CORE].running;
+    struct thread_entry *thread = thread_id_entry(thread_id);
+
+    SDL_Thread *t;
+    SDL_sem *s;
+
+    if (thread_id != THREAD_ID_CURRENT && thread->id != thread_id)
+        return;
+
+    int oldlevel = disable_irq_save();
+
+    t = thread->context.t;
+    s = thread->context.s;
+    thread->context.t = NULL;
+
+    if (thread != current)
+    {
+        switch (thread->state)
+        {
+        case STATE_BLOCKED:
+        case STATE_BLOCKED_W_TMO:
+            /* Remove thread from object it's waiting on */
+            remove_from_list_l(thread->bqp, thread);
+
+#ifdef HAVE_WAKEUP_EXT_CB
+            if (thread->wakeup_ext_cb != NULL)
+                thread->wakeup_ext_cb(thread);
+#endif
+            break;
+        }
+
+        SDL_SemPost(s);
+    }
+
+    THREAD_SDL_DEBUGF("Removing thread: %d (%s)\n",
+        thread - threads, THREAD_SDL_GET_NAME(thread));
+
+    new_thread_id(thread->id, thread);
+    thread->state = STATE_KILLED;
+    thread_queue_wake(&thread->queue);
+
+    SDL_DestroySemaphore(s);
+
+    if (thread == current)
+    {
+        /* Do a graceful exit - perform the longjmp back into the thread
+           function to return */
+        restore_irq(oldlevel);
+        longjmp(thread_jmpbufs[current - threads], 1);
+    }
+
+    SDL_KillThread(t);
+    restore_irq(oldlevel);
+}
+
+void thread_exit(void)
+{
+    remove_thread(THREAD_ID_CURRENT);
+}
+
+void thread_wait(unsigned int thread_id)
+{
+    struct thread_entry *current = cores[CURRENT_CORE].running;
+    struct thread_entry *thread = thread_id_entry(thread_id);
+
+    if (thread_id == THREAD_ID_CURRENT ||
+        (thread->id == thread_id && thread->state != STATE_KILLED))
+    {
+        current->bqp = &thread->queue;
+        block_thread(current);
+        switch_thread();
+    }
+}
+
+int thread_stack_usage(const struct thread_entry *thread)
+{
+    return 50;
+    (void)thread;
+}
+
+/* Return name if one or ID if none */
+void thread_get_name(char *buffer, int size,
+                     struct thread_entry *thread)
+{
+    if (size <= 0)
+        return;
+
+    *buffer = '\0';
+
+    if (thread)
+    {
+        /* Display thread name if one or ID if none */
+        bool named = thread->name && *thread->name;
+        const char *fmt = named ? "%s" : "%08lX";
+        intptr_t name = named ?
+            (intptr_t)thread->name : (intptr_t)thread;
+        snprintf(buffer, size, fmt, name);
+    }
+}