Sim I/O and threading that runs more like on target. Tweakable if any genuine slowness imitation is required for any one of them. One point of concern is the sim shutdown on an OS other than Linux just because terminating threads in a manner other than having the do it themselves is kind of dirty IMHO.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@14639 a1c6a512-1295-4272-9138-f99709370657

1 files changed, 310 insertions, 33 deletions

diff --git a/uisimulator/sdl/thread-sdl.c b/uisimulator/sdl/thread-sdl.c
index 90a4ecf4a7..5d2fe0b522 100644
--- a/uisimulator/sdl/thread-sdl.c
+++ b/uisimulator/sdl/thread-sdl.c
@@ -21,41 +21,157 @@
 #include <SDL.h>
 #include <SDL_thread.h>
 #include <stdlib.h>
+#include <memory.h>
 #include "thread-sdl.h"
 #include "kernel.h"
 #include "thread.h"
 #include "debug.h"
 
-SDL_Thread          *threads[256];
-int                 threadCount = 0;
-volatile long       current_tick = 0;
-SDL_mutex *m;
+/* Define this as 1 to show informational messages that are not errors. */
+#define THREAD_SDL_DEBUGF_ENABLED 0
 
-void yield(void)
+#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, sizeof(__name)/sizeof(__name[0]), thread); __name; })
+#else
+#define THREAD_SDL_DEBUGF(...)
+#define THREAD_SDL_GET_NAME(thread)
+#endif
+
+#define THREAD_PANICF(str...) \
+    ({ fprintf(stderr, str); exit(-1); })
+
+struct thread_entry threads[MAXTHREADS];            /* Thread entries as in core */
+static SDL_mutex *m;
+static SDL_sem *s;
+static struct thread_entry *running;
+
+void kill_sim_threads(void)
+{
+    int i;
+    SDL_LockMutex(m);
+    for (i = 0; i < MAXTHREADS; i++)
+    {
+        struct thread_entry *thread = &threads[i];
+        if (thread->context.t != NULL)
+        {
+            SDL_LockMutex(m);
+            if (thread->statearg == STATE_RUNNING)
+                SDL_SemPost(s);
+            else
+                SDL_CondSignal(thread->context.c);
+            SDL_KillThread(thread->context.t);
+            SDL_DestroyCond(thread->context.c);
+        }
+    }
+    SDL_DestroyMutex(m);
+    SDL_DestroySemaphore(s);
+}
+
+static int find_empty_thread_slot(void)
+{
+    int n;
+
+    for (n = 0; n < MAXTHREADS; n++)
+    {
+        if (threads[n].name == NULL)
+            break;
+    }
+
+    return n;
+}
+
+static void add_to_list(struct thread_entry **list,
+                        struct thread_entry *thread)
+{
+    if (*list == NULL)
+    {
+        /* Insert into unoccupied list */
+        thread->next = thread;
+        thread->prev = thread;
+        *list = thread;
+    }
+    else
+    {
+        /* Insert last */
+        thread->next = *list;
+        thread->prev = (*list)->prev;
+        thread->prev->next = thread;
+        (*list)->prev = thread;
+    }
+}
+
+static void remove_from_list(struct thread_entry **list,
+                             struct thread_entry *thread)
 {
-    static int counter = 0;
+    if (thread == thread->next)
+    {
+        /* The only item */
+        *list = NULL;
+        return;
+    }
 
-    SDL_mutexV(m);
-    if (counter++ >= 50)
+    if (thread == *list)
     {
-        SDL_Delay(1);
-        counter = 0;
+        /* List becomes next item */
+        *list = thread->next;
     }
-    SDL_mutexP(m);
+
+    /* Fix links to jump over the removed entry. */
+    thread->prev->next = thread->next;
+    thread->next->prev = thread->prev;
 }
 
-void sim_sleep(int ticks)
+struct thread_entry *thread_get_current(void)
 {
-    SDL_mutexV(m);
-    SDL_Delay((1000/HZ) * ticks);
-    SDL_mutexP(m);
+    return running;
+}
+
+void switch_thread(bool save_context, struct thread_entry **blocked_list)
+{
+    struct thread_entry *current = running;
+
+    SDL_UnlockMutex(m);
+
+    SDL_SemWait(s);
+
+    SDL_LockMutex(m);
+    running = current;
+
+    SDL_SemPost(s);
+
+    (void)save_context; (void)blocked_list;
+}
+
+void sleep_thread(int ticks)
+{
+    struct thread_entry *current;
+
+    current = running;
+    current->statearg = STATE_SLEEPING;
+
+    SDL_CondWaitTimeout(current->context.c, m, (1000/HZ) * ticks);
+    running = current;
+
+    current->statearg = STATE_RUNNING;
 }
 
 int runthread(void *data)
 {
-    SDL_mutexP(m);
-    ((void(*)())data) ();
-    SDL_mutexV(m);
+    struct thread_entry *current;
+
+    /* Cannot access thread variables before locking the mutex as the
+       data structures may not be filled-in yet. */
+    SDL_LockMutex(m);
+    running = (struct thread_entry *)data;
+    current = running;
+    current->context.start();
+
+    THREAD_SDL_DEBUGF("Thread Done: %d (%s)\n",
+                      current - threads, THREAD_SDL_GET_NAME(current));
+    remove_thread(NULL);
     return 0;
 }
 
@@ -64,37 +180,198 @@ struct thread_entry*
                   const char *name)
 {
     /** Avoid compiler warnings */
-    (void)stack;
-    (void)stack_size;
-    (void)name;
     SDL_Thread* t;
+    SDL_cond *cond;
+    int slot;
+
+    THREAD_SDL_DEBUGF("Creating thread: (%s)\n", name ? name : "");
 
-    if (threadCount == 256) {
+    slot = find_empty_thread_slot();
+    if (slot >= MAXTHREADS)
+    {
+        DEBUGF("Failed to find thread slot\n");
         return NULL;
     }
 
-    t = SDL_CreateThread(runthread, function);
-    threads[threadCount++] = t;
+    cond = SDL_CreateCond();
+    if (cond == NULL)
+    {
+        DEBUGF("Failed to create condition variable\n");
+        return NULL;
+    }
+
+    t = SDL_CreateThread(runthread, &threads[slot]);
+    if (t == NULL)
+    {
+        DEBUGF("Failed to create SDL thread\n");
+        SDL_DestroyCond(cond);
+        return NULL;
+    }
+
+    threads[slot].stack = stack;
+    threads[slot].stack_size = stack_size;
+    threads[slot].name = name;
+    threads[slot].statearg = STATE_RUNNING;
+    threads[slot].context.start = function;
+    threads[slot].context.t = t;
+    threads[slot].context.c = cond;
+
+    THREAD_SDL_DEBUGF("New Thread: %d (%s)\n",
+                      slot, THREAD_SDL_GET_NAME(&threads[slot]));
+
+    return &threads[slot];
+}
+
+void block_thread(struct thread_entry **list)
+{
+    struct thread_entry *thread = running;
+
+    thread->statearg = STATE_BLOCKED;
+    add_to_list(list, thread);
+
+    SDL_CondWait(thread->context.c, m);
+    running = thread;
+}
+
+void block_thread_w_tmo(struct thread_entry **list, int ticks)
+{
+    struct thread_entry *thread = running;
+
+    thread->statearg = STATE_BLOCKED_W_TMO;
+    add_to_list(list, thread);
+
+    SDL_CondWaitTimeout(thread->context.c, m, (1000/HZ) * ticks);
+    running = thread;
+
+    if (thread->statearg == STATE_BLOCKED_W_TMO)
+    {
+        /* Timed out */
+        remove_from_list(list, thread);
+        thread->statearg = STATE_RUNNING;
+    }
+}
+
+void wakeup_thread(struct thread_entry **list)
+{
+    struct thread_entry *thread = *list;
 
-    yield();
+    if (thread == NULL)
+    {
+        return;
+    }
 
-    /* The return value is never de-referenced outside thread.c so this
-       nastiness should be fine.  However, a better solution would be nice.
-      */
-    return (struct thread_entry*)t;
+    switch (thread->statearg)
+    {
+    case STATE_BLOCKED:
+    case STATE_BLOCKED_W_TMO:
+        remove_from_list(list, thread);
+        thread->statearg = STATE_RUNNING;
+        SDL_CondSignal(thread->context.c);
+        break;
+    }
 }
 
 void init_threads(void)
 {
+    int slot;
+
     m = SDL_CreateMutex();
+    s = SDL_CreateSemaphore(0);
+
+    memset(threads, 0, sizeof(threads));
+
+    slot = find_empty_thread_slot();
+    if (slot >= MAXTHREADS)
+    {
+        THREAD_PANICF("Couldn't find slot for main thread.\n");
+    }
+
+    threads[slot].stack = "       ";
+    threads[slot].stack_size = 8;
+    threads[slot].name = "main";
+    threads[slot].statearg = STATE_RUNNING;
+    threads[slot].context.t = gui_thread;
+    threads[slot].context.c = SDL_CreateCond();
+
+    running = &threads[slot];
+
+    THREAD_SDL_DEBUGF("First Thread: %d (%s)\n",
+            slot, THREAD_SDL_GET_NAME(&threads[slot]));
+
+    if (SDL_LockMutex(m) == -1) {
+        THREAD_PANICF("Couldn't lock mutex\n");
+    }
 
-    if (SDL_mutexP(m) == -1) {
-        fprintf(stderr, "Couldn't lock mutex\n");
-        exit(-1);
+    if (SDL_SemPost(s) == -1) {
+        THREAD_PANICF("Couldn't post to semaphore\n");
     }
 }
 
 void remove_thread(struct thread_entry *thread)
 {
-    SDL_KillThread((SDL_Thread*) thread);
+    struct thread_entry *current = running;
+    SDL_Thread *t;
+    SDL_cond *c;
+
+    if (thread == NULL)
+    {
+        thread = current;
+    }
+
+    t = thread->context.t;
+    c = thread->context.c;
+    thread->context.t = NULL;
+
+    if (thread != current)
+    {
+        if (thread->statearg == STATE_RUNNING)
+            SDL_SemPost(s);
+        else
+            SDL_CondSignal(c);
+    }
+
+    THREAD_SDL_DEBUGF("Removing thread: %d (%s)\n",
+        thread - threads, THREAD_SDL_GET_NAME(thread));
+
+    thread->name = NULL;
+
+    SDL_DestroyCond(c);
+
+    if (thread == current)
+    {
+        SDL_UnlockMutex(m);
+    }
+
+    SDL_KillThread(t);
+}
+
+int thread_stack_usage(const struct thread_entry *thread)
+{
+    return 50;
+    (void)thread;
+}
+
+int thread_get_status(const struct thread_entry *thread)
+{
+    return thread->statearg;
+}
+
+/* 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);
+    }
 }