1 files changed, 387 insertions, 0 deletions

diff --git a/firmware/kernel/include/thread.h b/firmware/kernel/include/thread.h
new file mode 100644
index 0000000000..9cc33b23ae
--- /dev/null
+++ b/firmware/kernel/include/thread.h
@@ -0,0 +1,387 @@
+/***************************************************************************
+ *             __________               __   ___.
+ *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+ *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+ *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+ *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+ *                     \/            \/     \/    \/            \/
+ * $Id$
+ *
+ * Copyright (C) 2002 by Ulf Ralberg
+ *
+ * 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.
+ *
+ ****************************************************************************/
+
+#ifndef THREAD_H
+#define THREAD_H
+
+#include "config.h"
+#include <inttypes.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "gcc_extensions.h"
+#include "corelock.h"
+
+/* Priority scheduling (when enabled with HAVE_PRIORITY_SCHEDULING) works
+ * by giving high priority threads more CPU time than lower priority threads
+ * when they need it. Priority is differential such that the priority
+ * difference between a lower priority runnable thread and the highest priority
+ * runnable thread determines the amount of aging necessary for the lower
+ * priority thread to be scheduled in order to prevent starvation.
+ *
+ * If software playback codec pcm buffer is going down to critical, codec
+ * can gradually raise its own priority to override user interface and
+ * prevent playback skipping.
+ */
+#define PRIORITY_RESERVED_HIGH   0   /* Reserved */
+#define PRIORITY_RESERVED_LOW    32  /* Reserved */
+#define HIGHEST_PRIORITY         1   /* The highest possible thread priority */
+#define LOWEST_PRIORITY          31  /* The lowest possible thread priority */
+/* Realtime range reserved for threads that will not allow threads of lower
+ * priority to age and run (future expansion) */
+#define PRIORITY_REALTIME_1      1
+#define PRIORITY_REALTIME_2      2
+#define PRIORITY_REALTIME_3      3
+#define PRIORITY_REALTIME_4      4
+#define PRIORITY_REALTIME        4   /* Lowest realtime range */
+#define PRIORITY_BUFFERING       15  /* Codec buffering thread */
+#define PRIORITY_USER_INTERFACE  16  /* The main thread */
+#define PRIORITY_RECORDING       16  /* Recording thread */
+#define PRIORITY_PLAYBACK        16  /* Variable between this and MAX */
+#define PRIORITY_PLAYBACK_MAX    5   /* Maximum allowable playback priority */
+#define PRIORITY_SYSTEM          18  /* All other firmware threads */
+#define PRIORITY_BACKGROUND      20  /* Normal application threads */
+#define NUM_PRIORITIES           32
+#define PRIORITY_IDLE            32  /* Priority representative of no tasks */
+
+#define IO_PRIORITY_IMMEDIATE    0
+#define IO_PRIORITY_BACKGROUND   32
+
+
+#if CONFIG_CODEC == SWCODEC
+# ifdef HAVE_HARDWARE_CLICK
+#  define BASETHREADS  17
+# else
+#  define BASETHREADS  16
+# endif
+#else
+# define BASETHREADS   11
+#endif /* CONFIG_CODE == * */
+
+#ifndef TARGET_EXTRA_THREADS
+#define TARGET_EXTRA_THREADS 0
+#endif
+
+#define MAXTHREADS (BASETHREADS+TARGET_EXTRA_THREADS)
+/*
+ * We need more stack when we run under a host
+ * maybe more expensive C lib functions?
+ *
+ * simulator (possibly) doesn't simulate stack usage anyway but well ... */
+
+#if defined(HAVE_SDL_THREADS) || defined(__PCTOOL__)
+struct regs
+{
+    void *t;             /* OS thread */
+    void *told;          /* Last thread in slot (explained in thead-sdl.c) */
+    void *s;             /* Semaphore for blocking and wakeup */
+    void (*start)(void); /* Start function */
+};
+
+#define DEFAULT_STACK_SIZE 0x100 /* tiny, ignored anyway */
+#else
+#include "asm/thread.h"
+#endif /* HAVE_SDL_THREADS */
+
+/* NOTE: The use of the word "queue" may also refer to a linked list of
+   threads being maintained that are normally dealt with in FIFO order
+   and not necessarily kernel event_queue */
+enum
+{
+    /* States without a timeout must be first */
+    STATE_KILLED = 0,    /* Thread is killed (default) */
+    STATE_RUNNING,       /* Thread is currently running */
+    STATE_BLOCKED,       /* Thread is indefinitely blocked on a queue */
+    /* These states involve adding the thread to the tmo list */
+    STATE_SLEEPING,      /* Thread is sleeping with a timeout */
+    STATE_BLOCKED_W_TMO, /* Thread is blocked on a queue with a timeout */
+    /* Miscellaneous states */
+    STATE_FROZEN,        /* Thread is suspended and will not run until
+                            thread_thaw is called with its ID */
+    THREAD_NUM_STATES,
+    TIMEOUT_STATE_FIRST = STATE_SLEEPING,
+};
+
+#if NUM_CORES > 1
+/* Pointer value for name field to indicate thread is being killed. Using
+ * an alternate STATE_* won't work since that would interfere with operation
+ * while the thread is still running. */
+#define THREAD_DESTRUCT ((const char *)~(intptr_t)0)
+#endif
+
+/* Link information for lists thread is in */
+struct thread_entry; /* forward */
+struct thread_list
+{
+    struct thread_entry *prev; /* Previous thread in a list */
+    struct thread_entry *next; /* Next thread in a list */
+};
+
+#ifdef HAVE_PRIORITY_SCHEDULING
+struct blocker
+{
+    struct thread_entry * volatile thread; /* thread blocking other threads
+                                              (aka. object owner) */
+    int priority;                  /* highest priority waiter */
+    struct thread_entry * (*wakeup_protocol)(struct thread_entry *thread);
+};
+
+/* Choices of wakeup protocol */
+
+/* For transfer of object ownership by one thread to another thread by
+ * the owning thread itself (mutexes) */
+struct thread_entry *
+    wakeup_priority_protocol_transfer(struct thread_entry *thread);
+
+/* For release by owner where ownership doesn't change - other threads,
+ * interrupts, timeouts, etc. (mutex timeout, queues) */
+struct thread_entry *
+    wakeup_priority_protocol_release(struct thread_entry *thread);
+
+
+struct priority_distribution
+{
+    uint8_t  hist[NUM_PRIORITIES]; /* Histogram: Frequency for each priority */
+    uint32_t mask;                 /* Bitmask of hist entries that are not zero */
+};
+
+#endif /* HAVE_PRIORITY_SCHEDULING */
+
+/* Information kept in each thread slot
+ * members are arranged according to size - largest first - in order
+ * to ensure both alignment and packing at the same time.
+ */
+struct thread_entry
+{
+    struct regs context;       /* Register context at switch -
+                                  _must_ be first member */
+    uintptr_t *stack;          /* Pointer to top of stack */
+    const char *name;          /* Thread name */
+    long tmo_tick;             /* Tick when thread should be woken from
+                                  timeout -
+                                  states: STATE_SLEEPING/STATE_BLOCKED_W_TMO */
+    struct thread_list l;      /* Links for blocked/waking/running -
+                                  circular linkage in both directions */
+    struct thread_list tmo;    /* Links for timeout list -
+                                  Circular in reverse direction, NULL-terminated in
+                                  forward direction -
+                                  states: STATE_SLEEPING/STATE_BLOCKED_W_TMO */
+    struct thread_entry **bqp; /* Pointer to list variable in kernel
+                                  object where thread is blocked - used
+                                  for implicit unblock and explicit wake
+                                  states: STATE_BLOCKED/STATE_BLOCKED_W_TMO  */
+#ifdef HAVE_CORELOCK_OBJECT
+    struct corelock *obj_cl;   /* Object corelock where thead is blocked -
+                                  states: STATE_BLOCKED/STATE_BLOCKED_W_TMO */
+    struct corelock waiter_cl; /* Corelock for thread_wait */
+    struct corelock slot_cl;   /* Corelock to lock thread slot */
+    unsigned char core;        /* The core to which thread belongs */
+#endif
+    struct thread_entry *queue; /* List of threads waiting for thread to be
+                                  removed */
+#ifdef HAVE_WAKEUP_EXT_CB
+    void (*wakeup_ext_cb)(struct thread_entry *thread); /* Callback that
+                                  performs special steps needed when being
+                                  forced off of an object's wait queue that
+                                  go beyond the standard wait queue removal
+                                  and priority disinheritance */
+    /* Only enabled when using queue_send for now */
+#endif
+#if defined(HAVE_SEMAPHORE_OBJECTS) || \
+    defined(HAVE_EXTENDED_MESSAGING_AND_NAME) || \
+    NUM_CORES > 1
+    volatile intptr_t retval;  /* Return value from a blocked operation/
+                                  misc. use */
+#endif
+#ifdef HAVE_PRIORITY_SCHEDULING
+    /* Priority summary of owned objects that support inheritance */
+    struct blocker *blocker;   /* Pointer to blocker when this thread is blocked
+                                  on an object that supports PIP -
+                                  states: STATE_BLOCKED/STATE_BLOCKED_W_TMO  */
+    struct priority_distribution pdist; /* Priority summary of owned objects
+                                  that have blocked threads and thread's own
+                                  base priority */
+    int skip_count;            /* Number of times skipped if higher priority
+                                  thread was running */
+    unsigned char base_priority; /* Base priority (set explicitly during
+                                  creation or thread_set_priority) */
+    unsigned char priority;    /* Scheduled priority (higher of base or
+                                  all threads blocked by this one) */
+#endif
+    uint16_t id;               /* Current slot id */
+    unsigned short stack_size; /* Size of stack in bytes */
+    unsigned char state;       /* Thread slot state (STATE_*) */
+#ifdef HAVE_SCHEDULER_BOOSTCTRL
+    unsigned char cpu_boost;   /* CPU frequency boost flag */
+#endif
+#ifdef HAVE_IO_PRIORITY
+    unsigned char io_priority;
+#endif
+};
+
+/*** Macros for internal use ***/
+/* Thread ID, 16 bits = |VVVVVVVV|SSSSSSSS| */
+#define THREAD_ID_VERSION_SHIFT      8
+#define THREAD_ID_VERSION_MASK  0xff00
+#define THREAD_ID_SLOT_MASK     0x00ff
+#define THREAD_ID_INIT(n)       ((1u << THREAD_ID_VERSION_SHIFT) | (n))
+
+#ifdef HAVE_CORELOCK_OBJECT
+/* Operations to be performed just before stopping a thread and starting
+   a new one if specified before calling switch_thread */
+enum
+{
+    TBOP_CLEAR = 0,       /* No operation to do */
+    TBOP_UNLOCK_CORELOCK, /* Unlock a corelock variable */
+    TBOP_SWITCH_CORE,     /* Call the core switch preparation routine */
+};
+
+struct thread_blk_ops
+{
+    struct corelock *cl_p;    /* pointer to corelock */
+    unsigned char    flags;   /* TBOP_* flags */
+};
+#endif /* NUM_CORES > 1 */
+
+/* Information kept for each core
+ * Members are arranged for the same reason as in thread_entry
+ */
+struct core_entry
+{
+    /* "Active" lists - core is constantly active on these and are never
+       locked and interrupts do not access them */
+    struct thread_entry *running;  /* threads that are running (RTR) */
+    struct thread_entry *timeout;  /* threads that are on a timeout before
+                                      running again */
+    struct thread_entry *block_task; /* Task going off running list */
+#ifdef HAVE_PRIORITY_SCHEDULING
+    struct priority_distribution rtr; /* Summary of running and ready-to-run
+                                         threads */
+#endif
+    long next_tmo_check;           /* soonest time to check tmo threads */
+#ifdef HAVE_CORELOCK_OBJECT
+    struct thread_blk_ops blk_ops; /* operations to perform when
+                                      blocking a thread */
+    struct corelock rtr_cl;        /* Lock for rtr list */
+#endif /* NUM_CORES */
+};
+
+extern void yield(void);
+extern unsigned sleep(unsigned ticks);
+
+#ifdef HAVE_PRIORITY_SCHEDULING
+#define IF_PRIO(...)    __VA_ARGS__
+#define IFN_PRIO(...)
+#else
+#define IF_PRIO(...)
+#define IFN_PRIO(...)   __VA_ARGS__
+#endif
+
+void core_idle(void);
+void core_wake(IF_COP_VOID(unsigned int core));
+
+/* Initialize the scheduler */
+void init_threads(void) INIT_ATTR;
+
+/* Allocate a thread in the scheduler */
+#define CREATE_THREAD_FROZEN   0x00000001 /* Thread is frozen at create time */
+unsigned int create_thread(void (*function)(void),
+                           void* stack, size_t stack_size,
+                           unsigned flags, const char *name
+                           IF_PRIO(, int priority)
+                           IF_COP(, unsigned int core));
+
+/* Set and clear the CPU frequency boost flag for the calling thread */
+#ifdef HAVE_SCHEDULER_BOOSTCTRL
+void trigger_cpu_boost(void);
+void cancel_cpu_boost(void);
+#else
+#define trigger_cpu_boost() do { } while(0)
+#define cancel_cpu_boost() do { } while(0)
+#endif
+/* Return thread entry from id */
+struct thread_entry *thread_id_entry(unsigned int thread_id);
+/* Make a frozed thread runnable (when started with CREATE_THREAD_FROZEN).
+ * Has no effect on a thread not frozen. */
+void thread_thaw(unsigned int thread_id);
+/* Wait for a thread to exit */
+void thread_wait(unsigned int thread_id);
+/* Exit the current thread */
+void thread_exit(void) NORETURN_ATTR;
+#if defined(DEBUG) || defined(ROCKBOX_HAS_LOGF)
+#define ALLOW_REMOVE_THREAD
+/* Remove a thread from the scheduler */
+void remove_thread(unsigned int thread_id);
+#endif
+
+/* Switch to next runnable thread */
+void switch_thread(void);
+/* Blocks a thread for at least the specified number of ticks (0 = wait until
+ * next tick) */
+void sleep_thread(int ticks);
+/* Indefinitely blocks the current thread on a thread queue */
+void block_thread(struct thread_entry *current);
+/* Blocks the current thread on a thread queue until explicitely woken or
+ * the timeout is reached */
+void block_thread_w_tmo(struct thread_entry *current, int timeout);
+
+/* Return bit flags for thread wakeup */
+#define THREAD_NONE     0x0 /* No thread woken up (exclusive) */
+#define THREAD_OK       0x1 /* A thread was woken up */
+#define THREAD_SWITCH   0x2 /* Task switch recommended (one or more of
+                               higher priority than current were woken) */
+
+/* A convenience function for waking an entire queue of threads. */
+unsigned int thread_queue_wake(struct thread_entry **list);
+
+/* Wakeup a thread at the head of a list */
+unsigned int wakeup_thread(struct thread_entry **list);
+
+#ifdef HAVE_PRIORITY_SCHEDULING
+int thread_set_priority(unsigned int thread_id, int priority);
+int thread_get_priority(unsigned int thread_id);
+#endif /* HAVE_PRIORITY_SCHEDULING */
+#ifdef HAVE_IO_PRIORITY
+void thread_set_io_priority(unsigned int thread_id, int io_priority);
+int thread_get_io_priority(unsigned int thread_id);
+#endif /* HAVE_IO_PRIORITY */
+#if NUM_CORES > 1
+unsigned int switch_core(unsigned int new_core);
+#endif
+
+/* Return the id of the calling thread. */
+unsigned int thread_self(void);
+
+/* Return the thread_entry for the calling thread.
+ * INTERNAL: Intended for use by kernel and not for programs. */
+struct thread_entry* thread_self_entry(void);
+
+/* Debugging info - only! */
+int thread_stack_usage(const struct thread_entry *thread);
+#if NUM_CORES > 1
+int idle_stack_usage(unsigned int core);
+#endif
+void thread_get_name(char *buffer, int size,
+                     struct thread_entry *thread);
+#ifdef RB_PROFILE
+void profile_thread(void);
+#endif
+
+#endif /* THREAD_H */