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/*

 * Copyright (c) 2001-2004 Jakub Jermar

 * All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 *

 * - Redistributions of source code must retain the above copyright

 *   notice, this list of conditions and the following disclaimer.

 * - Redistributions in binary form must reproduce the above copyright

 *   notice, this list of conditions and the following disclaimer in the

 *   documentation and/or other materials provided with the distribution.

 * - The name of the author may not be used to endorse or promote products

 *   derived from this software without specific prior written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR

 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES

 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.

 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,

 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT

 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,

 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY

 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF

 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 */

/** @addtogroup genericproc

 * @{

 */

/** @file

 */

#ifndef KERN_THREAD_H_

#define KERN_THREAD_H_

#include <synch/waitq.h>

#include <proc/task.h>

#include <time/timeout.h>

#include <cpu.h>

#include <synch/rwlock.h>

#include <adt/btree.h>

#include <mm/slab.h>

#include <arch/cpu.h>

#include <mm/tlb.h>

#include <proc/uarg.h>

#define THREAD_STACK_SIZE   STACK_SIZE

#define THREAD_NAME_BUFLEN  20

extern char *thread_states[];

/* Thread flags */

#define THREAD_FLAG_WIRED   (1 << 0)    /**< Thread cannot be migrated to another CPU. */

#define THREAD_FLAG_STOLEN  (1 << 1)    /**< Thread was migrated to another CPU and has not run yet. */

#define THREAD_FLAG_USPACE  (1 << 2)    /**< Thread executes in userspace. */

/** Thread states. */

typedef enum {

    Invalid,    /**< It is an error, if thread is found in this state. */

    Running,    /**< State of a thread that is currently executing on some CPU. */

    Sleeping,   /**< Thread in this state is waiting for an event. */

    Ready,      /**< State of threads in a run queue. */

    Entering,   /**< Threads are in this state before they are first readied. */

    Exiting,    /**< After a thread calls thread_exit(), it is put into Exiting state. */

    Undead      /**< Threads that were not detached but exited are in the Undead state. */

} state_t;

/** Join types. */

typedef enum {

    None,

    TaskClnp,   /**< The thread will be joined by ktaskclnp thread. */

    TaskGC      /**< The thread will be joined by ktaskgc thread. */

} thread_join_type_t;

/** Thread structure. There is one per thread. */

typedef struct thread {

    link_t rq_link;             /**< Run queue link. */

    link_t wq_link;             /**< Wait queue link. */

    link_t th_link;             /**< Links to threads within containing task. */

    /** Lock protecting thread structure.

     *

     * Protects the whole thread structure except list links above.

     */

    SPINLOCK_DECLARE(lock);

    char name[THREAD_NAME_BUFLEN];

    void (* thread_code)(void *);       /**< Function implementing the thread. */

    void *thread_arg;           /**< Argument passed to thread_code() function. */

    /** From here, the stored context is restored when the thread is scheduled. */

    context_t saved_context;

    /** From here, the stored timeout context is restored when sleep times out. */

    context_t sleep_timeout_context;

    /** From here, the stored interruption context is restored when sleep is interrupted. */

    context_t sleep_interruption_context;

    bool sleep_interruptible;       /**< If true, the thread can be interrupted from sleep. */

    waitq_t *sleep_queue;           /**< Wait queue in which this thread sleeps. */

    timeout_t sleep_timeout;        /**< Timeout used for timeoutable sleeping.  */

    volatile int timeout_pending;       /**< Flag signalling sleep timeout in progress. */

    /** True if this thread is executing copy_from_uspace(). False otherwise. */

    bool in_copy_from_uspace;

    /** True if this thread is executing copy_to_uspace(). False otherwise. */

    bool in_copy_to_uspace;

    /**

     * If true, the thread will not go to sleep at all and will

     * call thread_exit() before returning to userspace.

     */

    bool interrupted;          

    thread_join_type_t  join_type;  /**< Who joinins the thread. */

    bool detached;              /**< If true, thread_join_timeout() cannot be used on this thread. */

    waitq_t join_wq;            /**< Waitq for thread_join_timeout(). */

    fpu_context_t *saved_fpu_context;

    int fpu_context_exists;

    /*

     * Defined only if thread doesn't run.

     * It means that fpu context is in CPU that last time executes this thread.

     * This disables migration.

     */

    int fpu_context_engaged;

    rwlock_type_t rwlock_holder_type;

    void (* call_me)(void *);       /**< Funtion to be called in scheduler before the thread is put asleep. */

    void *call_me_with;         /**< Argument passed to call_me(). */

    state_t state;              /**< Thread's state. */

    int flags;              /**< Thread's flags. */

    cpu_t *cpu;             /**< Thread's CPU. */

    task_t *task;               /**< Containing task. */

    uint64_t ticks;             /**< Ticks before preemption. */

    uint64_t cycles;            /**< Thread accounting. */

    uint64_t last_cycle;        /**< Last sampled cycle. */

    bool uncounted;             /**< Thread doesn't affect accumulated accounting. */

    int priority;               /**< Thread's priority. Implemented as index to CPU->rq */

    uint32_t tid;               /**< Thread ID. */

    thread_arch_t arch;         /**< Architecture-specific data. */

    uint8_t *kstack;            /**< Thread's kernel stack. */

} thread_t;

/** Thread list lock.

 *

 * This lock protects all link_t structures chained in threads_head.

 * Must be acquired before T.lock for each T of type thread_t.

 *

 */

SPINLOCK_EXTERN(threads_lock);

extern btree_t threads_btree;           /**< B+tree containing all threads. */

extern void thread_init(void);

extern thread_t *thread_create(void (* func)(void *), void *arg, task_t *task, int flags, char *name, bool uncounted);

extern void thread_ready(thread_t *t);

extern void thread_exit(void) __attribute__((noreturn));

#ifndef thread_create_arch

extern void thread_create_arch(thread_t *t);

#endif

#ifndef thr_constructor_arch

extern void thr_constructor_arch(thread_t *t);

#endif

#ifndef thr_destructor_arch

extern void thr_destructor_arch(thread_t *t);

#endif

extern void thread_sleep(uint32_t sec);

extern void thread_usleep(uint32_t usec);

#define thread_join(t)  thread_join_timeout((t), SYNCH_NO_TIMEOUT, SYNCH_FLAGS_NONE)

extern int thread_join_timeout(thread_t *t, uint32_t usec, int flags);

extern void thread_detach(thread_t *t);

extern void thread_register_call_me(void (* call_me)(void *), void *call_me_with);

extern void thread_print_list(void);

extern void thread_destroy(thread_t *t);

extern void thread_update_accounting(void);

extern bool thread_exists(thread_t *t);

extern void thread_interrupt_sleep(thread_t *t);

/* Fpu context slab cache */

extern slab_cache_t *fpu_context_slab;

/** Thread syscall prototypes. */

unative_t sys_thread_create(uspace_arg_t *uspace_uarg, char *uspace_name);

unative_t sys_thread_exit(int uspace_status);

#endif

/** @}

 */