source: mainline/kernel/generic/include/proc/thread.h@ 831a04d0

/*
 * 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

/** @}
 */