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  1. /*
  2.  * Copyright (C) 2001-2004 Jakub Jermar
  3.  * All rights reserved.
  4.  *
  5.  * Redistribution and use in source and binary forms, with or without
  6.  * modification, are permitted provided that the following conditions
  7.  * are met:
  8.  *
  9.  * - Redistributions of source code must retain the above copyright
  10.  *   notice, this list of conditions and the following disclaimer.
  11.  * - Redistributions in binary form must reproduce the above copyright
  12.  *   notice, this list of conditions and the following disclaimer in the
  13.  *   documentation and/or other materials provided with the distribution.
  14.  * - The name of the author may not be used to endorse or promote products
  15.  *   derived from this software without specific prior written permission.
  16.  *
  17.  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  18.  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  19.  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  20.  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  21.  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  22.  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23.  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24.  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25.  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  26.  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27.  */
  28.  
  29. /**
  30.  * @file    thread.c
  31.  * @brief   Thread management functions.
  32.  */
  33.  
  34. #include <proc/scheduler.h>
  35. #include <proc/thread.h>
  36. #include <proc/task.h>
  37. #include <proc/uarg.h>
  38. #include <mm/frame.h>
  39. #include <mm/page.h>
  40. #include <arch/asm.h>
  41. #include <arch.h>
  42. #include <synch/synch.h>
  43. #include <synch/spinlock.h>
  44. #include <synch/waitq.h>
  45. #include <synch/rwlock.h>
  46. #include <cpu.h>
  47. #include <func.h>
  48. #include <context.h>
  49. #include <adt/btree.h>
  50. #include <adt/list.h>
  51. #include <typedefs.h>
  52. #include <time/clock.h>
  53. #include <config.h>
  54. #include <arch/interrupt.h>
  55. #include <smp/ipi.h>
  56. #include <arch/faddr.h>
  57. #include <atomic.h>
  58. #include <memstr.h>
  59. #include <print.h>
  60. #include <mm/slab.h>
  61. #include <debug.h>
  62. #include <main/uinit.h>
  63. #include <syscall/copy.h>
  64. #include <errno.h>
  65.  
  66.  
  67. /** Thread states */
  68. char *thread_states[] = {
  69.     "Invalid",
  70.     "Running",
  71.     "Sleeping",
  72.     "Ready",
  73.     "Entering",
  74.     "Exiting",
  75.     "Undead"
  76. };
  77.  
  78. /** Lock protecting threads_head list. For locking rules, see declaration thereof. */
  79. SPINLOCK_INITIALIZE(threads_lock);
  80. btree_t threads_btree;          /**< B+tree of all threads. */
  81.  
  82. SPINLOCK_INITIALIZE(tidlock);
  83. __u32 last_tid = 0;
  84.  
  85. static slab_cache_t *thread_slab;
  86. #ifdef ARCH_HAS_FPU
  87. slab_cache_t *fpu_context_slab;
  88. #endif
  89.  
  90. /** Thread wrapper
  91.  *
  92.  * This wrapper is provided to ensure that every thread
  93.  * makes a call to thread_exit() when its implementing
  94.  * function returns.
  95.  *
  96.  * interrupts_disable() is assumed.
  97.  *
  98.  */
  99. static void cushion(void)
  100. {
  101.     void (*f)(void *) = THREAD->thread_code;
  102.     void *arg = THREAD->thread_arg;
  103.  
  104.     /* this is where each thread wakes up after its creation */
  105.     spinlock_unlock(&THREAD->lock);
  106.     interrupts_enable();
  107.  
  108.     f(arg);
  109.     thread_exit();
  110.     /* not reached */
  111. }
  112.  
  113. /** Initialization and allocation for thread_t structure */
  114. static int thr_constructor(void *obj, int kmflags)
  115. {
  116.     thread_t *t = (thread_t *)obj;
  117.     pfn_t pfn;
  118.     int status;
  119.  
  120.     spinlock_initialize(&t->lock, "thread_t_lock");
  121.     link_initialize(&t->rq_link);
  122.     link_initialize(&t->wq_link);
  123.     link_initialize(&t->th_link);
  124.    
  125. #ifdef ARCH_HAS_FPU
  126. #  ifdef CONFIG_FPU_LAZY
  127.     t->saved_fpu_context = NULL;
  128. #  else
  129.     t->saved_fpu_context = slab_alloc(fpu_context_slab,kmflags);
  130.     if (!t->saved_fpu_context)
  131.         return -1;
  132. #  endif
  133. #endif 
  134.  
  135.     pfn = frame_alloc_rc(STACK_FRAMES, FRAME_KA | kmflags,&status);
  136.     if (status) {
  137. #ifdef ARCH_HAS_FPU
  138.         if (t->saved_fpu_context)
  139.             slab_free(fpu_context_slab,t->saved_fpu_context);
  140. #endif
  141.         return -1;
  142.     }
  143.     t->kstack = (__u8 *)PA2KA(PFN2ADDR(pfn));
  144.  
  145.     return 0;
  146. }
  147.  
  148. /** Destruction of thread_t object */
  149. static int thr_destructor(void *obj)
  150. {
  151.     thread_t *t = (thread_t *)obj;
  152.  
  153.     frame_free(ADDR2PFN(KA2PA(t->kstack)));
  154. #ifdef ARCH_HAS_FPU
  155.     if (t->saved_fpu_context)
  156.         slab_free(fpu_context_slab,t->saved_fpu_context);
  157. #endif
  158.     return 1; /* One page freed */
  159. }
  160.  
  161. /** Initialize threads
  162.  *
  163.  * Initialize kernel threads support.
  164.  *
  165.  */
  166. void thread_init(void)
  167. {
  168.     THREAD = NULL;
  169.     atomic_set(&nrdy,0);
  170.     thread_slab = slab_cache_create("thread_slab",
  171.                     sizeof(thread_t),0,
  172.                     thr_constructor, thr_destructor, 0);
  173. #ifdef ARCH_HAS_FPU
  174.     fpu_context_slab = slab_cache_create("fpu_slab",
  175.                          sizeof(fpu_context_t),
  176.                          FPU_CONTEXT_ALIGN,
  177.                          NULL, NULL, 0);
  178. #endif
  179.  
  180.     btree_create(&threads_btree);
  181. }
  182.  
  183. /** Make thread ready
  184.  *
  185.  * Switch thread t to the ready state.
  186.  *
  187.  * @param t Thread to make ready.
  188.  *
  189.  */
  190. void thread_ready(thread_t *t)
  191. {
  192.     cpu_t *cpu;
  193.     runq_t *r;
  194.     ipl_t ipl;
  195.     int i, avg;
  196.  
  197.     ipl = interrupts_disable();
  198.  
  199.     spinlock_lock(&t->lock);
  200.  
  201.     ASSERT(! (t->state == Ready));
  202.  
  203.     i = (t->priority < RQ_COUNT -1) ? ++t->priority : t->priority;
  204.    
  205.     cpu = CPU;
  206.     if (t->flags & X_WIRED) {
  207.         cpu = t->cpu;
  208.     }
  209.     t->state = Ready;
  210.     spinlock_unlock(&t->lock);
  211.    
  212.     /*
  213.      * Append t to respective ready queue on respective processor.
  214.      */
  215.     r = &cpu->rq[i];
  216.     spinlock_lock(&r->lock);
  217.     list_append(&t->rq_link, &r->rq_head);
  218.     r->n++;
  219.     spinlock_unlock(&r->lock);
  220.  
  221.     atomic_inc(&nrdy);
  222.     avg = atomic_get(&nrdy) / config.cpu_active;
  223.     atomic_inc(&cpu->nrdy);
  224.  
  225.     interrupts_restore(ipl);
  226. }
  227.  
  228. /** Destroy thread memory structure
  229.  *
  230.  * Detach thread from all queues, cpus etc. and destroy it.
  231.  *
  232.  * Assume thread->lock is held!!
  233.  */
  234. void thread_destroy(thread_t *t)
  235. {
  236.     ASSERT(t->state == Exiting);
  237.     ASSERT(t->task);
  238.     ASSERT(t->cpu);
  239.  
  240.     spinlock_lock(&t->cpu->lock);
  241.     if(t->cpu->fpu_owner==t)
  242.         t->cpu->fpu_owner=NULL;
  243.     spinlock_unlock(&t->cpu->lock);
  244.  
  245.     /*
  246.      * Detach from the containing task.
  247.      */
  248.     spinlock_lock(&t->task->lock);
  249.     list_remove(&t->th_link);
  250.     spinlock_unlock(&t->task->lock);
  251.    
  252.     spinlock_unlock(&t->lock);
  253.    
  254.     spinlock_lock(&threads_lock);
  255.     btree_remove(&threads_btree, (btree_key_t) ((__address ) t), NULL);
  256.     spinlock_unlock(&threads_lock);
  257.    
  258.     slab_free(thread_slab, t);
  259. }
  260.  
  261. /** Create new thread
  262.  *
  263.  * Create a new thread.
  264.  *
  265.  * @param func  Thread's implementing function.
  266.  * @param arg   Thread's implementing function argument.
  267.  * @param task  Task to which the thread belongs.
  268.  * @param flags Thread flags.
  269.  * @param name  Symbolic name.
  270.  *
  271.  * @return New thread's structure on success, NULL on failure.
  272.  *
  273.  */
  274. thread_t *thread_create(void (* func)(void *), void *arg, task_t *task, int flags, char *name)
  275. {
  276.     thread_t *t;
  277.     ipl_t ipl;
  278.    
  279.     t = (thread_t *) slab_alloc(thread_slab, 0);
  280.     if (!t)
  281.         return NULL;
  282.  
  283.     thread_create_arch(t);
  284.    
  285.     /* Not needed, but good for debugging */
  286.     memsetb((__address)t->kstack, THREAD_STACK_SIZE * 1<<STACK_FRAMES, 0);
  287.    
  288.     ipl = interrupts_disable();
  289.     spinlock_lock(&tidlock);
  290.     t->tid = ++last_tid;
  291.     spinlock_unlock(&tidlock);
  292.     interrupts_restore(ipl);
  293.    
  294.     context_save(&t->saved_context);
  295.     context_set(&t->saved_context, FADDR(cushion), (__address) t->kstack, THREAD_STACK_SIZE);
  296.    
  297.     the_initialize((the_t *) t->kstack);
  298.    
  299.     ipl = interrupts_disable();
  300.     t->saved_context.ipl = interrupts_read();
  301.     interrupts_restore(ipl);
  302.    
  303.     memcpy(t->name, name, THREAD_NAME_BUFLEN);
  304.    
  305.     t->thread_code = func;
  306.     t->thread_arg = arg;
  307.     t->ticks = -1;
  308.     t->priority = -1;       /* start in rq[0] */
  309.     t->cpu = NULL;
  310.     t->flags = 0;
  311.     t->state = Entering;
  312.     t->call_me = NULL;
  313.     t->call_me_with = NULL;
  314.    
  315.     timeout_initialize(&t->sleep_timeout);
  316.     t->sleep_interruptible = false;
  317.     t->sleep_queue = NULL;
  318.     t->timeout_pending = 0;
  319.  
  320.     t->in_copy_from_uspace = false;
  321.     t->in_copy_to_uspace = false;
  322.    
  323.     t->detached = false;
  324.     waitq_initialize(&t->join_wq);
  325.    
  326.     t->rwlock_holder_type = RWLOCK_NONE;
  327.        
  328.     t->task = task;
  329.    
  330.     t->fpu_context_exists = 0;
  331.     t->fpu_context_engaged = 0;
  332.    
  333.     /*
  334.      * Register this thread in the system-wide list.
  335.      */
  336.     ipl = interrupts_disable();
  337.     spinlock_lock(&threads_lock);
  338.     btree_insert(&threads_btree, (btree_key_t) ((__address) t), (void *) t, NULL);
  339.     spinlock_unlock(&threads_lock);
  340.    
  341.     /*
  342.      * Attach to the containing task.
  343.      */
  344.     spinlock_lock(&task->lock);
  345.     list_append(&t->th_link, &task->th_head);
  346.     spinlock_unlock(&task->lock);
  347.    
  348.     interrupts_restore(ipl);
  349.    
  350.     return t;
  351. }
  352.  
  353. /** Make thread exiting
  354.  *
  355.  * End current thread execution and switch it to the exiting
  356.  * state. All pending timeouts are executed.
  357.  *
  358.  */
  359. void thread_exit(void)
  360. {
  361.     ipl_t ipl;
  362.  
  363. restart:
  364.     ipl = interrupts_disable();
  365.     spinlock_lock(&THREAD->lock);
  366.     if (THREAD->timeout_pending) { /* busy waiting for timeouts in progress */
  367.         spinlock_unlock(&THREAD->lock);
  368.         interrupts_restore(ipl);
  369.         goto restart;
  370.     }
  371.     THREAD->state = Exiting;
  372.     spinlock_unlock(&THREAD->lock);
  373.     scheduler();
  374. }
  375.  
  376.  
  377. /** Thread sleep
  378.  *
  379.  * Suspend execution of the current thread.
  380.  *
  381.  * @param sec Number of seconds to sleep.
  382.  *
  383.  */
  384. void thread_sleep(__u32 sec)
  385. {
  386.     thread_usleep(sec*1000000);
  387. }
  388.  
  389. /** Wait for another thread to exit.
  390.  *
  391.  * @param t Thread to join on exit.
  392.  * @param usec Timeout in microseconds.
  393.  * @param flags Mode of operation.
  394.  *
  395.  * @return An error code from errno.h or an error code from synch.h.
  396.  */
  397. int thread_join_timeout(thread_t *t, __u32 usec, int flags)
  398. {
  399.     ipl_t ipl;
  400.     int rc;
  401.  
  402.     if (t == THREAD)
  403.         return EINVAL;
  404.  
  405.     /*
  406.      * Since thread join can only be called once on an undetached thread,
  407.      * the thread pointer is guaranteed to be still valid.
  408.      */
  409.    
  410.     ipl = interrupts_disable();
  411.     spinlock_lock(&t->lock);
  412.  
  413.     ASSERT(!t->detached);
  414.    
  415.     (void) waitq_sleep_prepare(&t->join_wq);
  416.     spinlock_unlock(&t->lock);
  417.    
  418.     rc = waitq_sleep_timeout_unsafe(&t->join_wq, usec, flags);
  419.    
  420.     waitq_sleep_finish(&t->join_wq, rc, ipl);
  421.    
  422.     return rc; 
  423. }
  424.  
  425. /** Detach thread.
  426.  *
  427.  * Mark the thread as detached, if the thread is already in the Undead state,
  428.  * deallocate its resources.
  429.  *
  430.  * @param t Thread to be detached.
  431.  */
  432. void thread_detach(thread_t *t)
  433. {
  434.     ipl_t ipl;
  435.  
  436.     /*
  437.      * Since the thread is expected to not be already detached,
  438.      * pointer to it must be still valid.
  439.      */
  440.    
  441.     ipl = interrupts_disable();
  442.     spinlock_lock(&t->lock);
  443.     ASSERT(!t->detached);
  444.     if (t->state == Undead) {
  445.         thread_destroy(t);  /* unlocks &t->lock */
  446.         interrupts_restore(ipl);
  447.         return;
  448.     } else {
  449.         t->detached = true;
  450.     }
  451.     spinlock_unlock(&t->lock);
  452.     interrupts_restore(ipl);
  453. }
  454.  
  455. /** Thread usleep
  456.  *
  457.  * Suspend execution of the current thread.
  458.  *
  459.  * @param usec Number of microseconds to sleep.
  460.  *
  461.  */
  462. void thread_usleep(__u32 usec)
  463. {
  464.     waitq_t wq;
  465.                  
  466.     waitq_initialize(&wq);
  467.  
  468.     (void) waitq_sleep_timeout(&wq, usec, SYNCH_FLAGS_NON_BLOCKING);
  469. }
  470.  
  471. /** Register thread out-of-context invocation
  472.  *
  473.  * Register a function and its argument to be executed
  474.  * on next context switch to the current thread.
  475.  *
  476.  * @param call_me      Out-of-context function.
  477.  * @param call_me_with Out-of-context function argument.
  478.  *
  479.  */
  480. void thread_register_call_me(void (* call_me)(void *), void *call_me_with)
  481. {
  482.     ipl_t ipl;
  483.    
  484.     ipl = interrupts_disable();
  485.     spinlock_lock(&THREAD->lock);
  486.     THREAD->call_me = call_me;
  487.     THREAD->call_me_with = call_me_with;
  488.     spinlock_unlock(&THREAD->lock);
  489.     interrupts_restore(ipl);
  490. }
  491.  
  492. /** Print list of threads debug info */
  493. void thread_print_list(void)
  494. {
  495.     link_t *cur;
  496.     ipl_t ipl;
  497.    
  498.     /* Messing with thread structures, avoid deadlock */
  499.     ipl = interrupts_disable();
  500.     spinlock_lock(&threads_lock);
  501.  
  502.     for (cur = threads_btree.leaf_head.next; cur != &threads_btree.leaf_head; cur = cur->next) {
  503.         btree_node_t *node;
  504.         int i;
  505.  
  506.         node = list_get_instance(cur, btree_node_t, leaf_link);
  507.         for (i = 0; i < node->keys; i++) {
  508.             thread_t *t;
  509.        
  510.             t = (thread_t *) node->value[i];
  511.             printf("%s: address=%#zX, tid=%zd, state=%s, task=%#zX, code=%#zX, stack=%#zX, cpu=",
  512.                 t->name, t, t->tid, thread_states[t->state], t->task, t->thread_code, t->kstack);
  513.             if (t->cpu)
  514.                 printf("cpu%zd", t->cpu->id);
  515.             else
  516.                 printf("none");
  517.             if (t->state == Sleeping) {
  518.                 printf(", kst=%#zX", t->kstack);
  519.                 printf(", wq=%#zX", t->sleep_queue);
  520.             }
  521.             printf("\n");
  522.         }
  523.     }
  524.  
  525.     spinlock_unlock(&threads_lock);
  526.     interrupts_restore(ipl);
  527. }
  528.  
  529. /** Check whether thread exists.
  530.  *
  531.  * Note that threads_lock must be already held and
  532.  * interrupts must be already disabled.
  533.  *
  534.  * @param t Pointer to thread.
  535.  *
  536.  * @return True if thread t is known to the system, false otherwise.
  537.  */
  538. bool thread_exists(thread_t *t)
  539. {
  540.     btree_node_t *leaf;
  541.    
  542.     return btree_search(&threads_btree, (btree_key_t) ((__address) t), &leaf) != NULL;
  543. }
  544.  
  545. /** Process syscall to create new thread.
  546.  *
  547.  */
  548. __native sys_thread_create(uspace_arg_t *uspace_uarg, char *uspace_name)
  549. {
  550.     thread_t *t;
  551.     char namebuf[THREAD_NAME_BUFLEN];
  552.     uspace_arg_t *kernel_uarg;
  553.     __u32 tid;
  554.     int rc;
  555.  
  556.     rc = copy_from_uspace(namebuf, uspace_name, THREAD_NAME_BUFLEN);
  557.     if (rc != 0)
  558.         return (__native) rc;
  559.  
  560.     kernel_uarg = (uspace_arg_t *) malloc(sizeof(uspace_arg_t), 0);
  561.     rc = copy_from_uspace(kernel_uarg, uspace_uarg, sizeof(uspace_arg_t));
  562.     if (rc != 0) {
  563.         free(kernel_uarg);
  564.         return (__native) rc;
  565.     }
  566.  
  567.     if ((t = thread_create(uinit, kernel_uarg, TASK, 0, namebuf))) {
  568.         tid = t->tid;
  569.         thread_ready(t);
  570.         return (__native) tid;
  571.     } else {
  572.         free(kernel_uarg);
  573.     }
  574.  
  575.     return (__native) ENOMEM;
  576. }
  577.  
  578. /** Process syscall to terminate thread.
  579.  *
  580.  */
  581. __native sys_thread_exit(int uspace_status)
  582. {
  583.     thread_exit();
  584.     /* Unreachable */
  585.     return 0;
  586. }
  587.