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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. char *thread_states[] = {"Invalid", "Running", "Sleeping", "Ready", "Entering", "Exiting"}; /**< Thread states */
  67.  
  68. /** Lock protecting threads_head list. For locking rules, see declaration thereof. */
  69. SPINLOCK_INITIALIZE(threads_lock);
  70. btree_t threads_btree;          /**< B+tree of all threads. */
  71.  
  72. SPINLOCK_INITIALIZE(tidlock);
  73. __u32 last_tid = 0;
  74.  
  75. static slab_cache_t *thread_slab;
  76. #ifdef ARCH_HAS_FPU
  77. slab_cache_t *fpu_context_slab;
  78. #endif
  79.  
  80. /** Thread wrapper
  81.  *
  82.  * This wrapper is provided to ensure that every thread
  83.  * makes a call to thread_exit() when its implementing
  84.  * function returns.
  85.  *
  86.  * interrupts_disable() is assumed.
  87.  *
  88.  */
  89. static void cushion(void)
  90. {
  91.     void (*f)(void *) = THREAD->thread_code;
  92.     void *arg = THREAD->thread_arg;
  93.  
  94.     /* this is where each thread wakes up after its creation */
  95.     spinlock_unlock(&THREAD->lock);
  96.     interrupts_enable();
  97.  
  98.     f(arg);
  99.     thread_exit();
  100.     /* not reached */
  101. }
  102.  
  103. /** Initialization and allocation for thread_t structure */
  104. static int thr_constructor(void *obj, int kmflags)
  105. {
  106.     thread_t *t = (thread_t *)obj;
  107.     pfn_t pfn;
  108.     int status;
  109.  
  110.     spinlock_initialize(&t->lock, "thread_t_lock");
  111.     link_initialize(&t->rq_link);
  112.     link_initialize(&t->wq_link);
  113.     link_initialize(&t->th_link);
  114.    
  115. #ifdef ARCH_HAS_FPU
  116. #  ifdef CONFIG_FPU_LAZY
  117.     t->saved_fpu_context = NULL;
  118. #  else
  119.     t->saved_fpu_context = slab_alloc(fpu_context_slab,kmflags);
  120.     if (!t->saved_fpu_context)
  121.         return -1;
  122. #  endif
  123. #endif 
  124.  
  125.     pfn = frame_alloc_rc(STACK_FRAMES, FRAME_KA | kmflags,&status);
  126.     if (status) {
  127. #ifdef ARCH_HAS_FPU
  128.         if (t->saved_fpu_context)
  129.             slab_free(fpu_context_slab,t->saved_fpu_context);
  130. #endif
  131.         return -1;
  132.     }
  133.     t->kstack = (__u8 *)PA2KA(PFN2ADDR(pfn));
  134.  
  135.     return 0;
  136. }
  137.  
  138. /** Destruction of thread_t object */
  139. static int thr_destructor(void *obj)
  140. {
  141.     thread_t *t = (thread_t *)obj;
  142.  
  143.     frame_free(ADDR2PFN(KA2PA(t->kstack)));
  144. #ifdef ARCH_HAS_FPU
  145.     if (t->saved_fpu_context)
  146.         slab_free(fpu_context_slab,t->saved_fpu_context);
  147. #endif
  148.     return 1; /* One page freed */
  149. }
  150.  
  151. /** Initialize threads
  152.  *
  153.  * Initialize kernel threads support.
  154.  *
  155.  */
  156. void thread_init(void)
  157. {
  158.     THREAD = NULL;
  159.     atomic_set(&nrdy,0);
  160.     thread_slab = slab_cache_create("thread_slab",
  161.                     sizeof(thread_t),0,
  162.                     thr_constructor, thr_destructor, 0);
  163. #ifdef ARCH_HAS_FPU
  164.     fpu_context_slab = slab_cache_create("fpu_slab",
  165.                          sizeof(fpu_context_t),
  166.                          FPU_CONTEXT_ALIGN,
  167.                          NULL, NULL, 0);
  168. #endif
  169.  
  170.     btree_create(&threads_btree);
  171. }
  172.  
  173. /** Make thread ready
  174.  *
  175.  * Switch thread t to the ready state.
  176.  *
  177.  * @param t Thread to make ready.
  178.  *
  179.  */
  180. void thread_ready(thread_t *t)
  181. {
  182.     cpu_t *cpu;
  183.     runq_t *r;
  184.     ipl_t ipl;
  185.     int i, avg;
  186.  
  187.     ipl = interrupts_disable();
  188.  
  189.     spinlock_lock(&t->lock);
  190.  
  191.     ASSERT(! (t->state == Ready));
  192.  
  193.     i = (t->priority < RQ_COUNT -1) ? ++t->priority : t->priority;
  194.    
  195.     cpu = CPU;
  196.     if (t->flags & X_WIRED) {
  197.         cpu = t->cpu;
  198.     }
  199.     t->state = Ready;
  200.     spinlock_unlock(&t->lock);
  201.    
  202.     /*
  203.      * Append t to respective ready queue on respective processor.
  204.      */
  205.     r = &cpu->rq[i];
  206.     spinlock_lock(&r->lock);
  207.     list_append(&t->rq_link, &r->rq_head);
  208.     r->n++;
  209.     spinlock_unlock(&r->lock);
  210.  
  211.     atomic_inc(&nrdy);
  212.     avg = atomic_get(&nrdy) / config.cpu_active;
  213.     atomic_inc(&cpu->nrdy);
  214.  
  215.     interrupts_restore(ipl);
  216. }
  217.  
  218. /** Destroy thread memory structure
  219.  *
  220.  * Detach thread from all queues, cpus etc. and destroy it.
  221.  *
  222.  * Assume thread->lock is held!!
  223.  */
  224. void thread_destroy(thread_t *t)
  225. {
  226.     ASSERT(t->state == Exiting);
  227.     ASSERT(t->task);
  228.     ASSERT(t->cpu);
  229.  
  230.     spinlock_lock(&t->cpu->lock);
  231.     if(t->cpu->fpu_owner==t)
  232.         t->cpu->fpu_owner=NULL;
  233.     spinlock_unlock(&t->cpu->lock);
  234.  
  235.     /*
  236.      * Detach from the containing task.
  237.      */
  238.     spinlock_lock(&t->task->lock);
  239.     list_remove(&t->th_link);
  240.     spinlock_unlock(&t->task->lock);
  241.    
  242.     spinlock_unlock(&t->lock);
  243.    
  244.     spinlock_lock(&threads_lock);
  245.     btree_remove(&threads_btree, (btree_key_t) ((__address ) t), NULL);
  246.     spinlock_unlock(&threads_lock);
  247.    
  248.     slab_free(thread_slab, t);
  249. }
  250.  
  251. /** Create new thread
  252.  *
  253.  * Create a new thread.
  254.  *
  255.  * @param func  Thread's implementing function.
  256.  * @param arg   Thread's implementing function argument.
  257.  * @param task  Task to which the thread belongs.
  258.  * @param flags Thread flags.
  259.  * @param name  Symbolic name.
  260.  *
  261.  * @return New thread's structure on success, NULL on failure.
  262.  *
  263.  */
  264. thread_t *thread_create(void (* func)(void *), void *arg, task_t *task, int flags, char *name)
  265. {
  266.     thread_t *t;
  267.     ipl_t ipl;
  268.    
  269.     t = (thread_t *) slab_alloc(thread_slab, 0);
  270.     if (!t)
  271.         return NULL;
  272.  
  273.     thread_create_arch(t);
  274.    
  275.     /* Not needed, but good for debugging */
  276.     memsetb((__address)t->kstack, THREAD_STACK_SIZE * 1<<STACK_FRAMES, 0);
  277.    
  278.     ipl = interrupts_disable();
  279.     spinlock_lock(&tidlock);
  280.     t->tid = ++last_tid;
  281.     spinlock_unlock(&tidlock);
  282.     interrupts_restore(ipl);
  283.    
  284.     context_save(&t->saved_context);
  285.     context_set(&t->saved_context, FADDR(cushion), (__address) t->kstack, THREAD_STACK_SIZE);
  286.    
  287.     the_initialize((the_t *) t->kstack);
  288.    
  289.     ipl = interrupts_disable();
  290.     t->saved_context.ipl = interrupts_read();
  291.     interrupts_restore(ipl);
  292.    
  293.     memcpy(t->name, name, THREAD_NAME_BUFLEN);
  294.    
  295.     t->thread_code = func;
  296.     t->thread_arg = arg;
  297.     t->ticks = -1;
  298.     t->priority = -1;       /* start in rq[0] */
  299.     t->cpu = NULL;
  300.     t->flags = 0;
  301.     t->state = Entering;
  302.     t->call_me = NULL;
  303.     t->call_me_with = NULL;
  304.    
  305.     timeout_initialize(&t->sleep_timeout);
  306.     t->sleep_interruptible = false;
  307.     t->sleep_queue = NULL;
  308.     t->timeout_pending = 0;
  309.  
  310.     t->in_copy_from_uspace = false;
  311.     t->in_copy_to_uspace = false;
  312.    
  313.     t->rwlock_holder_type = RWLOCK_NONE;
  314.        
  315.     t->task = task;
  316.    
  317.     t->fpu_context_exists = 0;
  318.     t->fpu_context_engaged = 0;
  319.    
  320.     /*
  321.      * Register this thread in the system-wide list.
  322.      */
  323.     ipl = interrupts_disable();
  324.     spinlock_lock(&threads_lock);
  325.     btree_insert(&threads_btree, (btree_key_t) ((__address) t), (void *) t, NULL);
  326.     spinlock_unlock(&threads_lock);
  327.    
  328.     /*
  329.      * Attach to the containing task.
  330.      */
  331.     spinlock_lock(&task->lock);
  332.     list_append(&t->th_link, &task->th_head);
  333.     spinlock_unlock(&task->lock);
  334.    
  335.     interrupts_restore(ipl);
  336.    
  337.     return t;
  338. }
  339.  
  340. /** Make thread exiting
  341.  *
  342.  * End current thread execution and switch it to the exiting
  343.  * state. All pending timeouts are executed.
  344.  *
  345.  */
  346. void thread_exit(void)
  347. {
  348.     ipl_t ipl;
  349.  
  350. restart:
  351.     ipl = interrupts_disable();
  352.     spinlock_lock(&THREAD->lock);
  353.     if (THREAD->timeout_pending) { /* busy waiting for timeouts in progress */
  354.         spinlock_unlock(&THREAD->lock);
  355.         interrupts_restore(ipl);
  356.         goto restart;
  357.     }
  358.     THREAD->state = Exiting;
  359.     spinlock_unlock(&THREAD->lock);
  360.     scheduler();
  361. }
  362.  
  363.  
  364. /** Thread sleep
  365.  *
  366.  * Suspend execution of the current thread.
  367.  *
  368.  * @param sec Number of seconds to sleep.
  369.  *
  370.  */
  371. void thread_sleep(__u32 sec)
  372. {
  373.     thread_usleep(sec*1000000);
  374. }
  375.  
  376. /** Thread usleep
  377.  *
  378.  * Suspend execution of the current thread.
  379.  *
  380.  * @param usec Number of microseconds to sleep.
  381.  *
  382.  */
  383. void thread_usleep(__u32 usec)
  384. {
  385.     waitq_t wq;
  386.                  
  387.     waitq_initialize(&wq);
  388.  
  389.     (void) waitq_sleep_timeout(&wq, usec, SYNCH_FLAGS_NON_BLOCKING);
  390. }
  391.  
  392. /** Register thread out-of-context invocation
  393.  *
  394.  * Register a function and its argument to be executed
  395.  * on next context switch to the current thread.
  396.  *
  397.  * @param call_me      Out-of-context function.
  398.  * @param call_me_with Out-of-context function argument.
  399.  *
  400.  */
  401. void thread_register_call_me(void (* call_me)(void *), void *call_me_with)
  402. {
  403.     ipl_t ipl;
  404.    
  405.     ipl = interrupts_disable();
  406.     spinlock_lock(&THREAD->lock);
  407.     THREAD->call_me = call_me;
  408.     THREAD->call_me_with = call_me_with;
  409.     spinlock_unlock(&THREAD->lock);
  410.     interrupts_restore(ipl);
  411. }
  412.  
  413. /** Print list of threads debug info */
  414. void thread_print_list(void)
  415. {
  416.     link_t *cur;
  417.     ipl_t ipl;
  418.    
  419.     /* Messing with thread structures, avoid deadlock */
  420.     ipl = interrupts_disable();
  421.     spinlock_lock(&threads_lock);
  422.  
  423.     for (cur = threads_btree.leaf_head.next; cur != &threads_btree.leaf_head; cur = cur->next) {
  424.         btree_node_t *node;
  425.         int i;
  426.  
  427.         node = list_get_instance(cur, btree_node_t, leaf_link);
  428.         for (i = 0; i < node->keys; i++) {
  429.             thread_t *t;
  430.        
  431.             t = (thread_t *) node->value[i];
  432.             printf("%s: address=%#zX, tid=%zd, state=%s, task=%#zX, code=%#zX, stack=%#zX, cpu=",
  433.                 t->name, t, t->tid, thread_states[t->state], t->task, t->thread_code, t->kstack);
  434.             if (t->cpu)
  435.                 printf("cpu%zd", t->cpu->id);
  436.             else
  437.                 printf("none");
  438.             if (t->state == Sleeping) {
  439.                 printf(", kst=%#zX", t->kstack);
  440.                 printf(", wq=%#zX", t->sleep_queue);
  441.             }
  442.             printf("\n");
  443.         }
  444.     }
  445.  
  446.     spinlock_unlock(&threads_lock);
  447.     interrupts_restore(ipl);
  448. }
  449.  
  450. /** Check whether thread exists.
  451.  *
  452.  * Note that threads_lock must be already held and
  453.  * interrupts must be already disabled.
  454.  *
  455.  * @param t Pointer to thread.
  456.  *
  457.  * @return True if thread t is known to the system, false otherwise.
  458.  */
  459. bool thread_exists(thread_t *t)
  460. {
  461.     btree_node_t *leaf;
  462.    
  463.     return btree_search(&threads_btree, (btree_key_t) ((__address) t), &leaf) != NULL;
  464. }
  465.  
  466. /** Process syscall to create new thread.
  467.  *
  468.  */
  469. __native sys_thread_create(uspace_arg_t *uspace_uarg, char *uspace_name)
  470. {
  471.     thread_t *t;
  472.     char namebuf[THREAD_NAME_BUFLEN];
  473.     uspace_arg_t *kernel_uarg;
  474.     __u32 tid;
  475.     int rc;
  476.  
  477.     rc = copy_from_uspace(namebuf, uspace_name, THREAD_NAME_BUFLEN);
  478.     if (rc != 0)
  479.         return (__native) rc;
  480.  
  481.     kernel_uarg = (uspace_arg_t *) malloc(sizeof(uspace_arg_t), 0);
  482.     rc = copy_from_uspace(kernel_uarg, uspace_uarg, sizeof(uspace_arg_t));
  483.     if (rc != 0) {
  484.         free(kernel_uarg);
  485.         return (__native) rc;
  486.     }
  487.  
  488.     if ((t = thread_create(uinit, kernel_uarg, TASK, 0, namebuf))) {
  489.         tid = t->tid;
  490.         thread_ready(t);
  491.         return (__native) tid;
  492.     } else {
  493.         free(kernel_uarg);
  494.     }
  495.  
  496.     return (__native) ENOMEM;
  497. }
  498.  
  499. /** Process syscall to terminate thread.
  500.  *
  501.  */
  502. __native sys_thread_exit(int uspace_status)
  503. {
  504.     thread_exit();
  505.     /* Unreachable */
  506.     return 0;
  507. }
  508.