WebSVN – HelenOS – Diff – /branches/fs/kernel/generic/src/proc/thread.c

 /*
  * 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.
  */
 #include <proc/scheduler.h>
 #include <proc/thread.h>
 #include <proc/task.h>
 #include <mm/heap.h>
 #include <mm/frame.h>
 #include <mm/page.h>
 #include <arch/asm.h>
 #include <arch.h>
 #include <synch/synch.h>
 #include <synch/spinlock.h>
 #include <synch/waitq.h>
 #include <synch/rwlock.h>
 #include <cpu.h>
 #include <func.h>
 #include <context.h>
 #include <list.h>
 #include <typedefs.h>
 #include <time/clock.h>
 #include <list.h>
 #include <config.h>
 #include <arch/interrupt.h>
 #include <smp/ipi.h>
 #include <arch/faddr.h>
-char *thread_states[] = {"Invalid", "Running", "Sleeping", "Ready", "Entering", "Exiting"};
+char *thread_states[] = {"Invalid", "Running", "Sleeping", "Ready", "Entering", "Exiting"}; /**< Thread states */
 spinlock_t threads_lock;
 link_t threads_head;
 static spinlock_t tidlock;
 __u32 last_tid = 0;
+/** Thread wrapper
-/*
+ *
- * cushion() is provided to ensure that every thread
+ * This wrapper is provided to ensure that every thread
  * makes a call to thread_exit() when its implementing
  * function returns.
+ *
- * cpu_priority_high()'d
+ * cpu_priority_high() is assumed.
+ *
  */
 void cushion(void)
+{
     void (*f)(void *) = THREAD->thread_code;
     void *arg = THREAD->thread_arg;
     before_thread_runs();
     /* this is where each thread wakes up after its creation */
     spinlock_unlock(&THREAD->lock);
     cpu_priority_low();
     f(arg);
     thread_exit();
     /* not reached */
+}
+/** Initialize threads
+ *
+ * Initialize kernel threads support.
+ *
+ */
 void thread_init(void)
+{
     THREAD = NULL;
     nrdy = 0;
     spinlock_initialize(&threads_lock);
     list_initialize(&threads_head);
+}
+/** Make thread ready
+ *
+ * Switch thread t to the ready state.
+ *
+ * @param t Thread to make ready.
+ *
+ */
 void thread_ready(thread_t *t)
+{
     cpu_t *cpu;
     runq_t *r;
     pri_t pri;
     int i, avg, send_ipi = 0;
     pri = cpu_priority_high();
     spinlock_lock(&t->lock);
     i = (t->pri < RQ_COUNT -1) ? ++t->pri : t->pri;
     cpu = CPU;
     if (t->flags & X_WIRED) {
         cpu = t->cpu;
+    }
     spinlock_unlock(&t->lock);
-        /*
+    /*
      * Append t to respective ready queue on respective processor.
      */
     r = &cpu->rq[i];
     spinlock_lock(&r->lock);
     list_append(&t->rq_link, &r->rq_head);
     r->n++;
     spinlock_unlock(&r->lock);
     spinlock_lock(&nrdylock);
     avg = ++nrdy / config.cpu_active;
     spinlock_unlock(&nrdylock);
     spinlock_lock(&cpu->lock);
     if ((++cpu->nrdy) > avg) {
         /*
          * If there are idle halted CPU's, this will wake them up.
          */
         ipi_broadcast(VECTOR_WAKEUP_IPI);
+    }
     spinlock_unlock(&cpu->lock);
     cpu_priority_restore(pri);
+}
+/** Create new thread
+ *
+ * Create a new thread.
+ *
+ * @param func  Thread's implementing function.
+ * @param arg   Thread's implementing function argument.
+ * @param task  Task to which the thread belongs.
+ * @param flags Thread flags.
+ *
+ * @return New thread's structure on success, NULL on failure.
+ *
+ */
 thread_t *thread_create(void (* func)(void *), void *arg, task_t *task, int flags)
+{
     thread_t *t;
     __address frame_ks, frame_us = NULL;
     t = (thread_t *) malloc(sizeof(thread_t));
     if (t) {
         pri_t pri;
         spinlock_initialize(&t->lock);
         frame_ks = frame_alloc(FRAME_KA);
         if (THREAD_USER_STACK & flags) {
             frame_us = frame_alloc(0);
+        }
         pri = cpu_priority_high();
         spinlock_lock(&tidlock);
         t->tid = ++last_tid;
         spinlock_unlock(&tidlock);
         cpu_priority_restore(pri);
         memsetb(frame_ks, THREAD_STACK_SIZE, 0);
         link_initialize(&t->rq_link);
         link_initialize(&t->wq_link);
         link_initialize(&t->th_link);
         link_initialize(&t->threads_link);
         t->kstack = (__u8 *) frame_ks;
         t->ustack = (__u8 *) frame_us;
         context_save(&t->saved_context);
         context_set(&t->saved_context, FADDR(cushion), t->kstack, THREAD_STACK_SIZE);
         pri = cpu_priority_high();
         t->saved_context.pri = cpu_priority_read();
         cpu_priority_restore(pri);
         t->thread_code = func;
         t->thread_arg = arg;
         t->ticks = -1;
         t->pri = -1;        /* start in rq[0] */
         t->cpu = NULL;
         t->flags = 0;
         t->state = Entering;
         t->call_me = NULL;
         t->call_me_with = NULL;
         timeout_initialize(&t->sleep_timeout);
         t->sleep_queue = NULL;
         t->timeout_pending = 0;
         t->rwlock_holder_type = RWLOCK_NONE;
         t->task = task;
         t->fpu_context_exists=0;
         t->fpu_context_engaged=0;
         /*
          * Register this thread in the system-wide list.
          */
         pri = cpu_priority_high();
         spinlock_lock(&threads_lock);
         list_append(&t->threads_link, &threads_head);
         spinlock_unlock(&threads_lock);
         /*
          * Attach to the containing task.
          */
         spinlock_lock(&task->lock);
         list_append(&t->th_link, &task->th_head);
         spinlock_unlock(&task->lock);
         cpu_priority_restore(pri);
+    }
     return t;
+}
+/** Make thread exiting
+ *
+ * End current thread execution and switch it to the exiting
+ * state. All pending timeouts are executed.
+ *
+ */
 void thread_exit(void)
+{
     pri_t pri;
 restart:
     pri = cpu_priority_high();
     spinlock_lock(&THREAD->lock);
     if (THREAD->timeout_pending) { /* busy waiting for timeouts in progress */
         spinlock_unlock(&THREAD->lock);
         cpu_priority_restore(pri);
         goto restart;
+    }
     THREAD->state = Exiting;
     spinlock_unlock(&THREAD->lock);
     scheduler();
+}
+/** Thread sleep
+ *
+ * Suspend execution of the current thread.
+ *
+ * @param sec Number of seconds to sleep.
+ *
+ */
 void thread_sleep(__u32 sec)
+{
         thread_usleep(sec*1000000);
+}
+/** Thread usleep
-/*
+ *
- * Suspend execution of current thread for usec microseconds.
+ * Suspend execution of the current thread.
+ *
+ * @param usec Number of microseconds to sleep.
+ *
  */
 void thread_usleep(__u32 usec)
+{
     waitq_t wq;
     waitq_initialize(&wq);
     (void) waitq_sleep_timeout(&wq, usec, SYNCH_NON_BLOCKING);
+}
+/** Register thread out-of-context invocation
+ *
+ * Register a function and its argument to be executed
+ * on next context switch to the current thread.
+ *
+ * @param call_me      Out-of-context function.
+ * @param call_me_with Out-of-context function argument.
+ *
+ */
 void thread_register_call_me(void (* call_me)(void *), void *call_me_with)
+{
     pri_t pri;
     pri = cpu_priority_high();
     spinlock_lock(&THREAD->lock);
     THREAD->call_me = call_me;
     THREAD->call_me_with = call_me_with;
     spinlock_unlock(&THREAD->lock);
     cpu_priority_restore(pri);
+}

Subversion Repositories HelenOS

(root)/branches/fs/kernel/generic/src/proc/thread.c @ 2422 – Rev 97 → 107