X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=src%2Fthreads%2Fthread.c;h=636caac22e0733a7df85d8c1861a3eb4b9a1a0ca;hb=204b629b838dd2b1481887ccf8abcd58e605e8b9;hp=0c3c54446eb8d5654690d998df4232ccc0ad4dbb;hpb=3fc16f6e9abc98a3bd5427eb210669860609a224;p=pintos-anon diff --git a/src/threads/thread.c b/src/threads/thread.c index 0c3c544..636caac 100644 --- a/src/threads/thread.c +++ b/src/threads/thread.c @@ -2,75 +2,151 @@ #include #include "debug.h" #include "interrupt.h" +#include "intr-stubs.h" #include "lib.h" #include "mmu.h" #include "palloc.h" +#include "random.h" +#include "switch.h" uint32_t thread_stack_ofs = offsetof (struct thread, stack); static struct list run_queue; -struct thread *thread_switch (struct thread *cur, struct thread *next); - void thread_init (void) { list_init (&run_queue); } +struct thread_root_frame + { + void *eip; /* Return address. */ + void (*function) (void *); /* Function to call. */ + void *aux; /* Auxiliary data for function. */ + }; + static void thread_root (void (*function) (void *aux), void *aux) { ASSERT (function != NULL); - + + intr_enable (); function (aux); thread_exit (); } +static struct thread * +new_thread (const char *name) +{ + struct thread *t; + + ASSERT (name != NULL); + + t = palloc_get (PAL_ZERO); + if (t != NULL) + { + strlcpy (t->name, name, sizeof t->name); + t->stack = (uint8_t *) t + PGSIZE; + t->status = THREAD_BLOCKED; + } + + return t; +} + +static void * +alloc_frame (struct thread *t, size_t size) +{ + ASSERT (size % sizeof (uint32_t) == 0); + + t->stack -= size; + return t->stack; +} + struct thread * thread_create (const char *name, void (*function) (void *aux), void *aux) { struct thread *t; + struct thread_root_frame *rf; + struct switch_entry_frame *ef; + struct switch_threads_frame *sf; - ASSERT (name != NULL); ASSERT (function != NULL); - t = palloc_get (0); - if (t == NULL) - return NULL; + t = new_thread (name); + + /* Stack frame for thread_root(). */ + rf = alloc_frame (t, sizeof *rf); + rf->eip = NULL; + rf->function = function; + rf->aux = aux; - memset (t, 0, NBPG); - strlcpy (t->name, name, sizeof t->name); + /* Stack frame for switch_entry(). */ + ef = alloc_frame (t, sizeof *ef); + ef->eip = (void (*) (void)) thread_root; - /* Set up stack. */ - t->stack = (uint32_t *) ((uint8_t *) t + NBPG); - *--t->stack = (uint32_t) aux; - *--t->stack = (uint32_t) function; - --t->stack; - *--t->stack = (uint32_t) thread_root; - t->stack -= 4; + /* Stack frame for thread_switch(). */ + sf = alloc_frame (t, sizeof *sf); + sf->eip = switch_entry; - /* Add to run_queue. */ - t->status = THREAD_BLOCKED; + /* Add to run queue. */ thread_ready (t); return t; } -static struct thread * -stack_to_thread (uint32_t *stack) -{ - return (struct thread *) ((uint32_t) (stack - 1) & ~((uint32_t) NBPG - 1)); -} - struct thread * thread_current (void) { uint32_t *esp; asm ("movl %%esp, %0\n" : "=g" (esp)); - return stack_to_thread (esp); + return pg_round_down (esp); } +#ifdef USERPROG +bool +thread_execute (const char *filename) +{ + struct thread *t; + struct intr_frame *if_; + struct switch_entry_frame *ef; + struct switch_threads_frame *sf; + void (*start) (void); + + ASSERT (filename != NULL); + + t = new_thread (filename); + if (t == NULL) + return false; + + if (!addrspace_load (&t->addrspace, filename, &start)) + panic ("%s: program load failed", filename); + + /* Interrupt frame. */ + if_ = alloc_frame (t, sizeof *if_); + if_->es = SEL_UDSEG; + if_->ds = SEL_UDSEG; + if_->eip = start; + if_->cs = SEL_UCSEG; + if_->eflags = FLAG_IF | 2; + if_->esp = PHYS_BASE; + if_->ss = SEL_UDSEG; + + /* Stack frame for switch_entry(). */ + ef = alloc_frame (t, sizeof *ef); + ef->eip = intr_exit; + + /* Stack frame for thread_switch(). */ + sf = alloc_frame (t, sizeof *sf); + sf->eip = switch_entry; + + /* Add to run queue. */ + thread_ready (t); + + return true; +} +#endif + void thread_ready (struct thread *t) { @@ -107,7 +183,24 @@ thread_destroy (struct thread *t) palloc_free (t); } +void schedule_tail (struct thread *prev); + void +schedule_tail (struct thread *prev) +{ + struct thread *cur = thread_current (); + + ASSERT (intr_get_level () == IF_OFF); + +#ifdef USERPROG + addrspace_activate (&cur->addrspace); +#endif + + if (prev != NULL && prev->status == THREAD_DYING) + thread_destroy (prev); +} + +static void thread_schedule (void) { struct thread *cur, *next, *prev; @@ -121,26 +214,29 @@ thread_schedule (void) idle (); next->status = THREAD_RUNNING; - prev = thread_switch (cur, next); - - /* Prevent GCC from reordering anything around the thread - switch. */ - asm volatile ("" : : : "memory"); + if (cur != next) + { + prev = switch_threads (cur, next); - if (prev != NULL && prev->status == THREAD_DYING) - thread_destroy (prev); + /* Prevent GCC from reordering anything around the thread + switch. */ + asm volatile ("" : : : "memory"); - intr_enable (); + schedule_tail (prev); + } } void thread_yield (void) { + enum if_level old_level; + ASSERT (!intr_context ()); - intr_disable (); + old_level = intr_disable (); thread_ready (thread_current ()); thread_schedule (); + intr_set_level (old_level); } void @@ -151,7 +247,8 @@ thread_start (struct thread *t) if (t->status == THREAD_READY) list_remove (&t->rq_elem); t->status = THREAD_RUNNING; - thread_switch (NULL, t); + switch_threads (NULL, t); + NOT_REACHED (); } void @@ -162,6 +259,7 @@ thread_exit (void) intr_disable (); thread_current ()->status = THREAD_DYING; thread_schedule (); + NOT_REACHED (); } void @@ -173,3 +271,37 @@ thread_sleep (void) thread_current ()->status = THREAD_BLOCKED; thread_schedule (); } + +static void +tfunc (void *aux UNUSED) +{ + for (;;) + { + size_t count, i; + if (random_ulong () % 5 == 0) + { + printk ("%s exiting\n", thread_current ()->name); + break; + } + count = random_ulong () % 25 * 10000; + printk ("%s waiting %zu: ", thread_current ()->name, count); + for (i = 0; i < count; i++); + printk ("%s\n", thread_current ()->name); + } +} + +void +thread_self_test (void) +{ + struct thread *t; + int i; + + for (i = 0; i < 4; i++) + { + char name[2]; + name[0] = 'a' + i; + name[1] = 0; + t = thread_create (name, tfunc, NULL); + } + thread_start (t); +}