pintos-doxygen/html/priority-sema_8c_source.html

/** Tests that the highest-priority thread waiting on a semaphore

   is the first to wake up. */


#include <stdio.h>

#include "tests/threads/tests.h"

#include "threads/init.h"

#include "threads/malloc.h"

#include "threads/synch.h"

#include "threads/thread.h"

#include "devices/timer.h"


static thread_func priority_sema_thread;

static struct semaphore sema;


void

test_priority_sema (void)

{

  int i;


  /* This test does not work with the MLFQS. */

  ASSERT (!thread_mlfqs);


  sema_init (&sema, 0);

  thread_set_priority (PRI_MIN);

  for (i = 0; i < 10; i++)

    {

      int priority = PRI_DEFAULT - (i + 3) % 10 - 1;

      char name[16];

      snprintf (name, sizeof name, "priority %d", priority);

      thread_create (name, priority, priority_sema_thread, NULL);

    }


  for (i = 0; i < 10; i++)

    {

      sema_up (&sema);

      msg ("Back in main thread.");

    }

}


static void

priority_sema_thread (void *aux UNUSED)

{

  sema_down (&sema);

  msg ("Thread %s woke up.", thread_name ());

}

ASSERT
#define ASSERT(CONDITION)
This is outside the header guard so that debug.h may be included multiple times with different settin...
Definition: debug.h:31

UNUSED
#define UNUSED
GCC lets us add "attributes" to functions, function parameters, etc.
Definition: debug.h:7

init.h

name
char * name[]
Definition: insult.c:47

snprintf
int snprintf(char *buffer, size_t buf_size, const char *format,...)
Like printf(), except that output is stored into BUFFER, which must have space for BUF_SIZE character...
Definition: stdio.c:62

msg
void msg(const char *format,...)
Definition: lib.c:28

malloc.h

test_priority_sema
void test_priority_sema(void)
Definition: priority-sema.c:16

priority_sema_thread
static thread_func priority_sema_thread
Tests that the highest-priority thread waiting on a semaphore is the first to wake up.
Definition: priority-sema.c:12

sema
static struct semaphore sema
Definition: priority-sema.c:13

NULL
#define NULL
Definition: stddef.h:4

semaphore
A counting semaphore.
Definition: synch.h:9

sema_init
void sema_init(struct semaphore *sema, unsigned value)
This file is derived from source code for the Nachos instructional operating system.
Definition: synch.c:45

sema_up
void sema_up(struct semaphore *sema)
Up or "V" operation on a semaphore.
Definition: synch.c:109

sema_down
void sema_down(struct semaphore *sema)
Down or "P" operation on a semaphore.
Definition: synch.c:61

synch.h

tests.h

thread_mlfqs
bool thread_mlfqs
If false (default), use round-robin scheduler.
Definition: thread.c:60

thread_name
const char * thread_name(void)
Returns the name of the running thread.
Definition: thread.c:247

thread_create
tid_t thread_create(const char *name, int priority, thread_func *function, void *aux)
Creates a new kernel thread named NAME with the given initial PRIORITY, which executes FUNCTION passi...
Definition: thread.c:166

thread_set_priority
void thread_set_priority(int new_priority)
Sets the current thread's priority to NEW_PRIORITY.
Definition: thread.c:336

thread.h

PRI_DEFAULT
#define PRI_DEFAULT
Default priority.
Definition: thread.h:24

thread_func
void thread_func(void *aux)
Definition: thread.h:116

PRI_MIN
#define PRI_MIN
Thread priorities.
Definition: thread.h:23

timer.h