X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=src%2Fthreads%2Fthread.h;h=7965c0607815eab3275da7babdf669177f18c8e2;hb=3edcfedb8e62970f3293fa676b6691f8658c3c11;hp=356fc30b68030f2c8b9ad2f6e3b6dee6c309c7f9;hpb=994aa9cbadb9bb822df3adfffad8de40997fc562;p=pintos-anon

diff --git a/src/threads/thread.h b/src/threads/thread.h
index 356fc30..7965c06 100644
--- a/src/threads/thread.h
+++ b/src/threads/thread.h
@@ -1,47 +1,141 @@
-#ifndef HEADER_THREAD_H
-#define HEADER_THREAD_H 1
+#ifndef THREADS_THREAD_H
+#define THREADS_THREAD_H
 
+#include <debug.h>
+#include <list.h>
 #include <stdint.h>
-#include "debug.h"
-#include "list.h"
 
-#ifdef USERPROG
-#include "addrspace.h"
-#endif
-
-enum thread_status 
+/* States in a thread's life cycle. */
+enum thread_status
   {
-    THREAD_INITIALIZING,
-    THREAD_RUNNING,
-    THREAD_READY,
-    THREAD_BLOCKED,
-    THREAD_DYING
+    THREAD_RUNNING,     /* Running thread. */
+    THREAD_READY,       /* Not running but ready to run. */
+    THREAD_BLOCKED,     /* Waiting for an event to trigger. */
+    THREAD_DYING        /* About to be destroyed. */
   };
 
-struct thread 
+/* Thread identifier type.
+   You can redefine this to whatever type you like. */
+typedef int tid_t;
+#define TID_ERROR ((tid_t) -1)          /* Error value for tid_t. */
+
+/* Thread priorities. */
+#define PRI_MIN 0                       /* Lowest priority. */
+#define PRI_DEFAULT 31                  /* Default priority. */
+#define PRI_MAX 63                      /* Highest priority. */
+
+/* A kernel thread or user process.
+
+   Each thread structure is stored in its own 4 kB page.  The
+   thread structure itself sits at the very bottom of the page
+   (at offset 0).  The rest of the page is reserved for the
+   thread's kernel stack, which grows downward from the top of
+   the page (at offset 4 kB).  Here's an illustration:
+
+        4 kB +---------------------------------+
+             |          kernel stack           |
+             |                |                |
+             |                |                |
+             |                V                |
+             |         grows downward          |
+             |                                 |
+             |                                 |
+             |                                 |
+             |                                 |
+             |                                 |
+             |                                 |
+             |                                 |
+             |                                 |
+             +---------------------------------+
+             |              magic              |
+             |                :                |
+             |                :                |
+             |               name              |
+             |              status             |
+        0 kB +---------------------------------+
+
+   The upshot of this is twofold:
+
+      1. First, `struct thread' must not be allowed to grow too
+         big.  If it does, then there will not be enough room for
+         the kernel stack.  Our base `struct thread' is only a
+         few bytes in size.  It probably should stay well under 1
+         kB.
+
+      2. Second, kernel stacks must not be allowed to grow too
+         large.  If a stack overflows, it will corrupt the thread
+         state.  Thus, kernel functions should not allocate large
+         structures or arrays as non-static local variables.  Use
+         dynamic allocation with malloc() or palloc_get_page()
+         instead.
+
+   The first symptom of either of these problems will probably be
+   an assertion failure in thread_current(), which checks that
+   the `magic' member of the running thread's `struct thread' is
+   set to THREAD_MAGIC.  Stack overflow will normally change this
+   value, triggering the assertion. */
+/* The `elem' member has a dual purpose.  It can be an element in
+   the run queue (thread.c), or it can be an element in a
+   semaphore wait list (synch.c).  It can be used these two ways
+   only because they are mutually exclusive: only a thread in the
+   ready state is on the run queue, whereas only a thread in the
+   blocked state is on a semaphore wait list. */
+struct thread
   {
-    enum thread_status status;
-    char name[16];
-    uint8_t *stack;
-    list_elem rq_elem;
+    /* Owned by thread.c. */
+    tid_t tid;                          /* Thread identifier. */
+    enum thread_status status;          /* Thread state. */
+    char name[16];                      /* Name (for debugging purposes). */
+    uint8_t *stack;                     /* Saved stack pointer. */
+    int priority;                       /* Priority. */
+    struct list_elem allelem;           /* List element for all threads list. */
+
+    /* Shared between thread.c and synch.c. */
+    struct list_elem elem;              /* List element. */
+
 #ifdef USERPROG
-    struct addrspace addrspace;
+    /* Owned by userprog/process.c. */
+    uint32_t *pagedir;                  /* Page directory. */
 #endif
+
+    /* Owned by thread.c. */
+    unsigned magic;                     /* Detects stack overflow. */
   };
 
-void thread_init (const char *name, void (*) (void *aux), void *) NO_RETURN;
+/* If false (default), use round-robin scheduler.
+   If true, use multi-level feedback queue scheduler.
+   Controlled by kernel command-line option "-o mlfqs". */
+extern bool thread_mlfqs;
 
-struct thread *thread_create (const char *name, void (*) (void *aux), void *);
-#ifdef USERPROG
-bool thread_execute (const char *filename);
-#endif
+void thread_init (void);
+void thread_start (void);
+
+void thread_tick (void);
+void thread_print_stats (void);
 
-void thread_destroy (struct thread *);
-void thread_ready (struct thread *);
+typedef void thread_func (void *aux);
+tid_t thread_create (const char *name, int priority, thread_func *, void *);
+
+void thread_block (void);
+void thread_unblock (struct thread *);
 
 struct thread *thread_current (void);
+tid_t thread_tid (void);
+const char *thread_name (void);
+
 void thread_exit (void) NO_RETURN;
 void thread_yield (void);
-void thread_sleep (void);
 
-#endif /* thread.h */
+/* Performs some operation on thread t, given auxiliary data AUX. */
+typedef void thread_action_func (struct thread *t, void *aux);
+void thread_foreach (thread_action_func *, void *);
+
+int thread_get_priority (void);
+void thread_set_priority (int);
+
+int thread_get_nice (void);
+void thread_set_nice (int);
+int thread_get_recent_cpu (void);
+int thread_get_load_avg (void);
+
+#endif /* threads/thread.h */