From 953a9a7091849ecdf97edeb6fbbe06f4a9ba39cb Mon Sep 17 00:00:00 2001
From: a3-alsayed <aisha2.alsayed@live.uwe.ac.uk>
Date: Tue, 10 Jan 2023 03:49:45 +0000
Subject: [PATCH] Update src/threads/thread.h
---
src/threads/thread.h | 188 ++++++++++++++++++-------------------------
1 file changed, 80 insertions(+), 108 deletions(-)
diff --git a/src/threads/thread.h b/src/threads/thread.h
index ed05654..af46028 100644
--- a/src/threads/thread.h
+++ b/src/threads/thread.h
@@ -1,143 +1,115 @@
#ifndef THREADS_THREAD_H
#define THREADS_THREAD_H
-
#include <debug.h>
#include <list.h>
#include <stdint.h>
-
-/* States in a thread's life cycle. */
-enum thread_status
- {
- 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. */
- };
-
+/* States in a thread's life cycle. */enum thread_status
+{
+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. */
+};
/* Thread identifier type.
- You can redefine this to whatever type you like. */
+You can redefine this to whatever type you like. */
typedef int tid_t;
-#define TID_ERROR ((tid_t) -1) /* Error value for 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. */
-
+#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. */
+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 forthe 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
- {
- /* Owned by thread.c. */
- tid_t tid; /* Thread identifier. */
- enum thread_status status; /* Thread state. */
- char name[16]; /* Name (for debugging purposes). */
- int8_t exit_code; /* Exit code. */
- 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. */
-
+{
+/* 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. */
+// add exit code
+int exit_code; /* Exit Code */
+/* Shared between thread.c and synch.c. */
+struct list_elem elem; /* List element. */
#ifdef USERPROG
- /* Owned by userprog/process.c. */
- int exit_status;
- uint32_t *pagedir; /* Page directory. */
+/* Owned by userprog/process.c. */
+uint32_t *pagedir; /* Page directory. */
#endif
-
- /* Owned by thread.c. */
- unsigned magic; /* Detects stack overflow. */
- };
-
+/* Owned by thread.c. */
+unsigned magic; /* Detects stack overflow. */
+};
/* 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;
-
-void thread_init (void);
+If true, use multi-level feedback queue scheduler.
+Controlled by kernel command-line option "-o mlfqs". */
+extern bool thread_mlfqs;void thread_init (void);
void thread_start (void);
-
void thread_tick (void);
void thread_print_stats (void);
-
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);
-
/* 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 */
--
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