update name of code to labcodes

labcodes/lab7/kern/sync/check_sync.c

@@ -0,0 +1,196 @@
+#include <stdio.h>
+#include <proc.h>
+#include <sem.h>
+#include <monitor.h>
+#include <assert.h>
+
+#define N 5 /* 哲学家数目 */
+#define LEFT (i-1+N)%N /* i的左邻号码 */
+#define RIGHT (i+1)%N /* i的右邻号码 */
+#define THINKING 0 /* 哲学家正在思考 */
+#define HUNGRY 1 /* 哲学家想取得叉子 */
+#define EATING 2 /* 哲学家正在吃面 */
+#define TIMES  4 /* 吃4次饭 */
+#define SLEEP_TIME 10
+
+//---------- philosophers problem using semaphore ----------------------
+int state_sema[N]; /* 记录每个人状态的数组 */
+/* 信号量是一个特殊的整型变量 */
+semaphore_t mutex; /* 临界区互斥 */
+semaphore_t s[N]; /* 每个哲学家一个信号量 */
+
+struct proc_struct *philosopher_proc_sema[N];
+
+void phi_test_sema(i) /* i：哲学家号码从0到N-1 */
+{ 
+    if(state_sema[i]==HUNGRY&&state_sema[LEFT]!=EATING
+            &&state_sema[RIGHT]!=EATING)
+    {
+        state_sema[i]=EATING;
+        up(&s[i]);
+    }
+}
+
+void phi_take_forks_sema(int i) /* i：哲学家号码从0到N-1 */
+{ 
+        down(&mutex); /* 进入临界区 */
+        state_sema[i]=HUNGRY; /* 记录下哲学家i饥饿的事实 */
+        phi_test_sema(i); /* 试图得到两只叉子 */
+        up(&mutex); /* 离开临界区 */
+        down(&s[i]); /* 如果得不到叉子就阻塞 */
+}
+
+void phi_put_forks_sema(int i) /* i：哲学家号码从0到N-1 */
+{ 
+        down(&mutex); /* 进入临界区 */
+        state_sema[i]=THINKING; /* 哲学家进餐结束 */
+        phi_test_sema(LEFT); /* 看一下左邻居现在是否能进餐 */
+        phi_test_sema(RIGHT); /* 看一下右邻居现在是否能进餐 */
+        up(&mutex); /* 离开临界区 */
+}
+
+int philosopher_using_semaphore(void * arg) /* i：哲学家号码，从0到N-1 */
+{
+    int i, iter=0;
+    i=(int)arg;
+    cprintf("I am No.%d philosopher_sema\n",i);
+    while(iter++<TIMES)
+    { /* 无限循环 */
+        cprintf("Iter %d, No.%d philosopher_sema is thinking\n",iter,i); /* 哲学家正在思考 */
+        do_sleep(SLEEP_TIME);
+        phi_take_forks_sema(i); 
+        /* 需要两只叉子，或者阻塞 */
+        cprintf("Iter %d, No.%d philosopher_sema is eating\n",iter,i); /* 进餐 */
+        do_sleep(SLEEP_TIME);
+        phi_put_forks_sema(i); 
+        /* 把两把叉子同时放回桌子 */
+    }
+    cprintf("No.%d philosopher_sema quit\n",i);
+    return 0;    
+}
+
+//-----------------philosopher problem using monitor ------------
+/*PSEUDO CODE :philosopher problem using monitor
+ * monitor dp
+ * {
+ *  enum {thinking, hungry, eating} state[5];
+ *  condition self[5];
+ *
+ *  void pickup(int i) {
+ *      state[i] = hungry;
+ *      if ((state[(i+4)%5] != eating) && (state[(i+1)%5] != eating)) {
+ *        state[i] = eating;
+ *      else
+ *         self[i].wait();
+ *   }
+ *
+ *   void putdown(int i) {
+ *      state[i] = thinking;
+ *      if ((state[(i+4)%5] == hungry) && (state[(i+3)%5] != eating)) {
+ *          state[(i+4)%5] = eating;
+ *          self[(i+4)%5].signal();
+ *      }
+ *      if ((state[(i+1)%5] == hungry) && (state[(i+2)%5] != eating)) {
+ *          state[(i+1)%5] = eating;
+ *          self[(i+1)%5].signal();
+ *      }
+ *   }
+ *
+ *   void init() {
+ *      for (int i = 0; i < 5; i++)
+ *         state[i] = thinking;
+ *   }
+ * }
+ */
+
+struct proc_struct *philosopher_proc_condvar[N]; // N philosopher
+int state_condvar[N];                            // the philosopher's state: EATING, HUNGARY, THINKING  
+monitor_t mt, *mtp=&mt;                          // monitor
+
+void phi_test_condvar (i) { 
+    if(state_condvar[i]==HUNGRY&&state_condvar[LEFT]!=EATING
+            &&state_condvar[RIGHT]!=EATING) {
+        cprintf("phi_test_condvar: state_condvar[%d] will eating\n",i);
+        state_condvar[i] = EATING ;
+        cprintf("phi_test_condvar: signal self_cv[%d] \n",i);
+        cond_signal(&mtp->cv[i]) ;
+    }
+}
+
+
+void phi_take_forks_condvar(int i) {
+     down(&(mtp->mutex));
+//--------into routine in monitor--------------
+     // LAB7 EXERCISE1: YOUR CODE
+     // I am hungry
+     // try to get fork
+//--------leave routine in monitor--------------
+      if(mtp->next_count>0)
+         up(&(mtp->next));
+      else
+         up(&(mtp->mutex));
+}
+
+void phi_put_forks_condvar(int i) {
+     down(&(mtp->mutex));
+
+//--------into routine in monitor--------------
+     // LAB7 EXERCISE1: YOUR CODE
+     // I ate over
+     // test left and right neighbors
+//--------leave routine in monitor--------------
+     if(mtp->next_count>0)
+        up(&(mtp->next));
+     else
+        up(&(mtp->mutex));
+}
+
+//---------- philosophers using monitor (condition variable) ----------------------
+int philosopher_using_condvar(void * arg) { /* arg is the No. of philosopher 0~N-1*/
+  
+    int i, iter=0;
+    i=(int)arg;
+    cprintf("I am No.%d philosopher_condvar\n",i);
+    while(iter++<TIMES)
+    { /* iterate*/
+        cprintf("Iter %d, No.%d philosopher_condvar is thinking\n",iter,i); /* thinking*/
+        do_sleep(SLEEP_TIME);
+        phi_take_forks_condvar(i); 
+        /* need two forks, maybe blocked */
+        cprintf("Iter %d, No.%d philosopher_condvar is eating\n",iter,i); /* eating*/
+        do_sleep(SLEEP_TIME);
+        phi_put_forks_condvar(i); 
+        /* return two forks back*/
+    }
+    cprintf("No.%d philosopher_condvar quit\n",i);
+    return 0;    
+}
+
+void check_sync(void){
+
+    int i;
+
+    //check semaphore
+    sem_init(&mutex, 1);
+    for(i=0;i<N;i++){
+        sem_init(&s[i], 0);
+        int pid = kernel_thread(philosopher_using_semaphore, (void *)i, 0);
+        if (pid <= 0) {
+            panic("create No.%d philosopher_using_semaphore failed.\n");
+        }
+        philosopher_proc_sema[i] = find_proc(pid);
+        set_proc_name(philosopher_proc_sema[i], "philosopher_sema_proc");
+    }
+
+    //check condition variable
+    monitor_init(&mt, N);
+    for(i=0;i<N;i++){
+        state_condvar[i]=THINKING;
+        int pid = kernel_thread(philosopher_using_condvar, (void *)i, 0);
+        if (pid <= 0) {
+            panic("create No.%d philosopher_using_condvar failed.\n");
+        }
+        philosopher_proc_condvar[i] = find_proc(pid);
+        set_proc_name(philosopher_proc_condvar[i], "philosopher_condvar_proc");
+    }
+}

labcodes/lab7/kern/sync/monitor.c

@@ -0,0 +1,59 @@
+#include <stdio.h>
+#include <monitor.h>
+#include <kmalloc.h>
+#include <assert.h>
+
+
+// Initialize monitor.
+void     
+monitor_init (monitor_t * mtp, size_t num_cv) {
+    int i;
+    assert(num_cv>0);
+    mtp->next_count = 0;
+    mtp->cv = NULL;
+    sem_init(&(mtp->mutex), 1); //unlocked
+    sem_init(&(mtp->next), 0);
+    mtp->cv =(condvar_t *) kmalloc(sizeof(condvar_t)*num_cv);
+    assert(mtp->cv!=NULL);
+    for(i=0; i<num_cv; i++){
+        mtp->cv[i].count=0;
+        sem_init(&(mtp->cv[i].sem),0);
+        mtp->cv[i].owner=mtp;
+    }
+}
+
+// Unlock one of threads waiting on the condition variable. 
+void 
+cond_signal (condvar_t *cvp) {
+   //LAB7 EXERCISE1: YOUR CODE
+   cprintf("cond_signal begin: cvp %x, cvp->count %d, cvp->owner->next_count %d\n", cvp, cvp->count, cvp->owner->next_count);  
+  /*
+   *      cond_signal(cv) {
+   *          if(cv.count>0) {
+   *             mt.next_count ++;
+   *             signal(cv.sem);
+   *             wait(mt.next);
+   *             mt.next_count--;
+   *          }
+   *       }
+   */
+   cprintf("cond_signal end: cvp %x, cvp->count %d, cvp->owner->next_count %d\n", cvp, cvp->count, cvp->owner->next_count);
+}
+
+// Suspend calling thread on a condition variable waiting for condition Atomically unlocks 
+// mutex and suspends calling thread on conditional variable after waking up locks mutex. Notice: mp is mutex semaphore for monitor's procedures
+void
+cond_wait (condvar_t *cvp) {
+    //LAB7 EXERCISE1: YOUR CODE
+    cprintf("cond_wait begin:  cvp %x, cvp->count %d, cvp->owner->next_count %d\n", cvp, cvp->count, cvp->owner->next_count);
+   /*
+    *         cv.count ++;
+    *         if(mt.next_count>0)
+    *            signal(mt.next)
+    *         else
+    *            signal(mt.mutex);
+    *         wait(cv.sem);
+    *         cv.count --;
+    */
+    cprintf("cond_wait end:  cvp %x, cvp->count %d, cvp->owner->next_count %d\n", cvp, cvp->count, cvp->owner->next_count);
+}

labcodes/lab7/kern/sync/monitor.h

@@ -0,0 +1,90 @@
+#ifndef __KERN_SYNC_MONITOR_CONDVAR_H__
+#define __KERN_SYNC_MOINTOR_CONDVAR_H__
+
+#include <sem.h>
+/* In [OS CONCEPT] 7.7 section, the accurate define and approximate implementation of MONITOR was introduced.
+ * INTRODUCTION:
+ *  Monitors were invented by C. A. R. Hoare and Per Brinch Hansen, and were first implemented in Brinch Hansen's
+ *  Concurrent Pascal language. Generally, a monitor is a language construct and the compiler usually enforces mutual exclusion. Compare this with semaphores, which are usually an OS construct.
+ * DEFNIE & CHARACTERISTIC:
+ *  A monitor is a collection of procedures, variables, and data structures grouped together.
+ *  Processes can call the monitor procedures but cannot access the internal data structures.
+ *  Only one process at a time may be be active in a monitor.
+ *  Condition variables allow for blocking and unblocking.
+ *     cv.wait() blocks a process.
+ *        The process is said to be waiting for (or waiting on) the condition variable cv.
+ *     cv.signal() (also called cv.notify) unblocks a process waiting for the condition variable cv.
+ *        When this occurs, we need to still require that only one process is active in the monitor. This can be done in several ways:
+ *            on some systems the old process (the one executing the signal) leaves the monitor and the new one enters
+ *            on some systems the signal must be the last statement executed inside the monitor.
+ *            on some systems the old process will block until the monitor is available again.
+ *            on some systems the new process (the one unblocked by the signal) will remain blocked until the monitor is available again.
+ *   If a condition variable is signaled with nobody waiting, the signal is lost. Compare this with semaphores, in which a signal will allow a process that executes a wait in the future to no block.
+ *   You should not think of a condition variable as a variable in the traditional sense.
+ *     It does not have a value.
+ *     Think of it as an object in the OOP sense.
+ *     It has two methods, wait and signal that manipulate the calling process.
+ * IMPLEMENTATION:
+ *   monitor mt {
+ *     ----------------variable------------------
+ *     semaphore mutex;
+ *     semaphore next;
+ *     int next_count;
+ *     condvar {int count, sempahore sem}  cv[N];
+ *     other variables in mt;
+ *     --------condvar wait/signal---------------
+ *     cond_wait (cv) {
+ *         cv.count ++;
+ *         if(mt.next_count>0)
+ *            signal(mt.next)
+ *         else
+ *            signal(mt.mutex);
+ *         wait(cv.sem);
+ *         cv.count --;
+ *      }
+ *
+ *      cond_signal(cv) {
+ *          if(cv.count>0) {
+ *             mt.next_count ++;
+ *             signal(cv.sem);
+ *             wait(mt.next);
+ *             mt.next_count--;
+ *          }
+ *       }
+ *     --------routines in monitor---------------
+ *     routineA_in_mt () {
+ *        wait(mt.mutex);
+ *        ...
+ *        real body of routineA
+ *        ...
+ *        if(next_count>0)
+ *            signal(mt.next);
+ *        else
+ *            signal(mt.mutex);
+ *     }
+ */
+
+typedef struct monitor monitor_t;
+
+typedef struct condvar{
+    semaphore_t sem;        // the sem semaphore  is used to down the waiting proc, and the signaling proc should up the waiting proc
+    int count;              // the number of waiters on condvar
+    monitor_t * owner;      // the owner(monitor) of this condvar
+} condvar_t;
+
+typedef struct monitor{
+    semaphore_t mutex;      // the mutex lock for going into the routines in monitor, should be initialized to 1
+    semaphore_t next;       // the next semaphore is used to down the signaling proc itself, and the other OR wakeuped waiting proc should wake up the sleeped signaling proc.
+    int next_count;         // the number of of sleeped signaling proc
+    condvar_t *cv;          // the condvars in monitor
+} monitor_t;
+
+// Initialize variables in monitor.
+void     monitor_init (monitor_t *cvp, size_t num_cv);
+// Unlock one of threads waiting on the condition variable. 
+void     cond_signal (condvar_t *cvp);
+// Suspend calling thread on a condition variable waiting for condition atomically unlock mutex in monitor,
+// and suspends calling thread on conditional variable after waking up locks mutex.
+void     cond_wait (condvar_t *cvp);
+     
+#endif /* !__KERN_SYNC_MONITOR_CONDVAR_H__ */

labcodes/lab7/kern/sync/sem.c

@@ -0,0 +1,77 @@
+#include <defs.h>
+#include <wait.h>
+#include <atomic.h>
+#include <kmalloc.h>
+#include <sem.h>
+#include <proc.h>
+#include <sync.h>
+#include <assert.h>
+
+void
+sem_init(semaphore_t *sem, int value) {
+    sem->value = value;
+    wait_queue_init(&(sem->wait_queue));
+}
+
+static __noinline void __up(semaphore_t *sem, uint32_t wait_state) {
+    bool intr_flag;
+    local_intr_save(intr_flag);
+    {
+        wait_t *wait;
+        if ((wait = wait_queue_first(&(sem->wait_queue))) == NULL) {
+            sem->value ++;
+        }
+        else {
+            assert(wait->proc->wait_state == wait_state);
+            wakeup_wait(&(sem->wait_queue), wait, wait_state, 1);
+        }
+    }
+    local_intr_restore(intr_flag);
+}
+
+static __noinline uint32_t __down(semaphore_t *sem, uint32_t wait_state) {
+    bool intr_flag;
+    local_intr_save(intr_flag);
+    if (sem->value > 0) {
+        sem->value --;
+        local_intr_restore(intr_flag);
+        return 0;
+    }
+    wait_t __wait, *wait = &__wait;
+    wait_current_set(&(sem->wait_queue), wait, wait_state);
+    local_intr_restore(intr_flag);
+
+    schedule();
+
+    local_intr_save(intr_flag);
+    wait_current_del(&(sem->wait_queue), wait);
+    local_intr_restore(intr_flag);
+
+    if (wait->wakeup_flags != wait_state) {
+        return wait->wakeup_flags;
+    }
+    return 0;
+}
+
+void
+up(semaphore_t *sem) {
+    __up(sem, WT_KSEM);
+}
+
+void
+down(semaphore_t *sem) {
+    uint32_t flags = __down(sem, WT_KSEM);
+    assert(flags == 0);
+}
+
+bool
+try_down(semaphore_t *sem) {
+    bool intr_flag, ret = 0;
+    local_intr_save(intr_flag);
+    if (sem->value > 0) {
+        sem->value --, ret = 1;
+    }
+    local_intr_restore(intr_flag);
+    return ret;
+}
+

labcodes/lab7/kern/sync/sem.h

@@ -0,0 +1,19 @@
+#ifndef __KERN_SYNC_SEM_H__
+#define __KERN_SYNC_SEM_H__
+
+#include <defs.h>
+#include <atomic.h>
+#include <wait.h>
+
+typedef struct {
+    int value;
+    wait_queue_t wait_queue;
+} semaphore_t;
+
+void sem_init(semaphore_t *sem, int value);
+void up(semaphore_t *sem);
+void down(semaphore_t *sem);
+bool try_down(semaphore_t *sem);
+
+#endif /* !__KERN_SYNC_SEM_H__ */
+

labcodes/lab7/kern/sync/sync.h

@@ -0,0 +1,31 @@
+#ifndef __KERN_SYNC_SYNC_H__
+#define __KERN_SYNC_SYNC_H__
+
+#include <x86.h>
+#include <intr.h>
+#include <mmu.h>
+#include <assert.h>
+#include <atomic.h>
+#include <sched.h>
+
+static inline bool
+__intr_save(void) {
+    if (read_eflags() & FL_IF) {
+        intr_disable();
+        return 1;
+    }
+    return 0;
+}
+
+static inline void
+__intr_restore(bool flag) {
+    if (flag) {
+        intr_enable();
+    }
+}
+
+#define local_intr_save(x)      do { x = __intr_save(); } while (0)
+#define local_intr_restore(x)   __intr_restore(x);
+
+#endif /* !__KERN_SYNC_SYNC_H__ */
+

labcodes/lab7/kern/sync/wait.c

@@ -0,0 +1,122 @@
+#include <defs.h>
+#include <list.h>
+#include <sync.h>
+#include <wait.h>
+#include <proc.h>
+
+void
+wait_init(wait_t *wait, struct proc_struct *proc) {
+    wait->proc = proc;
+    wait->wakeup_flags = WT_INTERRUPTED;
+    list_init(&(wait->wait_link));
+}
+
+void
+wait_queue_init(wait_queue_t *queue) {
+    list_init(&(queue->wait_head));
+}
+
+void
+wait_queue_add(wait_queue_t *queue, wait_t *wait) {
+    assert(list_empty(&(wait->wait_link)) && wait->proc != NULL);
+    wait->wait_queue = queue;
+    list_add_before(&(queue->wait_head), &(wait->wait_link));
+}
+
+void
+wait_queue_del(wait_queue_t *queue, wait_t *wait) {
+    assert(!list_empty(&(wait->wait_link)) && wait->wait_queue == queue);
+    list_del_init(&(wait->wait_link));
+}
+
+wait_t *
+wait_queue_next(wait_queue_t *queue, wait_t *wait) {
+    assert(!list_empty(&(wait->wait_link)) && wait->wait_queue == queue);
+    list_entry_t *le = list_next(&(wait->wait_link));
+    if (le != &(queue->wait_head)) {
+        return le2wait(le, wait_link);
+    }
+    return NULL;
+}
+
+wait_t *
+wait_queue_prev(wait_queue_t *queue, wait_t *wait) {
+    assert(!list_empty(&(wait->wait_link)) && wait->wait_queue == queue);
+    list_entry_t *le = list_prev(&(wait->wait_link));
+    if (le != &(queue->wait_head)) {
+        return le2wait(le, wait_link);
+    }
+    return NULL;
+}
+
+wait_t *
+wait_queue_first(wait_queue_t *queue) {
+    list_entry_t *le = list_next(&(queue->wait_head));
+    if (le != &(queue->wait_head)) {
+        return le2wait(le, wait_link);
+    }
+    return NULL;
+}
+
+wait_t *
+wait_queue_last(wait_queue_t *queue) {
+    list_entry_t *le = list_prev(&(queue->wait_head));
+    if (le != &(queue->wait_head)) {
+        return le2wait(le, wait_link);
+    }
+    return NULL;
+}
+
+bool
+wait_queue_empty(wait_queue_t *queue) {
+    return list_empty(&(queue->wait_head));
+}
+
+bool
+wait_in_queue(wait_t *wait) {
+    return !list_empty(&(wait->wait_link));
+}
+
+void
+wakeup_wait(wait_queue_t *queue, wait_t *wait, uint32_t wakeup_flags, bool del) {
+    if (del) {
+        wait_queue_del(queue, wait);
+    }
+    wait->wakeup_flags = wakeup_flags;
+    wakeup_proc(wait->proc);
+}
+
+void
+wakeup_first(wait_queue_t *queue, uint32_t wakeup_flags, bool del) {
+    wait_t *wait;
+    if ((wait = wait_queue_first(queue)) != NULL) {
+        wakeup_wait(queue, wait, wakeup_flags, del);
+    }
+}
+
+void
+wakeup_queue(wait_queue_t *queue, uint32_t wakeup_flags, bool del) {
+    wait_t *wait;
+    if ((wait = wait_queue_first(queue)) != NULL) {
+        if (del) {
+            do {
+                wakeup_wait(queue, wait, wakeup_flags, 1);
+            } while ((wait = wait_queue_first(queue)) != NULL);
+        }
+        else {
+            do {
+                wakeup_wait(queue, wait, wakeup_flags, 0);
+            } while ((wait = wait_queue_next(queue, wait)) != NULL);
+        }
+    }
+}
+
+void
+wait_current_set(wait_queue_t *queue, wait_t *wait, uint32_t wait_state) {
+    assert(current != NULL);
+    wait_init(wait, current);
+    current->state = PROC_SLEEPING;
+    current->wait_state = wait_state;
+    wait_queue_add(queue, wait);
+}
+

labcodes/lab7/kern/sync/wait.h

@@ -0,0 +1,48 @@
+#ifndef __KERN_SYNC_WAIT_H__
+#define __KERN_SYNC_WAIT_H__
+
+#include <list.h>
+
+typedef struct {
+    list_entry_t wait_head;
+} wait_queue_t;
+
+struct proc_struct;
+
+typedef struct {
+    struct proc_struct *proc;
+    uint32_t wakeup_flags;
+    wait_queue_t *wait_queue;
+    list_entry_t wait_link;
+} wait_t;
+
+#define le2wait(le, member)         \
+    to_struct((le), wait_t, member)
+
+void wait_init(wait_t *wait, struct proc_struct *proc);
+void wait_queue_init(wait_queue_t *queue);
+void wait_queue_add(wait_queue_t *queue, wait_t *wait);
+void wait_queue_del(wait_queue_t *queue, wait_t *wait);
+
+wait_t *wait_queue_next(wait_queue_t *queue, wait_t *wait);
+wait_t *wait_queue_prev(wait_queue_t *queue, wait_t *wait);
+wait_t *wait_queue_first(wait_queue_t *queue);
+wait_t *wait_queue_last(wait_queue_t *queue);
+
+bool wait_queue_empty(wait_queue_t *queue);
+bool wait_in_queue(wait_t *wait);
+void wakeup_wait(wait_queue_t *queue, wait_t *wait, uint32_t wakeup_flags, bool del);
+void wakeup_first(wait_queue_t *queue, uint32_t wakeup_flags, bool del);
+void wakeup_queue(wait_queue_t *queue, uint32_t wakeup_flags, bool del);
+
+void wait_current_set(wait_queue_t *queue, wait_t *wait, uint32_t wait_state);
+
+#define wait_current_del(queue, wait)                                       \
+    do {                                                                    \
+        if (wait_in_queue(wait)) {                                          \
+            wait_queue_del(queue, wait);                                    \
+        }                                                                   \
+    } while (0)
+
+#endif /* !__KERN_SYNC_WAIT_H__ */
+