improve wait_queue api

core/synchro.c

@@ -1,6 +1,6 @@
-#include "assert.h"
 #include "synchro.h"
 #include "alloc.h"
+#include "assert.h"
 #include "irq.h"
 #include "klibc.h"
 #include "list.h"
@@ -59,12 +59,7 @@ int mutexLock(struct mutex *m)
     disable_IRQs(flags);
     current = getCurrenThread();
     assert(m->owner != current);
-    while (m->owner) {
+    wait_event(m->wait, m->owner == NULL);
-        kthreadUnsched(current);
-        list_add_tail(m->wait->thread, current);
-        current->state = WAITING;
-        kthreadSaveAndYield(current);
-    }
     m->owner = current;
 
     restore_IRQs(flags);
@@ -74,7 +69,6 @@ int mutexLock(struct mutex *m)
 
 int mutexUnlock(struct mutex *m)
 {
-    struct kthread *th;
     uint32_t flags;
 
     disable_IRQs(flags);
@@ -82,9 +76,7 @@ int mutexUnlock(struct mutex *m)
 
     m->owner = NULL;
 
-    list_collapse(m->wait->thread, th){
+    wake_up(m->wait);
-        kthreadAddThread(th);
-    }
 
     restore_IRQs(flags);
 

core/wait.c

@@ -0,0 +1,37 @@
+#include "wait.h"
+#include "irq.h"
+#include "kthread.h"
+#include "list.h"
+
+int wake_up(struct wait_queue *wq)
+{
+    struct kthread *th;
+    uint32_t flags;
+
+    disable_IRQs(flags);
+    list_collapse(wq->thread, th)
+    {
+        kthreadAddThread(th);
+    }
+
+    restore_IRQs(flags);
+
+    return 0;
+}
+
+int wait(struct wait_queue *wq)
+{
+    struct kthread *current;
+    uint32_t flags;
+
+    disable_IRQs(flags);
+
+    current = getCurrenThread();
+    kthreadUnsched(current);
+    list_add_tail(wq->thread, current);
+    current->state = WAITING;
+    kthreadSaveAndYield(current);
+
+    restore_IRQs(flags);
+    return 0;
+}

core/wait.h

@@ -8,6 +8,16 @@ struct wait_queue {
     struct wait_queue *prev;
 };
 
+int wait(struct wait_queue *);
+int wake_up(struct wait_queue *);
+
+#define wait_event(wq, condition)                                                             \
+    do {                                                                                      \
+        if (condition)                                                                        \
+            break;                                                                            \
+        wait(wq);                                                                             \
+    } while (1)
+
 struct semaphore {
     int count;
     struct wait_queue *wait;