X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=src%2Fthreads%2Fsynch.c;h=c3b46a8c7f675708cacd2d68d0b35c894480c5f6;hb=9aeade22c073c7a94bc5b56f6c00c0edaeed2b00;hp=39e43c3d57868935224f2a77e7305b96e4cff6b6;hpb=750d21936d284127e265d050ccbce76fca1ece1a;p=pintos-anon

diff --git a/src/threads/synch.c b/src/threads/synch.c
index 39e43c3..c3b46a8 100644
--- a/src/threads/synch.c
+++ b/src/threads/synch.c
@@ -1,13 +1,12 @@
 #include "synch.h"
 #include "interrupt.h"
 #include "lib.h"
-#include "malloc.h"
 #include "thread.h"
 
 /* One thread in a list. */
 struct thread_elem
   {
-    struct list_elem elem;
+    list_elem elem;
     struct thread *thread;      
   };
 
@@ -35,7 +34,9 @@ sema_init (struct semaphore *sema, unsigned value, const char *name)
    atomically decrements it.
 
    This function may sleep, so it must not be called within an
-   interrupt handler. */
+   interrupt handler.  This function may be called with
+   interrupts disabled, but interrupts will be turned back on if
+   we need to sleep. */
 void
 sema_down (struct semaphore *sema) 
 {
@@ -117,9 +118,9 @@ sema_self_test (void)
 
 /* Initializes LOCK and names it NAME (for debugging purposes).
    A lock can be held by at most a single thread at any given
-   time.  Our locks are not "recursive", meaning that it is an
-   error for a thread that holds a lock to attempt to reacquire
-   it.
+   time.  Our locks are not "recursive", that is, it is an error
+   for the thread currently holding a lock to try to acquire that
+   lock.
 
    A lock is a specialization of a semaphore with an initial
    value of 1.  The difference between a lock and such a
@@ -147,7 +148,9 @@ lock_init (struct lock *lock, const char *name)
    thread.
 
    This function may sleep, so it must not be called within an
-   interrupt handler. */
+   interrupt handler.  This function may be called with
+   interrupts disabled, but interrupts will be turned back on if
+   we need to sleep. */
 void
 lock_acquire (struct lock *lock)
 {
@@ -205,7 +208,7 @@ lock_name (const struct lock *lock)
 /* One semaphore in a list. */
 struct semaphore_elem 
   {
-    struct list_elem elem;
+    list_elem elem;
     struct semaphore semaphore;
   };
 
@@ -240,7 +243,9 @@ cond_init (struct condition *cond, const char *name)
    from locks to condition variables.
 
    This function may sleep, so it must not be called within an
-   interrupt handler. */
+   interrupt handler.  This function may be called with
+   interrupts disabled, but interrupts will be turned back on if
+   we need to sleep. */
 void
 cond_wait (struct condition *cond, struct lock *lock) 
 {