Author: mjg
Date: Tue Jul 21 14:39:20 2020
New Revision: 363392
URL: https://svnweb.freebsd.org/changeset/base/363392

Log:
  lockmgr: add a helper for reading the lock value

Modified:
  head/sys/kern/kern_lock.c
  head/sys/sys/lockmgr.h

Modified: head/sys/kern/kern_lock.c
==============================================================================
--- head/sys/kern/kern_lock.c   Tue Jul 21 14:35:50 2020        (r363391)
+++ head/sys/kern/kern_lock.c   Tue Jul 21 14:39:20 2020        (r363392)
@@ -140,7 +140,7 @@ LK_CAN_SHARE(uintptr_t x, int flags, bool fp)
 #define        lockmgr_xlocked_v(v)                                            
\
        (((v) & ~(LK_FLAGMASK & ~LK_SHARE)) == (uintptr_t)curthread)
 
-#define        lockmgr_xlocked(lk) lockmgr_xlocked_v((lk)->lk_lock)
+#define        lockmgr_xlocked(lk) lockmgr_xlocked_v(lockmgr_read_value(lk))
 
 static void    assert_lockmgr(const struct lock_object *lock, int how);
 #ifdef DDB
@@ -233,7 +233,7 @@ static void
 lockmgr_note_exclusive_release(struct lock *lk, const char *file, int line)
 {
 
-       if (LK_HOLDER(lk->lk_lock) != LK_KERNPROC) {
+       if (LK_HOLDER(lockmgr_read_value(lk)) != LK_KERNPROC) {
                WITNESS_UNLOCK(&lk->lock_object, LOP_EXCLUSIVE, file, line);
                TD_LOCKS_DEC(curthread);
        }
@@ -246,7 +246,7 @@ lockmgr_xholder(const struct lock *lk)
 {
        uintptr_t x;
 
-       x = lk->lk_lock;
+       x = lockmgr_read_value(lk);
        return ((x & LK_SHARE) ? NULL : (struct thread *)LK_HOLDER(x));
 }
 
@@ -309,7 +309,7 @@ wakeupshlk(struct lock *lk, const char *file, int line
 
        wakeup_swapper = 0;
        for (;;) {
-               x = lk->lk_lock;
+               x = lockmgr_read_value(lk);
                if (lockmgr_sunlock_try(lk, &x))
                        break;
 
@@ -318,7 +318,7 @@ wakeupshlk(struct lock *lk, const char *file, int line
                 * path in order to handle wakeups correctly.
                 */
                sleepq_lock(&lk->lock_object);
-               orig_x = lk->lk_lock;
+               orig_x = lockmgr_read_value(lk);
 retry_sleepq:
                x = orig_x & (LK_ALL_WAITERS | LK_EXCLUSIVE_SPINNERS);
                v = LK_UNLOCKED;
@@ -515,7 +515,7 @@ lockmgr_slock_try(struct lock *lk, uintptr_t *xp, int 
         * waiters, if we fail to acquire the shared lock
         * loop back and retry.
         */
-       *xp = lk->lk_lock;
+       *xp = lockmgr_read_value(lk);
        while (LK_CAN_SHARE(*xp, flags, fp)) {
                if (atomic_fcmpset_acq_ptr(&lk->lk_lock, xp,
                    *xp + LK_ONE_SHARER)) {
@@ -603,7 +603,7 @@ lockmgr_slock_hard(struct lock *lk, u_int flags, struc
                 * probabilly will need to manipulate waiters flags.
                 */
                sleepq_lock(&lk->lock_object);
-               x = lk->lk_lock;
+               x = lockmgr_read_value(lk);
 retry_sleepq:
 
                /*
@@ -772,7 +772,7 @@ lockmgr_xlock_hard(struct lock *lk, u_int flags, struc
                 * probabilly will need to manipulate waiters flags.
                 */
                sleepq_lock(&lk->lock_object);
-               x = lk->lk_lock;
+               x = lockmgr_read_value(lk);
 retry_sleepq:
 
                /*
@@ -889,7 +889,7 @@ lockmgr_upgrade(struct lock *lk, u_int flags, struct l
        tid = (uintptr_t)curthread;
 
        _lockmgr_assert(lk, KA_SLOCKED, file, line);
-       v = lk->lk_lock;
+       v = lockmgr_read_value(lk);
        x = v & LK_ALL_WAITERS;
        v &= LK_EXCLUSIVE_SPINNERS;
 
@@ -970,7 +970,7 @@ lockmgr_lock_flags(struct lock *lk, u_int flags, struc
                            LOP_EXCLUSIVE, file, line, flags & LK_INTERLOCK ?
                            ilk : NULL);
                tid = (uintptr_t)curthread;
-               if (lk->lk_lock == LK_UNLOCKED &&
+               if (lockmgr_read_value(lk) == LK_UNLOCKED &&
                    atomic_cmpset_acq_ptr(&lk->lk_lock, LK_UNLOCKED, tid)) {
                        lockmgr_note_exclusive_acquire(lk, 0, 0, file, line,
                            flags);
@@ -1054,7 +1054,7 @@ lockmgr_xunlock_hard(struct lock *lk, uintptr_t x, u_i
                goto out;
 
        sleepq_lock(&lk->lock_object);
-       x = lk->lk_lock;
+       x = lockmgr_read_value(lk);
        v = LK_UNLOCKED;
 
        /*
@@ -1178,7 +1178,7 @@ lockmgr_unlock(struct lock *lk)
        line = __LINE__;
 
        _lockmgr_assert(lk, KA_LOCKED, file, line);
-       x = lk->lk_lock;
+       x = lockmgr_read_value(lk);
        if (__predict_true(x & LK_SHARE) != 0) {
                lockmgr_note_shared_release(lk, file, line);
                if (lockmgr_sunlock_try(lk, &x)) {
@@ -1292,7 +1292,7 @@ __lockmgr_args(struct lock *lk, u_int flags, struct lo
                 * In order to preserve waiters flags, just spin.
                 */
                for (;;) {
-                       x = lk->lk_lock;
+                       x = lockmgr_read_value(lk);
                        MPASS((x & LK_EXCLUSIVE_SPINNERS) == 0);
                        x &= LK_ALL_WAITERS;
                        if (atomic_cmpset_rel_ptr(&lk->lk_lock, tid | x,
@@ -1305,7 +1305,7 @@ __lockmgr_args(struct lock *lk, u_int flags, struct lo
                break;
        case LK_RELEASE:
                _lockmgr_assert(lk, KA_LOCKED, file, line);
-               x = lk->lk_lock;
+               x = lockmgr_read_value(lk);
 
                if (__predict_true(x & LK_SHARE) != 0) {
                        lockmgr_note_shared_release(lk, file, line);
@@ -1359,7 +1359,7 @@ __lockmgr_args(struct lock *lk, u_int flags, struct lo
                         * probabilly will need to manipulate waiters flags.
                         */
                        sleepq_lock(&lk->lock_object);
-                       x = lk->lk_lock;
+                       x = lockmgr_read_value(lk);
 
                        /*
                         * if the lock has been released while we spun on
@@ -1545,7 +1545,7 @@ _lockmgr_disown(struct lock *lk, const char *file, int
         * In order to preserve waiters flags, just spin.
         */
        for (;;) {
-               x = lk->lk_lock;
+               x = lockmgr_read_value(lk);
                MPASS((x & LK_EXCLUSIVE_SPINNERS) == 0);
                x &= LK_ALL_WAITERS;
                if (atomic_cmpset_rel_ptr(&lk->lk_lock, tid | x,
@@ -1597,7 +1597,7 @@ lockstatus(const struct lock *lk)
        int ret;
 
        ret = LK_SHARED;
-       x = lk->lk_lock;
+       x = lockmgr_read_value(lk);
        v = LK_HOLDER(x);
 
        if ((x & LK_SHARE) == 0) {

Modified: head/sys/sys/lockmgr.h
==============================================================================
--- head/sys/sys/lockmgr.h      Tue Jul 21 14:35:50 2020        (r363391)
+++ head/sys/sys/lockmgr.h      Tue Jul 21 14:39:20 2020        (r363392)
@@ -119,6 +119,7 @@ _lockmgr_args_rw(struct lock *lk, u_int flags, struct 
 /*
  * Define aliases in order to complete lockmgr KPI.
  */
+#define        lockmgr_read_value(lk)  ((lk)->lk_lock)
 #define        lockmgr(lk, flags, ilk)                                         
\
        _lockmgr_args((lk), (flags), (ilk), LK_WMESG_DEFAULT,           \
            LK_PRIO_DEFAULT, LK_TIMO_DEFAULT, LOCK_FILE, LOCK_LINE)
_______________________________________________
svn-src-all@freebsd.org mailing list
https://lists.freebsd.org/mailman/listinfo/svn-src-all
To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"

Reply via email to