Changeset 20448 in vbox for trunk/src

Timestamp:

Jun 9, 2009 10:21:09 PM (16 years ago)

Author:

vboxsync

Message:

Runtime/semevent-r0drv-freebsd: Use a sleeping mutex instead of a spinlock to fix the problems users are seeing (assertions with debugging enabled) while still being able to run on 100Hz hosts. No problems detected so far and Solaris doesn't use a spin mutex in this code too so it shouldn't do any harm (keeping fingers crossed)

File:

• trunk/src/VBox/Runtime/r0drv/freebsd/semevent-r0drv-freebsd.c (modified) (9 diffs)

trunk/src/VBox/Runtime/r0drv/freebsd/semevent-r0drv-freebsd.c

@@ -76 +76 @@
         pEventInt->cWaking = 0;
         pEventInt->fSignaled = 0;
-        mtx_init(&pEventInt->Mtx, "IPRT Event Semaphore", NULL, MTX_SPIN);
+        mtx_init(&pEventInt->Mtx, "IPRT Event Semaphore", NULL, 0);
         *pEventSem = pEventInt;
         return VINF_SUCCESS;
@@ -94 +94 @@
                     VERR_INVALID_HANDLE);
 
-    mtx_lock_spin(&pEventInt->Mtx);
+    mtx_lock(&pEventInt->Mtx);
     ASMAtomicIncU32(&pEventInt->u32Magic); /* make the handle invalid */
     if (pEventInt->cWaiters > 0)
@@ -101 +101 @@
         ASMAtomicXchgU32(&pEventInt->cWaking, pEventInt->cWaking + pEventInt->cWaiters);
         wakeup(pEventInt);
-        mtx_unlock_spin(&pEventInt->Mtx);
+        mtx_unlock(&pEventInt->Mtx);
     }
     else if (pEventInt->cWaking)
         /* the last waking thread is gonna do the cleanup */
-        mtx_unlock_spin(&pEventInt->Mtx);
+        mtx_unlock(&pEventInt->Mtx);
     else
     {
-        mtx_unlock_spin(&pEventInt->Mtx);
+        mtx_unlock(&pEventInt->Mtx);
         mtx_destroy(&pEventInt->Mtx);
         RTMemFree(pEventInt);
@@ -125 +125 @@
                     VERR_INVALID_HANDLE);
 
-    mtx_lock_spin(&pEventInt->Mtx);
+    mtx_lock(&pEventInt->Mtx);
 
     if (pEventInt->cWaiters > 0)
@@ -136 +136 @@
         ASMAtomicXchgU8(&pEventInt->fSignaled, true);
 
-    mtx_unlock_spin(&pEventInt->Mtx);
+    mtx_unlock(&pEventInt->Mtx);
     return VINF_SUCCESS;
 }
@@ -150 +150 @@
                     VERR_INVALID_HANDLE);
 
-    mtx_lock_spin(&pEventInt->Mtx);
+    mtx_lock(&pEventInt->Mtx);
 
     if (pEventInt->fSignaled)
@@ -173 +173 @@
         ASMAtomicIncU32(&pEventInt->cWaiters);
 
-        mtx_unlock_spin(&pEventInt->Mtx);
-/** @todo r=bird: This doesn't handle cMillies == 0 correctly, it will assert
- *        and or sleep for ever according to r47861. (That's probably an old bug
- *        of my making.)
- *
- *        And it really looks like it's racing signalling on MP systems. (It
- *        *looks* like you leave the lock and then tries to go to sleep on a
- *        block id, someone spinning on the lock attempt to wake us up before we
- *        go to sleep. That's why the code was originally trying to use msleep
- *        here.). */
-        rc = tsleep(pEventInt,          /* block id */
-                    fInterruptible ? PZERO | PCATCH : PZERO,
-                    "iprtev",           /* max 6 chars */
-                    cMillies == RT_INDEFINITE_WAIT
-                    ? 0
-                    : tvtohz(&tv));
-        mtx_lock_spin(&pEventInt->Mtx);
+        /** @todo r=bird: This doesn't handle cMillies == 0 correctly, it will assert
+         *        and or sleep for ever according to r47861. (That's probably an old bug
+         *        of my making.)
+         */
+        rc = mtx_sleep(pEventInt,          /* block id */
+                       &pEventInt->Mtx,    /* mtx */
+                       fInterruptible ? PZERO | PCATCH : PZERO,
+                       "iprtev",           /* max 6 chars */
+                       cMillies == RT_INDEFINITE_WAIT
+                       ? 0
+                       : tvtohz(&tv));
 
         switch (rc)
@@ -207 +201 @@
                         /* The event was destroyed, as the last thread do the cleanup.
                            we don't actually know whether */
-                        mtx_unlock_spin(&pEventInt->Mtx);
+                        mtx_unlock(&pEventInt->Mtx);
                         mtx_destroy(&pEventInt->Mtx);
                         RTMemFree(pEventInt);
@@ -237 +231 @@
     }
 
-    mtx_unlock_spin(&pEventInt->Mtx);
+    mtx_unlock(&pEventInt->Mtx);
     return rc;
 }