Changeset 47352 in vbox for trunk/src/VBox/Runtime/r0drv/linux

Timestamp:

Jul 23, 2013 4:19:20 PM (12 years ago)

Author:

vboxsync

svn:sync-xref-src-repo-rev:

87497

Message:

Runtime/r0drv: Reference counting for kernel thread-context hooks.

File:

• trunk/src/VBox/Runtime/r0drv/linux/threadctxhooks-r0drv-linux.c (modified) (8 diffs)

trunk/src/VBox/Runtime/r0drv/linux/threadctxhooks-r0drv-linux.c

@@ -52 +52 @@
     uint32_t volatile           u32Magic;
     /** The thread handle (owner) for which the context-hooks are registered. */
-    RTTHREAD                    hOwner;
+    RTNATIVETHREAD              hOwner;
     /** The preemption notifier object. */
     struct preempt_notifier     hPreemptNotifier;
@@ -63 +63 @@
     /** The thread-context operations. */
     struct preempt_ops          hPreemptOps;
+    /** The reference count for this object. */
+    uint32_t volatile           cRefs;
 } RTTHREADCTXINT, *PRTTHREADCTXINT;
 
@@ -109 +111 @@
 
 /**
- * Worker function for RTThreadCtxHooks(Deregister|Destroy)().
+ * Worker function for RTThreadCtxHooks(Deregister|Release)().
  *
  * @param   pThis   Pointer to the internal thread-context object.
@@ -131 +133 @@
         return VERR_NO_MEMORY;
     pThis->u32Magic    = RTTHREADCTXINT_MAGIC;
-    pThis->hOwner      = RTThreadSelf();
+    pThis->hOwner      = RTThreadNativeSelf();
     pThis->fRegistered = false;
     preempt_notifier_init(&pThis->hPreemptNotifier, &pThis->hPreemptOps);
+    pThis->cRefs       = 1;
 
     *phThreadCtx = pThis;
@@ -141 +144 @@
 
 
-RTDECL(void) RTThreadCtxHooksDestroy(RTTHREADCTX hThreadCtx)
+RTDECL(uint32_t) RTThreadCtxHooksRetain(RTTHREADCTX hThreadCtx)
 {
     /*
      * Validate input.
      */
+    uint32_t        cRefs;
+    PRTTHREADCTXINT pThis = hThreadCtx;
+    AssertPtr(pThis);
+    AssertMsgReturn(pThis->u32Magic == RTTHREADCTXINT_MAGIC, ("pThis->u32Magic=%RX32 pThis=%p\n", pThis->u32Magic, pThis),
+                    UINT32_MAX);
+
+    cRefs = ASMAtomicIncU32(&pThis->cRefs);
+    Assert(cRefs < UINT32_MAX / 2);
+    return cRefs;
+}
+RT_EXPORT_SYMBOL(RTThreadCtxHooksRetain);
+
+
+
+RTDECL(uint32_t) RTThreadCtxHooksRelease(RTTHREADCTX hThreadCtx)
+{
+    /*
+     * Validate input.
+     */
+    uint32_t        cRefs;
     PRTTHREADCTXINT pThis = hThreadCtx;
     if (pThis == NIL_RTTHREADCTX)
-        return;
-    AssertPtr(pThis);
-    AssertMsgReturnVoid(pThis->u32Magic == RTTHREADCTXINT_MAGIC, ("pThis->u32Magic=%RX32 pThis=%p\n", pThis->u32Magic, pThis));
-    Assert(pThis->hOwner == RTThreadSelf());
+        return 0;
+    AssertPtr(pThis);
+    AssertMsgReturn(pThis->u32Magic == RTTHREADCTXINT_MAGIC, ("pThis->u32Magic=%RX32 pThis=%p\n", pThis->u32Magic, pThis),
+                    UINT32_MAX);
     Assert(RTThreadPreemptIsEnabled(NIL_RTTHREAD));
 
-    /*
-     * If there's still a registered thread-context hook, deregister it now before destroying the object.
-     */
-    if (pThis->fRegistered)
-        rtThreadCtxHooksDeregister(pThis);
-
-    /*
-     * Paranoia... but since these are ring-0 threads we can't be too careful.
-     */
-    Assert(!pThis->fRegistered);
-    Assert(!pThis->hPreemptOps.sched_out);
-    Assert(!pThis->hPreemptOps.sched_in);
-
-    /*
-     * Destroy the object.
-     */
-    ASMAtomicWriteU32(&pThis->u32Magic, ~RTTHREADCTXINT_MAGIC);
-    RTMemFree(pThis);
-}
-RT_EXPORT_SYMBOL(RTThreadCtxHooksDestroy);
+    cRefs = ASMAtomicDecU32(&pThis->cRefs);
+    if (!cRefs)
+    {
+        /*
+         * If there's still a registered thread-context hook, deregister it now before destroying the object.
+         */
+        if (pThis->fRegistered)
+            rtThreadCtxHooksDeregister(pThis);
+
+        /*
+         * Paranoia... but since these are ring-0 threads we can't be too careful.
+         */
+        Assert(!pThis->fRegistered);
+        Assert(!pThis->hPreemptOps.sched_out);
+        Assert(!pThis->hPreemptOps.sched_in);
+
+        ASMAtomicWriteU32(&pThis->u32Magic, ~RTTHREADCTXINT_MAGIC);
+        RTMemFree(pThis);
+        printk("freed pThis=%p\n", pThis);
+    }
+    else
+        Assert(cRefs < UINT32_MAX / 2);
+
+    return cRefs;
+}
+RT_EXPORT_SYMBOL(RTThreadCtxHooksRelease);
 
 
@@ -187 +216 @@
     AssertMsgReturn(pThis->u32Magic == RTTHREADCTXINT_MAGIC, ("pThis->u32Magic=%RX32 pThis=%p\n", pThis->u32Magic, pThis),
                     VERR_INVALID_HANDLE);
-    Assert(pThis->hOwner == RTThreadSelf());
+    Assert(pThis->hOwner == RTThreadNativeSelf());
     Assert(!pThis->hPreemptOps.sched_out);
     Assert(!pThis->hPreemptOps.sched_in);
@@ -217 +246 @@
     AssertMsgReturn(pThis->u32Magic == RTTHREADCTXINT_MAGIC, ("pThis->u32Magic=%RX32 pThis=%p\n", pThis->u32Magic, pThis),
                     VERR_INVALID_HANDLE);
-    Assert(pThis->hOwner == RTThreadSelf());
+    Assert(pThis->hOwner == RTThreadNativeSelf());
     Assert(pThis->fRegistered);
 
@@ -238 +267 @@
 
 
-RTDECL(void) RTThreadCtxHooksDestroy(RTTHREADCTX hThreadCtx)
+RTDECL(uint32_t) RTThreadCtxHooksRetain(RTTHREADCTX hThreadCtx)
 {
     NOREF(hThreadCtx);
-}
-RT_EXPORT_SYMBOL(RTThreadCtxHooksDestroy);
+    return UINT32_MAX;
+}
+RT_EXPORT_SYMBOL(RTThreadCtxHooksRetain);
+
+
+RTDECL(uint32_t) RTThreadCtxHooksRelease(RTTHREADCTX hThreadCtx)
+{
+    NOREF(hThreadCtx);
+    return UINT32_MAX;
+}
+RT_EXPORT_SYMBOL(RTThreadCtxHooksRelease);