Bug 886255 - Let activatation of inactive JitActivation behave more closely to the construction of active JitAction, r=jandem

js/src/ion/AsmJS.cpp

@@ -5694,14 +5694,18 @@ static void
 EnableActivation(AsmJSActivation *activation)
 {
     JSContext *cx = activation->cx();
-    cx->mainThread().activation()->setActive();
+    Activation *act = cx->mainThread().activation();
+    JS_ASSERT(act->isJit());
+    act->asJit()->setActive(cx);
 }
 
 static void
 DisableActivation(AsmJSActivation *activation)
 {
     JSContext *cx = activation->cx();
-    cx->mainThread().activation()->setActive(false);
+    Activation *act = cx->mainThread().activation();
+    JS_ASSERT(act->isJit());
+    act->asJit()->setActive(cx, false);
 }
 
 static void

js/src/jscntxt.h

@@ -519,6 +519,7 @@ class PerThreadData : public js::PerThreadDataFriendFields
   private:
     friend class js::Activation;
     friend class js::ActivationIterator;
+    friend class js::ion::JitActivation;
     friend class js::AsmJSActivation;
 
     /*

js/src/jscntxtinlines.h

@@ -540,7 +540,7 @@ JSContext::currentScript(jsbytecode **ppc,
         *ppc = NULL;
 
     js::Activation *act = mainThread().activation();
-    while (act && (act->cx() != this || !act->isActive()))
+    while (act && (act->cx() != this || (act->isJit() && !act->asJit()->isActive())))
         act = act->prev();
 
     if (!act)

js/src/vm/Stack-inl.h

@@ -820,11 +820,10 @@ AbstractFramePtr::popWith(JSContext *cx) const
         MOZ_ASSUME_UNREACHABLE("Invalid frame");
 }
 
-Activation::Activation(JSContext *cx, Kind kind, bool active)
+Activation::Activation(JSContext *cx, Kind kind)
   : cx_(cx),
     compartment_(cx->compartment()),
     prev_(cx->mainThread().activation_),
-    active_(active),
     savedFrameChain_(0),
     kind_(kind)
 {

js/src/vm/Stack.cpp

@@ -1269,33 +1269,46 @@ js::CheckLocalUnaliased(MaybeCheckAliasing checkAliasing, JSScript *script,
 }
 #endif
 
-void
-Activation::setActive(bool active)
-{
-    // Only allowed to deactivate/activate if activation is top.
-    // (Not tested and will probably fail in other situations.)
-    JS_ASSERT(cx()->mainThread().activation_ == this);
-    JS_ASSERT(active != active_);
-    active_ = active;
-
-    // Restore ionTop
-    if (!active && isJit())
-        cx()->mainThread().ionTop = asJit()->prevIonTop();
-}
-
 ion::JitActivation::JitActivation(JSContext *cx, bool firstFrameIsConstructing, bool active)
-  : Activation(cx, Jit, active),
-    prevIonTop_(cx->mainThread().ionTop),
-    prevIonJSContext_(cx->mainThread().ionJSContext),
-    firstFrameIsConstructing_(firstFrameIsConstructing)
+  : Activation(cx, Jit),
+    firstFrameIsConstructing_(firstFrameIsConstructing),
+    active_(active)
 {
-    cx->mainThread().ionJSContext = cx;
+    if (active) {
+        prevIonTop_ = cx->mainThread().ionTop;
+        prevIonJSContext_ = cx->mainThread().ionJSContext;
+        cx->mainThread().ionJSContext = cx;
+    } else {
+        prevIonTop_ = NULL;
+        prevIonJSContext_ = NULL;
+    }
 }
 
 ion::JitActivation::~JitActivation()
 {
-    cx_->mainThread().ionTop = prevIonTop_;
-    cx_->mainThread().ionJSContext = prevIonJSContext_;
+    if (active_) {
+        cx_->mainThread().ionTop = prevIonTop_;
+        cx_->mainThread().ionJSContext = prevIonJSContext_;
+    }
+}
+
+void
+ion::JitActivation::setActive(JSContext *cx, bool active)
+{
+    // Only allowed to deactivate/activate if activation is top.
+    // (Not tested and will probably fail in other situations.)
+    JS_ASSERT(cx->mainThread().activation_ == this);
+    JS_ASSERT(active != active_);
+    active_ = active;
+
+    if (active) {
+        prevIonTop_ = cx->mainThread().ionTop;
+        prevIonJSContext_ = cx->mainThread().ionJSContext;
+        cx->mainThread().ionJSContext = cx;
+    } else {
+        cx->mainThread().ionTop = prevIonTop_;
+        cx->mainThread().ionJSContext = prevIonJSContext_;
+    }
 }
 
 InterpreterFrameIterator &
@@ -1325,7 +1338,7 @@ ActivationIterator &
 ActivationIterator::operator++()
 {
     JS_ASSERT(activation_);
-    if (activation_->isJit())
+    if (activation_->isJit() && activation_->asJit()->isActive())
         jitTop_ = activation_->asJit()->prevIonTop();
     activation_ = activation_->prev();
     settle();
@@ -1335,8 +1348,8 @@ ActivationIterator::operator++()
 void
 ActivationIterator::settle()
 {
-    while (!done() && !activation_->isActive()) {
-        if (activation_->isJit())
+    while (!done() && activation_->isJit() && !activation_->asJit()->isActive()) {
+        if (activation_->asJit()->isActive())
             jitTop_ = activation_->asJit()->prevIonTop();
         activation_ = activation_->prev();
     }

js/src/vm/Stack.h

@@ -1152,7 +1152,6 @@ class Activation
     JSContext *cx_;
     JSCompartment *compartment_;
     Activation *prev_;
-    bool active_;
 
     // Counter incremented by JS_SaveFrameChain on the top-most activation and
     // decremented by JS_RestoreFrameChain. If > 0, ScriptFrameIter should stop
@@ -1163,7 +1162,7 @@ class Activation
     enum Kind { Interpreter, Jit };
     Kind kind_;
 
-    inline Activation(JSContext *cx, Kind kind_, bool active = true);
+    inline Activation(JSContext *cx, Kind kind_);
     inline ~Activation();
 
   public:
@@ -1176,10 +1175,6 @@ class Activation
     Activation *prev() const {
         return prev_;
     }
-    bool isActive() const {
-        return active_;
-    }
-    void setActive(bool active = true);
 
     bool isInterpreter() const {
         return kind_ == Interpreter;
@@ -1280,11 +1275,17 @@ class JitActivation : public Activation
     uint8_t *prevIonTop_;
     JSContext *prevIonJSContext_;
     bool firstFrameIsConstructing_;
+    bool active_;
 
   public:
     JitActivation(JSContext *cx, bool firstFrameIsConstructing, bool active = true);
     ~JitActivation();
 
+    bool isActive() const {
+        return active_;
+    }
+    void setActive(JSContext *cx, bool active = true);
+
     uint8_t *prevIonTop() const {
         return prevIonTop_;
     }