Keep "static" objects per-context rather than per isolate.

Every time we initialize a new v8::Context, we make a new set of
pre-existing native objects, and overwrite the v8::Global
handles to those in the previous set. Thus, we may be
theoretically releasing some v8::Globals early.

R=jochen@chromium.org

Review URL: https://codereview.chromium.org/1424933013 .

5 files changed, 39 insertions, 28 deletions

diff --git a/fpdfsdk/include/jsapi/fxjs_v8.h b/fpdfsdk/include/jsapi/fxjs_v8.h
index c5a864026b..b8a63c6c7b 100644
--- a/fpdfsdk/include/jsapi/fxjs_v8.h
+++ b/fpdfsdk/include/jsapi/fxjs_v8.h
@@ -59,7 +59,6 @@ extern const wchar_t kFXJSValueNameFxobj[];
 extern const wchar_t kFXJSValueNameNull[];
 extern const wchar_t kFXJSValueNameUndefined[];
 
-
 class FXJS_ArrayBufferAllocator : public v8::ArrayBuffer::Allocator {
   void* Allocate(size_t length) override;
   void* AllocateUninitialized(size_t length) override;
@@ -123,11 +122,14 @@ void FXJS_DefineGlobalConst(v8::Isolate* pIsolate,
                             v8::Local<v8::Value> pDefault);
 
 // Called after FXJS_Define* calls made.
-void FXJS_InitializeRuntime(v8::Isolate* pIsolate,
-                            IJS_Runtime* pIRuntime,
-                            v8::Global<v8::Context>& v8PersistentContext);
+void FXJS_InitializeRuntime(
+    v8::Isolate* pIsolate,
+    IJS_Runtime* pIRuntime,
+    v8::Global<v8::Context>* pV8PersistentContext,
+    std::vector<v8::Global<v8::Object>*>* pStaticObjects);
 void FXJS_ReleaseRuntime(v8::Isolate* pIsolate,
-                         v8::Global<v8::Context>& v8PersistentContext);
+                         v8::Global<v8::Context>* pV8PersistentContext,
+                         std::vector<v8::Global<v8::Object>*>* pStaticObjects);
 IJS_Runtime* FXJS_GetRuntimeFromIsolate(v8::Isolate* pIsolate);
 
 // Called after FXJS_InitializeRuntime call made.
diff --git a/fpdfsdk/src/javascript/JS_Runtime.cpp b/fpdfsdk/src/javascript/JS_Runtime.cpp
index 34a18dc385..74d9a44a1c 100644
--- a/fpdfsdk/src/javascript/JS_Runtime.cpp
+++ b/fpdfsdk/src/javascript/JS_Runtime.cpp
@@ -64,7 +64,7 @@ CJS_Runtime::CJS_Runtime(CPDFDoc_Environment* pApp)
     DefineJSObjects();
 
   CJS_Context* pContext = (CJS_Context*)NewContext();
-  FXJS_InitializeRuntime(GetIsolate(), this, m_context);
+  FXJS_InitializeRuntime(GetIsolate(), this, &m_context, &m_StaticObjects);
   ReleaseContext(pContext);
 }
 
@@ -76,7 +76,7 @@ CJS_Runtime::~CJS_Runtime() {
     delete m_ContextArray.GetAt(i);
 
   m_ContextArray.RemoveAll();
-  FXJS_ReleaseRuntime(GetIsolate(), m_context);
+  FXJS_ReleaseRuntime(GetIsolate(), &m_context, &m_StaticObjects);
 
   m_pApp = NULL;
   m_pDocument = NULL;
diff --git a/fpdfsdk/src/javascript/JS_Runtime.h b/fpdfsdk/src/javascript/JS_Runtime.h
index 4a55c2e9e6..1bdd8e6fdd 100644
--- a/fpdfsdk/src/javascript/JS_Runtime.h
+++ b/fpdfsdk/src/javascript/JS_Runtime.h
@@ -9,6 +9,7 @@
 
 #include <set>
 #include <utility>
+#include <vector>
 
 #include "../../include/javascript/IJavaScript.h"
 #include "../../include/jsapi/fxjs_v8.h"
@@ -71,6 +72,7 @@ class CJS_Runtime : public IJS_Runtime {
   v8::Isolate* m_isolate;
   bool m_isolateManaged;
   v8::Global<v8::Context> m_context;
+  std::vector<v8::Global<v8::Object>*> m_StaticObjects;
   std::set<Observer*> m_observers;
 };
 
diff --git a/fpdfsdk/src/jsapi/fxjs_v8.cpp b/fpdfsdk/src/jsapi/fxjs_v8.cpp
index 0c58a1b01f..d21970e595 100644
--- a/fpdfsdk/src/jsapi/fxjs_v8.cpp
+++ b/fpdfsdk/src/jsapi/fxjs_v8.cpp
@@ -95,7 +95,6 @@ class CFXJS_ObjDefinition {
   v8::Isolate* m_pIsolate;
   v8::Global<v8::FunctionTemplate> m_FunctionTemplate;
   v8::Global<v8::Signature> m_Signature;
-  v8::Global<v8::Object> m_StaticObj;
 };
 
 static v8::Local<v8::ObjectTemplate> GetGlobalObjectTemplate(
@@ -273,9 +272,11 @@ void FXJS_DefineGlobalConst(v8::Isolate* pIsolate,
       pDefault, v8::ReadOnly);
 }
 
-void FXJS_InitializeRuntime(v8::Isolate* pIsolate,
-                            IJS_Runtime* pIRuntime,
-                            v8::Global<v8::Context>& v8PersistentContext) {
+void FXJS_InitializeRuntime(
+    v8::Isolate* pIsolate,
+    IJS_Runtime* pIRuntime,
+    v8::Global<v8::Context>* pV8PersistentContext,
+    std::vector<v8::Global<v8::Object>*>* pStaticObjects) {
   if (pIsolate == g_isolate)
     ++g_isolate_ref_count;
 
@@ -289,14 +290,9 @@ void FXJS_InitializeRuntime(v8::Isolate* pIsolate,
   v8Context->SetAlignedPointerInEmbedderData(kPerContextDataIndex, pIRuntime);
 
   int maxID = CFXJS_ObjDefinition::MaxID(pIsolate);
+  pStaticObjects->resize(maxID + 1);
   for (int i = 0; i < maxID; ++i) {
     CFXJS_ObjDefinition* pObjDef = CFXJS_ObjDefinition::ForID(pIsolate, i);
-    CFX_ByteString bs = CFX_WideString(pObjDef->m_ObjName).UTF8Encode();
-    v8::Local<v8::String> m_ObjName =
-        v8::String::NewFromUtf8(pIsolate, bs.c_str(),
-                                v8::NewStringType::kNormal,
-                                bs.GetLength()).ToLocalChecked();
-
     if (pObjDef->m_ObjType == FXJSOBJTYPE_GLOBAL) {
       v8Context->Global()
           ->GetPrototype()
@@ -310,23 +306,27 @@ void FXJS_InitializeRuntime(v8::Isolate* pIsolate,
                                                ->ToObject(v8Context)
                                                .ToLocalChecked());
     } else if (pObjDef->m_ObjType == FXJSOBJTYPE_STATIC) {
+      CFX_ByteString bs = CFX_WideString(pObjDef->m_ObjName).UTF8Encode();
+      v8::Local<v8::String> m_ObjName =
+          v8::String::NewFromUtf8(pIsolate, bs.c_str(),
+                                  v8::NewStringType::kNormal,
+                                  bs.GetLength()).ToLocalChecked();
+
       v8::Local<v8::Object> obj = FXJS_NewFxDynamicObj(pIsolate, pIRuntime, i);
       v8Context->Global()->Set(v8Context, m_ObjName, obj).FromJust();
-      pObjDef->m_StaticObj.Reset(pIsolate, obj);
+      pStaticObjects->at(i) = new v8::Global<v8::Object>(pIsolate, obj);
     }
   }
-  v8PersistentContext.Reset(pIsolate, v8Context);
+  pV8PersistentContext->Reset(pIsolate, v8Context);
 }
 
 void FXJS_ReleaseRuntime(v8::Isolate* pIsolate,
-                         v8::Global<v8::Context>& v8PersistentContext) {
-  if (pIsolate == g_isolate && --g_isolate_ref_count > 0)
-    return;
-
+                         v8::Global<v8::Context>* pV8PersistentContext,
+                         std::vector<v8::Global<v8::Object>*>* pStaticObjects) {
   v8::Isolate::Scope isolate_scope(pIsolate);
   v8::HandleScope handle_scope(pIsolate);
   v8::Local<v8::Context> context =
-      v8::Local<v8::Context>::New(pIsolate, v8PersistentContext);
+      v8::Local<v8::Context>::New(pIsolate, *pV8PersistentContext);
   v8::Context::Scope context_scope(context);
 
   FXJS_PerIsolateData* pData = FXJS_PerIsolateData::Get(pIsolate);
@@ -340,8 +340,10 @@ void FXJS_ReleaseRuntime(v8::Isolate* pIsolate,
     if (pObjDef->m_ObjType == FXJSOBJTYPE_GLOBAL) {
       pObj =
           context->Global()->GetPrototype()->ToObject(context).ToLocalChecked();
-    } else if (!pObjDef->m_StaticObj.IsEmpty()) {
-      pObj = v8::Local<v8::Object>::New(pIsolate, pObjDef->m_StaticObj);
+    } else if (pStaticObjects->at(i) && !pStaticObjects->at(i)->IsEmpty()) {
+      pObj = v8::Local<v8::Object>::New(pIsolate, *pStaticObjects->at(i));
+      delete pStaticObjects->at(i);
+      pStaticObjects->at(i) = nullptr;
     }
 
     if (!pObj.IsEmpty()) {
@@ -352,6 +354,9 @@ void FXJS_ReleaseRuntime(v8::Isolate* pIsolate,
     delete pObjDef;
   }
 
+  if (pIsolate == g_isolate && --g_isolate_ref_count > 0)
+    return;
+
   pIsolate->SetData(g_embedderDataSlot, nullptr);
   delete pData;
 }
diff --git a/fpdfsdk/src/jsapi/fxjs_v8_embeddertest.cpp b/fpdfsdk/src/jsapi/fxjs_v8_embeddertest.cpp
index b965ced32e..eaaee86d67 100644
--- a/fpdfsdk/src/jsapi/fxjs_v8_embeddertest.cpp
+++ b/fpdfsdk/src/jsapi/fxjs_v8_embeddertest.cpp
@@ -32,11 +32,12 @@ class FXJSV8Embeddertest : public EmbedderTest {
     v8::Isolate::Scope isolate_scope(m_pIsolate);
     v8::HandleScope handle_scope(m_pIsolate);
     FXJS_PerIsolateData::SetUp(m_pIsolate);
-    FXJS_InitializeRuntime(m_pIsolate, nullptr, m_pPersistentContext);
+    FXJS_InitializeRuntime(m_pIsolate, nullptr, &m_pPersistentContext,
+                           &m_StaticObjects);
   }
 
   void TearDown() override {
-    FXJS_ReleaseRuntime(m_pIsolate, m_pPersistentContext);
+    FXJS_ReleaseRuntime(m_pIsolate, &m_pPersistentContext, &m_StaticObjects);
     m_pPersistentContext.Reset();
     FXJS_Release();
     EmbedderTest::TearDown();
@@ -51,6 +52,7 @@ class FXJSV8Embeddertest : public EmbedderTest {
   nonstd::unique_ptr<FXJS_ArrayBufferAllocator> m_pArrayBufferAllocator;
   v8::Isolate* m_pIsolate;
   v8::Global<v8::Context> m_pPersistentContext;
+  std::vector<v8::Global<v8::Object>*> m_StaticObjects;
 };
 
 TEST_F(FXJSV8Embeddertest, Getters) {