Fix v8 isolate initialization / release, M46 edition.

BUG=531339,539106
R=tsepez@chromium.org

Review URL: https://codereview.chromium.org/1384223002 .

4 files changed, 36 insertions, 16 deletions

diff --git a/fpdfsdk/include/javascript/JS_Runtime.h b/fpdfsdk/include/javascript/JS_Runtime.h
index 0617597428..560d5035a2 100644
--- a/fpdfsdk/include/javascript/JS_Runtime.h
+++ b/fpdfsdk/include/javascript/JS_Runtime.h
@@ -40,7 +40,7 @@ class CJS_Runtime : public IFXJS_Runtime {
     virtual ~Observer() {}
   };
 
-  CJS_Runtime(CPDFDoc_Environment* pApp);
+  CJS_Runtime(CPDFDoc_Environment* pApp, bool bInitJsObjects);
   ~CJS_Runtime() override;
 
   // IFXJS_Runtime
diff --git a/fpdfsdk/include/jsapi/fxjs_v8.h b/fpdfsdk/include/jsapi/fxjs_v8.h
index 72f2a5de01..6d9e4c0474 100644
--- a/fpdfsdk/include/jsapi/fxjs_v8.h
+++ b/fpdfsdk/include/jsapi/fxjs_v8.h
@@ -88,8 +88,9 @@ void JS_InitialRuntime(IJS_Runtime* pJSRuntime,
                        IFXJS_Context* context,
                        v8::Global<v8::Context>& v8PersistentContext);
 void JS_ReleaseRuntime(IJS_Runtime* pJSRuntime,
+                       bool bReleaseGlobal,
                        v8::Global<v8::Context>& v8PersistentContext);
-void JS_Initial(unsigned int embedderDataSlot);
+void JS_Initial(unsigned int embedderDataSlot, v8::Isolate* isolate);
 void JS_Release();
 int JS_Parse(IJS_Runtime* pJSRuntime,
              IFXJS_Context* pJSContext,
diff --git a/fpdfsdk/src/javascript/JS_Runtime.cpp b/fpdfsdk/src/javascript/JS_Runtime.cpp
index 8efb277dd7..01bf9f2de0 100644
--- a/fpdfsdk/src/javascript/JS_Runtime.cpp
+++ b/fpdfsdk/src/javascript/JS_Runtime.cpp
@@ -26,23 +26,30 @@
 #include "../../include/javascript/global.h"
 #include "../../include/javascript/console.h"
 
+static bool g_only_one_js_runtime_left = false;
+
 CJS_RuntimeFactory::~CJS_RuntimeFactory() {}
 
 IFXJS_Runtime* CJS_RuntimeFactory::NewJSRuntime(CPDFDoc_Environment* pApp) {
+  bool bInitJsObjects = false;
   if (!m_bInit) {
     unsigned int embedderDataSlot = 0;
-    if (pApp->GetFormFillInfo()->m_pJsPlatform->version >= 2) {
-      embedderDataSlot =
-          pApp->GetFormFillInfo()->m_pJsPlatform->m_v8EmbedderSlot;
+    v8::Isolate* isolate = nullptr;
+    IPDF_JSPLATFORM* pJsPlatform = pApp->GetFormFillInfo()->m_pJsPlatform;
+    if (pJsPlatform->version >= 2) {
+      embedderDataSlot = pJsPlatform->m_v8EmbedderSlot;
+      isolate = static_cast<v8::Isolate*>(pJsPlatform->m_isolate);
     }
-    JS_Initial(embedderDataSlot);
+    JS_Initial(embedderDataSlot, isolate);
     m_bInit = TRUE;
+    bInitJsObjects = true;
   }
-  return new CJS_Runtime(pApp);
+  return new CJS_Runtime(pApp, bInitJsObjects);
 }
 void CJS_RuntimeFactory::AddRef() {
   // to do.Should be implemented as atom manipulation.
   m_nRef++;
+  g_only_one_js_runtime_left = (m_nRef == 1);
 }
 void CJS_RuntimeFactory::Release() {
   if (m_bInit) {
@@ -53,6 +60,7 @@ void CJS_RuntimeFactory::Release() {
       m_bInit = FALSE;
     }
   }
+  g_only_one_js_runtime_left = (m_nRef == 1);
 }
 
 void CJS_RuntimeFactory::DeleteJSRuntime(IFXJS_Runtime* pRuntime) {
@@ -92,16 +100,16 @@ void CJS_ArrayBufferAllocator::Free(void* data, size_t length) {
 
 /* ------------------------------ CJS_Runtime ------------------------------ */
 
-CJS_Runtime::CJS_Runtime(CPDFDoc_Environment* pApp)
+CJS_Runtime::CJS_Runtime(CPDFDoc_Environment* pApp, bool bInitJsObjects)
     : m_pApp(pApp),
       m_pDocument(NULL),
       m_bBlocking(FALSE),
       m_pFieldEventPath(NULL),
       m_isolate(NULL),
       m_isolateManaged(false) {
-  if (m_pApp->GetFormFillInfo()->m_pJsPlatform->version >= 2) {
-    m_isolate = reinterpret_cast<v8::Isolate*>(
-        m_pApp->GetFormFillInfo()->m_pJsPlatform->m_isolate);
+  IPDF_JSPLATFORM* pJsPlatform = pApp->GetFormFillInfo()->m_pJsPlatform;
+  if (pJsPlatform->version >= 2) {
+    m_isolate = static_cast<v8::Isolate*>(pJsPlatform->m_isolate);
   }
   if (!m_isolate) {
     m_pArrayBufferAllocator.reset(new CJS_ArrayBufferAllocator());
@@ -112,7 +120,8 @@ CJS_Runtime::CJS_Runtime(CPDFDoc_Environment* pApp)
     m_isolateManaged = true;
   }
 
-  InitJSObjects();
+  if (m_isolateManaged || bInitJsObjects)
+    InitJSObjects();
 
   CJS_Context* pContext = (CJS_Context*)NewContext();
   JS_InitialRuntime(*this, this, pContext, m_context);
@@ -128,7 +137,7 @@ CJS_Runtime::~CJS_Runtime() {
 
   m_ContextArray.RemoveAll();
 
-  JS_ReleaseRuntime(*this, m_context);
+  JS_ReleaseRuntime(*this, g_only_one_js_runtime_left, m_context);
 
   RemoveEventsInLoop(m_pFieldEventPath);
 
diff --git a/fpdfsdk/src/jsapi/fxjs_v8.cpp b/fpdfsdk/src/jsapi/fxjs_v8.cpp
index ba65d30755..bcea3e14cd 100644
--- a/fpdfsdk/src/jsapi/fxjs_v8.cpp
+++ b/fpdfsdk/src/jsapi/fxjs_v8.cpp
@@ -26,6 +26,7 @@ static double GetNan() {
   return *(double*)g_nan;
 }
 static unsigned int g_embedderDataSlot = 0u;
+static v8::Isolate* g_isolate = nullptr;
 
 class CJS_PrivateData {
  public:
@@ -338,8 +339,12 @@ void JS_InitialRuntime(IJS_Runtime* pJSRuntime,
 }
 
 void JS_ReleaseRuntime(IJS_Runtime* pJSRuntime,
+                       bool bReleaseGlobal,
                        v8::Global<v8::Context>& v8PersistentContext) {
   v8::Isolate* isolate = (v8::Isolate*)pJSRuntime;
+  if (isolate == g_isolate && !bReleaseGlobal)
+    return;
+
   v8::Isolate::Scope isolate_scope(isolate);
   v8::HandleScope handle_scope(isolate);
   v8::Local<v8::Context> context =
@@ -362,13 +367,18 @@ void JS_ReleaseRuntime(IJS_Runtime* pJSRuntime,
     delete pObjDef;
   }
   delete pArray;
-  isolate->SetData(g_embedderDataSlot, NULL);
 }
 
-void JS_Initial(unsigned int embedderDataSlot) {
+void JS_Initial(unsigned int embedderDataSlot, v8::Isolate* isolate) {
   g_embedderDataSlot = embedderDataSlot;
+  g_isolate = isolate;
 }
-void JS_Release() {}
+void JS_Release() {
+  g_isolate->SetData(g_embedderDataSlot, nullptr);
+  g_isolate = nullptr;
+  g_embedderDataSlot = 0;
+}
+
 int JS_Parse(IJS_Runtime* pJSRuntime,
              IFXJS_Context* pJSContext,
              const wchar_t* script,