Revert "Revert "Merge to master: contention over isolate data slots""

This reverts commit 3b4382a847b5a7439a3107512dbe54c317108579.
The difference between this CL and the one that failed is
fxjs_v8.cpp:271. In master, we pass the runtime information
as:
  v8::isolate -> v8::Context -> FXJS Runtime,

but in XFA:
  V8::Isolate -> PerIsolate struct -> FXJS Runtime.

The master way is more correct, in that FXJS_Runtime is 1:1
with v8 contexts and many:1 (in theory) with isolates.
It looks like the XFA branch missed a patch along the way.
I'll do that next.

Having made this change, the only data in the per-isolate
struct will be the ptr array (on master); it will also
include the XFA context (on XFA). I've kept the struct on
master for the sake of similarity.

R=thestig@chromium.org

Review URL: https://codereview.chromium.org/1365733003 .

3 files changed, 94 insertions, 84 deletions

diff --git a/fpdfsdk/include/jsapi/fxjs_v8.h b/fpdfsdk/include/jsapi/fxjs_v8.h
index a1541593a1..15800e24e9 100644
--- a/fpdfsdk/include/jsapi/fxjs_v8.h
+++ b/fpdfsdk/include/jsapi/fxjs_v8.h
@@ -11,7 +11,12 @@
 #define FPDFSDK_INCLUDE_JSAPI_FXJS_V8_H_
 
 #include <v8.h>
-#include "../../../core/include/fxcrt/fx_string.h"  // For CFX_WideString
+#include "../../../core/include/fxcrt/fx_basic.h"
+
+// FXJS_V8 places no interpretation on these two classes; it merely
+// passes them on to the caller-provided FXJS_CONSTRUCTORs.
+class IFXJS_Context;
+class IFXJS_Runtime;
 
 enum FXJSOBJTYPE {
   FXJS_DYNAMIC = 0,
@@ -24,6 +29,17 @@ struct FXJSErr {
   unsigned linnum;
 };
 
+class FXJS_PerIsolateData {
+ public:
+  static void SetUp(v8::Isolate* pIsolate);
+  static FXJS_PerIsolateData* Get(v8::Isolate* pIsolate);
+
+  CFX_PtrArray m_ObjectDefnArray;
+
+ protected:
+  FXJS_PerIsolateData() {}
+};
+
 extern const wchar_t kFXJSValueNameString[];
 extern const wchar_t kFXJSValueNameNumber[];
 extern const wchar_t kFXJSValueNameBoolean[];
@@ -33,10 +49,6 @@ extern const wchar_t kFXJSValueNameFxobj[];
 extern const wchar_t kFXJSValueNameNull[];
 extern const wchar_t kFXJSValueNameUndefined[];
 
-// FXJS_V8 places no interpretation on these two classes; it merely
-// passes them on to the caller-provided FXJS_CONSTRUCTORs.
-class IFXJS_Context;
-class IFXJS_Runtime;
 
 class FXJS_ArrayBufferAllocator : public v8::ArrayBuffer::Allocator {
   void* Allocate(size_t length) override;
diff --git a/fpdfsdk/src/jsapi/fxjs_v8.cpp b/fpdfsdk/src/jsapi/fxjs_v8.cpp
index 69ea2cb48b..d5673e6e87 100644
--- a/fpdfsdk/src/jsapi/fxjs_v8.cpp
+++ b/fpdfsdk/src/jsapi/fxjs_v8.cpp
@@ -17,22 +17,32 @@ const wchar_t kFXJSValueNameFxobj[] = L"fxobj";
 const wchar_t kFXJSValueNameNull[] = L"null";
 const wchar_t kFXJSValueNameUndefined[] = L"undefined";
 
-static unsigned int g_embedderDataSlot = 0u;
+static unsigned int g_embedderDataSlot = 1u;
 
 class CFXJS_PrivateData {
  public:
-  CFXJS_PrivateData() : ObjDefID(-1), pPrivate(NULL) {}
+  CFXJS_PrivateData(int nObjDefID) : ObjDefID(nObjDefID), pPrivate(NULL) {}
+
   int ObjDefID;
   void* pPrivate;
 };
 
-class CFXJS_ObjDefintion {
+class CFXJS_ObjDefinition {
  public:
-  CFXJS_ObjDefintion(v8::Isolate* isolate,
-                     const wchar_t* sObjName,
-                     FXJSOBJTYPE eObjType,
-                     FXJS_CONSTRUCTOR pConstructor,
-                     FXJS_DESTRUCTOR pDestructor)
+  static int MaxID(v8::Isolate* pIsolate) {
+    return static_cast<int>(
+        FXJS_PerIsolateData::Get(pIsolate)->m_ObjectDefnArray.GetSize());
+  }
+  static CFXJS_ObjDefinition* ForID(v8::Isolate* pIsolate, int id) {
+    // Note: GetAt() halts if out-of-range even in release builds.
+    return static_cast<CFXJS_ObjDefinition*>(
+        FXJS_PerIsolateData::Get(pIsolate)->m_ObjectDefnArray.GetAt(id));
+  }
+  CFXJS_ObjDefinition(v8::Isolate* isolate,
+                      const wchar_t* sObjName,
+                      FXJSOBJTYPE eObjType,
+                      FXJS_CONSTRUCTOR pConstructor,
+                      FXJS_DESTRUCTOR pDestructor)
       : objName(sObjName),
         objType(eObjType),
         m_pConstructor(pConstructor),
@@ -51,12 +61,11 @@ class CFXJS_ObjDefintion {
       m_bSetAsGlobalObject = TRUE;
     }
   }
-  ~CFXJS_ObjDefintion() {
+  ~CFXJS_ObjDefinition() {
     m_objTemplate.Reset();
     m_StaticObj.Reset();
   }
 
- public:
   const wchar_t* objName;
   FXJSOBJTYPE objType;
   FXJS_CONSTRUCTOR m_pConstructor;
@@ -79,9 +88,16 @@ void FXJS_ArrayBufferAllocator::Free(void* data, size_t length) {
   free(data);
 }
 
-void FXJS_PrepareIsolate(v8::Isolate* pIsolate) {
+// static
+void FXJS_PerIsolateData::SetUp(v8::Isolate* pIsolate) {
   if (!pIsolate->GetData(g_embedderDataSlot))
-    pIsolate->SetData(g_embedderDataSlot, new CFX_PtrArray());
+    pIsolate->SetData(g_embedderDataSlot, new FXJS_PerIsolateData());
+}
+
+// static
+FXJS_PerIsolateData* FXJS_PerIsolateData::Get(v8::Isolate* pIsolate) {
+  return static_cast<FXJS_PerIsolateData*>(
+      pIsolate->GetData(g_embedderDataSlot));
 }
 
 int FXJS_DefineObj(v8::Isolate* pIsolate,
@@ -92,12 +108,11 @@ int FXJS_DefineObj(v8::Isolate* pIsolate,
   v8::Isolate::Scope isolate_scope(pIsolate);
   v8::HandleScope handle_scope(pIsolate);
 
-  FXJS_PrepareIsolate(pIsolate);
-  CFX_PtrArray* pArray = (CFX_PtrArray*)pIsolate->GetData(g_embedderDataSlot);
-  CFXJS_ObjDefintion* pObjDef = new CFXJS_ObjDefintion(
-      pIsolate, sObjName, eObjType, pConstructor, pDestructor);
-  pArray->Add(pObjDef);
-  return pArray->GetSize() - 1;
+  FXJS_PerIsolateData::SetUp(pIsolate);
+  FXJS_PerIsolateData* pData = FXJS_PerIsolateData::Get(pIsolate);
+  pData->m_ObjectDefnArray.Add(new CFXJS_ObjDefinition(
+      pIsolate, sObjName, eObjType, pConstructor, pDestructor));
+  return pData->m_ObjectDefnArray.GetSize() - 1;
 }
 
 void FXJS_DefineObjMethod(v8::Isolate* pIsolate,
@@ -107,14 +122,12 @@ void FXJS_DefineObjMethod(v8::Isolate* pIsolate,
   v8::Isolate::Scope isolate_scope(pIsolate);
   v8::HandleScope handle_scope(pIsolate);
 
-  CFX_WideString ws = CFX_WideString(sMethodName);
-  CFX_ByteString bsMethodName = ws.UTF8Encode();
-  CFX_PtrArray* pArray = (CFX_PtrArray*)pIsolate->GetData(g_embedderDataSlot);
-
-  // Note: GetAt() halts if out-of-range even in release builds.
-  CFXJS_ObjDefintion* pObjDef = (CFXJS_ObjDefintion*)pArray->GetAt(nObjDefnID);
+  CFX_ByteString bsMethodName = CFX_WideString(sMethodName).UTF8Encode();
+  CFXJS_ObjDefinition* pObjDef =
+      CFXJS_ObjDefinition::ForID(pIsolate, nObjDefnID);
   v8::Local<v8::ObjectTemplate> objTemp =
       v8::Local<v8::ObjectTemplate>::New(pIsolate, pObjDef->m_objTemplate);
+
   objTemp->Set(
       v8::String::NewFromUtf8(pIsolate, bsMethodName.c_str(),
                               v8::NewStringType::kNormal).ToLocalChecked(),
@@ -130,12 +143,9 @@ void FXJS_DefineObjProperty(v8::Isolate* pIsolate,
   v8::Isolate::Scope isolate_scope(pIsolate);
   v8::HandleScope handle_scope(pIsolate);
 
-  CFX_WideString ws = CFX_WideString(sPropName);
-  CFX_ByteString bsPropertyName = ws.UTF8Encode();
-  CFX_PtrArray* pArray = (CFX_PtrArray*)pIsolate->GetData(g_embedderDataSlot);
-
-  // Note: GetAt() halts if out-of-range even in release builds.
-  CFXJS_ObjDefintion* pObjDef = (CFXJS_ObjDefintion*)pArray->GetAt(nObjDefnID);
+  CFX_ByteString bsPropertyName = CFX_WideString(sPropName).UTF8Encode();
+  CFXJS_ObjDefinition* pObjDef =
+      CFXJS_ObjDefinition::ForID(pIsolate, nObjDefnID);
   v8::Local<v8::ObjectTemplate> objTemp =
       v8::Local<v8::ObjectTemplate>::New(pIsolate, pObjDef->m_objTemplate);
   objTemp->SetAccessor(
@@ -153,10 +163,9 @@ void FXJS_DefineObjAllProperties(v8::Isolate* pIsolate,
                                  v8::NamedPropertyDeleterCallback pPropDel) {
   v8::Isolate::Scope isolate_scope(pIsolate);
   v8::HandleScope handle_scope(pIsolate);
-  CFX_PtrArray* pArray = (CFX_PtrArray*)pIsolate->GetData(g_embedderDataSlot);
 
-  // Note: GetAt() halts if out-of-range even in release builds.
-  CFXJS_ObjDefintion* pObjDef = (CFXJS_ObjDefintion*)pArray->GetAt(nObjDefnID);
+  CFXJS_ObjDefinition* pObjDef =
+      CFXJS_ObjDefinition::ForID(pIsolate, nObjDefnID);
   v8::Local<v8::ObjectTemplate> objTemp =
       v8::Local<v8::ObjectTemplate>::New(pIsolate, pObjDef->m_objTemplate);
   objTemp->SetNamedPropertyHandler(pPropGet, pPropPut, pPropQurey, pPropDel);
@@ -170,12 +179,9 @@ void FXJS_DefineObjConst(v8::Isolate* pIsolate,
   v8::Isolate::Scope isolate_scope(pIsolate);
   v8::HandleScope handle_scope(pIsolate);
 
-  CFX_WideString ws = CFX_WideString(sConstName);
-  CFX_ByteString bsConstName = ws.UTF8Encode();
-  CFX_PtrArray* pArray = (CFX_PtrArray*)pIsolate->GetData(g_embedderDataSlot);
-
-  // Note: GetAt() halts if out-of-range even in release builds.
-  CFXJS_ObjDefintion* pObjDef = (CFXJS_ObjDefintion*)pArray->GetAt(nObjDefnID);
+  CFX_ByteString bsConstName = CFX_WideString(sConstName).UTF8Encode();
+  CFXJS_ObjDefinition* pObjDef =
+      CFXJS_ObjDefinition::ForID(pIsolate, nObjDefnID);
   v8::Local<v8::ObjectTemplate> objTemp =
       v8::Local<v8::ObjectTemplate>::New(pIsolate, pObjDef->m_objTemplate);
   objTemp->Set(pIsolate, bsConstName.c_str(), pDefault);
@@ -187,10 +193,9 @@ static v8::Global<v8::ObjectTemplate>& _getGlobalObjectTemplate(
   v8::Isolate::Scope isolate_scope(pIsolate);
   v8::HandleScope handle_scope(pIsolate);
 
-  CFX_PtrArray* pArray = (CFX_PtrArray*)pIsolate->GetData(g_embedderDataSlot);
-  ASSERT(pArray != NULL);
-  for (int i = 0; i < pArray->GetSize(); i++) {
-    CFXJS_ObjDefintion* pObjDef = (CFXJS_ObjDefintion*)pArray->GetAt(i);
+  int maxID = CFXJS_ObjDefinition::MaxID(pIsolate);
+  for (int i = 0; i < maxID; ++i) {
+    CFXJS_ObjDefinition* pObjDef = CFXJS_ObjDefinition::ForID(pIsolate, i);
     if (pObjDef->m_bSetAsGlobalObject)
       return pObjDef->m_objTemplate;
   }
@@ -204,9 +209,7 @@ void FXJS_DefineGlobalMethod(v8::Isolate* pIsolate,
   v8::Isolate::Scope isolate_scope(pIsolate);
   v8::HandleScope handle_scope(pIsolate);
 
-  CFX_WideString ws = CFX_WideString(sMethodName);
-  CFX_ByteString bsMethodName = ws.UTF8Encode();
-
+  CFX_ByteString bsMethodName = CFX_WideString(sMethodName).UTF8Encode();
   v8::Local<v8::FunctionTemplate> funTempl =
       v8::FunctionTemplate::New(pIsolate, pMethodCall);
   v8::Local<v8::ObjectTemplate> objTemp;
@@ -264,15 +267,13 @@ void FXJS_InitializeRuntime(v8::Isolate* pIsolate,
       v8::Local<v8::ObjectTemplate>::New(pIsolate, globalObjTemp));
   v8::Context::Scope context_scope(v8Context);
 
+  FXJS_PerIsolateData::SetUp(pIsolate);
   v8::Local<v8::External> ptr = v8::External::New(pIsolate, pFXRuntime);
   v8Context->SetEmbedderData(1, ptr);
 
-  CFX_PtrArray* pArray = (CFX_PtrArray*)pIsolate->GetData(g_embedderDataSlot);
-  if (!pArray)
-    return;
-
-  for (int i = 0; i < pArray->GetSize(); i++) {
-    CFXJS_ObjDefintion* pObjDef = (CFXJS_ObjDefintion*)pArray->GetAt(i);
+  int maxID = CFXJS_ObjDefinition::MaxID(pIsolate);
+  for (int i = 0; i < maxID; ++i) {
+    CFXJS_ObjDefinition* pObjDef = CFXJS_ObjDefinition::ForID(pIsolate, i);
     CFX_WideString ws = CFX_WideString(pObjDef->objName);
     CFX_ByteString bs = ws.UTF8Encode();
     v8::Local<v8::String> objName =
@@ -283,14 +284,11 @@ void FXJS_InitializeRuntime(v8::Isolate* pIsolate,
     if (pObjDef->objType == FXJS_DYNAMIC) {
       // Document is set as global object, need to construct it first.
       if (ws.Equal(L"Document")) {
-        CFXJS_PrivateData* pPrivateData = new CFXJS_PrivateData;
-        pPrivateData->ObjDefID = i;
-
         v8Context->Global()
             ->GetPrototype()
             ->ToObject(v8Context)
             .ToLocalChecked()
-            ->SetAlignedPointerInInternalField(0, pPrivateData);
+            ->SetAlignedPointerInInternalField(0, new CFXJS_PrivateData(i));
 
         if (pObjDef->m_pConstructor)
           pObjDef->m_pConstructor(context, v8Context->Global()
@@ -319,12 +317,13 @@ void FXJS_ReleaseRuntime(v8::Isolate* pIsolate,
       v8::Local<v8::Context>::New(pIsolate, v8PersistentContext);
   v8::Context::Scope context_scope(context);
 
-  CFX_PtrArray* pArray = (CFX_PtrArray*)pIsolate->GetData(g_embedderDataSlot);
-  if (!pArray)
+  FXJS_PerIsolateData* pData = FXJS_PerIsolateData::Get(pIsolate);
+  if (!pData)
     return;
 
-  for (int i = 0; i < pArray->GetSize(); i++) {
-    CFXJS_ObjDefintion* pObjDef = (CFXJS_ObjDefintion*)pArray->GetAt(i);
+  int maxID = CFXJS_ObjDefinition::MaxID(pIsolate);
+  for (int i = 0; i < maxID; ++i) {
+    CFXJS_ObjDefinition* pObjDef = CFXJS_ObjDefinition::ForID(pIsolate, i);
     if (!pObjDef->m_StaticObj.IsEmpty()) {
       v8::Local<v8::Object> pObj =
           v8::Local<v8::Object>::New(pIsolate, pObjDef->m_StaticObj);
@@ -334,8 +333,9 @@ void FXJS_ReleaseRuntime(v8::Isolate* pIsolate,
     }
     delete pObjDef;
   }
-  delete pArray;
-  pIsolate->SetData(g_embedderDataSlot, NULL);
+
+  pIsolate->SetData(g_embedderDataSlot, nullptr);
+  delete pData;
 }
 
 void FXJS_Initialize(unsigned int embedderDataSlot) {
@@ -382,7 +382,7 @@ v8::Local<v8::Object> FXJS_NewFxDynamicObj(v8::Isolate* pIsolate,
                                            int nObjDefnID) {
   v8::Isolate::Scope isolate_scope(pIsolate);
   v8::Local<v8::Context> context = pIsolate->GetCurrentContext();
-  if (-1 == nObjDefnID) {
+  if (nObjDefnID == -1) {
     v8::Local<v8::ObjectTemplate> objTempl = v8::ObjectTemplate::New(pIsolate);
     v8::Local<v8::Object> obj;
     if (objTempl->NewInstance(context).ToLocal(&obj))
@@ -390,13 +390,15 @@ v8::Local<v8::Object> FXJS_NewFxDynamicObj(v8::Isolate* pIsolate,
     return v8::Local<v8::Object>();
   }
 
-  CFX_PtrArray* pArray = (CFX_PtrArray*)pIsolate->GetData(g_embedderDataSlot);
-  if (!pArray)
+  FXJS_PerIsolateData* pData = FXJS_PerIsolateData::Get(pIsolate);
+  if (!pData)
     return v8::Local<v8::Object>();
 
-  if (nObjDefnID < 0 || nObjDefnID >= pArray->GetSize())
+  if (nObjDefnID < 0 || nObjDefnID >= CFXJS_ObjDefinition::MaxID(pIsolate))
     return v8::Local<v8::Object>();
-  CFXJS_ObjDefintion* pObjDef = (CFXJS_ObjDefintion*)pArray->GetAt(nObjDefnID);
+
+  CFXJS_ObjDefinition* pObjDef =
+      CFXJS_ObjDefinition::ForID(pIsolate, nObjDefnID);
 
   v8::Local<v8::ObjectTemplate> objTemp =
       v8::Local<v8::ObjectTemplate>::New(pIsolate, pObjDef->m_objTemplate);
@@ -404,10 +406,7 @@ v8::Local<v8::Object> FXJS_NewFxDynamicObj(v8::Isolate* pIsolate,
   if (!objTemp->NewInstance(context).ToLocal(&obj))
     return v8::Local<v8::Object>();
 
-  CFXJS_PrivateData* pPrivateData = new CFXJS_PrivateData;
-  pPrivateData->ObjDefID = nObjDefnID;
-
-  obj->SetAlignedPointerInInternalField(0, pPrivateData);
+  obj->SetAlignedPointerInInternalField(0, new CFXJS_PrivateData(nObjDefnID));
   if (pObjDef->m_pConstructor)
     pObjDef->m_pConstructor(
         pJSContext, obj,
@@ -417,12 +416,11 @@ v8::Local<v8::Object> FXJS_NewFxDynamicObj(v8::Isolate* pIsolate,
 }
 
 v8::Local<v8::Object> FXJS_GetThisObj(v8::Isolate* pIsolate) {
-  // Return the global object.
   v8::Isolate::Scope isolate_scope(pIsolate);
-  CFX_PtrArray* pArray = (CFX_PtrArray*)pIsolate->GetData(g_embedderDataSlot);
-  if (!pArray)
+  if (!FXJS_PerIsolateData::Get(pIsolate))
     return v8::Local<v8::Object>();
 
+  // Return the global object.
   v8::Local<v8::Context> context = pIsolate->GetCurrentContext();
   return context->Global()->GetPrototype()->ToObject(context).ToLocalChecked();
 }
@@ -448,12 +446,12 @@ v8::Isolate* FXJS_GetRuntime(v8::Local<v8::Object> pObj) {
 
 int FXJS_GetObjDefnID(v8::Isolate* pIsolate, const wchar_t* pObjName) {
   v8::Isolate::Scope isolate_scope(pIsolate);
-  CFX_PtrArray* pArray = (CFX_PtrArray*)pIsolate->GetData(g_embedderDataSlot);
-  if (!pArray)
+  if (!FXJS_PerIsolateData::Get(pIsolate))
     return -1;
 
-  for (int i = 0; i < pArray->GetSize(); i++) {
-    CFXJS_ObjDefintion* pObjDef = (CFXJS_ObjDefintion*)pArray->GetAt(i);
+  int maxID = CFXJS_ObjDefinition::MaxID(pIsolate);
+  for (int i = 0; i < maxID; ++i) {
+    CFXJS_ObjDefinition* pObjDef = CFXJS_ObjDefinition::ForID(pIsolate, i);
     if (FXSYS_wcscmp(pObjDef->objName, pObjName) == 0)
       return i;
   }
diff --git a/fpdfsdk/src/jsapi/fxjs_v8_embeddertest.cpp b/fpdfsdk/src/jsapi/fxjs_v8_embeddertest.cpp
index 2671a91fff..7726c40c5e 100644
--- a/fpdfsdk/src/jsapi/fxjs_v8_embeddertest.cpp
+++ b/fpdfsdk/src/jsapi/fxjs_v8_embeddertest.cpp
@@ -31,7 +31,7 @@ class FXJSV8Embeddertest : public EmbedderTest {
     v8::Isolate::Scope isolate_scope(m_pIsolate);
     v8::HandleScope handle_scope(m_pIsolate);
     FXJS_Initialize(0);
-    FXJS_PrepareIsolate(m_pIsolate);
+    FXJS_PerIsolateData::SetUp(m_pIsolate);
     FXJS_InitializeRuntime(m_pIsolate, nullptr, nullptr, m_pPersistentContext);
   }