[libclang] Introduce options to control the priority for the threads

that libclang creates.

-Introduce CXGlobalOptFlags enum for the new options that can be
 set on the CXIndex object.

-CXGlobalOpt_ThreadBackgroundPriorityForIndexing affects:
  clang_indexSourceFile
  clang_indexTranslationUnit
  clang_parseTranslationUnit
  clang_saveTranslationUnit

-CXGlobalOpt_ThreadBackgroundPriorityForEditing affects:
  clang_reparseTranslationUnit
  clang_codeCompleteAt
  clang_annotateTokens

rdar://9075282

llvm-svn: 153562

1 files changed, 45 insertions, 3 deletions

diff --git a/clang/tools/libclang/CIndex.cpp b/clang/tools/libclang/CIndex.cpp
index b3a29ef1052..3882d7bc953 100644
--- a/clang/tools/libclang/CIndex.cpp
+++ b/clang/tools/libclang/CIndex.cpp
@@ -52,10 +52,11 @@ using namespace clang::cxcursor;
 using namespace clang::cxstring;
 using namespace clang::cxtu;
 
-CXTranslationUnit cxtu::MakeCXTranslationUnit(ASTUnit *TU) {
+CXTranslationUnit cxtu::MakeCXTranslationUnit(CIndexer *CIdx, ASTUnit *TU) {
   if (!TU)
     return 0;
   CXTranslationUnit D = new CXTranslationUnitImpl();
+  D->CIdx = CIdx;
   D->TUData = TU;
   D->StringPool = createCXStringPool();
   D->Diagnostics = 0;
@@ -2411,6 +2412,14 @@ CXIndex clang_createIndex(int excludeDeclarationsFromPCH,
     CIdxr->setOnlyLocalDecls();
   if (displayDiagnostics)
     CIdxr->setDisplayDiagnostics();
+
+  if (getenv("LIBCLANG_BGPRIO_INDEX"))
+    CIdxr->setCXGlobalOptFlags(CIdxr->getCXGlobalOptFlags() |
+                               CXGlobalOpt_ThreadBackgroundPriorityForIndexing);
+  if (getenv("LIBCLANG_BGPRIO_EDIT"))
+    CIdxr->setCXGlobalOptFlags(CIdxr->getCXGlobalOptFlags() |
+                               CXGlobalOpt_ThreadBackgroundPriorityForEditing);
+
   return CIdxr;
 }
 
@@ -2419,6 +2428,17 @@ void clang_disposeIndex(CXIndex CIdx) {
     delete static_cast<CIndexer *>(CIdx);
 }
 
+void clang_CXIndex_setGlobalOptions(CXIndex CIdx, unsigned options) {
+  if (CIdx)
+    static_cast<CIndexer *>(CIdx)->setCXGlobalOptFlags(options);
+}
+
+unsigned clang_CXIndex_getGlobalOptions(CXIndex CIdx) {
+  if (CIdx)
+    return static_cast<CIndexer *>(CIdx)->getCXGlobalOptFlags();
+  return 0;
+}
+
 void clang_toggleCrashRecovery(unsigned isEnabled) {
   if (isEnabled)
     llvm::CrashRecoveryContext::Enable();
@@ -2441,7 +2461,7 @@ CXTranslationUnit clang_createTranslationUnit(CXIndex CIdx,
                                   0, 0,
                                   /*CaptureDiagnostics=*/true,
                                   /*AllowPCHWithCompilerErrors=*/true);
-  return MakeCXTranslationUnit(TU);
+  return MakeCXTranslationUnit(CXXIdx, TU);
 }
 
 unsigned clang_defaultEditingTranslationUnitOptions() {
@@ -2490,6 +2510,9 @@ static void clang_parseTranslationUnit_Impl(void *UserData) {
 
   CIndexer *CXXIdx = static_cast<CIndexer *>(CIdx);
 
+  if (CXXIdx->isOptEnabled(CXGlobalOpt_ThreadBackgroundPriorityForIndexing))
+    setBackGroundPriority();
+
   bool PrecompilePreamble = options & CXTranslationUnit_PrecompiledPreamble;
   // FIXME: Add a flag for modules.
   TranslationUnitKind TUKind
@@ -2601,7 +2624,7 @@ static void clang_parseTranslationUnit_Impl(void *UserData) {
     }
   }
 
-  PTUI->result = MakeCXTranslationUnit(Unit.take());
+  PTUI->result = MakeCXTranslationUnit(CXXIdx, Unit.take());
 }
 CXTranslationUnit clang_parseTranslationUnit(CXIndex CIdx,
                                              const char *source_filename,
@@ -2663,6 +2686,10 @@ static void clang_saveTranslationUnit_Impl(void *UserData) {
   SaveTranslationUnitInfo *STUI =
     static_cast<SaveTranslationUnitInfo*>(UserData);
 
+  CIndexer *CXXIdx = (CIndexer*)STUI->TU->CIdx;
+  if (CXXIdx->isOptEnabled(CXGlobalOpt_ThreadBackgroundPriorityForIndexing))
+    setBackGroundPriority();
+
   STUI->result = static_cast<ASTUnit *>(STUI->TU->TUData)->Save(STUI->FileName);
 }
 
@@ -2750,6 +2777,10 @@ static void clang_reparseTranslationUnit_Impl(void *UserData) {
   if (!TU)
     return;
 
+  CIndexer *CXXIdx = (CIndexer*)TU->CIdx;
+  if (CXXIdx->isOptEnabled(CXGlobalOpt_ThreadBackgroundPriorityForEditing))
+    setBackGroundPriority();
+
   ASTUnit *CXXUnit = static_cast<ASTUnit *>(TU->TUData);
   ASTUnit::ConcurrencyCheck Check(*CXXUnit);
   
@@ -5133,6 +5164,10 @@ static void clang_annotateTokensImpl(void *UserData) {
   const unsigned NumTokens = ((clang_annotateTokens_Data*)UserData)->NumTokens;
   CXCursor *Cursors = ((clang_annotateTokens_Data*)UserData)->Cursors;
 
+  CIndexer *CXXIdx = (CIndexer*)TU->CIdx;
+  if (CXXIdx->isOptEnabled(CXGlobalOpt_ThreadBackgroundPriorityForEditing))
+    setBackGroundPriority();
+
   // Determine the region of interest, which contains all of the tokens.
   SourceRange RegionOfInterest;
   RegionOfInterest.setBegin(
@@ -5704,6 +5739,13 @@ void SetSafetyThreadStackSize(unsigned Value) {
   SafetyStackThreadSize = Value;
 }
 
+void clang::setBackGroundPriority() {
+  // FIXME: Move to llvm/Support and make it cross-platform.
+#ifdef __APPLE__
+  setpriority(PRIO_DARWIN_THREAD, 0, PRIO_DARWIN_BG);
+#endif
+}
+
 }
 
 extern "C" {