Add C API for thread yielding callback.

[oota-llvm.git] / include / llvm / IR / LLVMContext.h

diff --git a/include/llvm/IR/LLVMContext.h b/include/llvm/IR/LLVMContext.h
index b80f7c82db248fc6410d897f8dd2d79d11b7d4ce..f9644aca6b47ba3a94d0aa0669c55acb4d616d97 100644 (file)
--- a/include/llvm/IR/LLVMContext.h
+++ b/include/llvm/IR/LLVMContext.h
@@ -15,9 +15,9 @@
 #ifndef LLVM_IR_LLVMCONTEXT_H
 #define LLVM_IR_LLVMCONTEXT_H
 
+#include "llvm-c/Core.h"
 #include "llvm/Support/CBindingWrapping.h"
 #include "llvm/Support/Compiler.h"
-#include "llvm-c/Core.h"
 
 namespace llvm {
 
@@ -29,6 +29,8 @@ class Module;
 class SMDiagnostic;
 class DiagnosticInfo;
 template <typename T> class SmallVectorImpl;
+class Function;
+class DebugLoc;
 
 /// This is an important class for using LLVM in a threaded context.  It
 /// (opaquely) owns and manages the core "global" data of LLVM's core
@@ -70,6 +72,10 @@ public:
   /// \see LLVMContext::diagnose.
   typedef void (*DiagnosticHandlerTy)(const DiagnosticInfo &DI, void *Context);
 
+  /// Defines the type of a yield callback.
+  /// \see LLVMContext::setYieldCallback.
+  typedef void (*YieldCallbackTy)(LLVMContext *Context, void *OpaqueHandle);
+
   /// setInlineAsmDiagnosticHandler - This method sets a handler that is invoked
   /// when problems with inline asm are detected by the backend.  The first
   /// argument is a function pointer and the second is a context pointer that
@@ -78,7 +84,7 @@ public:
   /// LLVMContext doesn't take ownership or interpret either of these
   /// pointers.
   void setInlineAsmDiagnosticHandler(InlineAsmDiagHandlerTy DiagHandler,
-                                     void *DiagContext = 0);
+                                     void *DiagContext = nullptr);
 
   /// getInlineAsmDiagnosticHandler - Return the diagnostic handler set by
   /// setInlineAsmDiagnosticHandler.
@@ -96,7 +102,7 @@ public:
   /// LLVMContext doesn't take ownership or interpret either of these
   /// pointers.
   void setDiagnosticHandler(DiagnosticHandlerTy DiagHandler,
-                            void *DiagContext = 0);
+                            void *DiagContext = nullptr);
 
   /// getDiagnosticHandler - Return the diagnostic handler set by
   /// setDiagnosticHandler.
@@ -116,6 +122,32 @@ public:
   /// for RS_Error, "warning: " for RS_Warning, and "note: " for RS_Note.
   void diagnose(const DiagnosticInfo &DI);
 
+  /// \brief Registers a yield callback with the given context.
+  ///
+  /// The yield callback function may be called by LLVM to transfer control back
+  /// to the client that invoked the LLVM compilation. This can be used to yield
+  /// control of the thread, or perform periodic work needed by the client.
+  /// There is no guaranteed frequency at which callbacks must occur; in fact,
+  /// the client is not guaranteed to ever receive this callback. It is at the
+  /// sole discretion of LLVM to do so and only if it can guarantee that
+  /// suspending the thread won't block any forward progress in other LLVM
+  /// contexts in the same process.
+  ///
+  /// At a suspend point, the state of the current LLVM context is intentionally
+  /// undefined. No assumptions about it can or should be made. Only LLVM
+  /// context API calls that explicitly state that they can be used during a
+  /// yield callback are allowed to be used. Any other API calls into the
+  /// context are not supported until the yield callback function returns
+  /// control to LLVM. Other LLVM contexts are unaffected by this restriction.
+  void setYieldCallback(YieldCallbackTy Callback, void *OpaqueHandle);
+
+  /// \brief Calls the yield callback (if applicable).
+  ///
+  /// This transfers control of the current thread back to the client, which may
+  /// suspend the current thread. Only call this method when LLVM doesn't hold
+  /// any global mutex or cannot block the execution in another LLVM context.
+  void yield();
+
   /// emitError - Emit an error message to the currently installed error handler
   /// with optional location information.  This function returns, so code should
   /// be prepared to drop the erroneous construct on the floor and "not crash".
@@ -125,6 +157,15 @@ public:
   void emitError(const Instruction *I, const Twine &ErrorStr);
   void emitError(const Twine &ErrorStr);
 
+  /// emitOptimizationRemark - Emit an optimization remark message. \p PassName
+  /// is the name of the pass emitting the message. If -Rpass= is given
+  /// and \p PassName matches the regular expression in -Rpass, then the
+  /// remark will be emitted. \p Fn is the function triggering the remark,
+  /// \p DLoc is the debug location where the diagnostic is generated.
+  /// \p Msg is the message string to use.
+  void emitOptimizationRemark(const char *PassName, const Function &Fn,
+                              const DebugLoc &DLoc, const Twine &Msg);
+
 private:
   LLVMContext(LLVMContext&) LLVM_DELETED_FUNCTION;
   void operator=(LLVMContext&) LLVM_DELETED_FUNCTION;