Add an atomic increment and decrement implementation, which will be used for

[oota-llvm.git] / include / llvm / System / Memory.h

diff --git a/include/llvm/System/Memory.h b/include/llvm/System/Memory.h
index 3b319cb3bafa28c91c003e0c2d2381bd55176142..136dc8a32895a105a658690d03827dbcc59fe33a 100644 (file)
--- a/include/llvm/System/Memory.h
+++ b/include/llvm/System/Memory.h
@@ -1,10 +1,10 @@
 //===- llvm/System/Memory.h - Memory Support --------------------*- C++ -*-===//
-// 
+//
 //                     The LLVM Compiler Infrastructure
 //
-// This file was developed by Reid Spencer and is distributed under the 
-// University of Illinois Open Source License. See LICENSE.TXT for details.
-// 
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
 //===----------------------------------------------------------------------===//
 //
 // This file declares the llvm::sys::Memory class.
@@ -14,6 +14,8 @@
 #ifndef LLVM_SYSTEM_MEMORY_H
 #define LLVM_SYSTEM_MEMORY_H
 
+#include <string>
+
 namespace llvm {
 namespace sys {
 
@@ -24,10 +26,10 @@ namespace sys {
   /// @brief Memory block abstraction.
   class MemoryBlock {
   public:
-    void* base() const { return Address; }
+    void *base() const { return Address; }
     unsigned size() const { return Size; }
   private:
-    void * Address;   ///< Address of first byte of memory area
+    void *Address;    ///< Address of first byte of memory area
     unsigned Size;    ///< Size, in bytes of the memory area
     friend class Memory;
   };
@@ -37,27 +39,56 @@ namespace sys {
   /// @since 1.4
   /// @brief An abstraction for memory operations.
   class Memory {
-    /// @name Functions
-    /// @{
-    public:
-      /// This method allocates a block of Read/Write/Execute memory that is
-      /// suitable for executing dynamically generated code (e.g. JIT). An
-      /// attempt to allocate \p NumBytes bytes of virtual memory is made. 
-      /// @throws std::string if an error occurred.
-      /// @brief Allocate Read/Write/Execute memory.
-      static MemoryBlock AllocateRWX(unsigned NumBytes);
-
-      /// This method releases a block of Read/Write/Execute memory that was
-      /// allocated with the AllocateRWX method. It should not be used to release
-      /// any memory block allocated any other way.
-      /// @throws std::string if an error occurred.
-      /// @brief Release Read/Write/Execute memory.
-      static void ReleaseRWX(MemoryBlock& block);
-    /// @}
+  public:
+    /// This method allocates a block of Read/Write/Execute memory that is
+    /// suitable for executing dynamically generated code (e.g. JIT). An
+    /// attempt to allocate \p NumBytes bytes of virtual memory is made.
+    /// \p NearBlock may point to an existing allocation in which case
+    /// an attempt is made to allocate more memory near the existing block.
+    ///
+    /// On success, this returns a non-null memory block, otherwise it returns
+    /// a null memory block and fills in *ErrMsg.
+    /// 
+    /// @brief Allocate Read/Write/Execute memory.
+    static MemoryBlock AllocateRWX(unsigned NumBytes,
+                                   const MemoryBlock *NearBlock,
+                                   std::string *ErrMsg = 0);
+
+    /// This method releases a block of Read/Write/Execute memory that was
+    /// allocated with the AllocateRWX method. It should not be used to
+    /// release any memory block allocated any other way.
+    ///
+    /// On success, this returns false, otherwise it returns true and fills
+    /// in *ErrMsg.
+    /// @throws std::string if an error occurred.
+    /// @brief Release Read/Write/Execute memory.
+    static bool ReleaseRWX(MemoryBlock &block, std::string *ErrMsg = 0);
+    
+    
+    /// InvalidateInstructionCache - Before the JIT can run a block of code
+    /// that has been emitted it must invalidate the instruction cache on some
+    /// platforms.
+    static void InvalidateInstructionCache(const void *Addr, size_t Len);
+
+    /// setExecutable - Before the JIT can run a block of code, it has to be
+    /// given read and executable privilege. Return true if it is already r-x
+    /// or the system is able to change its previlege.
+    static bool setExecutable (MemoryBlock &M, std::string *ErrMsg = 0);
+
+    /// setWritable - When adding to a block of code, the JIT may need
+    /// to mark a block of code as RW since the protections are on page
+    /// boundaries, and the JIT internal allocations are not page aligned.
+    static bool setWritable (MemoryBlock &M, std::string *ErrMsg = 0);
+
+    /// setRangeExecutable - Mark the page containing a range of addresses 
+    /// as executable.
+    static bool setRangeExecutable(const void *Addr, size_t Size);
+
+    /// setRangeWritable - Mark the page containing a range of addresses 
+    /// as writable.
+    static bool setRangeWritable(const void *Addr, size_t Size);
   };
 }
 }
 
-// vim: sw=2
-
 #endif