[SYCL] Add implementation of kernel_bundle. Part 3

sycl/include/CL/sycl/detail/cg.hpp

@@ -36,18 +36,119 @@ namespace sycl {
 
 // Forward declarations
 class queue;
-namespace detail {
-class queue_impl;
-} // namespace detail
 
 namespace detail {
 
+// Periodically there is a need to extend handler and CG classes to hold more
+// data(members) than it has now. But any modification of the layout of those
+// classes is an ABI break. To have an ability to have more data the following
+// approach is implemented:
+//
+// Those classes have a member - MSharedPtrStorage which is an std::vector of
+// std::shared_ptr's and is supposed to hold reference counters of user
+// provided shared_ptr's.
+//
+// The first element of this vector is reused to store a vector of additional
+// members handler and CG need to have.
+//
+// These additional arguments are represented using "ExtendedMemberT" structure
+// which has a pointer to an arbitrary value and an integer which is used to
+// understand how the value the pointer points to should be interpreted.
+//
+// ========  ========      ========
+// |      |  |      | ...  |      | std::vector<std::shared_ptr<void>>
+// ========  ========      ========
+//    ||        ||            ||
+//    ||        \/            \/
+//    ||       user          user
+//    ||       data          data
+//    \/
+// ========  ========      ========
+// | Type |  | Type | ...  | Type | std::vector<ExtendedMemberT>
+// |      |  |      |      |      |
+// | Ptr  |  | Ptr  | ...  | Ptr  |
+// ========  ========      ========
+//
+// Prior to this change this vector was supposed to have user's values only, so
+// it is not legal to expect that the first argument is a special one.
+// Versioning is implemented to overcome this problem - if the first element of
+// the MSharedPtrStorage is a pointer to the special vector then CGType value
+// has version "1" encoded.
+//
+// The version of CG type is encoded in the highest byte of the value:
+//
+// 0x00000001 - CG type KERNEL version 0
+// 0x01000001 - CG type KERNEL version 1
+//   /\
+//   ||
+// The byte specifies the version
+//
+// A user of this vector should not expect that a specific data is stored at a
+// specific position, but iterate over all looking for an ExtendedMemberT value
+// with the desired type.
+// This allows changing/extending the contents of this vector without changing
+// the version.
+//
+
+// Used to represent a type of an extended member
+enum class ExtendedMembersType : unsigned int {
+  HANDLER_KERNEL_BUNDLE = 0,
+};
+
+// Holds a pointer to an object of an arbitrary type and an ID value which
+// should be used to understand what type pointer points to.
+// Used as to extend handler class without introducing new class members which
+// would change handler layout.
+struct ExtendedMemberT {
+  ExtendedMembersType MType;
+  std::shared_ptr<void> MData;
+};
+
+static std::shared_ptr<std::vector<ExtendedMemberT>>
+convertToExtendedMembers(const std::shared_ptr<const void> &SPtr) {
+  return std::const_pointer_cast<std::vector<ExtendedMemberT>>(
+      std::static_pointer_cast<const std::vector<ExtendedMemberT>>(SPtr));
+}
+
 class stream_impl;
+class queue_impl;
+class kernel_bundle_impl;
+
+// The constant is used to left shift a CG type value to access it's version
+constexpr unsigned int ShiftBitsForVersion = 24;
+
+// Constructs versioned type
+constexpr unsigned int getVersionedCGType(unsigned int Type,
+                                          unsigned char Version) {
+  return Type | (static_cast<unsigned int>(Version) << ShiftBitsForVersion);
+}
+
+// Returns the type without version encoded
+constexpr unsigned char getUnversionedCGType(unsigned int Type) {
+  unsigned int Mask = -1;
+  Mask >>= (sizeof(Mask) * 8 - ShiftBitsForVersion);
+  return Type & Mask;
+}
+
+// Returns the version encoded to the type
+constexpr unsigned char getCGTypeVersion(unsigned int Type) {
+  return Type >> ShiftBitsForVersion;
+}
+
 /// Base class for all types of command groups.
 class CG {
 public:
+  // Used to version CG and handler classes. Using unsigned char as the version
+  // is encoded in the highest byte of CGType value. So it is not possible to
+  // encode a value > 255 anyway which should be big enough room for version
+  // bumping.
+  enum class CG_VERSION : unsigned char {
+    V0 = 0,
+    V1 = 1,
+  };
+
   /// Type of the command group.
-  enum CGTYPE {
+  enum CGTYPE : unsigned int {
     NONE = 0,
     KERNEL = 1,
     COPY_ACC_TO_PTR = 2,
@@ -62,7 +163,9 @@ class CG {
     FILL_USM = 11,
     PREFETCH_USM = 12,
     CODEPLAY_INTEROP_TASK = 13,
-    CODEPLAY_HOST_TASK = 14
+    CODEPLAY_HOST_TASK = 14,
+    KERNEL_V1 =
+        getVersionedCGType(KERNEL, static_cast<unsigned int>(CG_VERSION::V1)),
   };
 
   CG(CGTYPE Type, vector_class<vector_class<char>> ArgsStorage,
@@ -87,7 +190,17 @@ class CG {
 
   CG(CG &&CommandGroup) = default;
 
-  CGTYPE getType() { return MType; }
+  CGTYPE getType() { return static_cast<CGTYPE>(getUnversionedCGType(MType)); }
+
+  std::shared_ptr<std::vector<ExtendedMemberT>> getExtendedMembers() {
+    if (getCGTypeVersion(MType) == static_cast<unsigned int>(CG_VERSION::V0) ||
+        MSharedPtrStorage.empty())
+      return nullptr;
+
+    // The first value in shared_ptr storage is supposed to store a vector of
+    // extended members.
+    return convertToExtendedMembers(MSharedPtrStorage[0]);
+  }
 
   virtual ~CG() = default;
 
@@ -146,7 +259,8 @@ class CGExecKernel : public CG {
         MSyclKernel(std::move(SyclKernel)), MArgs(std::move(Args)),
         MKernelName(std::move(KernelName)), MOSModuleHandle(OSModuleHandle),
         MStreams(std::move(Streams)) {
-    assert((getType() == RUN_ON_HOST_INTEL || getType() == KERNEL) &&
+    assert((getType() == RUN_ON_HOST_INTEL || getType() == KERNEL ||
+            getType() == KERNEL_V1) &&
            "Wrong type of exec kernel CG.");
   }
 
@@ -155,6 +269,19 @@ class CGExecKernel : public CG {
   vector_class<shared_ptr_class<detail::stream_impl>> getStreams() const {
     return MStreams;
   }
+
+  std::shared_ptr<detail::kernel_bundle_impl> getKernelBundle() {
+    const std::shared_ptr<std::vector<ExtendedMemberT>> &ExtendedMembers =
+        getExtendedMembers();
+    if (!ExtendedMembers)
+      return nullptr;
+    for (const ExtendedMemberT &EMember : *ExtendedMembers)
+      if (ExtendedMembersType::HANDLER_KERNEL_BUNDLE == EMember.MType)
+        return std::static_pointer_cast<detail::kernel_bundle_impl>(
+            EMember.MData);
+    return nullptr;
+  }
+
   void clearStreams() { MStreams.clear(); }
 };