openmp/libomptarget/include/OmptConnector.h

   1 //===- OmptConnector.h - Target independent OpenMP target RTL -- C++ ------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // Support used by OMPT implementation to establish communication between
  10 // various OpenMP runtime libraries: host openmp library, target-independent
  11 // runtime library, and device-dependent runtime libraries.
  12 //
  13 //===----------------------------------------------------------------------===//
  14
  15 #ifndef _OMPTCONNECTOR_H
  16 #define _OMPTCONNECTOR_H
  17
  18 #ifdef OMPT_SUPPORT
  19
  20 #include "llvm/Support/DynamicLibrary.h"
  21
  22 #include <memory>
  23 #include <string>
  24
  25 #include "omp-tools.h"
  26
  27 #include "Debug.h"
  28 #include "omptarget.h"
  29
  30 #pragma push_macro("DEBUG_PREFIX")
  31 #undef DEBUG_PREFIX
  32 #define DEBUG_PREFIX "OMPT"
  33
  34 /// Type for the function to be invoked for connecting two libraries.
  35 typedef void (*OmptConnectRtnTy)(ompt_start_tool_result_t *result);
  36
  37 /// Establish connection between openmp runtime libraries
  38 ///
  39 /// This class is used to communicate between an OMPT implementation in
  40 /// libomptarget and libomp. It is also used to communicate between an
  41 /// OMPT implementation in a device-specific plugin and
  42 /// libomptarget. The decision whether OMPT is enabled or not needs to
  43 /// be made when the library is loaded before any functions in the
  44 /// library are invoked. For that reason, an instance of this class is
  45 /// intended to be defined in the constructor for libomptarget or a
  46 /// plugin so that the decision about whether OMPT is supposed to be
  47 /// enabled is known before any interface function in the library is
  48 /// invoked.
  49 class OmptLibraryConnectorTy {
  50 public:
  51   /// Use \p LibName as the prefix of the global function used for connecting
  52   /// two libraries, the source indicated by \p LibName and the destination
  53   /// being the one that creates this object.
  54   OmptLibraryConnectorTy(const char *Ident) {
  55     LibIdent.append(Ident);
  56     IsInitialized = false;
  57   }
  58   OmptLibraryConnectorTy() = delete;
  59   /// Use \p OmptResult init to connect the two libraries denoted by this
  60   /// object. The init function of \p OmptResult will be used during connection
  61   /// and the fini function of \p OmptResult will be used during teardown.
  62   void connect(ompt_start_tool_result_t *OmptResult) {
  63     initialize();
  64     if (!LibConnHandle)
  65       return;
  66     // Call the function provided by the source library for connect
  67     LibConnHandle(OmptResult);
  68   }
  69
  70 private:
  71   void initialize() {
  72     if (IsInitialized)
  73       return;
  74
  75     std::string ErrMsg;
  76     std::string LibName = LibIdent;
  77     LibName += ".so";
  78
  79     DP("OMPT: Trying to load library %s\n", LibName.c_str());
  80     auto DynLibHandle = std::make_unique<llvm::sys::DynamicLibrary>(
  81         llvm::sys::DynamicLibrary::getPermanentLibrary(LibName.c_str(),
  82                                                        &ErrMsg));
  83     if (!DynLibHandle->isValid()) {
  84       // The upper layer will bail out if the handle is null.
  85       LibConnHandle = nullptr;
  86     } else {
  87       auto LibConnRtn = "ompt_" + LibIdent + "_connect";
  88       DP("OMPT: Trying to get address of connection routine %s\n",
  89          LibConnRtn.c_str());
  90       LibConnHandle = reinterpret_cast<OmptConnectRtnTy>(
  91           DynLibHandle->getAddressOfSymbol(LibConnRtn.c_str()));
  92     }
  93     DP("OMPT: Library connection handle = %p\n", LibConnHandle);
  94     IsInitialized = true;
  95   }
  96
  97   /// Ensure initialization occurs only once
  98   bool IsInitialized;
  99   /// Handle of connect routine provided by source library
 100   OmptConnectRtnTy LibConnHandle;
 101   /// Name of connect routine provided by source library
 102   std::string LibIdent;
 103 };
 104
 105 #endif // OMPT_SUPPORT
 106
 107 #pragma pop_macro("DEBUG_PREFIX")
 108
 109 #endif // _OMPTCONNECTOR_H