path: root/openmp/libomptarget/src/rtl.cpp

//===----------- rtl.cpp - Target independent OpenMP target RTL -----------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// Functionality for handling RTL plugins.
//
//===----------------------------------------------------------------------===//

#include "llvm/Object/OffloadBinary.h"

#include "DeviceImage.h"
#include "OpenMP/OMPT/Callback.h"
#include "PluginManager.h"
#include "device.h"
#include "private.h"
#include "rtl.h"

#include "Shared/Debug.h"
#include "Shared/Profile.h"
#include "Shared/Utils.h"

#include <cassert>
#include <cstdlib>
#include <cstring>
#include <mutex>
#include <string>

using namespace llvm;
using namespace llvm::sys;
using namespace llvm::omp::target;

#ifdef OMPT_SUPPORT
extern void ompt::connectLibrary();
#endif

__attribute__((constructor(101))) void init() {
  DP("Init target library!\n");

  PM = new PluginManager();

#ifdef OMPT_SUPPORT
  // Initialize OMPT first
  ompt::connectLibrary();
#endif

  PM->init();

  Profiler::get();
  PM->registerDelayedLibraries();
}

__attribute__((destructor(101))) void deinit() {
  DP("Deinit target library!\n");
  delete PM;
}

////////////////////////////////////////////////////////////////////////////////
// Functionality for registering libs

static void registerImageIntoTranslationTable(TranslationTable &TT,
                                              PluginAdaptorTy &RTL,
                                              __tgt_device_image *Image) {

  // same size, as when we increase one, we also increase the other.
  assert(TT.TargetsTable.size() == TT.TargetsImages.size() &&
         "We should have as many images as we have tables!");

  // Resize the Targets Table and Images to accommodate the new targets if
  // required
  unsigned TargetsTableMinimumSize = RTL.DeviceOffset + RTL.NumberOfDevices;

  if (TT.TargetsTable.size() < TargetsTableMinimumSize) {
    TT.TargetsImages.resize(TargetsTableMinimumSize, 0);
    TT.TargetsTable.resize(TargetsTableMinimumSize, 0);
  }

  // Register the image in all devices for this target type.
  for (int32_t I = 0; I < RTL.NumberOfDevices; ++I) {
    // If we are changing the image we are also invalidating the target table.
    if (TT.TargetsImages[RTL.DeviceOffset + I] != Image) {
      TT.TargetsImages[RTL.DeviceOffset + I] = Image;
      TT.TargetsTable[RTL.DeviceOffset + I] =
          0; // lazy initialization of target table.
    }
  }
}

////////////////////////////////////////////////////////////////////////////////
// Functionality for registering Ctors/Dtors

static void registerGlobalCtorsDtorsForImage(__tgt_bin_desc *Desc,
                                             __tgt_device_image *Img,
                                             PluginAdaptorTy *RTL) {

  for (int32_t I = 0; I < RTL->NumberOfDevices; ++I) {
    DeviceTy &Device = *PM->Devices[RTL->DeviceOffset + I];
    Device.PendingGlobalsMtx.lock();
    Device.HasPendingGlobals = true;
    for (__tgt_offload_entry *Entry = Img->EntriesBegin;
         Entry != Img->EntriesEnd; ++Entry) {
      // Globals are not callable and use a different set of flags.
      if (Entry->size != 0)
        continue;

      if (Entry->flags & OMP_DECLARE_TARGET_CTOR) {
        DP("Adding ctor " DPxMOD " to the pending list.\n",
           DPxPTR(Entry->addr));
        Device.PendingCtorsDtors[Desc].PendingCtors.push_back(Entry->addr);
        MESSAGE("WARNING: Calling deprecated constructor for entry %s will be "
                "removed in a future release \n",
                Entry->name);
      } else if (Entry->flags & OMP_DECLARE_TARGET_DTOR) {
        // Dtors are pushed in reverse order so they are executed from end
        // to beginning when unregistering the library!
        DP("Adding dtor " DPxMOD " to the pending list.\n",
           DPxPTR(Entry->addr));
        Device.PendingCtorsDtors[Desc].PendingDtors.push_front(Entry->addr);
        MESSAGE("WARNING: Calling deprecated destructor for entry %s will be "
                "removed in a future release \n",
                Entry->name);
      }

      if (Entry->flags & OMP_DECLARE_TARGET_LINK) {
        DP("The \"link\" attribute is not yet supported!\n");
      }
    }
    Device.PendingGlobalsMtx.unlock();
  }
}

void PluginAdaptorManagerTy::registerLib(__tgt_bin_desc *Desc) {
  PM->RTLsMtx.lock();

  // Extract the exectuable image and extra information if availible.
  for (int32_t i = 0; i < Desc->NumDeviceImages; ++i)
    PM->addDeviceImage(Desc->DeviceImages[i]);

  // Register the images with the RTLs that understand them, if any.
  for (DeviceImageTy &DI : PM->deviceImages()) {
    // Obtain the image and information that was previously extracted.
    __tgt_device_image *Img = &DI.getExecutableImage();
    __tgt_image_info *Info = &DI.getImageInfo();

    PluginAdaptorTy *FoundRTL = nullptr;

    // Scan the RTLs that have associated images until we find one that supports
    // the current image.
    for (auto &R : PM->pluginAdaptors()) {
      if (R.is_valid_binary_info) {
        if (!R.is_valid_binary_info(Img, Info)) {
          DP("Image " DPxMOD " is NOT compatible with RTL %s!\n",
             DPxPTR(Img->ImageStart), R.Name.c_str());
          continue;
        }
      } else if (!R.is_valid_binary(Img)) {
        DP("Image " DPxMOD " is NOT compatible with RTL %s!\n",
           DPxPTR(Img->ImageStart), R.Name.c_str());
        continue;
      }

      DP("Image " DPxMOD " is compatible with RTL %s!\n",
         DPxPTR(Img->ImageStart), R.Name.c_str());

      PM->initPlugin(R);

      // Initialize (if necessary) translation table for this library.
      PM->TrlTblMtx.lock();
      if (!PM->HostEntriesBeginToTransTable.count(Desc->HostEntriesBegin)) {
        PM->HostEntriesBeginRegistrationOrder.push_back(Desc->HostEntriesBegin);
        TranslationTable &TransTable =
            (PM->HostEntriesBeginToTransTable)[Desc->HostEntriesBegin];
        TransTable.HostTable.EntriesBegin = Desc->HostEntriesBegin;
        TransTable.HostTable.EntriesEnd = Desc->HostEntriesEnd;
      }

      // Retrieve translation table for this library.
      TranslationTable &TransTable =
          (PM->HostEntriesBeginToTransTable)[Desc->HostEntriesBegin];

      DP("Registering image " DPxMOD " with RTL %s!\n", DPxPTR(Img->ImageStart),
         R.Name.c_str());
      registerImageIntoTranslationTable(TransTable, R, Img);
      R.UsedImages.insert(Img);

      PM->TrlTblMtx.unlock();
      FoundRTL = &R;

      // Load ctors/dtors for static objects
      registerGlobalCtorsDtorsForImage(Desc, Img, FoundRTL);

      // if an RTL was found we are done - proceed to register the next image
      break;
    }

    if (!FoundRTL) {
      DP("No RTL found for image " DPxMOD "!\n", DPxPTR(Img->ImageStart));
    }
  }
  PM->RTLsMtx.unlock();

  DP("Done registering entries!\n");
}

void PluginAdaptorManagerTy::unregisterLib(__tgt_bin_desc *Desc) {
  DP("Unloading target library!\n");

  PM->RTLsMtx.lock();
  // Find which RTL understands each image, if any.
  for (DeviceImageTy &DI : PM->deviceImages()) {
    // Obtain the image and information that was previously extracted.
    __tgt_device_image *Img = &DI.getExecutableImage();

    PluginAdaptorTy *FoundRTL = NULL;

    // Scan the RTLs that have associated images until we find one that supports
    // the current image. We only need to scan RTLs that are already being used.
    for (auto &R : PM->pluginAdaptors()) {
      if (!R.isUsed())
        continue;

      // Ensure that we do not use any unused images associated with this RTL.
      if (!R.UsedImages.contains(Img))
        continue;

      FoundRTL = &R;

      // Execute dtors for static objects if the device has been used, i.e.
      // if its PendingCtors list has been emptied.
      for (int32_t I = 0; I < FoundRTL->NumberOfDevices; ++I) {
        DeviceTy &Device = *PM->Devices[FoundRTL->DeviceOffset + I];
        Device.PendingGlobalsMtx.lock();
        if (Device.PendingCtorsDtors[Desc].PendingCtors.empty()) {
          AsyncInfoTy AsyncInfo(Device);
          for (auto &Dtor : Device.PendingCtorsDtors[Desc].PendingDtors) {
            int Rc =
                target(nullptr, Device, Dtor, CTorDTorKernelArgs, AsyncInfo);
            if (Rc != OFFLOAD_SUCCESS) {
              DP("Running destructor " DPxMOD " failed.\n", DPxPTR(Dtor));
            }
          }
          // Remove this library's entry from PendingCtorsDtors
          Device.PendingCtorsDtors.erase(Desc);
          // All constructors have been issued, wait for them now.
          if (AsyncInfo.synchronize() != OFFLOAD_SUCCESS)
            DP("Failed synchronizing destructors kernels.\n");
        }
        Device.PendingGlobalsMtx.unlock();
      }

      DP("Unregistered image " DPxMOD " from RTL " DPxMOD "!\n",
         DPxPTR(Img->ImageStart), DPxPTR(R.LibraryHandler.get()));

      break;
    }

    // if no RTL was found proceed to unregister the next image
    if (!FoundRTL) {
      DP("No RTLs in use support the image " DPxMOD "!\n",
         DPxPTR(Img->ImageStart));
    }
  }
  PM->RTLsMtx.unlock();
  DP("Done unregistering images!\n");

  // Remove entries from PM->HostPtrToTableMap
  PM->TblMapMtx.lock();
  for (__tgt_offload_entry *Cur = Desc->HostEntriesBegin;
       Cur < Desc->HostEntriesEnd; ++Cur) {
    PM->HostPtrToTableMap.erase(Cur->addr);
  }

  // Remove translation table for this descriptor.
  auto TransTable =
      PM->HostEntriesBeginToTransTable.find(Desc->HostEntriesBegin);
  if (TransTable != PM->HostEntriesBeginToTransTable.end()) {
    DP("Removing translation table for descriptor " DPxMOD "\n",
       DPxPTR(Desc->HostEntriesBegin));
    PM->HostEntriesBeginToTransTable.erase(TransTable);
  } else {
    DP("Translation table for descriptor " DPxMOD " cannot be found, probably "
       "it has been already removed.\n",
       DPxPTR(Desc->HostEntriesBegin));
  }

  PM->TblMapMtx.unlock();

  DP("Done unregistering library!\n");
}