1 files changed, 250 insertions, 0 deletions
diff --git a/contrib/llvm-project/llvm/lib/ExecutionEngine/Orc/Shared/SimpleRemoteEPCUtils.cpp b/contrib/llvm-project/llvm/lib/ExecutionEngine/Orc/Shared/SimpleRemoteEPCUtils.cpp
new file mode 100644
index 000000000000..64fc717b7b56
--- /dev/null
+++ b/contrib/llvm-project/llvm/lib/ExecutionEngine/Orc/Shared/SimpleRemoteEPCUtils.cpp
@@ -0,0 +1,250 @@
+//===------ SimpleRemoteEPCUtils.cpp - Utils for Simple Remote EPC --------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// Message definitions and other utilities for SimpleRemoteEPC and
+// SimpleRemoteEPCServer.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/ExecutionEngine/Orc/Shared/SimpleRemoteEPCUtils.h"
+#include "llvm/Support/Endian.h"
+#include "llvm/Support/FormatVariadic.h"
+
+#if !defined(_MSC_VER) && !defined(__MINGW32__)
+#include <unistd.h>
+#else
+#include <io.h>
+#endif
+
+namespace {
+
+struct FDMsgHeader {
+  static constexpr unsigned MsgSizeOffset = 0;
+  static constexpr unsigned OpCOffset = MsgSizeOffset + sizeof(uint64_t);
+  static constexpr unsigned SeqNoOffset = OpCOffset + sizeof(uint64_t);
+  static constexpr unsigned TagAddrOffset = SeqNoOffset + sizeof(uint64_t);
+  static constexpr unsigned Size = TagAddrOffset + sizeof(uint64_t);
+};
+
+} // namespace
+
+namespace llvm {
+namespace orc {
+namespace SimpleRemoteEPCDefaultBootstrapSymbolNames {
+
+const char *ExecutorSessionObjectName =
+    "__llvm_orc_SimpleRemoteEPC_dispatch_ctx";
+const char *DispatchFnName = "__llvm_orc_SimpleRemoteEPC_dispatch_fn";
+
+} // end namespace SimpleRemoteEPCDefaultBootstrapSymbolNames
+
+SimpleRemoteEPCTransportClient::~SimpleRemoteEPCTransportClient() {}
+SimpleRemoteEPCTransport::~SimpleRemoteEPCTransport() {}
+
+Expected<std::unique_ptr<FDSimpleRemoteEPCTransport>>
+FDSimpleRemoteEPCTransport::Create(SimpleRemoteEPCTransportClient &C, int InFD,
+                                   int OutFD) {
+#if LLVM_ENABLE_THREADS
+  if (InFD == -1)
+    return make_error<StringError>("Invalid input file descriptor " +
+                                       Twine(InFD),
+                                   inconvertibleErrorCode());
+  if (OutFD == -1)
+    return make_error<StringError>("Invalid output file descriptor " +
+                                       Twine(OutFD),
+                                   inconvertibleErrorCode());
+  std::unique_ptr<FDSimpleRemoteEPCTransport> FDT(
+      new FDSimpleRemoteEPCTransport(C, InFD, OutFD));
+  return std::move(FDT);
+#else
+  return make_error<StringError>("FD-based SimpleRemoteEPC transport requires "
+                                 "thread support, but llvm was built with "
+                                 "LLVM_ENABLE_THREADS=Off",
+                                 inconvertibleErrorCode());
+#endif
+}
+
+FDSimpleRemoteEPCTransport::~FDSimpleRemoteEPCTransport() {
+#if LLVM_ENABLE_THREADS
+  ListenerThread.join();
+#endif
+}
+
+Error FDSimpleRemoteEPCTransport::start() {
+#if LLVM_ENABLE_THREADS
+  ListenerThread = std::thread([this]() { listenLoop(); });
+  return Error::success();
+#endif
+  llvm_unreachable("Should not be called with LLVM_ENABLE_THREADS=Off");
+}
+
+Error FDSimpleRemoteEPCTransport::sendMessage(SimpleRemoteEPCOpcode OpC,
+                                              uint64_t SeqNo,
+                                              ExecutorAddr TagAddr,
+                                              ArrayRef<char> ArgBytes) {
+  char HeaderBuffer[FDMsgHeader::Size];
+
+  *((support::ulittle64_t *)(HeaderBuffer + FDMsgHeader::MsgSizeOffset)) =
+      FDMsgHeader::Size + ArgBytes.size();
+  *((support::ulittle64_t *)(HeaderBuffer + FDMsgHeader::OpCOffset)) =
+      static_cast<uint64_t>(OpC);
+  *((support::ulittle64_t *)(HeaderBuffer + FDMsgHeader::SeqNoOffset)) = SeqNo;
+  *((support::ulittle64_t *)(HeaderBuffer + FDMsgHeader::TagAddrOffset)) =
+      TagAddr.getValue();
+
+  std::lock_guard<std::mutex> Lock(M);
+  if (Disconnected)
+    return make_error<StringError>("FD-transport disconnected",
+                                   inconvertibleErrorCode());
+  if (int ErrNo = writeBytes(HeaderBuffer, FDMsgHeader::Size))
+    return errorCodeToError(std::error_code(ErrNo, std::generic_category()));
+  if (int ErrNo = writeBytes(ArgBytes.data(), ArgBytes.size()))
+    return errorCodeToError(std::error_code(ErrNo, std::generic_category()));
+  return Error::success();
+}
+
+void FDSimpleRemoteEPCTransport::disconnect() {
+  if (Disconnected)
+    return; // Return if already disconnected.
+
+  Disconnected = true;
+  bool CloseOutFD = InFD != OutFD;
+
+  // Close InFD.
+  while (close(InFD) == -1) {
+    if (errno == EBADF)
+      break;
+  }
+
+  // Close OutFD.
+  if (CloseOutFD) {
+    while (close(OutFD) == -1) {
+      if (errno == EBADF)
+        break;
+    }
+  }
+}
+
+static Error makeUnexpectedEOFError() {
+  return make_error<StringError>("Unexpected end-of-file",
+                                 inconvertibleErrorCode());
+}
+
+Error FDSimpleRemoteEPCTransport::readBytes(char *Dst, size_t Size,
+                                            bool *IsEOF) {
+  assert(Dst && "Attempt to read into null.");
+  ssize_t Completed = 0;
+  while (Completed < static_cast<ssize_t>(Size)) {
+    ssize_t Read = ::read(InFD, Dst + Completed, Size - Completed);
+    if (Read <= 0) {
+      auto ErrNo = errno;
+      if (Read == 0) {
+        if (Completed == 0 && IsEOF) {
+          *IsEOF = true;
+          return Error::success();
+        } else
+          return makeUnexpectedEOFError();
+      } else if (ErrNo == EAGAIN || ErrNo == EINTR)
+        continue;
+      else {
+        std::lock_guard<std::mutex> Lock(M);
+        if (Disconnected && IsEOF) { // disconnect called,  pretend this is EOF.
+          *IsEOF = true;
+          return Error::success();
+        }
+        return errorCodeToError(
+            std::error_code(ErrNo, std::generic_category()));
+      }
+    }
+    Completed += Read;
+  }
+  return Error::success();
+}
+
+int FDSimpleRemoteEPCTransport::writeBytes(const char *Src, size_t Size) {
+  assert(Src && "Attempt to append from null.");
+  ssize_t Completed = 0;
+  while (Completed < static_cast<ssize_t>(Size)) {
+    ssize_t Written = ::write(OutFD, Src + Completed, Size - Completed);
+    if (Written < 0) {
+      auto ErrNo = errno;
+      if (ErrNo == EAGAIN || ErrNo == EINTR)
+        continue;
+      else
+        return ErrNo;
+    }
+    Completed += Written;
+  }
+  return 0;
+}
+
+void FDSimpleRemoteEPCTransport::listenLoop() {
+  Error Err = Error::success();
+  do {
+
+    char HeaderBuffer[FDMsgHeader::Size];
+    // Read the header buffer.
+    {
+      bool IsEOF = false;
+      if (auto Err2 = readBytes(HeaderBuffer, FDMsgHeader::Size, &IsEOF)) {
+        Err = joinErrors(std::move(Err), std::move(Err2));
+        break;
+      }
+      if (IsEOF)
+        break;
+    }
+
+    // Decode header buffer.
+    uint64_t MsgSize;
+    SimpleRemoteEPCOpcode OpC;
+    uint64_t SeqNo;
+    ExecutorAddr TagAddr;
+
+    MsgSize =
+        *((support::ulittle64_t *)(HeaderBuffer + FDMsgHeader::MsgSizeOffset));
+    OpC = static_cast<SimpleRemoteEPCOpcode>(static_cast<uint64_t>(
+        *((support::ulittle64_t *)(HeaderBuffer + FDMsgHeader::OpCOffset))));
+    SeqNo =
+        *((support::ulittle64_t *)(HeaderBuffer + FDMsgHeader::SeqNoOffset));
+    TagAddr.setValue(
+        *((support::ulittle64_t *)(HeaderBuffer + FDMsgHeader::TagAddrOffset)));
+
+    if (MsgSize < FDMsgHeader::Size) {
+      Err = joinErrors(std::move(Err),
+                       make_error<StringError>("Message size too small",
+                                               inconvertibleErrorCode()));
+      break;
+    }
+
+    // Read the argument bytes.
+    SimpleRemoteEPCArgBytesVector ArgBytes;
+    ArgBytes.resize(MsgSize - FDMsgHeader::Size);
+    if (auto Err2 = readBytes(ArgBytes.data(), ArgBytes.size())) {
+      Err = joinErrors(std::move(Err), std::move(Err2));
+      break;
+    }
+
+    if (auto Action = C.handleMessage(OpC, SeqNo, TagAddr, ArgBytes)) {
+      if (*Action == SimpleRemoteEPCTransportClient::EndSession)
+        break;
+    } else {
+      Err = joinErrors(std::move(Err), Action.takeError());
+      break;
+    }
+  } while (true);
+
+  // Attempt to close FDs, set Disconnected to true so that subsequent
+  // sendMessage calls fail.
+  disconnect();
+
+  // Call up to the client to handle the disconnection.
+  C.handleDisconnect(std::move(Err));
+}
+
+} // end namespace orc
+} // end namespace llvm