1 files changed, 69 insertions, 0 deletions
diff --git a/lib/fuzzer/FuzzerShmem.h b/lib/fuzzer/FuzzerShmem.h
new file mode 100644
index 000000000000..53568e0acb69
--- /dev/null
+++ b/lib/fuzzer/FuzzerShmem.h
@@ -0,0 +1,69 @@
+//===- FuzzerShmem.h - shared memory interface ------------------*- C++ -* ===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+// SharedMemoryRegion
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_FUZZER_SHMEM_H
+#define LLVM_FUZZER_SHMEM_H
+
+#include <algorithm>
+#include <cstring>
+#include <string>
+
+#include "FuzzerDefs.h"
+
+namespace fuzzer {
+
+class SharedMemoryRegion {
+ public:
+  bool Create(const char *Name);
+  bool Open(const char *Name);
+  bool Destroy(const char *Name);
+  uint8_t *GetData() { return Data; }
+  void PostServer() {Post(0);}
+  void WaitServer() {Wait(0);}
+  void PostClient() {Post(1);}
+  void WaitClient() {Wait(1);}
+
+  size_t WriteByteArray(const uint8_t *Bytes, size_t N) {
+    assert(N <= kShmemSize - sizeof(N));
+    memcpy(GetData(), &N, sizeof(N));
+    memcpy(GetData() + sizeof(N), Bytes, N);
+    assert(N == ReadByteArraySize());
+    return N;
+  }
+  size_t ReadByteArraySize() {
+    size_t Res;
+    memcpy(&Res, GetData(), sizeof(Res));
+    return Res;
+  }
+  uint8_t *GetByteArray() { return GetData() + sizeof(size_t); }
+
+  bool IsServer() const { return Data && IAmServer; }
+  bool IsClient() const { return Data && !IAmServer; }
+
+private:
+
+  static const size_t kShmemSize = 1 << 22;
+  bool IAmServer;
+  std::string Path(const char *Name);
+  std::string SemName(const char *Name, int Idx);
+  void Post(int Idx);
+  void Wait(int Idx);
+
+  bool Map(int fd);
+  uint8_t *Data = nullptr;
+  void *Semaphore[2];
+};
+
+extern SharedMemoryRegion SMR;
+
+}  // namespace fuzzer
+
+#endif  // LLVM_FUZZER_SHMEM_H