From 7c52fa8545ca94f20d394f86f5685b17aae6b238 Mon Sep 17 00:00:00 2001
From: range3 <white.line.oar@gmail.com>
Date: Sat, 16 Jul 2022 06:54:44 +0000
Subject: [PATCH] Fix wrong RAII impls

---
 src/rdbench/main.cpp       | 38 ++++++--------------------
 src/rdbench/raii_types.hpp | 56 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 65 insertions(+), 29 deletions(-)
 create mode 100644 src/rdbench/raii_types.hpp

diff --git a/src/rdbench/main.cpp b/src/rdbench/main.cpp
index c4a1f8c..c3cae89 100644
--- a/src/rdbench/main.cpp
+++ b/src/rdbench/main.cpp
@@ -22,6 +22,7 @@
 #include <type_traits>
 #include <vector>
 
+#include "raii_types.hpp"
 #include "stopwatch.hpp"
 
 using json = nlohmann::json;
@@ -34,28 +35,7 @@ const double Dv = 0.1;
 
 typedef std::vector<double> vd;
 
-struct mpi_datatype_deleter {
-  template <typename T> void operator()(T *p) const {
-    MPI_Datatype type = p;
-    if (type != MPI_DATATYPE_NULL) {
-      MPI_Type_free(&type);
-    }
-  }
-};
-
-struct mpi_comm_deleter {
-  template <typename T> void operator()(T *p) const {
-    MPI_Comm comm = p;
-    if (comm != MPI_COMM_NULL) {
-      MPI_Comm_free(&comm);
-    }
-  }
-};
-
 struct RdbenchInfo {
-  using unique_mpi_datatype
-      = std::unique_ptr<std::remove_pointer<MPI_Datatype>::type, mpi_datatype_deleter>;
-  using unique_mpi_comm = std::unique_ptr<std::remove_pointer<MPI_Comm>::type, mpi_comm_deleter>;
   int rank;
   int nprocs;
   int xnp;
@@ -74,10 +54,10 @@ struct RdbenchInfo {
   bool view = false;
   bool sync = true;
   bool validate = true;
-  unique_mpi_datatype filetype;
-  unique_mpi_datatype memtype;
-  unique_mpi_datatype vertical_halo_type;
-  unique_mpi_comm comm_2d;
+  Datatype filetype;
+  Datatype memtype;
+  Datatype vertical_halo_type;
+  Comm comm_2d;
   size_t total_steps;
   size_t interval;
   bool fixed_x = false;
@@ -110,7 +90,7 @@ struct RdbenchInfo {
     MPI_Comm comm_2d;
     int periods[] = {info.fixed_y ? 0 : 1, info.fixed_x ? 0 : 1};
     MPI_Cart_create(MPI_COMM_WORLD, 2, dims, periods, 0, &comm_2d);
-    info.comm_2d = unique_mpi_comm{comm_2d};
+    info.comm_2d = Comm{comm_2d};
     int coords[2];
     MPI_Cart_coords(info.comm_2d.get(), info.rank, 2, coords);
     MPI_Cart_shift(info.comm_2d.get(), 0, 1, &info.rank_up, &info.rank_down);
@@ -138,7 +118,7 @@ struct RdbenchInfo {
       MPI_Type_create_subarray(2, array_shape, chunk_shape, chunk_start, MPI_ORDER_C, MPI_DOUBLE,
                                &t);
       MPI_Type_commit(&t);
-      info.filetype = unique_mpi_datatype{t};
+      info.filetype = Datatype{t};
 
       array_shape[0] = info.chunk_size_y + 2;
       array_shape[1] = info.chunk_size_x + 2;
@@ -148,11 +128,11 @@ struct RdbenchInfo {
       MPI_Type_create_subarray(2, array_shape, chunk_shape, chunk_start, MPI_ORDER_C, MPI_DOUBLE,
                                &t);
       MPI_Type_commit(&t);
-      info.memtype = unique_mpi_datatype{t};
+      info.memtype = Datatype{t};
     }
     MPI_Type_vector(info.chunk_size_y, 1, info.chunk_size_x + 2, MPI_DOUBLE, &t);
     MPI_Type_commit(&t);
-    info.vertical_halo_type = unique_mpi_datatype{t};
+    info.vertical_halo_type = Datatype{t};
 
     return info;
   }
diff --git a/src/rdbench/raii_types.hpp b/src/rdbench/raii_types.hpp
new file mode 100644
index 0000000..406011d
--- /dev/null
+++ b/src/rdbench/raii_types.hpp
@@ -0,0 +1,56 @@
+// SPDX-License-Identifier: Apache-2.0
+// Copyright 2022 range3 ( https://github.com/range3 )
+#pragma once
+
+#include <mpi.h>
+
+#include <cstddef>
+#include <memory>
+
+struct DatatypeWrap {
+  DatatypeWrap() = default;
+  DatatypeWrap(std::nullptr_t) {}
+  explicit DatatypeWrap(MPI_Datatype dt) : dt(dt) {}
+  explicit operator bool() const { return dt != MPI_DATATYPE_NULL; }
+  friend bool operator==(DatatypeWrap l, DatatypeWrap r) { return l.dt == r.dt; }
+  friend bool operator!=(DatatypeWrap l, DatatypeWrap r) { return !(l == r); }
+  MPI_Datatype dt = MPI_DATATYPE_NULL;
+};
+
+class Datatype {
+public:
+  Datatype() = default;
+  Datatype(MPI_Datatype dt) { dt_ = decltype(dt_)(DatatypeWrap(dt), Deleter()); }
+  MPI_Datatype get() { return dt_.get().dt; }
+
+private:
+  struct Deleter {
+    using pointer = DatatypeWrap;
+    void operator()(DatatypeWrap dt) { MPI_Type_free(&dt.dt); }
+  };
+  std::unique_ptr<void, Deleter> dt_;
+};
+
+struct CommWrap {
+  CommWrap() = default;
+  CommWrap(std::nullptr_t) {}
+  explicit CommWrap(MPI_Comm comm) : comm(comm) {}
+  explicit operator bool() const { return comm != MPI_COMM_NULL; }
+  friend bool operator==(CommWrap l, CommWrap r) { return l.comm == r.comm; }
+  friend bool operator!=(CommWrap l, CommWrap r) { return !(l == r); }
+  MPI_Comm comm = MPI_COMM_NULL;
+};
+
+struct Comm {
+public:
+  Comm() = default;
+  Comm(MPI_Comm comm) { comm_ = decltype(comm_)(CommWrap(comm), Deleter()); }
+  MPI_Comm get() { return comm_.get().comm; }
+
+private:
+  struct Deleter {
+    using pointer = CommWrap;
+    void operator()(CommWrap comm) { MPI_Comm_free(&comm.comm); }
+  };
+  std::unique_ptr<void, Deleter> comm_;
+};