libc/test/shared/shared_rpc_test.cpp

//===-- Unittests for shared RPC server -----------------------------------===//
//
// 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
//
//===----------------------------------------------------------------------===//

#include "shared/rpc.h"
#include "shared/rpc_server.h"
#include "test/UnitTest/Test.h"

TEST(LlvmLibcSharedRpcTest, TestIncrement) {
  constexpr uint32_t port_count = 8;
  constexpr uint32_t lane_size = 4;
  alignas(64)
      uint8_t buffer[::rpc::Server::allocation_size(lane_size, port_count)] = {
          0};

  using ProcAType = ::rpc::Process<false>;
  using ProcBType = ::rpc::Process<true>;

  ProcAType ProcA(port_count, buffer);
  ProcBType ProcB(port_count, buffer);

  uint32_t index = 0; // any < port_count
  uint64_t lane_mask = 1;

  // Each process has its own local lock for index
  EXPECT_TRUE(ProcA.try_lock(lane_mask, index));
  EXPECT_TRUE(ProcB.try_lock(lane_mask, index));

  // All zero to begin with
  EXPECT_EQ(ProcA.load_inbox(lane_mask, index), 0u);
  EXPECT_EQ(ProcB.load_inbox(lane_mask, index), 0u);
  EXPECT_EQ(ProcA.load_outbox(lane_mask, index), 0u);
  EXPECT_EQ(ProcB.load_outbox(lane_mask, index), 0u);

  // Available for ProcA and not for ProcB
  EXPECT_FALSE(ProcA.buffer_unavailable(ProcA.load_inbox(lane_mask, index),
                                        ProcA.load_outbox(lane_mask, index)));
  EXPECT_TRUE(ProcB.buffer_unavailable(ProcB.load_inbox(lane_mask, index),
                                       ProcB.load_outbox(lane_mask, index)));

  // ProcA write to outbox
  uint32_t ProcAOutbox = ProcA.load_outbox(lane_mask, index);
  EXPECT_EQ(ProcAOutbox, 0u);
  ProcAOutbox = ProcA.invert_outbox(lane_mask, index, ProcAOutbox);
  EXPECT_EQ(ProcAOutbox, 1u);

  // No longer available for ProcA
  EXPECT_TRUE(ProcA.buffer_unavailable(ProcA.load_inbox(lane_mask, index),
                                       ProcAOutbox));

  // Outbox is still zero, hasn't been written to
  EXPECT_EQ(ProcB.load_outbox(lane_mask, index), 0u);

  // Wait for ownership will terminate because load_inbox returns 1
  EXPECT_EQ(ProcB.load_inbox(lane_mask, index), 1u);
  ProcB.wait_for_ownership(lane_mask, index, 0u, 0u);

  // and B now has the buffer available
  EXPECT_FALSE(ProcB.buffer_unavailable(ProcB.load_inbox(lane_mask, index),
                                        ProcB.load_outbox(lane_mask, index)));

  // Enough checks for one test, close the locks
  ProcA.unlock(lane_mask, index);
  ProcB.unlock(lane_mask, index);
}