From 7746758ed7087d1d05e9ad2c6693dfd39adbabc4 Mon Sep 17 00:00:00 2001
From: Laurent Morichetti <laurent.morichetti@amd.com>
Date: Fri, 29 Apr 2022 08:48:16 -0700
Subject: [PATCH] Add a trace_buffer directed test

This test stresses the concurrent writing of trace buffer records while
frequently allocating new storage to hold the records.

Due to race conditions, this test fails with the current trace buffer
implementation.

Change-Id: I0b77c64005e776319bf21f1ee1e6d7c99ddccfff


[ROCm/roctracer commit: 200e27f12d9e840893920b24578419ff88009693]
---
 .../roctracer/test/directed/trace_buffer.cpp  | 79 +++++++++++++++++++
 1 file changed, 79 insertions(+)
 create mode 100644 projects/roctracer/test/directed/trace_buffer.cpp

diff --git a/projects/roctracer/test/directed/trace_buffer.cpp b/projects/roctracer/test/directed/trace_buffer.cpp
new file mode 100644
index 0000000000..4adbdb72f5
--- /dev/null
+++ b/projects/roctracer/test/directed/trace_buffer.cpp
@@ -0,0 +1,79 @@
+/* Copyright (c) 2022 Advanced Micro Devices, Inc.
+
+ Permission is hereby granted, free of charge, to any person obtaining a copy
+ of this software and associated documentation files (the "Software"), to deal
+ in the Software without restriction, including without limitation the rights
+ to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ copies of the Software, and to permit persons to whom the Software is
+ furnished to do so, subject to the following conditions:
+
+ The above copyright notice and this permission notice shall be included in
+ all copies or substantial portions of the Software.
+
+ THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ THE SOFTWARE. */
+
+#include "trace_buffer.h"
+
+#include <algorithm>
+#include <atomic>
+#include <fstream>
+#include <iostream>
+#include <iterator>
+#include <string>
+#include <thread>
+#include <vector>
+
+
+struct TraceEntry {
+  std::atomic<roctracer::TraceEntryState> valid;
+};
+
+TRACE_BUFFER_INSTANTIATE();
+
+namespace {
+
+std::ifstream cpuinfo("/proc/cpuinfo");
+const std::size_t num_cpu_cores =
+    std::count(std::istream_iterator<std::string>(cpuinfo), std::istream_iterator<std::string>(),
+               std::string("processor"));
+
+constexpr std::size_t num_iterations = 1000;
+constexpr std::size_t min_num_threads = 10;
+constexpr std::size_t max_num_threads = 50;
+
+}  // namespace
+
+int main() {
+  const std::size_t num_threads = std::clamp(num_cpu_cores, min_num_threads, max_num_threads);
+  std::vector<std::thread> threads(num_threads);
+
+  std::atomic<size_t> flush_count(0);  // Count the number of times the flush callback is called.
+  roctracer::TraceBuffer<TraceEntry> trace_buffer("Test", 10,
+                                                  [&flush_count](auto* entry) { ++flush_count; });
+
+  // Start the worker threads. Each thread will request 'num_iterations' entries from the
+  // 'trace_buffer', then exit.
+  for (auto&& thread : threads) {
+    thread = std::thread([&trace_buffer]() {
+      for (std::size_t j = 0; j < num_iterations; ++j) {
+        auto* entry = trace_buffer.GetEntry();
+        entry->valid.store(roctracer::TRACE_ENTRY_COMPLETE, std::memory_order_release);
+      }
+    });
+  }
+
+  // Wait for all the threads to complete, then flush the trace buffer.
+  for (auto&& thread : threads) thread.join();
+  trace_buffer.Flush();
+
+  std::cout << "number of records flushed = " << flush_count << std::endl;
+  if (flush_count != num_iterations * threads.size()) abort();
+
+  return EXIT_SUCCESS;
+}
\ No newline at end of file