1 files changed, 80 insertions, 0 deletions
diff --git a/src/crimson/os/alienstore/thread_pool.cc b/src/crimson/os/alienstore/thread_pool.cc
new file mode 100644
index 000000000..e127d87d5
--- /dev/null
+++ b/src/crimson/os/alienstore/thread_pool.cc
@@ -0,0 +1,80 @@
+#include "thread_pool.h"
+
+#include <chrono>
+#include <pthread.h>
+
+#include "include/ceph_assert.h"
+#include "crimson/common/config_proxy.h"
+
+using crimson::common::local_conf;
+
+namespace crimson::os {
+
+ThreadPool::ThreadPool(size_t n_threads,
+                       size_t queue_sz,
+                       long cpu_id)
+  : queue_size{round_up_to(queue_sz, seastar::smp::count)},
+    pending{queue_size}
+{
+  auto queue_max_wait = std::chrono::seconds(local_conf()->threadpool_empty_queue_max_wait);
+  for (size_t i = 0; i < n_threads; i++) {
+    threads.emplace_back([this, cpu_id, queue_max_wait] {
+      if (cpu_id >= 0) {
+        pin(cpu_id);
+      }
+      loop(queue_max_wait);
+    });
+  }
+}
+
+ThreadPool::~ThreadPool()
+{
+  for (auto& thread : threads) {
+    thread.join();
+  }
+}
+
+void ThreadPool::pin(unsigned cpu_id)
+{
+  cpu_set_t cs;
+  CPU_ZERO(&cs);
+  CPU_SET(cpu_id, &cs);
+  [[maybe_unused]] auto r = pthread_setaffinity_np(pthread_self(),
+                                                   sizeof(cs), &cs);
+  ceph_assert(r == 0);
+}
+
+void ThreadPool::loop(std::chrono::milliseconds queue_max_wait)
+{
+  for (;;) {
+    WorkItem* work_item = nullptr;
+    {
+      std::unique_lock lock{mutex};
+      cond.wait_for(lock, queue_max_wait,
+                    [this, &work_item] {
+        return pending.pop(work_item) || is_stopping();
+      });
+    }
+    if (work_item) {
+      work_item->process();
+    } else if (is_stopping()) {
+      break;
+    }
+  }
+}
+
+seastar::future<> ThreadPool::start()
+{
+  auto slots_per_shard = queue_size / seastar::smp::count;
+  return submit_queue.start(slots_per_shard);
+}
+
+seastar::future<> ThreadPool::stop()
+{
+  return submit_queue.stop().then([this] {
+    stopping = true;
+    cond.notify_all();
+  });
+}
+
+} // namespace crimson::os