[L0 v2] Add raii wrapper for L0 handles

that encapsulate lifetime management logic (including
support for ownZeHandle).

Author: igchor

source/adapters/level_zero/v2/common.hpp

@@ -0,0 +1,97 @@
+//===--------- common.hpp - Level Zero Adapter ---------------------------===//
+//
+// Copyright (C) 2024 Intel Corporation
+//
+// Part of the Unified-Runtime Project, under the Apache License v2.0 with LLVM
+// Exceptions. See LICENSE.TXT
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#pragma once
+
+#include <exception>
+#include <ze_api.h>
+
+#include "../common.hpp"
+
+namespace v2 {
+
+namespace raii {
+
+template <typename ZeHandleT, ze_result_t (*destroy)(ZeHandleT)>
+struct ze_handle_wrapper {
+  ze_handle_wrapper(bool ownZeHandle = true)
+      : handle(nullptr), ownZeHandle(ownZeHandle) {}
+
+  ze_handle_wrapper(ZeHandleT handle, bool ownZeHandle = true)
+      : handle(handle), ownZeHandle(ownZeHandle) {}
+
+  ze_handle_wrapper(const ze_handle_wrapper &) = delete;
+  ze_handle_wrapper &operator=(const ze_handle_wrapper &) = delete;
+
+  ze_handle_wrapper(ze_handle_wrapper &&other)
+      : handle(other.handle), ownZeHandle(other.ownZeHandle) {
+    other.handle = nullptr;
+  }
+
+  ze_handle_wrapper &operator=(ze_handle_wrapper &&other) {
+    if (this == &other) {
+      return *this;
+    }
+
+    if (handle) {
+      reset();
+    }
+    handle = other.handle;
+    ownZeHandle = other.ownZeHandle;
+    other.handle = nullptr;
+    return *this;
+  }
+
+  ~ze_handle_wrapper() {
+    try {
+      reset();
+    } catch (...) {
+    }
+  }
+
+  void reset() {
+    if (!handle) {
+      return;
+    }
+
+    auto zeResult = ZE_CALL_NOCHECK(destroy, (handle));
+    // Gracefully handle the case that L0 was already unloaded.
+    if (zeResult && zeResult != ZE_RESULT_ERROR_UNINITIALIZED)
+      throw ze2urResult(zeResult);
+
+    handle = nullptr;
+  }
+
+  ZeHandleT release() {
+    auto handle = this->handle;
+    this->handle = nullptr;
+    return handle;
+  }
+
+  ZeHandleT get() const { return handle; }
+
+  ZeHandleT *ptr() { return &handle; }
+
+private:
+  ZeHandleT handle;
+  bool ownZeHandle;
+};
+
+using ze_kernel_handle_t =
+    ze_handle_wrapper<::ze_kernel_handle_t, zeKernelDestroy>;
+
+using ze_event_handle_t =
+    ze_handle_wrapper<::ze_event_handle_t, zeEventDestroy>;
+
+using ze_event_pool_handle_t =
+    ze_handle_wrapper<::ze_event_pool_handle_t, zeEventPoolDestroy>;
+
+} // namespace raii
+} // namespace v2

source/adapters/level_zero/v2/event_provider_counter.cpp

@@ -33,12 +33,6 @@ provider_counter::provider_counter(ur_platform_handle_t platform,
       (ZEL_HANDLE_DEVICE, device->ZeDevice, (void **)&translatedDevice));
 }
 
-provider_counter::~provider_counter() {
-  for (auto &e : freelist) {
-    ZE_CALL_NOCHECK(zeEventDestroy, (e));
-  }
-}
-
 event_allocation provider_counter::allocate() {
   if (freelist.empty()) {
     ZeStruct<ze_event_desc_t> desc;
@@ -54,11 +48,11 @@ event_allocation provider_counter::allocate() {
     freelist.emplace_back(handle);
   }
 
-  auto event = freelist.back();
+  auto event = std::move(freelist.back());
   freelist.pop_back();
 
   return {event_type::EVENT_COUNTER,
-          event_borrowed(event, [this](ze_event_handle_t handle) {
+          event_borrowed(event.release(), [this](ze_event_handle_t handle) {
             freelist.push_back(handle);
           })};
 }

source/adapters/level_zero/v2/event_provider_counter.hpp

@@ -35,7 +35,6 @@ class provider_counter : public event_provider {
 public:
   provider_counter(ur_platform_handle_t platform, ur_context_handle_t,
                    ur_device_handle_t);
-  ~provider_counter() override;
 
   event_allocation allocate() override;
   ur_device_handle_t device() override;
@@ -48,7 +47,7 @@ class provider_counter : public event_provider {
 
   zexCounterBasedEventCreate eventCreateFunc;
 
-  std::vector<ze_event_handle_t> freelist;
+  std::vector<raii::ze_event_handle_t> freelist;
 };
 
 } // namespace v2

source/adapters/level_zero/v2/event_provider_normal.cpp

@@ -38,33 +38,27 @@ provider_pool::provider_pool(ur_context_handle_t context,
   ZE2UR_CALL_THROWS(zeEventPoolCreate,
                     (context->ZeContext, &desc, 1,
                      const_cast<ze_device_handle_t *>(&device->ZeDevice),
-                     &pool));
+                     pool.ptr()));
 
   freelist.resize(EVENTS_BURST);
   for (int i = 0; i < EVENTS_BURST; ++i) {
     ZeStruct<ze_event_desc_t> desc;
     desc.index = i;
     desc.signal = 0;
     desc.wait = 0;
-    ZE2UR_CALL_THROWS(zeEventCreate, (pool, &desc, &freelist[i]));
+    ZE2UR_CALL_THROWS(zeEventCreate, (pool.get(), &desc, freelist[i].ptr()));
   }
 }
 
-provider_pool::~provider_pool() {
-  for (auto e : freelist) {
-    ZE_CALL_NOCHECK(zeEventDestroy, (e));
-  }
-  ZE_CALL_NOCHECK(zeEventPoolDestroy, (pool));
-}
-
 event_borrowed provider_pool::allocate() {
   if (freelist.empty()) {
     return nullptr;
   }
-  ze_event_handle_t e = freelist.back();
+  auto e = std::move(freelist.back());
   freelist.pop_back();
-  return event_borrowed(
-      e, [this](ze_event_handle_t handle) { freelist.push_back(handle); });
+  return event_borrowed(e.release(), [this](ze_event_handle_t handle) {
+    freelist.push_back(handle);
+  });
 }
 
 size_t provider_pool::nfree() const { return freelist.size(); }

source/adapters/level_zero/v2/event_provider_normal.hpp

@@ -34,16 +34,13 @@ class provider_pool {
 public:
   provider_pool(ur_context_handle_t, ur_device_handle_t, event_type,
                 queue_type);
-  ~provider_pool();
 
   event_borrowed allocate();
   size_t nfree() const;
 
 private:
-  // TODO: use a RAII wrapper for the pool handle
-  ze_event_pool_handle_t pool;
-
-  std::vector<ze_event_handle_t> freelist;
+  raii::ze_event_pool_handle_t pool;
+  std::vector<raii::ze_event_handle_t> freelist;
 };
 
 class provider_normal : public event_provider {