xref: /llvm-project/mlir/include/mlir/ExecutionEngine/AsyncRuntime.h (revision f9bce19e2e2be09768260d2a297d933f46bc3efd)
1 //===- AsyncRuntime.h - Async runtime reference implementation ------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file declares basic Async runtime API for supporting Async dialect
10 // to LLVM dialect lowering.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #ifndef MLIR_EXECUTIONENGINE_ASYNCRUNTIME_H_
15 #define MLIR_EXECUTIONENGINE_ASYNCRUNTIME_H_
16 
17 #include <cstddef>
18 #include <stdint.h>
19 
20 #ifdef _WIN32
21 #ifndef MLIR_ASYNC_RUNTIME_EXPORT
22 #ifdef mlir_async_runtime_EXPORTS
23 // We are building this library
24 #define MLIR_ASYNC_RUNTIME_EXPORT __declspec(dllexport)
25 #else
26 // We are using this library
27 #define MLIR_ASYNC_RUNTIME_EXPORT __declspec(dllimport)
28 #endif // mlir_async_runtime_EXPORTS
29 #endif // MLIR_ASYNC_RUNTIME_EXPORT
30 #else
31 // Non-windows: use visibility attributes.
32 #define MLIR_ASYNC_RUNTIME_EXPORT __attribute__((visibility("default")))
33 #endif // _WIN32
34 
35 namespace mlir {
36 namespace runtime {
37 
38 //===----------------------------------------------------------------------===//
39 // Async runtime API.
40 //===----------------------------------------------------------------------===//
41 
42 // Runtime implementation of `async.token` data type.
43 using AsyncToken = struct AsyncToken;
44 
45 // Runtime implementation of `async.group` data type.
46 using AsyncGroup = struct AsyncGroup;
47 
48 // Runtime implementation of `async.value` data type.
49 using AsyncValue = struct AsyncValue;
50 
51 // Async value payload stored in a memory owned by the async.value.
52 using ValueStorage = std::byte *;
53 
54 // Async runtime uses LLVM coroutines to represent asynchronous tasks. Task
55 // function is a coroutine handle and a resume function that continue coroutine
56 // execution from a suspension point.
57 using CoroHandle = void *;           // coroutine handle
58 using CoroResume = void (*)(void *); // coroutine resume function
59 
60 // Async runtime uses reference counting to manage the lifetime of async values
61 // (values of async types like tokens, values and groups).
62 using RefCountedObjPtr = void *;
63 
64 // Adds references to reference counted runtime object.
65 extern "C" MLIR_ASYNC_RUNTIME_EXPORT void
66     mlirAsyncRuntimeAddRef(RefCountedObjPtr, int64_t);
67 
68 // Drops references from reference counted runtime object.
69 extern "C" MLIR_ASYNC_RUNTIME_EXPORT void
70     mlirAsyncRuntimeDropRef(RefCountedObjPtr, int64_t);
71 
72 // Create a new `async.token` in not-ready state.
73 extern "C" MLIR_ASYNC_RUNTIME_EXPORT AsyncToken *mlirAsyncRuntimeCreateToken();
74 
75 // Create a new `async.value` in not-ready state. Size parameter specifies the
76 // number of bytes that will be allocated for the async value storage. Storage
77 // is owned by the `async.value` and deallocated when the async value is
78 // destructed (reference count drops to zero).
79 extern "C" MLIR_ASYNC_RUNTIME_EXPORT AsyncValue *
80     mlirAsyncRuntimeCreateValue(int64_t);
81 
82 // Create a new `async.group` in empty state.
83 extern "C" MLIR_ASYNC_RUNTIME_EXPORT AsyncGroup *
84 mlirAsyncRuntimeCreateGroup(int64_t size);
85 
86 extern "C" MLIR_ASYNC_RUNTIME_EXPORT int64_t
87 mlirAsyncRuntimeAddTokenToGroup(AsyncToken *, AsyncGroup *);
88 
89 // Switches `async.token` to ready state and runs all awaiters.
90 extern "C" MLIR_ASYNC_RUNTIME_EXPORT void
91 mlirAsyncRuntimeEmplaceToken(AsyncToken *);
92 
93 // Switches `async.value` to ready state and runs all awaiters.
94 extern "C" MLIR_ASYNC_RUNTIME_EXPORT void
95 mlirAsyncRuntimeEmplaceValue(AsyncValue *);
96 
97 // Switches `async.token` to error state and runs all awaiters.
98 extern "C" MLIR_ASYNC_RUNTIME_EXPORT void
99 mlirAsyncRuntimeSetTokenError(AsyncToken *);
100 
101 // Switches `async.value` to error state and runs all awaiters.
102 extern "C" MLIR_ASYNC_RUNTIME_EXPORT void
103 mlirAsyncRuntimeSetValueError(AsyncValue *);
104 
105 // Returns true if token is in the error state.
106 extern "C" MLIR_ASYNC_RUNTIME_EXPORT bool
107 mlirAsyncRuntimeIsTokenError(AsyncToken *);
108 
109 // Returns true if value is in the error state.
110 extern "C" MLIR_ASYNC_RUNTIME_EXPORT bool
111 mlirAsyncRuntimeIsValueError(AsyncValue *);
112 
113 // Returns true if group is in the error state (any of the tokens or values
114 // added to the group are in the error state).
115 extern "C" MLIR_ASYNC_RUNTIME_EXPORT bool
116 mlirAsyncRuntimeIsGroupError(AsyncGroup *);
117 
118 // Blocks the caller thread until the token becomes ready.
119 extern "C" MLIR_ASYNC_RUNTIME_EXPORT void
120 mlirAsyncRuntimeAwaitToken(AsyncToken *);
121 
122 // Blocks the caller thread until the value becomes ready.
123 extern "C" MLIR_ASYNC_RUNTIME_EXPORT void
124 mlirAsyncRuntimeAwaitValue(AsyncValue *);
125 
126 // Blocks the caller thread until the elements in the group become ready.
127 extern "C" MLIR_ASYNC_RUNTIME_EXPORT void
128 mlirAsyncRuntimeAwaitAllInGroup(AsyncGroup *);
129 
130 // Returns a pointer to the storage owned by the async value.
131 extern "C" MLIR_ASYNC_RUNTIME_EXPORT ValueStorage
132 mlirAsyncRuntimeGetValueStorage(AsyncValue *);
133 
134 // Executes the task (coro handle + resume function) in one of the threads
135 // managed by the runtime.
136 extern "C" MLIR_ASYNC_RUNTIME_EXPORT void mlirAsyncRuntimeExecute(CoroHandle,
137                                                                   CoroResume);
138 
139 // Executes the task (coro handle + resume function) in one of the threads
140 // managed by the runtime after the token becomes ready.
141 extern "C" MLIR_ASYNC_RUNTIME_EXPORT void
142 mlirAsyncRuntimeAwaitTokenAndExecute(AsyncToken *, CoroHandle, CoroResume);
143 
144 // Executes the task (coro handle + resume function) in one of the threads
145 // managed by the runtime after the value becomes ready.
146 extern "C" MLIR_ASYNC_RUNTIME_EXPORT void
147 mlirAsyncRuntimeAwaitValueAndExecute(AsyncValue *, CoroHandle, CoroResume);
148 
149 // Executes the task (coro handle + resume function) in one of the threads
150 // managed by the runtime after the all members of the group become ready.
151 extern "C" MLIR_ASYNC_RUNTIME_EXPORT void
152 mlirAsyncRuntimeAwaitAllInGroupAndExecute(AsyncGroup *, CoroHandle, CoroResume);
153 
154 // Returns the current number of available worker threads in the threadpool.
155 extern "C" MLIR_ASYNC_RUNTIME_EXPORT int64_t
156 mlirAsyncRuntimGetNumWorkerThreads();
157 
158 //===----------------------------------------------------------------------===//
159 // Small async runtime support library for testing.
160 //===----------------------------------------------------------------------===//
161 
162 extern "C" MLIR_ASYNC_RUNTIME_EXPORT void
163 mlirAsyncRuntimePrintCurrentThreadId();
164 
165 } // namespace runtime
166 } // namespace mlir
167 
168 #endif // MLIR_EXECUTIONENGINE_ASYNCRUNTIME_H_
169