All Classes Namespaces Files Functions Variables Typedefs Enumerations Enumerator Friends Macros Groups Pages
pyLock.h
1 //
2 // Copyright 2016 Pixar
3 //
4 // Licensed under the Apache License, Version 2.0 (the "Apache License")
5 // with the following modification; you may not use this file except in
6 // compliance with the Apache License and the following modification to it:
7 // Section 6. Trademarks. is deleted and replaced with:
8 //
9 // 6. Trademarks. This License does not grant permission to use the trade
10 // names, trademarks, service marks, or product names of the Licensor
11 // and its affiliates, except as required to comply with Section 4(c) of
12 // the License and to reproduce the content of the NOTICE file.
13 //
14 // You may obtain a copy of the Apache License at
15 //
16 // http://www.apache.org/licenses/LICENSE-2.0
17 //
18 // Unless required by applicable law or agreed to in writing, software
19 // distributed under the Apache License with the above modification is
20 // distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
21 // KIND, either express or implied. See the Apache License for the specific
22 // language governing permissions and limitations under the Apache License.
23 //
24 #ifndef TF_PYLOCK_H
25 #define TF_PYLOCK_H
26 
27 #include "pxr/pxr.h"
28 
29 #ifdef PXR_PYTHON_SUPPORT_ENABLED
30 
31 #include <Python.h>
32 
33 #include "pxr/base/tf/api.h"
34 
35 PXR_NAMESPACE_OPEN_SCOPE
36 
122 class TfPyLock {
123 public:
125  TF_API TfPyLock();
126 
128  TF_API ~TfPyLock();
129 
131  TF_API void Acquire();
132 
134  TF_API void Release();
135 
139  TF_API void BeginAllowThreads();
140 
143  TF_API void EndAllowThreads();
144 
145 private:
146  // Non-acquiring constructor for TfPyEnsureGILUnlockedObj's use.
147  friend struct TfPyEnsureGILUnlockedObj;
148  enum _UnlockedTag { _ConstructUnlocked };
149  explicit TfPyLock(_UnlockedTag);
150 
151  PyGILState_STATE _gilState;
152  PyThreadState *_savedState;
153  bool _acquired:1;
154  bool _allowingThreads:1;
155 };
156 
157 // Helper class for TF_PY_ALLOW_THREADS_IN_SCOPE()
158 struct TfPyEnsureGILUnlockedObj
159 {
160  // Do nothing if the current thread does not have the GIL, otherwise unlock
161  // the GIL, and relock upon destruction.
162  TF_API TfPyEnsureGILUnlockedObj();
163 private:
164  TfPyLock _lock;
165 };
166 
190 #define TF_PY_ALLOW_THREADS_IN_SCOPE() \
191  TfPyEnsureGILUnlockedObj __py_lock_allow_threads__
192 
193 PXR_NAMESPACE_CLOSE_SCOPE
194 
195 #else
196 
197 // When python is disabled, we stub this macro out to nothing.
198 #define TF_PY_ALLOW_THREADS_IN_SCOPE()
199 
200 #endif // PXR_PYTHON_SUPPORT_ENABLED
201 
202 #endif // TF_PYLOCK_H