| // Copyright 2011 Google Inc. |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| // |
| // Author: morlovich@google.com (Maksim Orlovich) |
| |
| #ifndef PAGESPEED_KERNEL_BASE_NULL_SHARED_MEM_H_ |
| #define PAGESPEED_KERNEL_BASE_NULL_SHARED_MEM_H_ |
| |
| #include <cstddef> |
| #include "pagespeed/kernel/base/abstract_shared_mem.h" |
| #include "pagespeed/kernel/base/basictypes.h" |
| #include "pagespeed/kernel/base/string.h" |
| |
| namespace net_instaweb { |
| |
| class MessageHandler; |
| |
| // A stub implementation of shared memory for systems where we do not |
| // have a real one. Fails all the operations. |
| class NullSharedMem : public AbstractSharedMem { |
| public: |
| NullSharedMem(); |
| virtual ~NullSharedMem(); |
| |
| virtual size_t SharedMutexSize() const; |
| |
| virtual AbstractSharedMemSegment* CreateSegment( |
| const GoogleString& name, size_t size, MessageHandler* handler); |
| |
| // Attaches to an existing segment, which must have been created already. |
| // May return NULL on failure |
| virtual AbstractSharedMemSegment* AttachToSegment( |
| const GoogleString& name, size_t size, MessageHandler* handler); |
| |
| virtual void DestroySegment(const GoogleString& name, |
| MessageHandler* handler); |
| |
| // Does not actually support any operations. |
| virtual bool IsDummy() { return true; } |
| |
| private: |
| DISALLOW_COPY_AND_ASSIGN(NullSharedMem); |
| }; |
| |
| } // namespace net_instaweb |
| |
| #endif // PAGESPEED_KERNEL_BASE_NULL_SHARED_MEM_H_ |