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Diffstat (limited to 'indra/llplugin/llpluginsharedmemory.h')
-rw-r--r-- | indra/llplugin/llpluginsharedmemory.h | 125 |
1 files changed, 125 insertions, 0 deletions
diff --git a/indra/llplugin/llpluginsharedmemory.h b/indra/llplugin/llpluginsharedmemory.h new file mode 100644 index 0000000000..c6cd49cabb --- /dev/null +++ b/indra/llplugin/llpluginsharedmemory.h @@ -0,0 +1,125 @@ +/** + * @file llpluginsharedmemory.h + * + * @cond + * $LicenseInfo:firstyear=2008&license=viewerlgpl$ + * Second Life Viewer Source Code + * Copyright (C) 2010, Linden Research, Inc. + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; + * version 2.1 of the License only. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + * + * Linden Research, Inc., 945 Battery Street, San Francisco, CA 94111 USA + * $/LicenseInfo$ + * @endcond + */ + +#ifndef LL_LLPLUGINSHAREDMEMORY_H +#define LL_LLPLUGINSHAREDMEMORY_H + +class LLPluginSharedMemoryPlatformImpl; + +/** + * @brief LLPluginSharedMemory manages a shared memory segment for use by the LLPlugin API. + * + */ +class LLPluginSharedMemory +{ + LOG_CLASS(LLPluginSharedMemory); +public: + LLPluginSharedMemory(); + ~LLPluginSharedMemory(); + + // Parent will use create/destroy, child will use attach/detach. + // Message transactions will ensure child attaches after parent creates and detaches before parent destroys. + + /** + * Creates a shared memory segment, with a name which is guaranteed to be unique on the host at the current time. Used by parent. + * Message transactions will (? TODO:DOC - should? must?) ensure child attaches after parent creates and detaches before parent destroys. + * + * @param[in] size Shared memory size in TODO:DOC units = bytes?. + * + * @return False for failure, true for success. + */ + bool create(size_t size); + /** + * Destroys a shared memory segment. Used by parent. + * Message transactions will (? TODO:DOC - should? must?) ensure child attaches after parent creates and detaches before parent destroys. + * + * @return True. TODO:DOC - always returns true. Is this the intended behavior? + */ + bool destroy(void); + + /** + * Creates and attaches a name to a shared memory segment. TODO:DOC what's the difference between attach() and create()? + * + * @param[in] name Name to attach to memory segment + * @param[in] size Size of memory segment TODO:DOC in bytes? + * + * @return False on failure, true otherwise. + */ + bool attach(const std::string &name, size_t size); + /** + * Detaches shared memory segment. + * + * @return False on failure, true otherwise. + */ + bool detach(void); + + /** + * Checks if shared memory is mapped to a non-null address. + * + * @return True if memory address is non-null, false otherwise. + */ + bool isMapped(void) const { return (mMappedAddress != NULL); }; + /** + * Get pointer to shared memory. + * + * @return Pointer to shared memory. + */ + void *getMappedAddress(void) const { return mMappedAddress; }; + /** + * Get size of shared memory. + * + * @return Size of shared memory in bytes. TODO:DOC are bytes the correct unit? + */ + size_t getSize(void) const { return mSize; }; + /** + * Get name of shared memory. + * + * @return Name of shared memory. + */ + std::string getName() const { return mName; }; + +private: + bool map(void); + bool unmap(void); + bool close(void); + bool unlink(void); + + std::string mName; + size_t mSize; + void *mMappedAddress; + bool mNeedsDestroy; + + LLPluginSharedMemoryPlatformImpl *mImpl; + + static int sSegmentNumber; + static std::string createName(); + +}; + + + +#endif // LL_LLPLUGINSHAREDMEMORY_H |