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diff --git a/linden/indra/llplugin/llpluginsharedmemory.cpp b/linden/indra/llplugin/llpluginsharedmemory.cpp
new file mode 100644
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--- /dev/null
+++ b/linden/indra/llplugin/llpluginsharedmemory.cpp
@@ -0,0 +1,506 @@
+/** 
+ * @file llpluginsharedmemory.cpp
+ * @brief LLPluginSharedMemory manages a shared memory segment for use by the LLPlugin API.
+ *
+ * $LicenseInfo:firstyear=2008&license=viewergpl$
+ * 
+ * Copyright (c) 2008-2009, Linden Research, Inc.
+ * 
+ * Second Life Viewer Source Code
+ * The source code in this file ("Source Code") is provided by Linden Lab
+ * to you under the terms of the GNU General Public License, version 2.0
+ * ("GPL"), unless you have obtained a separate licensing agreement
+ * ("Other License"), formally executed by you and Linden Lab.  Terms of
+ * the GPL can be found in doc/GPL-license.txt in this distribution, or
+ * online at http://secondlifegrid.net/programs/open_source/licensing/gplv2
+ * 
+ * There are special exceptions to the terms and conditions of the GPL as
+ * it is applied to this Source Code. View the full text of the exception
+ * in the file doc/FLOSS-exception.txt in this software distribution, or
+ * online at
+ * http://secondlifegrid.net/programs/open_source/licensing/flossexception
+ * 
+ * By copying, modifying or distributing this software, you acknowledge
+ * that you have read and understood your obligations described above,
+ * and agree to abide by those obligations.
+ * 
+ * ALL LINDEN LAB SOURCE CODE IS PROVIDED "AS IS." LINDEN LAB MAKES NO
+ * WARRANTIES, EXPRESS, IMPLIED OR OTHERWISE, REGARDING ITS ACCURACY,
+ * COMPLETENESS OR PERFORMANCE.
+ * $/LicenseInfo$
+ */
+
+#include "linden_common.h"
+
+#include "llpluginsharedmemory.h"
+
+// on Mac and Linux, we use the native shm_open/mmap interface by using
+//      #define USE_SHM_OPEN_SHARED_MEMORY 1
+// in the appropriate sections below.
+
+// For Windows, use:
+//      #define USE_WIN32_SHARED_MEMORY 1
+
+// If we ever want to fall back to the apr implementation for a platform, use:
+//      #define USE_APR_SHARED_MEMORY 1
+
+#if LL_WINDOWS
+//      #define USE_APR_SHARED_MEMORY 1
+        #define USE_WIN32_SHARED_MEMORY 1
+#elif LL_DARWIN
+        #define USE_SHM_OPEN_SHARED_MEMORY 1
+#elif LL_LINUX
+        #define USE_SHM_OPEN_SHARED_MEMORY 1
+#endif
+
+
+// FIXME: This path thing is evil and unacceptable.
+#if LL_WINDOWS
+        #define APR_SHARED_MEMORY_PREFIX_STRING "C:\\LLPlugin_"
+        // Apparnently using the "Global\\" prefix here only works from administrative accounts under Vista.
+        // Other options I've seen referenced are "Local\\" and "Session\\".
+        #define WIN32_SHARED_MEMORY_PREFIX_STRING "Local\\LL_"
+#else
+        // mac and linux
+        #define APR_SHARED_MEMORY_PREFIX_STRING "/tmp/LLPlugin_"
+        #define SHM_OPEN_SHARED_MEMORY_PREFIX_STRING "/LL"
+#endif
+
+#if USE_APR_SHARED_MEMORY 
+        #include "llapr.h"
+        #include "apr_shm.h"
+#elif USE_SHM_OPEN_SHARED_MEMORY
+        #include <sys/fcntl.h>
+        #include <sys/mman.h>
+        #include <errno.h>
+#elif USE_WIN32_SHARED_MEMORY
+#include <windows.h>
+#endif // USE_APR_SHARED_MEMORY
+
+
+int LLPluginSharedMemory::sSegmentNumber = 0;
+
+std::string LLPluginSharedMemory::createName(void)
+{
+        std::stringstream newname;
+
+#if LL_WINDOWS
+        newname << GetCurrentProcessId();
+#else // LL_WINDOWS
+        newname << getpid();
+#endif // LL_WINDOWS
+                
+        newname << "_" << sSegmentNumber++;
+        
+        return newname.str();
+}
+
+/**
+ * @brief LLPluginSharedMemoryImpl is the platform-dependent implementation of LLPluginSharedMemory. TODO:DOC is this necessary/sufficient? kinda obvious.
+ *
+ */
+class LLPluginSharedMemoryPlatformImpl
+{
+public:
+        LLPluginSharedMemoryPlatformImpl();
+        ~LLPluginSharedMemoryPlatformImpl();
+        
+#if USE_APR_SHARED_MEMORY
+        apr_shm_t* mAprSharedMemory;    
+#elif USE_SHM_OPEN_SHARED_MEMORY
+        int mSharedMemoryFD;
+#elif USE_WIN32_SHARED_MEMORY
+        HANDLE mMapFile;
+#endif
+
+};
+
+/**
+ * Constructor. Creates a shared memory segment.
+ */
+LLPluginSharedMemory::LLPluginSharedMemory()
+{
+        mSize = 0;
+        mMappedAddress = NULL;
+        mNeedsDestroy = false;
+
+        mImpl = new LLPluginSharedMemoryPlatformImpl;
+}
+
+/**
+ * Destructor. Uses destroy() and detach() to ensure shared memory segment is cleaned up.
+ */
+LLPluginSharedMemory::~LLPluginSharedMemory()
+{
+        if(mNeedsDestroy)
+                destroy();
+        else
+                detach();
+                
+        unlink();
+        
+        delete mImpl;
+}
+
+#if USE_APR_SHARED_MEMORY
+// MARK: apr implementation
+
+LLPluginSharedMemoryPlatformImpl::LLPluginSharedMemoryPlatformImpl()
+{
+        mAprSharedMemory = NULL;
+}
+
+LLPluginSharedMemoryPlatformImpl::~LLPluginSharedMemoryPlatformImpl()
+{
+        
+}
+
+bool LLPluginSharedMemory::map(void)
+{
+        mMappedAddress = apr_shm_baseaddr_get(mImpl->mAprSharedMemory);
+        if(mMappedAddress == NULL)
+        {
+                return false;
+        }
+        
+        return true;
+}
+
+bool LLPluginSharedMemory::unmap(void)
+{
+        // This is a no-op under apr.
+        return true;
+}
+
+bool LLPluginSharedMemory::close(void)
+{
+        // This is a no-op under apr.
+        return true;
+}
+
+bool LLPluginSharedMemory::unlink(void)
+{
+        // This is a no-op under apr.
+        return true;
+}
+
+
+bool LLPluginSharedMemory::create(size_t size)
+{
+        mName = APR_SHARED_MEMORY_PREFIX_STRING;
+        mName += createName();
+        mSize = size;
+        
+        apr_status_t status = apr_shm_create( &(mImpl->mAprSharedMemory), mSize, mName.c_str(), gAPRPoolp );
+        
+        if(ll_apr_warn_status(status))
+        {
+                return false;
+        }
+
+        mNeedsDestroy = true;
+        
+        return map();
+}
+
+bool LLPluginSharedMemory::destroy(void)
+{
+        if(mImpl->mAprSharedMemory)
+        {
+                apr_status_t status = apr_shm_destroy(mImpl->mAprSharedMemory);
+                if(ll_apr_warn_status(status))
+                {
+                        // TODO: Is this a fatal error?  I think not...
+                }
+                mImpl->mAprSharedMemory = NULL;
+        }
+        
+        return true;
+}
+
+bool LLPluginSharedMemory::attach(const std::string &name, size_t size)
+{
+        mName = name;
+        mSize = size;
+        
+        apr_status_t status = apr_shm_attach( &(mImpl->mAprSharedMemory), mName.c_str(), gAPRPoolp );
+        
+        if(ll_apr_warn_status(status))
+        {
+                return false;
+        }
+
+        return map();
+}
+
+
+bool LLPluginSharedMemory::detach(void)
+{
+        if(mImpl->mAprSharedMemory)
+        {
+                apr_status_t status = apr_shm_detach(mImpl->mAprSharedMemory);
+                if(ll_apr_warn_status(status))
+                {
+                        // TODO: Is this a fatal error?  I think not...
+                }
+                mImpl->mAprSharedMemory = NULL;
+        }
+        
+        return true;
+}
+
+
+#elif USE_SHM_OPEN_SHARED_MEMORY
+// MARK: shm_open/mmap implementation
+
+LLPluginSharedMemoryPlatformImpl::LLPluginSharedMemoryPlatformImpl()
+{
+        mSharedMemoryFD = -1;
+}
+
+LLPluginSharedMemoryPlatformImpl::~LLPluginSharedMemoryPlatformImpl()
+{
+}
+
+bool LLPluginSharedMemory::map(void)
+{
+        mMappedAddress = ::mmap(NULL, mSize, PROT_READ | PROT_WRITE, MAP_SHARED, mImpl->mSharedMemoryFD, 0);
+        if(mMappedAddress == NULL)
+        {
+                return false;
+        }
+        
+        LL_DEBUGS("Plugin") << "memory mapped at " << mMappedAddress << LL_ENDL;
+
+        return true;
+}
+
+bool LLPluginSharedMemory::unmap(void)
+{
+        if(mMappedAddress != NULL)
+        {
+                LL_DEBUGS("Plugin") << "calling munmap(" << mMappedAddress << ", " << mSize << ")" << LL_ENDL;
+                if(::munmap(mMappedAddress, mSize) == -1)       
+                {
+                        // TODO: Is this a fatal error?  I think not...
+                }
+                
+                mMappedAddress = NULL;
+        }
+
+        return true;
+}
+
+bool LLPluginSharedMemory::close(void)
+{
+        if(mImpl->mSharedMemoryFD != -1)
+        {
+                LL_DEBUGS("Plugin") << "calling close(" << mImpl->mSharedMemoryFD << ")" << LL_ENDL;
+                if(::close(mImpl->mSharedMemoryFD) == -1)
+                {
+                        // TODO: Is this a fatal error?  I think not...
+                }
+                
+                mImpl->mSharedMemoryFD = -1;
+        }
+        return true;
+}
+
+bool LLPluginSharedMemory::unlink(void)
+{
+        if(!mName.empty())
+        {
+                if(::shm_unlink(mName.c_str()) == -1)
+                {
+                        return false;
+                }
+        }
+                
+        return true;
+}
+
+
+bool LLPluginSharedMemory::create(size_t size)
+{
+        mName = SHM_OPEN_SHARED_MEMORY_PREFIX_STRING;
+        mName += createName();
+        mSize = size;
+        
+        // Preemptive unlink, just in case something didn't get cleaned up.
+        unlink();
+
+        mImpl->mSharedMemoryFD = ::shm_open(mName.c_str(), O_CREAT | O_RDWR, S_IRUSR | S_IWUSR);
+        if(mImpl->mSharedMemoryFD == -1)
+        {
+                return false;
+        }
+        
+        mNeedsDestroy = true;
+        
+        if(::ftruncate(mImpl->mSharedMemoryFD, mSize) == -1)
+        {
+                return false;
+        }
+        
+        
+        return map();
+}
+
+bool LLPluginSharedMemory::destroy(void)
+{
+        unmap();
+        close();        
+        
+        return true;
+}
+
+
+bool LLPluginSharedMemory::attach(const std::string &name, size_t size)
+{
+        mName = name;
+        mSize = size;
+
+        mImpl->mSharedMemoryFD = ::shm_open(mName.c_str(), O_RDWR, S_IRUSR | S_IWUSR);
+        if(mImpl->mSharedMemoryFD == -1)
+        {
+                return false;
+        }
+        
+        // unlink here so the segment will be cleaned up automatically after the last close.
+        unlink();
+        
+        return map();
+}
+
+bool LLPluginSharedMemory::detach(void)
+{
+        unmap();
+        close();        
+        return true;
+}
+
+#elif USE_WIN32_SHARED_MEMORY
+// MARK: Win32 CreateFileMapping-based implementation
+
+// Reference: http://msdn.microsoft.com/en-us/library/aa366551(VS.85).aspx
+
+LLPluginSharedMemoryPlatformImpl::LLPluginSharedMemoryPlatformImpl()
+{
+        mMapFile = NULL;
+}
+
+LLPluginSharedMemoryPlatformImpl::~LLPluginSharedMemoryPlatformImpl()
+{
+        
+}
+
+bool LLPluginSharedMemory::map(void)
+{
+        mMappedAddress = MapViewOfFile(
+                mImpl->mMapFile,                        // handle to map object
+                FILE_MAP_ALL_ACCESS,            // read/write permission
+                0,                   
+                0,                   
+                mSize);
+                
+        if(mMappedAddress == NULL)
+        {
+                LL_WARNS("Plugin") << "MapViewOfFile failed: " << GetLastError() << LL_ENDL;
+                return false;
+        }
+        
+        LL_DEBUGS("Plugin") << "memory mapped at " << mMappedAddress << LL_ENDL;
+
+        return true;
+}
+
+bool LLPluginSharedMemory::unmap(void)
+{
+        if(mMappedAddress != NULL)
+        {
+                UnmapViewOfFile(mMappedAddress);        
+                mMappedAddress = NULL;
+        }
+
+        return true;
+}
+
+bool LLPluginSharedMemory::close(void)
+{
+        if(mImpl->mMapFile != NULL)
+        {
+                CloseHandle(mImpl->mMapFile);
+                mImpl->mMapFile = NULL;
+        }
+        
+        return true;
+}
+
+bool LLPluginSharedMemory::unlink(void)
+{
+        // This is a no-op on Windows.
+        return true;
+}
+
+
+bool LLPluginSharedMemory::create(size_t size)
+{
+        mName = WIN32_SHARED_MEMORY_PREFIX_STRING;
+        mName += createName();
+        mSize = size;
+
+        mImpl->mMapFile = CreateFileMappingA(
+                 INVALID_HANDLE_VALUE,          // use paging file
+                 NULL,                                          // default security 
+                 PAGE_READWRITE,                        // read/write access
+                 0,                                                     // max. object size 
+                 mSize,                                         // buffer size  
+                 mName.c_str());                        // name of mapping object
+
+        if(mImpl->mMapFile == NULL)
+        {
+                LL_WARNS("Plugin") << "CreateFileMapping failed: " << GetLastError() << LL_ENDL;
+                return false;
+        }
+
+        mNeedsDestroy = true;
+                
+        return map();
+}
+
+bool LLPluginSharedMemory::destroy(void)
+{
+        unmap();
+        close();
+        return true;
+}
+
+bool LLPluginSharedMemory::attach(const std::string &name, size_t size)
+{
+        mName = name;
+        mSize = size;
+
+        mImpl->mMapFile = OpenFileMappingA(
+                                FILE_MAP_ALL_ACCESS,            // read/write access
+                                FALSE,                                          // do not inherit the name
+                                mName.c_str());                         // name of mapping object
+        
+        if(mImpl->mMapFile == NULL)
+        {
+                LL_WARNS("Plugin") << "OpenFileMapping failed: " << GetLastError() << LL_ENDL;
+                return false;
+        }
+                
+        return map();
+}
+
+bool LLPluginSharedMemory::detach(void)
+{
+        unmap();
+        close();
+        return true;
+}
+
+
+
+#endif