1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/LibOVR/Src/Kernel/OVR_SharedMemory.h	Wed Jan 14 06:51:16 2015 +0200
     1.3 @@ -0,0 +1,240 @@
     1.4 +/************************************************************************************
     1.5 +
     1.6 +PublicHeader:   OVR
     1.7 +Filename    :   OVR_SharedMemory.h
     1.8 +Content     :   Inter-process shared memory subsystem
     1.9 +Created     :   June 1, 2014
    1.10 +Notes       : 
    1.11 +
    1.12 +Copyright   :   Copyright 2014 Oculus VR, LLC All Rights reserved.
    1.13 +
    1.14 +Licensed under the Oculus VR Rift SDK License Version 3.2 (the "License"); 
    1.15 +you may not use the Oculus VR Rift SDK except in compliance with the License, 
    1.16 +which is provided at the time of installation or download, or which 
    1.17 +otherwise accompanies this software in either electronic or hard copy form.
    1.18 +
    1.19 +You may obtain a copy of the License at
    1.20 +
    1.21 +http://www.oculusvr.com/licenses/LICENSE-3.2 
    1.22 +
    1.23 +Unless required by applicable law or agreed to in writing, the Oculus VR SDK 
    1.24 +distributed under the License is distributed on an "AS IS" BASIS,
    1.25 +WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    1.26 +See the License for the specific language governing permissions and
    1.27 +limitations under the License.
    1.28 +
    1.29 +************************************************************************************/
    1.30 +
    1.31 +#ifndef OVR_SharedMemory_h
    1.32 +#define OVR_SharedMemory_h
    1.33 +
    1.34 +#include "OVR_Types.h"
    1.35 +#include "OVR_RefCount.h"
    1.36 +#include "OVR_Allocator.h"
    1.37 +#include "OVR_System.h"
    1.38 +
    1.39 +#ifdef OVR_SINGLE_PROCESS /* Everything running in one process usually for debugging */
    1.40 +#define OVR_FAKE_SHAREDMEMORY /* Single-process version to avoid admin privs */
    1.41 +#endif
    1.42 +
    1.43 +namespace OVR {
    1.44 +
    1.45 +class SharedMemoryInternal; // Opaque
    1.46 +
    1.47 +
    1.48 +// SharedMemory
    1.49 +// Note: Safe when used between 32-bit and 64-bit processes
    1.50 +class SharedMemory : public RefCountBase<SharedMemory>
    1.51 +{
    1.52 +	friend class SharedMemoryFactory;
    1.53 +
    1.54 +	OVR_NON_COPYABLE(SharedMemory);
    1.55 +
    1.56 +public:
    1.57 +	// Only constructed by the SharedMemory Factory
    1.58 +    SharedMemory(int size, void* data, SharedMemoryInternal* pInternal);
    1.59 +	// Call close when it goes out of scope
    1.60 +    ~SharedMemory();
    1.61 +
    1.62 +	// Modes for opening a new shared memory region
    1.63 +	enum OpenMode
    1.64 +	{
    1.65 +		// Note: On Windows, Create* requires Administrator priviledges or running as a Service.
    1.66 +		OpenMode_CreateOnly,		// Must not already exist
    1.67 +		OpenMode_OpenOnly,			// Must already exist
    1.68 +		OpenMode_CreateOrOpen		// May exist or not
    1.69 +	};
    1.70 +
    1.71 +	// Local access restrictions
    1.72 +	enum AccessMode
    1.73 +	{
    1.74 +		AccessMode_ReadOnly,		// Acquire read-only access
    1.75 +		AccessMode_ReadWrite,		// Acquire read or write access
    1.76 +	};
    1.77 +
    1.78 +	// Remote access restrictions
    1.79 +	enum RemoteMode
    1.80 +	{
    1.81 +		RemoteMode_ReadOnly,		// Other processes will need to open in read-only mode
    1.82 +		RemoteMode_ReadWrite		// Other processes can open in read-write mode
    1.83 +	};
    1.84 +
    1.85 +	// Modes for opening a new shared memory region
    1.86 +	struct OpenParameters
    1.87 +	{
    1.88 +		OpenParameters() :
    1.89 +			globalName(NULL),
    1.90 +			minSizeBytes(0),
    1.91 +			openMode(SharedMemory::OpenMode_CreateOrOpen),
    1.92 +			remoteMode(SharedMemory::RemoteMode_ReadWrite),
    1.93 +			accessMode(SharedMemory::AccessMode_ReadWrite)
    1.94 +		{
    1.95 +		}
    1.96 +
    1.97 +		// Creation parameters
    1.98 +		const char*					globalName;		// Name of the shared memory region
    1.99 +		int							minSizeBytes;	// Minimum number of bytes to request
   1.100 +		SharedMemory::OpenMode		openMode;		// Creating the file or opening the file?
   1.101 +		SharedMemory::RemoteMode	remoteMode;		// When creating, what access should other processes get?
   1.102 +		SharedMemory::AccessMode	accessMode;		// When opening/creating, what access should this process get?
   1.103 +	};
   1.104 +
   1.105 +public:
   1.106 +	// Returns the size of the shared memory region
   1.107 +	int GetSizeI() const
   1.108 +	{
   1.109 +		return Size;
   1.110 +	}
   1.111 +
   1.112 +	// Returns the process-local pointer to the shared memory region
   1.113 +	// Note: This may be different on different processes
   1.114 +	void* GetData() const
   1.115 +	{
   1.116 +		return Data;
   1.117 +	}
   1.118 +
   1.119 +protected:
   1.120 +	int Size;		// How many shared bytes are shared at the pointer address?
   1.121 +	void* Data;		// Pointer to the shared memory region.
   1.122 +
   1.123 +	// Hidden implementation class for OS-specific behavior
   1.124 +	SharedMemoryInternal* Internal;
   1.125 +
   1.126 +	// Close and cleanup the shared memory region
   1.127 +	// Note: This is called on destruction
   1.128 +	void Close();
   1.129 +};
   1.130 +
   1.131 +
   1.132 +// SharedMemoryFactory
   1.133 +class SharedMemoryFactory : public NewOverrideBase, public SystemSingletonBase<SharedMemoryFactory>
   1.134 +{
   1.135 +    OVR_DECLARE_SINGLETON(SharedMemoryFactory);
   1.136 +
   1.137 +public:
   1.138 +    // Construct a SharedMemory object.
   1.139 +	// Note: The new object is reference-counted so it should be stored with Ptr<>.  Initial reference count is 1.
   1.140 +	Ptr<SharedMemory> Open(const SharedMemory::OpenParameters&);
   1.141 +};
   1.142 +
   1.143 +
   1.144 +// A shared object
   1.145 +// Its constructor will be called when creating a writer
   1.146 +// Its destructor will not be called
   1.147 +template<class SharedType>
   1.148 +class ISharedObject : public NewOverrideBase
   1.149 +{
   1.150 +public:
   1.151 +	static const int RegionSize = (int)sizeof(SharedType);
   1.152 +
   1.153 +protected:
   1.154 +	Ptr<SharedMemory> pSharedMemory;
   1.155 +
   1.156 +	bool Open(const char* name, bool readOnly)
   1.157 +	{
   1.158 +		// Configure open parameters based on read-only mode
   1.159 +		SharedMemory::OpenParameters params;
   1.160 +
   1.161 +        // FIXME: This is a hack.  We currently need to allow clients to open this for read-write even
   1.162 +        // though they only need read-only access.  This is because in the first 0.4 release the
   1.163 +        // LocklessUpdater class technically writes to it (increments by 0) to read from the space.
   1.164 +        // This was quickly corrected in 0.4.1 and we are waiting for the right time to disallow write
   1.165 +        // access when everyone upgrades to 0.4.1+.
   1.166 +        //params.remoteMode = SharedMemory::RemoteMode_ReadOnly;
   1.167 +        params.remoteMode = SharedMemory::RemoteMode_ReadWrite;
   1.168 +
   1.169 +        params.globalName = name;
   1.170 +        params.accessMode = readOnly ? SharedMemory::AccessMode_ReadOnly : SharedMemory::AccessMode_ReadWrite;
   1.171 +        params.minSizeBytes = RegionSize;
   1.172 +		params.openMode = readOnly ? SharedMemory::OpenMode_OpenOnly : SharedMemory::OpenMode_CreateOrOpen;
   1.173 +
   1.174 +		// Attempt to open the shared memory file
   1.175 +		pSharedMemory = SharedMemoryFactory::GetInstance()->Open(params);
   1.176 +
   1.177 +		// If it was not able to be opened,
   1.178 +		if (pSharedMemory && pSharedMemory->GetSizeI() >= RegionSize && pSharedMemory->GetData())
   1.179 +		{
   1.180 +			// If writing,
   1.181 +			if (!readOnly)
   1.182 +			{
   1.183 +				// Construct the object also
   1.184 +				Construct<SharedType>(pSharedMemory->GetData());
   1.185 +			}
   1.186 +
   1.187 +			return true;
   1.188 +		}
   1.189 +
   1.190 +		return false;
   1.191 +	}
   1.192 +
   1.193 +	SharedType* Get() const
   1.194 +	{
   1.195 +		if (!pSharedMemory)
   1.196 +		{
   1.197 +			return NULL;
   1.198 +		}
   1.199 +
   1.200 +		void* data = pSharedMemory->GetData();
   1.201 +		if (!data)
   1.202 +		{
   1.203 +			return NULL;
   1.204 +		}
   1.205 +
   1.206 +		return reinterpret_cast<SharedType*>(data);
   1.207 +	}
   1.208 +};
   1.209 +
   1.210 +// Writer specialized shared object: Ctor will be called on Open()
   1.211 +template<class SharedType>
   1.212 +class SharedObjectWriter : public ISharedObject<SharedType>
   1.213 +{
   1.214 +public:
   1.215 +	OVR_FORCE_INLINE bool Open(const char* name)
   1.216 +	{
   1.217 +		return ISharedObject<SharedType>::Open(name, false);
   1.218 +	}
   1.219 +	OVR_FORCE_INLINE SharedType* Get()
   1.220 +	{
   1.221 +		return ISharedObject<SharedType>::Get();
   1.222 +	}
   1.223 +};
   1.224 +
   1.225 +// Reader specialized shared object: Ctor will not be called
   1.226 +template<class SharedType>
   1.227 +class SharedObjectReader : public ISharedObject<SharedType>
   1.228 +{
   1.229 +public:
   1.230 +	OVR_FORCE_INLINE bool Open(const char* name)
   1.231 +	{
   1.232 +		return ISharedObject<SharedType>::Open(name, true);
   1.233 +	}
   1.234 +	OVR_FORCE_INLINE const SharedType* Get() const
   1.235 +	{
   1.236 +		return ISharedObject<SharedType>::Get();
   1.237 +	}
   1.238 +};
   1.239 +
   1.240 +
   1.241 +} // namespace OVR
   1.242 +
   1.243 +#endif // OVR_SharedMemory_h