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<ul>
<li>
<div class="section-link"><a href="api-sync-behavior.html#api-sync-behavior">1. API synchronization behavior </a></div>
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<div class="section-link"><a href="stream-sync-behavior.html#stream-sync-behavior">2. Stream synchronization behavior</a></div>
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<div class="section-link"><a href="modules.html#modules">3. Modules</a></div>
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<div class="section-link"><a href="group__CUDA__TYPES.html#group__CUDA__TYPES">3.1. Data types used by CUDA driver</a></div>
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<div class="section-link"><a href="group__CUDA__ERROR.html#group__CUDA__ERROR">3.2. Error Handling</a></div>
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<div class="section-link"><a href="group__CUDA__INITIALIZE.html#group__CUDA__INITIALIZE">3.3. Initialization</a></div>
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<div class="section-link"><a href="group__CUDA__VERSION.html#group__CUDA__VERSION">3.4. Version Management</a></div>
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<div class="section-link"><a href="group__CUDA__DEVICE.html#group__CUDA__DEVICE">3.5. Device Management</a></div>
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<div class="section-link"><a href="group__CUDA__DEVICE__DEPRECATED.html#group__CUDA__DEVICE__DEPRECATED">3.6. Device Management [DEPRECATED]</a></div>
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<div class="section-link"><a href="group__CUDA__CTX.html#group__CUDA__CTX">3.7. Context Management</a></div>
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<div class="section-link"><a href="group__CUDA__CTX__DEPRECATED.html#group__CUDA__CTX__DEPRECATED">3.8. Context Management [DEPRECATED]</a></div>
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<div class="section-link"><a href="group__CUDA__MODULE.html#group__CUDA__MODULE">3.9. Module Management</a></div>
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<div class="section-link"><a href="group__CUDA__MEM.html#group__CUDA__MEM">3.10. Memory Management</a></div>
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<div class="section-link"><a href="group__CUDA__UNIFIED.html#group__CUDA__UNIFIED">3.11. Unified Addressing</a></div>
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<div class="section-link"><a href="group__CUDA__STREAM.html#group__CUDA__STREAM">3.12. Stream Management</a></div>
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<div class="section-link"><a href="group__CUDA__EVENT.html#group__CUDA__EVENT">3.13. Event Management</a></div>
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<div class="section-link"><a href="group__CUDA__EXEC.html#group__CUDA__EXEC">3.14. Execution Control</a></div>
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<div class="section-link"><a href="group__CUDA__EXEC__DEPRECATED.html#group__CUDA__EXEC__DEPRECATED">3.15. Execution Control [DEPRECATED]</a></div>
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<div class="section-link"><a href="group__CUDA__OCCUPANCY.html#group__CUDA__OCCUPANCY">3.16. Occupancy</a></div>
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<div class="section-link"><a href="group__CUDA__TEXREF.html#group__CUDA__TEXREF">3.17. Texture Reference Management</a></div>
</li>
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<div class="section-link"><a href="group__CUDA__TEXREF__DEPRECATED.html#group__CUDA__TEXREF__DEPRECATED">3.18. Texture Reference Management [DEPRECATED]</a></div>
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<div class="section-link"><a href="group__CUDA__SURFREF.html#group__CUDA__SURFREF">3.19. Surface Reference Management</a></div>
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<div class="section-link"><a href="group__CUDA__TEXOBJECT.html#group__CUDA__TEXOBJECT">3.20. Texture Object Management</a></div>
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<div class="section-link"><a href="group__CUDA__SURFOBJECT.html#group__CUDA__SURFOBJECT">3.21. Surface Object Management</a></div>
</li>
<li>
<div class="section-link"><a href="group__CUDA__PEER__ACCESS.html#group__CUDA__PEER__ACCESS">3.22. Peer Context Memory Access</a></div>
</li>
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<div class="section-link"><a href="group__CUDA__GRAPHICS.html#group__CUDA__GRAPHICS">3.23. Graphics Interoperability</a></div>
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<div class="section-link"><a href="group__CUDA__PROFILER.html#group__CUDA__PROFILER">3.24. Profiler Control</a></div>
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<div class="section-link"><a href="group__CUDA__GL.html#group__CUDA__GL">3.25. OpenGL Interoperability</a></div>
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<div class="section-link"><a href="group__CUDA__GL__DEPRECATED.html#group__CUDA__GL__DEPRECATED">3.25.1. OpenGL Interoperability [DEPRECATED]</a></div>
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<div class="section-link"><a href="group__CUDA__D3D9.html#group__CUDA__D3D9">3.26. Direct3D 9 Interoperability</a></div>
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<div class="section-link"><a href="group__CUDA__D3D9__DEPRECATED.html#group__CUDA__D3D9__DEPRECATED">3.26.1. Direct3D 9 Interoperability [DEPRECATED]</a></div>
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<div class="section-link"><a href="group__CUDA__D3D11.html#group__CUDA__D3D11">3.28. Direct3D 11 Interoperability</a></div>
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<div class="section-link"><a href="group__CUDA__D3D11__DEPRECATED.html#group__CUDA__D3D11__DEPRECATED">3.28.1. Direct3D 11 Interoperability [DEPRECATED]</a></div>
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<div class="section-link"><a href="group__CUDA__VDPAU.html#group__CUDA__VDPAU">3.29. VDPAU Interoperability</a></div>
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<div class="section-link"><a href="annotated.html#annotated">4. Data Structures</a></div>
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<div class="section-link"><a href="structCUDA__ARRAY3D__DESCRIPTOR.html#structCUDA__ARRAY3D__DESCRIPTOR">4.1. CUDA_ARRAY3D_DESCRIPTOR</a></div>
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<div class="section-link"><a href="structCUDA__ARRAY__DESCRIPTOR.html#structCUDA__ARRAY__DESCRIPTOR">4.2. CUDA_ARRAY_DESCRIPTOR</a></div>
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<div class="section-link"><a href="structCUDA__MEMCPY2D.html#structCUDA__MEMCPY2D">4.3. CUDA_MEMCPY2D</a></div>
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<div class="section-link"><a href="structCUDA__MEMCPY3D.html#structCUDA__MEMCPY3D">4.4. CUDA_MEMCPY3D</a></div>
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<div class="section-link"><a href="structCUDA__MEMCPY3D__PEER.html#structCUDA__MEMCPY3D__PEER">4.5. CUDA_MEMCPY3D_PEER</a></div>
</li>
<li>
<div class="section-link"><a href="structCUDA__POINTER__ATTRIBUTE__P2P__TOKENS.html#structCUDA__POINTER__ATTRIBUTE__P2P__TOKENS">4.6. CUDA_POINTER_ATTRIBUTE_P2P_TOKENS</a></div>
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<div class="section-link"><a href="structCUDA__RESOURCE__DESC.html#structCUDA__RESOURCE__DESC">4.7. CUDA_RESOURCE_DESC</a></div>
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<div class="section-link"><a href="structCUDA__RESOURCE__VIEW__DESC.html#structCUDA__RESOURCE__VIEW__DESC">4.8. CUDA_RESOURCE_VIEW_DESC</a></div>
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<div class="section-link"><a href="structCUDA__TEXTURE__DESC.html#structCUDA__TEXTURE__DESC">4.9. CUDA_TEXTURE_DESC</a></div>
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<div class="section-link"><a href="structCUdevprop.html#structCUdevprop">4.10. CUdevprop</a></div>
</li>
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<div class="section-link"><a href="structCUipcEventHandle.html#structCUipcEventHandle">4.11. CUipcEventHandle</a></div>
</li>
<li>
<div class="section-link"><a href="structCUipcMemHandle.html#structCUipcMemHandle">4.12. CUipcMemHandle</a></div>
</li>
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<div class="section-link"><a href="functions.html#functions">5. Data Fields</a></div>
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<div class="section-link"><a href="deprecated.html#deprecated">6. Deprecated List</a></div>
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<article id="contents">
<div class="topic reference apiRef apiPackage cppModule" id="group__CUDA__PEER__ACCESS"><a name="group__CUDA__PEER__ACCESS" shape="rect">
<!-- --></a><h2 class="topictitle2 cppModule">3.22. Peer Context Memory Access</h2>
<div class="section">
<p>This section describes the direct peer context memory access functions of the low-level CUDA driver application programming
interface.
</p>
</div>
<h3 class="fake_sectiontitle member_header">Functions</h3>
<dl class="members">
<dt><span class="member_type"><a href="group__CUDA__TYPES.html#group__CUDA__TYPES_1gc6c391505e117393cc2558fff6bfc2e9" title="" shape="rect">CUresult</a> </span><span class="member_name"><a href="#group__CUDA__PEER__ACCESS_1g5b4b6936ea868d4954ce4d841a3b4810" shape="rect">cuCtxDisablePeerAccess</a> ( <a href="group__CUDA__TYPES.html#group__CUDA__TYPES_1gf9f5bd81658f866613785b3a0bb7d7d9" title="" shape="rect">CUcontext</a><span> </span><span class="keyword keyword apiItemName">peerContext</span> ) </span></dt>
<dd class="shortdesc"><span></span><span class="desc">Disables direct access to memory allocations in a peer context and unregisters any registered allocations. </span></dd>
<dt><span class="member_type"><a href="group__CUDA__TYPES.html#group__CUDA__TYPES_1gc6c391505e117393cc2558fff6bfc2e9" title="" shape="rect">CUresult</a> </span><span class="member_name"><a href="#group__CUDA__PEER__ACCESS_1g0889ec6728e61c05ed359551d67b3f5a" shape="rect">cuCtxEnablePeerAccess</a> ( <a href="group__CUDA__TYPES.html#group__CUDA__TYPES_1gf9f5bd81658f866613785b3a0bb7d7d9" title="" shape="rect">CUcontext</a><span> </span><span class="keyword keyword apiItemName">peerContext</span>, unsigned int <span> </span><span class="keyword keyword apiItemName">Flags</span> ) </span></dt>
<dd class="shortdesc"><span></span><span class="desc">Enables direct access to memory allocations in a peer context. </span></dd>
<dt><span class="member_type"><a href="group__CUDA__TYPES.html#group__CUDA__TYPES_1gc6c391505e117393cc2558fff6bfc2e9" title="" shape="rect">CUresult</a> </span><span class="member_name"><a href="#group__CUDA__PEER__ACCESS_1g496bdaae1f632ebfb695b99d2c40f19e" shape="rect">cuDeviceCanAccessPeer</a> ( int*<span> </span><span class="keyword keyword apiItemName">canAccessPeer</span>, <a href="group__CUDA__TYPES.html#group__CUDA__TYPES_1gcd81b70eb9968392bb5cdf582af8eab4" title="" shape="rect">CUdevice</a><span> </span><span class="keyword keyword apiItemName">dev</span>, <a href="group__CUDA__TYPES.html#group__CUDA__TYPES_1gcd81b70eb9968392bb5cdf582af8eab4" title="" shape="rect">CUdevice</a><span> </span><span class="keyword keyword apiItemName">peerDev</span> ) </span></dt>
<dd class="shortdesc"><span></span><span class="desc">Queries if a device may directly access a peer device's memory. </span></dd>
</dl>
<div class="description">
<h3 class="sectiontitle">Functions</h3>
<dl class="description">
<dt class="description"><a name="group__CUDA__PEER__ACCESS_1g5b4b6936ea868d4954ce4d841a3b4810" id="group__CUDA__PEER__ACCESS_1g5b4b6936ea868d4954ce4d841a3b4810" shape="rect">
<!-- --></a><span><a href="group__CUDA__TYPES.html#group__CUDA__TYPES_1gc6c391505e117393cc2558fff6bfc2e9" title="" shape="rect">CUresult</a> cuCtxDisablePeerAccess ( <a href="group__CUDA__TYPES.html#group__CUDA__TYPES_1gf9f5bd81658f866613785b3a0bb7d7d9" title="" shape="rect">CUcontext</a><span> </span><span class="keyword keyword apiItemName">peerContext</span> ) </span></dt>
<dd class="description">
<div class="section">Disables direct access to memory allocations in a peer context and unregisters any registered allocations. </div>
<div class="section">
<h6 class="parameter_header">
Parameters
</h6>
<dl class="table-display-params">
<dt><tt class="code"><span class="keyword keyword apiItemName">peerContext</span></tt></dt>
<dd>- Peer context to disable direct access to</dd>
</dl>
</div>
<div class="section">
<h6 class="return_header">Returns</h6>
<p class="return"><a class="xref" href="group__CUDA__TYPES.html#group__CUDA__TYPES_1ggc6c391505e117393cc2558fff6bfc2e9a0eed720f8a87cd1c5fd1c453bc7a03d" shape="rect">CUDA_SUCCESS</a>, <a class="xref" href="group__CUDA__TYPES.html#group__CUDA__TYPES_1ggc6c391505e117393cc2558fff6bfc2e9acf52f132faf29b473cdda6061f0f44a" shape="rect">CUDA_ERROR_DEINITIALIZED</a>, <a class="xref" href="group__CUDA__TYPES.html#group__CUDA__TYPES_1ggc6c391505e117393cc2558fff6bfc2e98feb999f0af99b4a25ab26b3866f4df8" shape="rect">CUDA_ERROR_NOT_INITIALIZED</a>, <a class="xref" href="group__CUDA__TYPES.html#group__CUDA__TYPES_1ggc6c391505e117393cc2558fff6bfc2e95e985a1735204ae8455e9eec402d46c3" shape="rect">CUDA_ERROR_PEER_ACCESS_NOT_ENABLED</a>, <a class="xref" href="group__CUDA__TYPES.html#group__CUDA__TYPES_1ggc6c391505e117393cc2558fff6bfc2e9a484e9af32c1e9893ff21f0e0191a12d" shape="rect">CUDA_ERROR_INVALID_CONTEXT</a>,
</p>
</div>
<div class="section">
<h6 class="description_header">Description</h6>
<p>Returns <a class="xref" href="group__CUDA__TYPES.html#group__CUDA__TYPES_1ggc6c391505e117393cc2558fff6bfc2e95e985a1735204ae8455e9eec402d46c3" shape="rect">CUDA_ERROR_PEER_ACCESS_NOT_ENABLED</a> if direct peer access has not yet been enabled from <tt class="ph tt code">peerContext</tt> to the current context.
</p>
<p class="p">Returns <a class="xref" href="group__CUDA__TYPES.html#group__CUDA__TYPES_1ggc6c391505e117393cc2558fff6bfc2e9a484e9af32c1e9893ff21f0e0191a12d" shape="rect">CUDA_ERROR_INVALID_CONTEXT</a> if there is no current context, or if <tt class="ph tt code">peerContext</tt> is not a valid context.
</p>
<p class="p"></p>
<p class="p"></p>
<p class="p">
<div class="note note"><span class="notetitle">Note:</span><p class="p">Note that this function may also return error codes from previous, asynchronous launches.</p>
</div>
</p>
<p class="p"></p>
<p class="p apiDesc_subtitle"><strong class="ph b">See also:</strong></p>
<p class="p see_subsection"><a class="xref" href="group__CUDA__PEER__ACCESS.html#group__CUDA__PEER__ACCESS_1g496bdaae1f632ebfb695b99d2c40f19e" title="Queries if a device may directly access a peer device's memory." shape="rect">cuDeviceCanAccessPeer</a>, <a class="xref" href="group__CUDA__PEER__ACCESS.html#group__CUDA__PEER__ACCESS_1g0889ec6728e61c05ed359551d67b3f5a" title="Enables direct access to memory allocations in a peer context." shape="rect">cuCtxEnablePeerAccess</a></p>
<p class="p"></p>
</div>
</dd>
<dt class="description"><a name="group__CUDA__PEER__ACCESS_1g0889ec6728e61c05ed359551d67b3f5a" id="group__CUDA__PEER__ACCESS_1g0889ec6728e61c05ed359551d67b3f5a" shape="rect">
<!-- --></a><span><a href="group__CUDA__TYPES.html#group__CUDA__TYPES_1gc6c391505e117393cc2558fff6bfc2e9" title="" shape="rect">CUresult</a> cuCtxEnablePeerAccess ( <a href="group__CUDA__TYPES.html#group__CUDA__TYPES_1gf9f5bd81658f866613785b3a0bb7d7d9" title="" shape="rect">CUcontext</a><span> </span><span class="keyword keyword apiItemName">peerContext</span>, unsigned int <span> </span><span class="keyword keyword apiItemName">Flags</span> ) </span></dt>
<dd class="description">
<div class="section">Enables direct access to memory allocations in a peer context. </div>
<div class="section">
<h6 class="parameter_header">
Parameters
</h6>
<dl class="table-display-params">
<dt><tt class="code"><span class="keyword keyword apiItemName">peerContext</span></tt></dt>
<dd>- Peer context to enable direct access to from the current context </dd>
<dt><tt class="code"><span class="keyword keyword apiItemName">Flags</span></tt></dt>
<dd>- Reserved for future use and must be set to 0</dd>
</dl>
</div>
<div class="section">
<h6 class="return_header">Returns</h6>
<p class="return"><a class="xref" href="group__CUDA__TYPES.html#group__CUDA__TYPES_1ggc6c391505e117393cc2558fff6bfc2e9a0eed720f8a87cd1c5fd1c453bc7a03d" shape="rect">CUDA_SUCCESS</a>, <a class="xref" href="group__CUDA__TYPES.html#group__CUDA__TYPES_1ggc6c391505e117393cc2558fff6bfc2e9acf52f132faf29b473cdda6061f0f44a" shape="rect">CUDA_ERROR_DEINITIALIZED</a>, <a class="xref" href="group__CUDA__TYPES.html#group__CUDA__TYPES_1ggc6c391505e117393cc2558fff6bfc2e98feb999f0af99b4a25ab26b3866f4df8" shape="rect">CUDA_ERROR_NOT_INITIALIZED</a>, <a class="xref" href="group__CUDA__TYPES.html#group__CUDA__TYPES_1ggc6c391505e117393cc2558fff6bfc2e947c18606be796573aa2957402fa89a9c" shape="rect">CUDA_ERROR_PEER_ACCESS_ALREADY_ENABLED</a>, <a class="xref" href="group__CUDA__TYPES.html#group__CUDA__TYPES_1ggc6c391505e117393cc2558fff6bfc2e9168ef870793a31ef4cdd7cb6e279b34a" shape="rect">CUDA_ERROR_TOO_MANY_PEERS</a>, <a class="xref" href="group__CUDA__TYPES.html#group__CUDA__TYPES_1ggc6c391505e117393cc2558fff6bfc2e9a484e9af32c1e9893ff21f0e0191a12d" shape="rect">CUDA_ERROR_INVALID_CONTEXT</a>, <a class="xref" href="group__CUDA__TYPES.html#group__CUDA__TYPES_1ggc6c391505e117393cc2558fff6bfc2e9d60abcaa3f2710f961db8c383bb95cae" shape="rect">CUDA_ERROR_PEER_ACCESS_UNSUPPORTED</a>, <a class="xref" href="group__CUDA__TYPES.html#group__CUDA__TYPES_1ggc6c391505e117393cc2558fff6bfc2e990696c86fcee1f536a1ec7d25867feeb" shape="rect">CUDA_ERROR_INVALID_VALUE</a></p>
</div>
<div class="section">
<h6 class="description_header">Description</h6>
<p>If both the current context and <tt class="ph tt code">peerContext</tt> are on devices which support unified addressing (as may be queried using <a class="xref" href="group__CUDA__TYPES.html#group__CUDA__TYPES_1gge12b8a782bebe21b1ac0091bf9f4e2a3dc11dd6d9f149a7bae32499f2b802c0d" shape="rect">CU_DEVICE_ATTRIBUTE_UNIFIED_ADDRESSING</a>) and same major compute capability, then on success all allocations from <tt class="ph tt code">peerContext</tt> will immediately be accessible by the current context. See <a class="xref" href="group__CUDA__UNIFIED.html#group__CUDA__UNIFIED" shape="rect">Unified Addressing</a> for additional details.
</p>
<p class="p">Note that access granted by this call is unidirectional and that in order to access memory from the current context in <tt class="ph tt code">peerContext</tt>, a separate symmetric call to <a class="xref" href="group__CUDA__PEER__ACCESS.html#group__CUDA__PEER__ACCESS_1g0889ec6728e61c05ed359551d67b3f5a" title="Enables direct access to memory allocations in a peer context." shape="rect">cuCtxEnablePeerAccess()</a> is required.
</p>
<p class="p">Returns <a class="xref" href="group__CUDA__TYPES.html#group__CUDA__TYPES_1ggc6c391505e117393cc2558fff6bfc2e9d60abcaa3f2710f961db8c383bb95cae" shape="rect">CUDA_ERROR_PEER_ACCESS_UNSUPPORTED</a> if <a class="xref" href="group__CUDA__PEER__ACCESS.html#group__CUDA__PEER__ACCESS_1g496bdaae1f632ebfb695b99d2c40f19e" title="Queries if a device may directly access a peer device's memory." shape="rect">cuDeviceCanAccessPeer()</a> indicates that the <a class="xref" href="group__CUDA__TYPES.html#group__CUDA__TYPES_1gcd81b70eb9968392bb5cdf582af8eab4" shape="rect">CUdevice</a> of the current context cannot directly access memory from the <a class="xref" href="group__CUDA__TYPES.html#group__CUDA__TYPES_1gcd81b70eb9968392bb5cdf582af8eab4" shape="rect">CUdevice</a> of <tt class="ph tt code">peerContext</tt>.
</p>
<p class="p">Returns <a class="xref" href="group__CUDA__TYPES.html#group__CUDA__TYPES_1ggc6c391505e117393cc2558fff6bfc2e947c18606be796573aa2957402fa89a9c" shape="rect">CUDA_ERROR_PEER_ACCESS_ALREADY_ENABLED</a> if direct access of <tt class="ph tt code">peerContext</tt> from the current context has already been enabled.
</p>
<p class="p">Returns <a class="xref" href="group__CUDA__TYPES.html#group__CUDA__TYPES_1ggc6c391505e117393cc2558fff6bfc2e9168ef870793a31ef4cdd7cb6e279b34a" shape="rect">CUDA_ERROR_TOO_MANY_PEERS</a> if direct peer access is not possible because hardware resources required for peer access have been exhausted.
</p>
<p class="p">Returns <a class="xref" href="group__CUDA__TYPES.html#group__CUDA__TYPES_1ggc6c391505e117393cc2558fff6bfc2e9a484e9af32c1e9893ff21f0e0191a12d" shape="rect">CUDA_ERROR_INVALID_CONTEXT</a> if there is no current context, <tt class="ph tt code">peerContext</tt> is not a valid context, or if the current context is <tt class="ph tt code">peerContext</tt>.
</p>
<p class="p">Returns <a class="xref" href="group__CUDA__TYPES.html#group__CUDA__TYPES_1ggc6c391505e117393cc2558fff6bfc2e990696c86fcee1f536a1ec7d25867feeb" shape="rect">CUDA_ERROR_INVALID_VALUE</a> if <tt class="ph tt code">Flags</tt> is not 0.
</p>
<p class="p"></p>
<p class="p"></p>
<p class="p">
<div class="note note"><span class="notetitle">Note:</span><p class="p">Note that this function may also return error codes from previous, asynchronous launches.</p>
</div>
</p>
<p class="p"></p>
<p class="p apiDesc_subtitle"><strong class="ph b">See also:</strong></p>
<p class="p see_subsection"><a class="xref" href="group__CUDA__PEER__ACCESS.html#group__CUDA__PEER__ACCESS_1g496bdaae1f632ebfb695b99d2c40f19e" title="Queries if a device may directly access a peer device's memory." shape="rect">cuDeviceCanAccessPeer</a>, <a class="xref" href="group__CUDA__PEER__ACCESS.html#group__CUDA__PEER__ACCESS_1g5b4b6936ea868d4954ce4d841a3b4810" title="Disables direct access to memory allocations in a peer context and unregisters any registered allocations." shape="rect">cuCtxDisablePeerAccess</a></p>
<p class="p"></p>
</div>
</dd>
<dt class="description"><a name="group__CUDA__PEER__ACCESS_1g496bdaae1f632ebfb695b99d2c40f19e" id="group__CUDA__PEER__ACCESS_1g496bdaae1f632ebfb695b99d2c40f19e" shape="rect">
<!-- --></a><span><a href="group__CUDA__TYPES.html#group__CUDA__TYPES_1gc6c391505e117393cc2558fff6bfc2e9" title="" shape="rect">CUresult</a> cuDeviceCanAccessPeer ( int*<span> </span><span class="keyword keyword apiItemName">canAccessPeer</span>, <a href="group__CUDA__TYPES.html#group__CUDA__TYPES_1gcd81b70eb9968392bb5cdf582af8eab4" title="" shape="rect">CUdevice</a><span> </span><span class="keyword keyword apiItemName">dev</span>, <a href="group__CUDA__TYPES.html#group__CUDA__TYPES_1gcd81b70eb9968392bb5cdf582af8eab4" title="" shape="rect">CUdevice</a><span> </span><span class="keyword keyword apiItemName">peerDev</span> ) </span></dt>
<dd class="description">
<div class="section">Queries if a device may directly access a peer device's memory. </div>
<div class="section">
<h6 class="parameter_header">
Parameters
</h6>
<dl class="table-display-params">
<dt><tt class="code"><span class="keyword keyword apiItemName">canAccessPeer</span></tt></dt>
<dd>- Returned access capability </dd>
<dt><tt class="code"><span class="keyword keyword apiItemName">dev</span></tt></dt>
<dd>- Device from which allocations on <tt class="ph tt code">peerDev</tt> are to be directly accessed.
</dd>
<dt><tt class="code"><span class="keyword keyword apiItemName">peerDev</span></tt></dt>
<dd>- Device on which the allocations to be directly accessed by <tt class="ph tt code">dev</tt> reside.
</dd>
</dl>
</div>
<div class="section">
<h6 class="return_header">Returns</h6>
<p class="return"><a class="xref" href="group__CUDA__TYPES.html#group__CUDA__TYPES_1ggc6c391505e117393cc2558fff6bfc2e9a0eed720f8a87cd1c5fd1c453bc7a03d" shape="rect">CUDA_SUCCESS</a>, <a class="xref" href="group__CUDA__TYPES.html#group__CUDA__TYPES_1ggc6c391505e117393cc2558fff6bfc2e9acf52f132faf29b473cdda6061f0f44a" shape="rect">CUDA_ERROR_DEINITIALIZED</a>, <a class="xref" href="group__CUDA__TYPES.html#group__CUDA__TYPES_1ggc6c391505e117393cc2558fff6bfc2e98feb999f0af99b4a25ab26b3866f4df8" shape="rect">CUDA_ERROR_NOT_INITIALIZED</a>, <a class="xref" href="group__CUDA__TYPES.html#group__CUDA__TYPES_1ggc6c391505e117393cc2558fff6bfc2e96f047e7215788ca96c81af92a04bfb6c" shape="rect">CUDA_ERROR_INVALID_DEVICE</a></p>
</div>
<div class="section">
<h6 class="description_header">Description</h6>
<p>Returns in <tt class="ph tt code">*canAccessPeer</tt> a value of 1 if contexts on <tt class="ph tt code">dev</tt> are capable of directly accessing memory from contexts on <tt class="ph tt code">peerDev</tt> and 0 otherwise. If direct access of <tt class="ph tt code">peerDev</tt> from <tt class="ph tt code">dev</tt> is possible, then access may be enabled on two specific contexts by calling <a class="xref" href="group__CUDA__PEER__ACCESS.html#group__CUDA__PEER__ACCESS_1g0889ec6728e61c05ed359551d67b3f5a" title="Enables direct access to memory allocations in a peer context." shape="rect">cuCtxEnablePeerAccess()</a>.
</p>
<p class="p"></p>
<p class="p"></p>
<p class="p">
<div class="note note"><span class="notetitle">Note:</span><p class="p">Note that this function may also return error codes from previous, asynchronous launches.</p>
</div>
</p>
<p class="p"></p>
<p class="p apiDesc_subtitle"><strong class="ph b">See also:</strong></p>
<p class="p see_subsection"><a class="xref" href="group__CUDA__PEER__ACCESS.html#group__CUDA__PEER__ACCESS_1g0889ec6728e61c05ed359551d67b3f5a" title="Enables direct access to memory allocations in a peer context." shape="rect">cuCtxEnablePeerAccess</a>, <a class="xref" href="group__CUDA__PEER__ACCESS.html#group__CUDA__PEER__ACCESS_1g5b4b6936ea868d4954ce4d841a3b4810" title="Disables direct access to memory allocations in a peer context and unregisters any registered allocations." shape="rect">cuCtxDisablePeerAccess</a></p>
<p class="p"></p>
</div>
</dd>
</dl>
</div>
</div>
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