Adding NV_timeline_semaphore
diff --git a/extensions/NV/NV_timeline_semaphore.txt b/extensions/NV/NV_timeline_semaphore.txt
new file mode 100755
index 0000000..3479fa3
--- /dev/null
+++ b/extensions/NV/NV_timeline_semaphore.txt
@@ -0,0 +1,223 @@
+Name
+
+ NV_timeline_semaphore
+
+Name Strings
+
+ GL_NV_timeline_semaphore
+
+Contributors
+
+ Carsten Rohde, NVIDIA
+ James Jones, NVIDIA
+
+Contact
+
+ Carsten Rohde, NVIDIA Corporation (crohde 'at' nvidia.com)
+
+Status
+
+ Complete
+
+Version
+
+ Last Modified Date: Jul 10, 2020
+ Revision: 1
+
+Number
+
+ 551
+ OpenGL ES Extension #330
+
+Dependencies
+
+ Written against the OpenGL 4.6 and OpenGL ES 3.2 specifications.
+
+ GL_NV_timeline_semaphore requires GL_EXT_semaphore or a version of
+ OpenGL or OpenGL ES that incorporates it.
+
+Overview
+
+ The Vulkan API introduces the concept of timeline semaphores.
+ This extension brings those concepts to the OpenGL API by adding
+ a semaphore type to the semaphore object. In OpenGL, timeline semaphore
+ signal and wait operations are similar to the corresponding operations on
+ imported Direct3D 12 fences defined in EXT_external_objects_win32.
+
+New Procedures and Functions
+
+ void CreateSemaphoresNV(sizei n, uint *semaphores);
+
+ void SemaphoreParameterivNV(uint semaphore,
+ enum pname,
+ const GLint *params);
+
+ void GetSemaphoreParameterivNV(uint semaphore,
+ enum pname,
+ int *params);
+
+New Tokens
+
+ Accepted by the <pname> parameter of SemaphoreParameterivNV
+ and GetSemaphoreParameterivNV:
+
+ SEMAPHORE_TYPE_NV 0x95B3
+
+ Accepted by the <param> parameter of SemaphoreParameterivNV and
+ GetSemaphoreParameterivNV when <pname> parameter is SEMAPHORE_TYPE_NV:
+
+ SEMAPHORE_TYPE_BINARY_NV 0x95B4
+ SEMAPHORE_TYPE_TIMELINE_NV 0x95B5
+
+ Accepted by the <pname> parameter of SemaphoreParameterui64vNV
+ and GetSemaphoreParameterui64vNV:
+
+ TIMELINE_SEMAPHORE_VALUE_NV 0x9595
+
+ Accepted by the <pname> parameter to GetIntegerv, GetFloatv, GetDoublev,
+ GetInteger64v, and GetBooleanv:
+
+ MAX_TIMELINE_SEMAPHORE_VALUE_DIFFERENCE_NV 0x95B6
+
+
+Additions to Chapter 4 of the OpenGL 4.6 Specification (Event Model)
+
+ Add the following to section 4.2 Semaphore Objects after paragraph
+ which describes command GenSemaphoresEXT:
+
+ The command
+
+ void CreateSemaphoresNV(sizei n,
+ uint *semaphores);
+
+ returns <n> previously unused semaphore names in <semaphores>.
+ The semaphores named contain default state, but initially have no
+ external semaphores associated with them.
+
+ Replace section 4.2.2 Semaphore Parameters with the following:
+
+ Semaphore parameters control the type of the semaphore and how
+ semaphore wait and signal operations behave.
+ Table 4.3 defines which parameters are available for a semaphore
+ based on the external handle type from which it was imported.
+ Semaphore parameters are set using the commands
+
+ void SemaphoreParameterivNV(uint semaphore,
+ enum pname,
+ const int *params);
+
+ and
+
+ void SemaphoreParameterui64vEXT(uint semaphore,
+ enum pname,
+ const uint64 *params);
+
+ <semaphore> is the name of the semaphore object on which the
+ parameter <pname> will be set to the value(s) in <pname>.
+
+ Table 4.3: Semaphore parameters
+
+ | Name | Handle Types | Legal Values |
+ +-----------------------------+-----------------------------+--------------------------------------+
+ | SEMAPHORE_TYPE_NV | any handle type | SEMAPHORE_TYPE_BINARY_NV (default) |
+ | | | SEMAPHORE_TYPE_TIMELINE_NV |
+ +-----------------------------+-----------------------------+--------------------------------------+
+ | TIMELINE_SEMAPHORE_VALUE_NV | any handle type | any value |
+ +-----------------------------+-----------------------------+--------------------------------------+
+
+ The default type of a semaphore is SEMAPHORE_TYPE_BINARY_NV. Only when the semaphore is imported
+ from a D3D fence, the semaphore type defaults to SEMAPHORE_TYPE_TIMELINE_NV.
+
+ Parameters of a semaphore object may be queried with the commands
+
+ void GetSemaphoreParameteriEXT(uint semaphore,
+ enum pname,
+ uint64 *params);
+
+ and
+
+ void GetSemaphoreParameterui64EXT(uint semaphore,
+ enum pname,
+ uint64 *params);
+
+ <semaphore> is the semaphore object from with the parameter <pname>
+ is queried. The value(s) of the parameter are returned in <params>.
+ <pname> may be any value in table 4.3.
+
+ Add the following after the first paragraph of section 4.2.3 "Waiting
+ for Semaphores"
+
+ If <semaphore> is of the type SEMAPHORE_TYPE_TIMELINE_NV, it will
+ reach the signaled state when its value is greater than or equal
+ to the value specified by its TIMELINE_SEMAPHORE_VALUE_NV parameter.
+
+ Add the following at the end of section 4.2.3 "Waiting for Semaphores":
+
+ When using binary semaphores, for every wait on a semaphore there must
+ be a prior signal of that semaphore that will not be consumed by a
+ different wait on the semaphore.
+ When using timeline semaphores, wait-before-signal behavior is
+ well-defined and applications can wait for semaphore before the
+ corresponding semaphore signal operation is flushed.
+
+ MAX_TIMELINE_SEMAPHORE_VALUE_DIFFERENCE_NV indicates the maximum
+ difference allowed by the implementation between the current value
+ of a timeline semaphore and any pending wait operations
+
+ Add the following after the first paragraph of section 4.2.4 "Signaling
+ Semaphores"
+
+ If <semaphore> is of the type SEMAPHORE_TYPE_TIMELINE_NV, its value
+ will be set to the value specified by its TIMELINE_SEMAPHORE_VALUE_NV
+ parameter when the signal operation completes.
+
+ Add the following at the end of section 4.2.4 "Signaling for Semaphores":
+
+ MAX_TIMELINE_SEMAPHORE_VALUE_DIFFERENCE_NV indicates the maximum
+ difference allowed by the implementation between the current value
+ of a timeline semaphore and any pending signal operations.
+
+
+Example
+
+ GLuint semapohre;
+ glCreateSemaphoresNV(1, &semaphore);
+ GLenum semaphoreType = GL_SEMAPHORE_TYPE_TIMELINE_NV;
+ glSemaphoreParameterivNV(semaphore, GL_SEMAPHORE_TYPE_NV, (GLint*)&semaphoreType);
+ glImportSemaphoreFdEXT(semaphore, GL_HANDLE_TYPE_OPAQUE_FD_EXT, fd); // or win32 equivalent
+
+ GLuint64 semaphoreValue = 0;
+
+ while (...) {
+ glSemaphoreParameterui64vEXT(semaphore, GL_TIMELINE_SEMAPHORE_VALUE_NV, &semaphoreValue);
+ glWaitSemaphoreEXT(semaphore, ...);
+
+ ...
+
+ semaphoreValue ++;
+ glSemaphoreParameterui64vEXT(semaphore, GL_TIMELINE_SEMAPHORE_VALUE_NV, &semaphoreValue);
+ glSignalSemaphoreEXT(semaphore, ...);
+ }
+
+ glDeleteSemaphoresEXT(1, &semaphore);
+
+
+Issues
+
+ (1) Should we add client functions to signal and wait for the semaphore on
+ the CPU?
+
+ RESOLVED: No. We already declined to add external Vulkan fence interop
+ with GL on the basis that you can just do that with Vulkan
+ if you need it.
+
+ (2) Should GetIntegerv and GetBooleanv be allowed to query
+ MAX_TIMELINE_SEMAPHORE_VALUE_DIFFERENCE_NV?
+
+ RESOLVED: Yes. Although it's dangerous to use them they don't throw an
+ error but you are advised to use GetInteger64v.
+
+Revision History
+
+ Revision 1, 2020-07-10 (Carsten Rohde)
+ - Initial draft.
diff --git a/extensions/esext.php b/extensions/esext.php
index 35de028..9625b28 100644
--- a/extensions/esext.php
+++ b/extensions/esext.php
@@ -683,4 +683,6 @@
</li>
<li value=328><a href="extensions/MESA/MESA_framebuffer_swap_xy.txt">GL_MESA_framebuffer_swap_xy</a>
</li>
+<li value=330><a href="extensions/NV/GL_NV_timeline_semaphore.txt">GL_NV_timeline_semaphore</a>
+</li>
</ol>
diff --git a/extensions/glext.php b/extensions/glext.php
index 321dda8..d8533d7 100644
--- a/extensions/glext.php
+++ b/extensions/glext.php
@@ -1037,4 +1037,6 @@
</li>
<li value=549><a href="extensions/MESA/MESA_framebuffer_swap_xy.txt">GL_MESA_framebuffer_swap_xy</a>
</li>
+<li value=551><a href="extensions/NV/GL_NV_timeline_semaphore.txt">GL_NV_timeline_semaphore</a>
+</li>
</ol>
diff --git a/extensions/registry.py b/extensions/registry.py
index c0bea5c..977ba90 100644
--- a/extensions/registry.py
+++ b/extensions/registry.py
@@ -3937,6 +3937,13 @@
'supporters' : { 'NVIDIA' },
'url' : 'extensions/NV/NV_transform_feedback2.txt',
},
+ 'GL_NV_timeline_semaphore' : {
+ 'number' : 551,
+ 'esnumber' : 330,
+ 'flags' : { 'public' },
+ 'supporters' : { 'NVIDIA' },
+ 'url' : 'extensions/NV/NV_timeline_semaphore.txt',
+ },
'GL_NV_uniform_buffer_unified_memory' : {
'number' : 459,
'flags' : { 'public' },
diff --git a/xml/gl.xml b/xml/gl.xml
index 6a01874..ce01480 100644
--- a/xml/gl.xml
+++ b/xml/gl.xml
@@ -11571,6 +11571,7 @@
<enum value="0x9593" name="GL_LAYOUT_TRANSFER_DST_EXT" group="TextureLayout"/>
<enum value="0x9594" name="GL_HANDLE_TYPE_D3D12_FENCE_EXT" group="ExternalHandleType"/>
<enum value="0x9595" name="GL_D3D12_FENCE_VALUE_EXT" group="SemaphoreParameterName"/>
+ <enum value="0x9595" name="GL_TIMELINE_SEMAPHORE_VALUE_NV" group="SemaphoreParameterName"/>
<enum value="0x9596" name="GL_NUM_DEVICE_UUIDS_EXT" group="GetPName"/>
<enum value="0x9597" name="GL_DEVICE_UUID_EXT" group="GetPName"/>
<enum value="0x9598" name="GL_DRIVER_UUID_EXT" group="GetPName"/>
@@ -11598,7 +11599,12 @@
<enum value="0x95AE" name="GL_SHADING_RATE_SAMPLE_ORDER_DEFAULT_NV"/>
<enum value="0x95AF" name="GL_SHADING_RATE_SAMPLE_ORDER_PIXEL_MAJOR_NV"/>
<enum value="0x95B0" name="GL_SHADING_RATE_SAMPLE_ORDER_SAMPLE_MAJOR_NV"/>
- <unused start="0x9581" end="0x962F" vendor="NV"/>
+ <unused start="0x95B1" end="0x95B2" vendor="NV"/>
+ <enum value="0x95B3" name="GL_SEMAPHORE_TYPE_NV"/>
+ <enum value="0x95B4" name="GL_SEMAPHORE_TYPE_BINARY_NV"/>
+ <enum value="0x95B5" name="GL_SEMAPHORE_TYPE_TIMELINE_NV"/>
+ <enum value="0x95B6" name="GL_MAX_TIMELINE_SEMAPHORE_VALUE_DIFFERENCE_NV"/>
+ <unused start="0x95B7" end="0x962F" vendor="NV"/>
</enums>
<enums namespace="GL" start="0x9630" end="0x963F" vendor="Oculus" comment="Email from Cass Everitt">
@@ -14967,6 +14973,11 @@
<param len="n"><ptype>GLuint</ptype> *<name>samplers</name></param>
</command>
<command>
+ <proto>void <name>glCreateSemaphoresNV</name></proto>
+ <param><ptype>GLsizei</ptype> <name>n</name></param>
+ <param len="n"><ptype>GLuint</ptype> *<name>semaphores</name></param>
+ </command>
+ <command>
<proto><ptype>GLuint</ptype> <name>glCreateShader</name></proto>
<param group="ShaderType"><ptype>GLenum</ptype> <name>type</name></param>
</command>
@@ -19710,6 +19721,12 @@
<param len="COMPSIZE(pname)"><ptype>GLint</ptype> *<name>params</name></param>
</command>
<command>
+ <proto>void <name>glGetSemaphoreParameterivNV</name></proto>
+ <param><ptype>GLuint</ptype> <name>semaphore</name></param>
+ <param group="SemaphoreParameterName"><ptype>GLenum</ptype> <name>pname</name></param>
+ <param><ptype>GLint</ptype> *<name>params</name></param>
+ </command>
+ <command>
<proto>void <name>glGetSemaphoreParameterui64vEXT</name></proto>
<param><ptype>GLuint</ptype> <name>semaphore</name></param>
<param group="SemaphoreParameterName"><ptype>GLenum</ptype> <name>pname</name></param>
@@ -27762,6 +27779,12 @@
<param len="numCounters"><ptype>GLuint</ptype> *<name>counterList</name></param>
</command>
<command>
+ <proto>void <name>glSemaphoreParameterivNV</name></proto>
+ <param><ptype>GLuint</ptype> <name>semaphore</name></param>
+ <param group="SemaphoreParameterName"><ptype>GLenum</ptype> <name>pname</name></param>
+ <param>const <ptype>GLint</ptype> *<name>params</name></param>
+ </command>
+ <command>
<proto>void <name>glSemaphoreParameterui64vEXT</name></proto>
<param><ptype>GLuint</ptype> <name>semaphore</name></param>
<param group="SemaphoreParameterName"><ptype>GLenum</ptype> <name>pname</name></param>
@@ -46839,6 +46862,18 @@
<command name="glTextureViewEXT"/>
</require>
</extension>
+ <extension name="GL_NV_timeline_semaphore" supported="gl|gles2">
+ <require>
+ <enum name="GL_TIMELINE_SEMAPHORE_VALUE_NV"/>
+ <enum name="GL_SEMAPHORE_TYPE_NV"/>
+ <enum name="GL_SEMAPHORE_TYPE_BINARY_NV"/>
+ <enum name="GL_SEMAPHORE_TYPE_TIMELINE_NV"/>
+ <enum name="GL_MAX_TIMELINE_SEMAPHORE_VALUE_DIFFERENCE_NV"/>
+ <command name="glCreateSemaphoresNV"/>
+ <command name="glSemaphoreParameterivNV"/>
+ <command name="glGetSemaphoreParameterivNV"/>
+ </require>
+ </extension>
<extension name="GL_EXT_timer_query" supported="gl">
<require>
<enum name="GL_TIME_ELAPSED_EXT"/>
