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<base href="https://bugs.freedesktop.org/">
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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - call eglSwapBuffers causes app execution block"
href="https://bugs.freedesktop.org/show_bug.cgi?id=99332">99332</a>
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<th>Summary</th>
<td>call eglSwapBuffers causes app execution block
</td>
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<th>Product</th>
<td>Wayland
</td>
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<th>Version</th>
<td>unspecified
</td>
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<th>Hardware</th>
<td>All
</td>
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<th>OS</th>
<td>All
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<th>Status</th>
<td>NEW
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<th>Severity</th>
<td>minor
</td>
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<th>Priority</th>
<td>medium
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<th>Component</th>
<td>weston
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<th>Assignee</th>
<td>wayland-bugs@lists.freedesktop.org
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<th>Reporter</th>
<td>sergey.stepanov@lge.com
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<p>
<div>
<pre>Hi all,
if we call eglSwapBuffers twice (or even call glClear in EGL mode) it can
causes app execution block.
I found 2 independent cases:
1. eglSwapBuffers implementation does not request wl_surface.frame callback(as
Mesa do)
2. surface is not mapped in weston
I believe in both cases EGL driver is blocked on waiting wl_buffer.release
event.
I suppose it happens because of the next code
in function weston_buffer_reference:
wl_resource_queue_event(ref->buffer->resource,
WL_BUFFER_RELEASE);
If there is no other events for the client a message buffer will not be
flushed. So, client will not receive wl_buffer.release event until other event
occurred.
We can implement a workaround by calling display_roundtrip after each
swapBuffers call, but i believe it is not a proper way.
I did not check current version (but I took a look at source code,
implementation is the same) but it is true for 1.6 and 1.9</pre>
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