2003-2014
The Khronos Group Inc.
eglReleaseThread
3G
eglReleaseThread
Release EGL per-thread state
C Specification
EGLBoolean eglReleaseThread
Description
eglReleaseThread returns the EGL to its
state at thread initialization, releasing all per-thread
state including the error status returned by
eglGetError, the currently bound
rendering API defined by eglBindAPI, and
the current contexts for each supported client API. The
overhead of maintaining this state may be objectionable in
applications which create and destroy many threads, but only
call EGL or client APIs in a few of those threads at any
given time.
EGL_TRUE is returned on success, and the
following actions are taken:
For each client API supported by EGL, if there is a
currently bound context, that context is released.
This is equivalent to calling
eglMakeCurrent with ctx set to
EGL_NO_CONTEXT and both draw
and read set to EGL_NO_SURFACE
(see section 3.7.3).
The current rendering API is reset to its value at
thread initialization (see
eglBindAPI).
Any additional implementation-dependent per-thread
state maintained by EGL is marked for deletion as
soon as possible.
eglReleaseThread may be called in any
thread at any time, and may be called more than once in a
single thread. The initialization status of EGL (see section
3.2) is not affected by releasing the thread; only
per-thread state is affected.
Resources explicitly allocated by calls to EGL, such as
contexts, surfaces, and configuration lists, are not
affected by eglReleaseThread. Such
resources belong not to the thread, but to the EGL
implementation as a whole.
Notes
eglReleaseThread is supported only if the
EGL version is 1.2 or greater.
Applications may call other EGL routines from a thread
following eglReleaseThread, but any
such call may reallocate the EGL state previously released.
In particular, calling eglGetError
immediately following a successful call to
eglReleaseThread will return
EGL_SUCCESS, but will also result in
reallocating per-thread state.
Errors
EGL_FALSE is returned on failure,
EGL_TRUE otherwise. There are no
defined conditions under which failure will occur. Even if
EGL is not initialized on any EGLDisplay,
eglReleaseThread should succeed.
However, platform-dependent failures may be signaled through
the value returned from eglGetError.
Unless the platform-dependent behavior is known, a failed
call to eglReleaseThread should be
assumed to leave the current rendering API, and the
currently bound contexts for each supported client API, in
an unknown state.
See Also
eglBindAPI,
eglGetError,
eglMakeCurrent