opengl/libs/EGL/egl_display.cpp - android_frameworks_native - Gitiles

 /*
  ** Copyright 2007, The Android Open Source Project
  **
  ** Licensed under the Apache License, Version 2.0 (the "License");
  ** you may not use this file except in compliance with the License.
  ** You may obtain a copy of the License at
  **
  **     http://www.apache.org/licenses/LICENSE-2.0
  **
  ** Unless required by applicable law or agreed to in writing, software
  ** distributed under the License is distributed on an "AS IS" BASIS,
  ** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  ** See the License for the specific language governing permissions and
  ** limitations under the License.
  */

 #define __STDC_LIMIT_MACROS 1

 #include <string.h>

 #include "../egl_impl.h"

 #include "egl_cache.h"
 #include "egl_display.h"
 #include "egl_object.h"
 #include "egl_tls.h"
 #include "Loader.h"
 #include <cutils/properties.h>

 // ----------------------------------------------------------------------------
 namespace android {
 // ----------------------------------------------------------------------------

 static char const * const sVendorString     = "Android";
 static char const * const sVersionString    = "1.4 Android META-EGL";
 static char const * const sClientApiString  = "OpenGL_ES";

 extern char const * const gBuiltinExtensionString;
 extern char const * const gExtensionString;

 extern void initEglTraceLevel();
 extern void initEglDebugLevel();
 extern void setGLHooksThreadSpecific(gl_hooks_t const *value);

 // ----------------------------------------------------------------------------

 static bool findExtension(const char* exts, const char* name, size_t nameLen) {
     if (exts) {
         const char* match = strstr(exts, name);
         if (match && (match[nameLen] == '\0' || match[nameLen] == ' ')) {
             return true;
         }
     }
     return false;
 }

 egl_display_t egl_display_t::sDisplay[NUM_DISPLAYS];

 egl_display_t::egl_display_t() :
     magic('_dpy'), finishOnSwap(false), traceGpuCompletion(false), refs(0) {
 }

 egl_display_t::~egl_display_t() {
     magic = 0;
     egl_cache_t::get()->terminate();
 }

 egl_display_t* egl_display_t::get(EGLDisplay dpy) {
     uintptr_t index = uintptr_t(dpy)-1U;
     return (index >= NUM_DISPLAYS) ? NULL : &sDisplay[index];
 }

 void egl_display_t::addObject(egl_object_t* object) {
     Mutex::Autolock _l(lock);
     objects.add(object);
 }

 void egl_display_t::removeObject(egl_object_t* object) {
     Mutex::Autolock _l(lock);
     objects.remove(object);
 }

 bool egl_display_t::getObject(egl_object_t* object) const {
     Mutex::Autolock _l(lock);
     if (objects.indexOf(object) >= 0) {
         if (object->getDisplay() == this) {
             object->incRef();
             return true;
         }
     }
     return false;
 }

 EGLDisplay egl_display_t::getFromNativeDisplay(EGLNativeDisplayType disp) {
     if (uintptr_t(disp) >= NUM_DISPLAYS)
         return NULL;

     return sDisplay[uintptr_t(disp)].getDisplay(disp);
 }

 EGLDisplay egl_display_t::getDisplay(EGLNativeDisplayType display) {

     Mutex::Autolock _l(lock);

     // get our driver loader
     Loader& loader(Loader::getInstance());

     egl_connection_t* const cnx = &gEGLImpl;
     if (cnx->dso && disp.dpy == EGL_NO_DISPLAY) {
         EGLDisplay dpy = cnx->egl.eglGetDisplay(display);
         disp.dpy = dpy;
         if (dpy == EGL_NO_DISPLAY) {
             loader.close(cnx->dso);
             cnx->dso = NULL;
         }
     }

     return EGLDisplay(uintptr_t(display) + 1U);
 }

 EGLBoolean egl_display_t::initialize(EGLint *major, EGLint *minor) {

     Mutex::Autolock _l(lock);

     if (refs > 0) {
         if (major != NULL)
             *major = VERSION_MAJOR;
         if (minor != NULL)
             *minor = VERSION_MINOR;
         refs++;
         return EGL_TRUE;
     }

 #if EGL_TRACE

     // Called both at early_init time and at this time. (Early_init is pre-zygote, so
     // the information from that call may be stale.)
     initEglTraceLevel();
     initEglDebugLevel();

 #endif

     setGLHooksThreadSpecific(&gHooksNoContext);

     // initialize each EGL and
     // build our own extension string first, based on the extension we know
     // and the extension supported by our client implementation

     egl_connection_t* const cnx = &gEGLImpl;
     cnx->major = -1;
     cnx->minor = -1;
     if (cnx->dso) {
         EGLDisplay idpy = disp.dpy;
         if (cnx->egl.eglInitialize(idpy, &cnx->major, &cnx->minor)) {
             //ALOGD("initialized dpy=%p, ver=%d.%d, cnx=%p",
             //        idpy, cnx->major, cnx->minor, cnx);

             // display is now initialized
             disp.state = egl_display_t::INITIALIZED;

             // get the query-strings for this display for each implementation
             disp.queryString.vendor = cnx->egl.eglQueryString(idpy,
                     EGL_VENDOR);
             disp.queryString.version = cnx->egl.eglQueryString(idpy,
                     EGL_VERSION);
             disp.queryString.extensions = cnx->egl.eglQueryString(idpy,
                     EGL_EXTENSIONS);
             disp.queryString.clientApi = cnx->egl.eglQueryString(idpy,
                     EGL_CLIENT_APIS);

         } else {
             ALOGW("eglInitialize(%p) failed (%s)", idpy,
                     egl_tls_t::egl_strerror(cnx->egl.eglGetError()));
         }
     }

     // the query strings are per-display
     mVendorString.setTo(sVendorString);
     mVersionString.setTo(sVersionString);
     mClientApiString.setTo(sClientApiString);

     mExtensionString.setTo(gBuiltinExtensionString);
     char const* start = gExtensionString;
     char const* end;
     do {
         // find the space separating this extension for the next one
         end = strchr(start, ' ');
         if (end) {
             // length of the extension string
             const size_t len = end - start;
             if (len) {
                 // NOTE: we could avoid the copy if we had strnstr.
                 const String8 ext(start, len);
                 if (findExtension(disp.queryString.extensions, ext.string(),
                         len)) {
                     mExtensionString.append(start, len+1);
                 }
             }
             // process the next extension string, and skip the space.
             start = end + 1;
         }
     } while (end);

     egl_cache_t::get()->initialize(this);

     char value[PROPERTY_VALUE_MAX];
     property_get("debug.egl.finish", value, "0");
     if (atoi(value)) {
         finishOnSwap = true;
     }

     property_get("debug.egl.traceGpuCompletion", value, "0");
     if (atoi(value)) {
         traceGpuCompletion = true;
     }

     refs++;
     if (major != NULL)
         *major = VERSION_MAJOR;
     if (minor != NULL)
         *minor = VERSION_MINOR;

     mHibernation.setDisplayValid(true);

     return EGL_TRUE;
 }

 EGLBoolean egl_display_t::terminate() {

     Mutex::Autolock _l(lock);

     if (refs == 0) {
         /*
          * From the EGL spec (3.2):
          * "Termination of a display that has already been terminated,
          *  (...), is allowed, but the only effect of such a call is
          *  to return EGL_TRUE (...)
          */
         return EGL_TRUE;
     }

     // this is specific to Android, display termination is ref-counted.
     if (refs > 1) {
         refs--;
         return EGL_TRUE;
     }

     EGLBoolean res = EGL_FALSE;
     egl_connection_t* const cnx = &gEGLImpl;
     if (cnx->dso && disp.state == egl_display_t::INITIALIZED) {
         if (cnx->egl.eglTerminate(disp.dpy) == EGL_FALSE) {
             ALOGW("eglTerminate(%p) failed (%s)", disp.dpy,
                     egl_tls_t::egl_strerror(cnx->egl.eglGetError()));
         }
         // REVISIT: it's unclear what to do if eglTerminate() fails
         disp.state = egl_display_t::TERMINATED;
         res = EGL_TRUE;
     }

     mHibernation.setDisplayValid(false);

     // Reset the extension string since it will be regenerated if we get
     // reinitialized.
     mExtensionString.setTo("");

     // Mark all objects remaining in the list as terminated, unless
     // there are no reference to them, it which case, we're free to
     // delete them.
     size_t count = objects.size();
     ALOGW_IF(count, "eglTerminate() called w/ %d objects remaining", count);
     for (size_t i=0 ; i<count ; i++) {
         egl_object_t* o = objects.itemAt(i);
         o->destroy();
     }

     // this marks all object handles are "terminated"
     objects.clear();

     refs--;
     return res;
 }

 void egl_display_t::loseCurrent(egl_context_t * cur_c)
 {
     if (cur_c) {
         egl_display_t* display = cur_c->getDisplay();
         if (display) {
             display->loseCurrentImpl(cur_c);
         }
     }
 }

 void egl_display_t::loseCurrentImpl(egl_context_t * cur_c)
 {
     // by construction, these are either 0 or valid (possibly terminated)
     // it should be impossible for these to be invalid
     ContextRef _cur_c(cur_c);
     SurfaceRef _cur_r(cur_c ? get_surface(cur_c->read) : NULL);
     SurfaceRef _cur_d(cur_c ? get_surface(cur_c->draw) : NULL);

     { // scope for the lock
         Mutex::Autolock _l(lock);
         cur_c->onLooseCurrent();

     }

     // This cannot be called with the lock held because it might end-up
     // calling back into EGL (in particular when a surface is destroyed
     // it calls ANativeWindow::disconnect
     _cur_c.release();
     _cur_r.release();
     _cur_d.release();
 }

 EGLBoolean egl_display_t::makeCurrent(egl_context_t* c, egl_context_t* cur_c,
         EGLSurface draw, EGLSurface read, EGLContext /*ctx*/,
         EGLSurface impl_draw, EGLSurface impl_read, EGLContext impl_ctx)
 {
     EGLBoolean result;

     // by construction, these are either 0 or valid (possibly terminated)
     // it should be impossible for these to be invalid
     ContextRef _cur_c(cur_c);
     SurfaceRef _cur_r(cur_c ? get_surface(cur_c->read) : NULL);
     SurfaceRef _cur_d(cur_c ? get_surface(cur_c->draw) : NULL);

     { // scope for the lock
         Mutex::Autolock _l(lock);
         if (c) {
             result = c->cnx->egl.eglMakeCurrent(
                     disp.dpy, impl_draw, impl_read, impl_ctx);
             if (result == EGL_TRUE) {
                 c->onMakeCurrent(draw, read);
                 if (!cur_c) {
                     mHibernation.incWakeCount(HibernationMachine::STRONG);
                 }
             }
         } else {
             result = cur_c->cnx->egl.eglMakeCurrent(
                     disp.dpy, impl_draw, impl_read, impl_ctx);
             if (result == EGL_TRUE) {
                 cur_c->onLooseCurrent();
                 mHibernation.decWakeCount(HibernationMachine::STRONG);
             }
         }
     }

     if (result == EGL_TRUE) {
         // This cannot be called with the lock held because it might end-up
         // calling back into EGL (in particular when a surface is destroyed
         // it calls ANativeWindow::disconnect
         _cur_c.release();
         _cur_r.release();
         _cur_d.release();
     }

     return result;
 }

 bool egl_display_t::haveExtension(const char* name, size_t nameLen) const {
     if (!nameLen) {
         nameLen = strlen(name);
     }
     return findExtension(mExtensionString.string(), name, nameLen);
 }

 // ----------------------------------------------------------------------------

 bool egl_display_t::HibernationMachine::incWakeCount(WakeRefStrength strength) {
     Mutex::Autolock _l(mLock);
     ALOGE_IF(mWakeCount < 0 || mWakeCount == INT32_MAX,
              "Invalid WakeCount (%d) on enter\n", mWakeCount);

     mWakeCount++;
     if (strength == STRONG)
         mAttemptHibernation = false;

     if (CC_UNLIKELY(mHibernating)) {
         ALOGV("Awakening\n");
         egl_connection_t* const cnx = &gEGLImpl;

         // These conditions should be guaranteed before entering hibernation;
         // we don't want to get into a state where we can't wake up.
         ALOGD_IF(!mDpyValid || !cnx->egl.eglAwakenProcessIMG,
                  "Invalid hibernation state, unable to awaken\n");

         if (!cnx->egl.eglAwakenProcessIMG()) {
             ALOGE("Failed to awaken EGL implementation\n");
             return false;
         }
         mHibernating = false;
     }
     return true;
 }

 void egl_display_t::HibernationMachine::decWakeCount(WakeRefStrength strength) {
     Mutex::Autolock _l(mLock);
     ALOGE_IF(mWakeCount <= 0, "Invalid WakeCount (%d) on leave\n", mWakeCount);

     mWakeCount--;
     if (strength == STRONG)
         mAttemptHibernation = true;

     if (mWakeCount == 0 && CC_UNLIKELY(mAttemptHibernation)) {
         egl_connection_t* const cnx = &gEGLImpl;
         mAttemptHibernation = false;
         if (mAllowHibernation && mDpyValid &&
                 cnx->egl.eglHibernateProcessIMG &&
                 cnx->egl.eglAwakenProcessIMG) {
             ALOGV("Hibernating\n");
             if (!cnx->egl.eglHibernateProcessIMG()) {
                 ALOGE("Failed to hibernate EGL implementation\n");
                 return;
             }
             mHibernating = true;
         }
     }
 }

 void egl_display_t::HibernationMachine::setDisplayValid(bool valid) {
     Mutex::Autolock _l(mLock);
     mDpyValid = valid;
 }

 // ----------------------------------------------------------------------------
 }; // namespace android
 // ----------------------------------------------------------------------------
	/*
	** Copyright 2007, The Android Open Source Project
	**
	** Licensed under the Apache License, Version 2.0 (the "License");
	** you may not use this file except in compliance with the License.
	** You may obtain a copy of the License at
	**
	** http://www.apache.org/licenses/LICENSE-2.0
	**
	** Unless required by applicable law or agreed to in writing, software
	** distributed under the License is distributed on an "AS IS" BASIS,
	** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	** See the License for the specific language governing permissions and
	** limitations under the License.
	*/

	#define __STDC_LIMIT_MACROS 1

	#include <string.h>

	#include "../egl_impl.h"

	#include "egl_cache.h"
	#include "egl_display.h"
	#include "egl_object.h"
	#include "egl_tls.h"
	#include "Loader.h"
	#include <cutils/properties.h>

	// ----------------------------------------------------------------------------
	namespace android {
	// ----------------------------------------------------------------------------

	static char const * const sVendorString = "Android";
	static char const * const sVersionString = "1.4 Android META-EGL";
	static char const * const sClientApiString = "OpenGL_ES";

	extern char const * const gBuiltinExtensionString;
	extern char const * const gExtensionString;

	extern void initEglTraceLevel();
	extern void initEglDebugLevel();
	extern void setGLHooksThreadSpecific(gl_hooks_t const *value);

	// ----------------------------------------------------------------------------

	static bool findExtension(const char* exts, const char* name, size_t nameLen) {
	if (exts) {
	const char* match = strstr(exts, name);
	if (match && (match[nameLen] == '\0' \|\| match[nameLen] == ' ')) {
	return true;
	}
	}
	return false;
	}

	egl_display_t egl_display_t::sDisplay[NUM_DISPLAYS];

	egl_display_t::egl_display_t() :
	magic('_dpy'), finishOnSwap(false), traceGpuCompletion(false), refs(0) {
	}

	egl_display_t::~egl_display_t() {
	magic = 0;
	egl_cache_t::get()->terminate();
	}

	egl_display_t* egl_display_t::get(EGLDisplay dpy) {
	uintptr_t index = uintptr_t(dpy)-1U;
	return (index >= NUM_DISPLAYS) ? NULL : &sDisplay[index];
	}

	void egl_display_t::addObject(egl_object_t* object) {
	Mutex::Autolock _l(lock);
	objects.add(object);
	}

	void egl_display_t::removeObject(egl_object_t* object) {
	Mutex::Autolock _l(lock);
	objects.remove(object);
	}

	bool egl_display_t::getObject(egl_object_t* object) const {
	Mutex::Autolock _l(lock);
	if (objects.indexOf(object) >= 0) {
	if (object->getDisplay() == this) {
	object->incRef();
	return true;
	}
	}
	return false;
	}

	EGLDisplay egl_display_t::getFromNativeDisplay(EGLNativeDisplayType disp) {
	if (uintptr_t(disp) >= NUM_DISPLAYS)
	return NULL;

	return sDisplay[uintptr_t(disp)].getDisplay(disp);
	}

	EGLDisplay egl_display_t::getDisplay(EGLNativeDisplayType display) {

	Mutex::Autolock _l(lock);

	// get our driver loader
	Loader& loader(Loader::getInstance());

	egl_connection_t* const cnx = &gEGLImpl;
	if (cnx->dso && disp.dpy == EGL_NO_DISPLAY) {
	EGLDisplay dpy = cnx->egl.eglGetDisplay(display);
	disp.dpy = dpy;
	if (dpy == EGL_NO_DISPLAY) {
	loader.close(cnx->dso);
	cnx->dso = NULL;
	}
	}

	return EGLDisplay(uintptr_t(display) + 1U);
	}

	EGLBoolean egl_display_t::initialize(EGLint major, EGLint minor) {

	Mutex::Autolock _l(lock);

	if (refs > 0) {
	if (major != NULL)
	*major = VERSION_MAJOR;
	if (minor != NULL)
	*minor = VERSION_MINOR;
	refs++;
	return EGL_TRUE;
	}

	#if EGL_TRACE

	// Called both at early_init time and at this time. (Early_init is pre-zygote, so
	// the information from that call may be stale.)
	initEglTraceLevel();
	initEglDebugLevel();

	#endif

	setGLHooksThreadSpecific(&gHooksNoContext);

	// initialize each EGL and
	// build our own extension string first, based on the extension we know
	// and the extension supported by our client implementation

	egl_connection_t* const cnx = &gEGLImpl;
	cnx->major = -1;
	cnx->minor = -1;
	if (cnx->dso) {
	EGLDisplay idpy = disp.dpy;
	if (cnx->egl.eglInitialize(idpy, &cnx->major, &cnx->minor)) {
	//ALOGD("initialized dpy=%p, ver=%d.%d, cnx=%p",
	// idpy, cnx->major, cnx->minor, cnx);

	// display is now initialized
	disp.state = egl_display_t::INITIALIZED;

	// get the query-strings for this display for each implementation
	disp.queryString.vendor = cnx->egl.eglQueryString(idpy,
	EGL_VENDOR);
	disp.queryString.version = cnx->egl.eglQueryString(idpy,
	EGL_VERSION);
	disp.queryString.extensions = cnx->egl.eglQueryString(idpy,
	EGL_EXTENSIONS);
	disp.queryString.clientApi = cnx->egl.eglQueryString(idpy,
	EGL_CLIENT_APIS);

	} else {
	ALOGW("eglInitialize(%p) failed (%s)", idpy,
	egl_tls_t::egl_strerror(cnx->egl.eglGetError()));
	}
	}

	// the query strings are per-display
	mVendorString.setTo(sVendorString);
	mVersionString.setTo(sVersionString);
	mClientApiString.setTo(sClientApiString);

	mExtensionString.setTo(gBuiltinExtensionString);
	char const* start = gExtensionString;
	char const* end;
	do {
	// find the space separating this extension for the next one
	end = strchr(start, ' ');
	if (end) {
	// length of the extension string
	const size_t len = end - start;
	if (len) {
	// NOTE: we could avoid the copy if we had strnstr.
	const String8 ext(start, len);
	if (findExtension(disp.queryString.extensions, ext.string(),
	len)) {
	mExtensionString.append(start, len+1);
	}
	}
	// process the next extension string, and skip the space.
	start = end + 1;
	}
	} while (end);

	egl_cache_t::get()->initialize(this);

	char value[PROPERTY_VALUE_MAX];
	property_get("debug.egl.finish", value, "0");
	if (atoi(value)) {
	finishOnSwap = true;
	}

	property_get("debug.egl.traceGpuCompletion", value, "0");
	if (atoi(value)) {
	traceGpuCompletion = true;
	}

	refs++;
	if (major != NULL)
	*major = VERSION_MAJOR;
	if (minor != NULL)
	*minor = VERSION_MINOR;

	mHibernation.setDisplayValid(true);

	return EGL_TRUE;
	}

	EGLBoolean egl_display_t::terminate() {

	Mutex::Autolock _l(lock);

	if (refs == 0) {
	/*
	* From the EGL spec (3.2):
	* "Termination of a display that has already been terminated,
	* (...), is allowed, but the only effect of such a call is
	* to return EGL_TRUE (...)
	*/
	return EGL_TRUE;
	}

	// this is specific to Android, display termination is ref-counted.
	if (refs > 1) {
	refs--;
	return EGL_TRUE;
	}

	EGLBoolean res = EGL_FALSE;
	egl_connection_t* const cnx = &gEGLImpl;
	if (cnx->dso && disp.state == egl_display_t::INITIALIZED) {
	if (cnx->egl.eglTerminate(disp.dpy) == EGL_FALSE) {
	ALOGW("eglTerminate(%p) failed (%s)", disp.dpy,
	egl_tls_t::egl_strerror(cnx->egl.eglGetError()));
	}
	// REVISIT: it's unclear what to do if eglTerminate() fails
	disp.state = egl_display_t::TERMINATED;
	res = EGL_TRUE;
	}

	mHibernation.setDisplayValid(false);

	// Reset the extension string since it will be regenerated if we get
	// reinitialized.
	mExtensionString.setTo("");

	// Mark all objects remaining in the list as terminated, unless
	// there are no reference to them, it which case, we're free to
	// delete them.
	size_t count = objects.size();
	ALOGW_IF(count, "eglTerminate() called w/ %d objects remaining", count);
	for (size_t i=0 ; i<count ; i++) {
	egl_object_t* o = objects.itemAt(i);
	o->destroy();
	}

	// this marks all object handles are "terminated"
	objects.clear();

	refs--;
	return res;
	}

	void egl_display_t::loseCurrent(egl_context_t * cur_c)
	{
	if (cur_c) {
	egl_display_t* display = cur_c->getDisplay();
	if (display) {
	display->loseCurrentImpl(cur_c);
	}
	}
	}

	void egl_display_t::loseCurrentImpl(egl_context_t * cur_c)
	{
	// by construction, these are either 0 or valid (possibly terminated)
	// it should be impossible for these to be invalid
	ContextRef _cur_c(cur_c);
	SurfaceRef _cur_r(cur_c ? get_surface(cur_c->read) : NULL);
	SurfaceRef _cur_d(cur_c ? get_surface(cur_c->draw) : NULL);

	{ // scope for the lock
	Mutex::Autolock _l(lock);
	cur_c->onLooseCurrent();

	}

	// This cannot be called with the lock held because it might end-up
	// calling back into EGL (in particular when a surface is destroyed
	// it calls ANativeWindow::disconnect
	_cur_c.release();
	_cur_r.release();
	_cur_d.release();
	}

	EGLBoolean egl_display_t::makeCurrent(egl_context_t* c, egl_context_t* cur_c,
	EGLSurface draw, EGLSurface read, EGLContext /ctx/,
	EGLSurface impl_draw, EGLSurface impl_read, EGLContext impl_ctx)
	{
	EGLBoolean result;

	// by construction, these are either 0 or valid (possibly terminated)
	// it should be impossible for these to be invalid
	ContextRef _cur_c(cur_c);
	SurfaceRef _cur_r(cur_c ? get_surface(cur_c->read) : NULL);
	SurfaceRef _cur_d(cur_c ? get_surface(cur_c->draw) : NULL);

	{ // scope for the lock
	Mutex::Autolock _l(lock);
	if (c) {
	result = c->cnx->egl.eglMakeCurrent(
	disp.dpy, impl_draw, impl_read, impl_ctx);
	if (result == EGL_TRUE) {
	c->onMakeCurrent(draw, read);
	if (!cur_c) {
	mHibernation.incWakeCount(HibernationMachine::STRONG);
	}
	}
	} else {
	result = cur_c->cnx->egl.eglMakeCurrent(
	disp.dpy, impl_draw, impl_read, impl_ctx);
	if (result == EGL_TRUE) {
	cur_c->onLooseCurrent();
	mHibernation.decWakeCount(HibernationMachine::STRONG);
	}
	}
	}

	if (result == EGL_TRUE) {
	// This cannot be called with the lock held because it might end-up
	// calling back into EGL (in particular when a surface is destroyed
	// it calls ANativeWindow::disconnect
	_cur_c.release();
	_cur_r.release();
	_cur_d.release();
	}

	return result;
	}

	bool egl_display_t::haveExtension(const char* name, size_t nameLen) const {
	if (!nameLen) {
	nameLen = strlen(name);
	}
	return findExtension(mExtensionString.string(), name, nameLen);
	}

	// ----------------------------------------------------------------------------

	bool egl_display_t::HibernationMachine::incWakeCount(WakeRefStrength strength) {
	Mutex::Autolock _l(mLock);
	ALOGE_IF(mWakeCount < 0 \|\| mWakeCount == INT32_MAX,
	"Invalid WakeCount (%d) on enter\n", mWakeCount);

	mWakeCount++;
	if (strength == STRONG)
	mAttemptHibernation = false;

	if (CC_UNLIKELY(mHibernating)) {
	ALOGV("Awakening\n");
	egl_connection_t* const cnx = &gEGLImpl;

	// These conditions should be guaranteed before entering hibernation;
	// we don't want to get into a state where we can't wake up.
	ALOGD_IF(!mDpyValid \|\| !cnx->egl.eglAwakenProcessIMG,
	"Invalid hibernation state, unable to awaken\n");

	if (!cnx->egl.eglAwakenProcessIMG()) {
	ALOGE("Failed to awaken EGL implementation\n");
	return false;
	}
	mHibernating = false;
	}
	return true;
	}

	void egl_display_t::HibernationMachine::decWakeCount(WakeRefStrength strength) {
	Mutex::Autolock _l(mLock);
	ALOGE_IF(mWakeCount <= 0, "Invalid WakeCount (%d) on leave\n", mWakeCount);

	mWakeCount--;
	if (strength == STRONG)
	mAttemptHibernation = true;

	if (mWakeCount == 0 && CC_UNLIKELY(mAttemptHibernation)) {
	egl_connection_t* const cnx = &gEGLImpl;
	mAttemptHibernation = false;
	if (mAllowHibernation && mDpyValid &&
	cnx->egl.eglHibernateProcessIMG &&
	cnx->egl.eglAwakenProcessIMG) {
	ALOGV("Hibernating\n");
	if (!cnx->egl.eglHibernateProcessIMG()) {
	ALOGE("Failed to hibernate EGL implementation\n");
	return;
	}
	mHibernating = true;
	}
	}
	}

	void egl_display_t::HibernationMachine::setDisplayValid(bool valid) {
	Mutex::Autolock _l(mLock);
	mDpyValid = valid;
	}

	// ----------------------------------------------------------------------------
	}; // namespace android
	// ----------------------------------------------------------------------------