SurfaceTextureClient.cpp revision 5bfc24515bb5c8ea7975f72d538df37753733a2f 
1/*
2 * Copyright (C) 2010 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#define LOG_TAG "SurfaceTextureClient"
18//#define LOG_NDEBUG 0
19
20#include <gui/SurfaceTextureClient.h>
21
22#include <utils/Log.h>
23
24namespace android {
25
26SurfaceTextureClient::SurfaceTextureClient(
27        const sp<ISurfaceTexture>& surfaceTexture)
28{
29    SurfaceTextureClient::init();
30    SurfaceTextureClient::setISurfaceTexture(surfaceTexture);
31}
32
33SurfaceTextureClient::SurfaceTextureClient() {
34    SurfaceTextureClient::init();
35}
36
37void SurfaceTextureClient::init() {
38    // Initialize the ANativeWindow function pointers.
39    ANativeWindow::setSwapInterval  = hook_setSwapInterval;
40    ANativeWindow::dequeueBuffer    = hook_dequeueBuffer;
41    ANativeWindow::cancelBuffer     = hook_cancelBuffer;
42    ANativeWindow::lockBuffer       = hook_lockBuffer;
43    ANativeWindow::queueBuffer      = hook_queueBuffer;
44    ANativeWindow::query            = hook_query;
45    ANativeWindow::perform          = hook_perform;
46
47    const_cast<int&>(ANativeWindow::minSwapInterval) = 0;
48    const_cast<int&>(ANativeWindow::maxSwapInterval) = 1;
49
50    mReqWidth = 0;
51    mReqHeight = 0;
52    mReqFormat = 0;
53    mReqUsage = 0;
54    mTimestamp = NATIVE_WINDOW_TIMESTAMP_AUTO;
55    mDefaultWidth = 0;
56    mDefaultHeight = 0;
57    mTransformHint = 0;
58    mConnectedToCpu = false;
59}
60
61void SurfaceTextureClient::setISurfaceTexture(
62        const sp<ISurfaceTexture>& surfaceTexture)
63{
64    mSurfaceTexture = surfaceTexture;
65}
66
67sp<ISurfaceTexture> SurfaceTextureClient::getISurfaceTexture() const {
68    return mSurfaceTexture;
69}
70
71int SurfaceTextureClient::hook_setSwapInterval(ANativeWindow* window, int interval) {
72    SurfaceTextureClient* c = getSelf(window);
73    return c->setSwapInterval(interval);
74}
75
76int SurfaceTextureClient::hook_dequeueBuffer(ANativeWindow* window,
77        ANativeWindowBuffer** buffer) {
78    SurfaceTextureClient* c = getSelf(window);
79    return c->dequeueBuffer(buffer);
80}
81
82int SurfaceTextureClient::hook_cancelBuffer(ANativeWindow* window,
83        ANativeWindowBuffer* buffer) {
84    SurfaceTextureClient* c = getSelf(window);
85    return c->cancelBuffer(buffer);
86}
87
88int SurfaceTextureClient::hook_lockBuffer(ANativeWindow* window,
89        ANativeWindowBuffer* buffer) {
90    SurfaceTextureClient* c = getSelf(window);
91    return c->lockBuffer(buffer);
92}
93
94int SurfaceTextureClient::hook_queueBuffer(ANativeWindow* window,
95        ANativeWindowBuffer* buffer) {
96    SurfaceTextureClient* c = getSelf(window);
97    return c->queueBuffer(buffer);
98}
99
100int SurfaceTextureClient::hook_query(const ANativeWindow* window,
101                                int what, int* value) {
102    const SurfaceTextureClient* c = getSelf(window);
103    return c->query(what, value);
104}
105
106int SurfaceTextureClient::hook_perform(ANativeWindow* window, int operation, ...) {
107    va_list args;
108    va_start(args, operation);
109    SurfaceTextureClient* c = getSelf(window);
110    return c->perform(operation, args);
111}
112
113int SurfaceTextureClient::setSwapInterval(int interval) {
114    // EGL specification states:
115    //  interval is silently clamped to minimum and maximum implementation
116    //  dependent values before being stored.
117    // Although we don't have to, we apply the same logic here.
118
119    if (interval < minSwapInterval)
120        interval = minSwapInterval;
121
122    if (interval > maxSwapInterval)
123        interval = maxSwapInterval;
124
125    status_t res = mSurfaceTexture->setSynchronousMode(interval ? true : false);
126
127    return res;
128}
129
130int SurfaceTextureClient::dequeueBuffer(android_native_buffer_t** buffer) {
131    LOGV("SurfaceTextureClient::dequeueBuffer");
132    Mutex::Autolock lock(mMutex);
133    int buf = -1;
134    status_t result = mSurfaceTexture->dequeueBuffer(&buf, mReqWidth, mReqHeight,
135            mReqFormat, mReqUsage);
136    if (result < 0) {
137        LOGV("dequeueBuffer: ISurfaceTexture::dequeueBuffer(%d, %d, %d, %d)"
138             "failed: %d", mReqWidth, mReqHeight, mReqFormat, mReqUsage,
139             result);
140        return result;
141    }
142    sp<GraphicBuffer>& gbuf(mSlots[buf]);
143    if (result & ISurfaceTexture::RELEASE_ALL_BUFFERS) {
144        freeAllBuffers();
145    }
146
147    if ((result & ISurfaceTexture::BUFFER_NEEDS_REALLOCATION) || gbuf == 0) {
148        result = mSurfaceTexture->requestBuffer(buf, &gbuf);
149        if (result != NO_ERROR) {
150            LOGE("dequeueBuffer: ISurfaceTexture::requestBuffer failed: %d",
151                    result);
152            return result;
153        }
154    }
155    *buffer = gbuf.get();
156    return OK;
157}
158
159int SurfaceTextureClient::cancelBuffer(android_native_buffer_t* buffer) {
160    LOGV("SurfaceTextureClient::cancelBuffer");
161    Mutex::Autolock lock(mMutex);
162    int i = getSlotFromBufferLocked(buffer);
163    if (i < 0) {
164        return i;
165    }
166    mSurfaceTexture->cancelBuffer(i);
167    return OK;
168}
169
170int SurfaceTextureClient::getSlotFromBufferLocked(
171        android_native_buffer_t* buffer) const {
172    bool dumpedState = false;
173    for (int i = 0; i < NUM_BUFFER_SLOTS; i++) {
174        // XXX: Dump the slots whenever we hit a NULL entry while searching for
175        // a buffer.
176        if (mSlots[i] == NULL) {
177            if (!dumpedState) {
178                LOGD("getSlotFromBufferLocked: encountered NULL buffer in slot %d "
179                        "looking for buffer %p", i, buffer->handle);
180                for (int j = 0; j < NUM_BUFFER_SLOTS; j++) {
181                    if (mSlots[j] == NULL) {
182                        LOGD("getSlotFromBufferLocked:   %02d: NULL", j);
183                    } else {
184                        LOGD("getSlotFromBufferLocked:   %02d: %p", j, mSlots[j]->handle);
185                    }
186                }
187                dumpedState = true;
188            }
189        }
190
191        if (mSlots[i] != NULL && mSlots[i]->handle == buffer->handle) {
192            return i;
193        }
194    }
195    LOGE("getSlotFromBufferLocked: unknown buffer: %p", buffer->handle);
196    return BAD_VALUE;
197}
198
199int SurfaceTextureClient::lockBuffer(android_native_buffer_t* buffer) {
200    LOGV("SurfaceTextureClient::lockBuffer");
201    Mutex::Autolock lock(mMutex);
202    return OK;
203}
204
205int SurfaceTextureClient::queueBuffer(android_native_buffer_t* buffer) {
206    LOGV("SurfaceTextureClient::queueBuffer");
207    Mutex::Autolock lock(mMutex);
208    int64_t timestamp;
209    if (mTimestamp == NATIVE_WINDOW_TIMESTAMP_AUTO) {
210        timestamp = systemTime(SYSTEM_TIME_MONOTONIC);
211        LOGV("SurfaceTextureClient::queueBuffer making up timestamp: %.2f ms",
212             timestamp / 1000000.f);
213    } else {
214        timestamp = mTimestamp;
215    }
216    int i = getSlotFromBufferLocked(buffer);
217    if (i < 0) {
218        return i;
219    }
220    mSurfaceTexture->queueBuffer(i, timestamp,
221            &mDefaultWidth, &mDefaultHeight, &mTransformHint);
222    return OK;
223}
224
225int SurfaceTextureClient::query(int what, int* value) const {
226    LOGV("SurfaceTextureClient::query");
227    { // scope for the lock
228        Mutex::Autolock lock(mMutex);
229        switch (what) {
230            case NATIVE_WINDOW_FORMAT:
231                if (mReqFormat) {
232                    *value = mReqFormat;
233                    return NO_ERROR;
234                }
235                break;
236            case NATIVE_WINDOW_QUEUES_TO_WINDOW_COMPOSER:
237                *value = 0;
238                return NO_ERROR;
239            case NATIVE_WINDOW_CONCRETE_TYPE:
240                *value = NATIVE_WINDOW_SURFACE_TEXTURE_CLIENT;
241                return NO_ERROR;
242            case NATIVE_WINDOW_DEFAULT_WIDTH:
243                *value = mDefaultWidth;
244                return NO_ERROR;
245            case NATIVE_WINDOW_DEFAULT_HEIGHT:
246                *value = mDefaultHeight;
247                return NO_ERROR;
248            case NATIVE_WINDOW_TRANSFORM_HINT:
249                *value = mTransformHint;
250                return NO_ERROR;
251        }
252    }
253    return mSurfaceTexture->query(what, value);
254}
255
256int SurfaceTextureClient::perform(int operation, va_list args)
257{
258    int res = NO_ERROR;
259    switch (operation) {
260    case NATIVE_WINDOW_CONNECT:
261        // deprecated. must return NO_ERROR.
262        break;
263    case NATIVE_WINDOW_DISCONNECT:
264        // deprecated. must return NO_ERROR.
265        break;
266    case NATIVE_WINDOW_SET_USAGE:
267        res = dispatchSetUsage(args);
268        break;
269    case NATIVE_WINDOW_SET_CROP:
270        res = dispatchSetCrop(args);
271        break;
272    case NATIVE_WINDOW_SET_BUFFER_COUNT:
273        res = dispatchSetBufferCount(args);
274        break;
275    case NATIVE_WINDOW_SET_BUFFERS_GEOMETRY:
276        res = dispatchSetBuffersGeometry(args);
277        break;
278    case NATIVE_WINDOW_SET_BUFFERS_TRANSFORM:
279        res = dispatchSetBuffersTransform(args);
280        break;
281    case NATIVE_WINDOW_SET_BUFFERS_TIMESTAMP:
282        res = dispatchSetBuffersTimestamp(args);
283        break;
284    case NATIVE_WINDOW_SET_BUFFERS_DIMENSIONS:
285        res = dispatchSetBuffersDimensions(args);
286        break;
287    case NATIVE_WINDOW_SET_BUFFERS_FORMAT:
288        res = dispatchSetBuffersFormat(args);
289        break;
290    case NATIVE_WINDOW_LOCK:
291        res = dispatchLock(args);
292        break;
293    case NATIVE_WINDOW_UNLOCK_AND_POST:
294        res = dispatchUnlockAndPost(args);
295        break;
296    case NATIVE_WINDOW_SET_SCALING_MODE:
297        res = dispatchSetScalingMode(args);
298        break;
299    case NATIVE_WINDOW_API_CONNECT:
300        res = dispatchConnect(args);
301        break;
302    case NATIVE_WINDOW_API_DISCONNECT:
303        res = dispatchDisconnect(args);
304        break;
305    default:
306        res = NAME_NOT_FOUND;
307        break;
308    }
309    return res;
310}
311
312int SurfaceTextureClient::dispatchConnect(va_list args) {
313    int api = va_arg(args, int);
314    return connect(api);
315}
316
317int SurfaceTextureClient::dispatchDisconnect(va_list args) {
318    int api = va_arg(args, int);
319    return disconnect(api);
320}
321
322int SurfaceTextureClient::dispatchSetUsage(va_list args) {
323    int usage = va_arg(args, int);
324    return setUsage(usage);
325}
326
327int SurfaceTextureClient::dispatchSetCrop(va_list args) {
328    android_native_rect_t const* rect = va_arg(args, android_native_rect_t*);
329    return setCrop(reinterpret_cast<Rect const*>(rect));
330}
331
332int SurfaceTextureClient::dispatchSetBufferCount(va_list args) {
333    size_t bufferCount = va_arg(args, size_t);
334    return setBufferCount(bufferCount);
335}
336
337int SurfaceTextureClient::dispatchSetBuffersGeometry(va_list args) {
338    int w = va_arg(args, int);
339    int h = va_arg(args, int);
340    int f = va_arg(args, int);
341    int err = setBuffersDimensions(w, h);
342    if (err != 0) {
343        return err;
344    }
345    return setBuffersFormat(f);
346}
347
348int SurfaceTextureClient::dispatchSetBuffersDimensions(va_list args) {
349    int w = va_arg(args, int);
350    int h = va_arg(args, int);
351    return setBuffersDimensions(w, h);
352}
353
354int SurfaceTextureClient::dispatchSetBuffersFormat(va_list args) {
355    int f = va_arg(args, int);
356    return setBuffersFormat(f);
357}
358
359int SurfaceTextureClient::dispatchSetScalingMode(va_list args) {
360    int m = va_arg(args, int);
361    return setScalingMode(m);
362}
363
364int SurfaceTextureClient::dispatchSetBuffersTransform(va_list args) {
365    int transform = va_arg(args, int);
366    return setBuffersTransform(transform);
367}
368
369int SurfaceTextureClient::dispatchSetBuffersTimestamp(va_list args) {
370    int64_t timestamp = va_arg(args, int64_t);
371    return setBuffersTimestamp(timestamp);
372}
373
374int SurfaceTextureClient::dispatchLock(va_list args) {
375    ANativeWindow_Buffer* outBuffer = va_arg(args, ANativeWindow_Buffer*);
376    ARect* inOutDirtyBounds = va_arg(args, ARect*);
377    return lock(outBuffer, inOutDirtyBounds);
378}
379
380int SurfaceTextureClient::dispatchUnlockAndPost(va_list args) {
381    return unlockAndPost();
382}
383
384
385int SurfaceTextureClient::connect(int api) {
386    LOGV("SurfaceTextureClient::connect");
387    Mutex::Autolock lock(mMutex);
388    int err = mSurfaceTexture->connect(api,
389            &mDefaultWidth, &mDefaultHeight, &mTransformHint);
390    if (!err && api == NATIVE_WINDOW_API_CPU) {
391        mConnectedToCpu = true;
392    }
393    return err;
394}
395
396int SurfaceTextureClient::disconnect(int api) {
397    LOGV("SurfaceTextureClient::disconnect");
398    Mutex::Autolock lock(mMutex);
399    int err = mSurfaceTexture->disconnect(api);
400    if (!err && api == NATIVE_WINDOW_API_CPU) {
401        mConnectedToCpu = false;
402    }
403    return err;
404}
405
406int SurfaceTextureClient::setUsage(uint32_t reqUsage)
407{
408    LOGV("SurfaceTextureClient::setUsage");
409    Mutex::Autolock lock(mMutex);
410    mReqUsage = reqUsage;
411    return OK;
412}
413
414int SurfaceTextureClient::setCrop(Rect const* rect)
415{
416    LOGV("SurfaceTextureClient::setCrop");
417    Mutex::Autolock lock(mMutex);
418
419    Rect realRect;
420    if (rect == NULL || rect->isEmpty()) {
421        realRect = Rect(0, 0);
422    } else {
423        realRect = *rect;
424    }
425
426    status_t err = mSurfaceTexture->setCrop(*rect);
427    LOGE_IF(err, "ISurfaceTexture::setCrop(...) returned %s", strerror(-err));
428
429    return err;
430}
431
432int SurfaceTextureClient::setBufferCount(int bufferCount)
433{
434    LOGV("SurfaceTextureClient::setBufferCount");
435    Mutex::Autolock lock(mMutex);
436
437    status_t err = mSurfaceTexture->setBufferCount(bufferCount);
438    LOGE_IF(err, "ISurfaceTexture::setBufferCount(%d) returned %s",
439            bufferCount, strerror(-err));
440
441    if (err == NO_ERROR) {
442        freeAllBuffers();
443    }
444
445    return err;
446}
447
448int SurfaceTextureClient::setBuffersDimensions(int w, int h)
449{
450    LOGV("SurfaceTextureClient::setBuffersDimensions");
451    Mutex::Autolock lock(mMutex);
452
453    if (w<0 || h<0)
454        return BAD_VALUE;
455
456    if ((w && !h) || (!w && h))
457        return BAD_VALUE;
458
459    mReqWidth = w;
460    mReqHeight = h;
461
462    status_t err = mSurfaceTexture->setCrop(Rect(0, 0));
463    LOGE_IF(err, "ISurfaceTexture::setCrop(...) returned %s", strerror(-err));
464
465    return err;
466}
467
468int SurfaceTextureClient::setBuffersFormat(int format)
469{
470    LOGV("SurfaceTextureClient::setBuffersFormat");
471    Mutex::Autolock lock(mMutex);
472
473    if (format<0)
474        return BAD_VALUE;
475
476    mReqFormat = format;
477
478    return NO_ERROR;
479}
480
481int SurfaceTextureClient::setScalingMode(int mode)
482{
483    LOGV("SurfaceTextureClient::setScalingMode(%d)", mode);
484    Mutex::Autolock lock(mMutex);
485    // mode is validated on the server
486    status_t err = mSurfaceTexture->setScalingMode(mode);
487    LOGE_IF(err, "ISurfaceTexture::setScalingMode(%d) returned %s",
488            mode, strerror(-err));
489
490    return err;
491}
492
493int SurfaceTextureClient::setBuffersTransform(int transform)
494{
495    LOGV("SurfaceTextureClient::setBuffersTransform");
496    Mutex::Autolock lock(mMutex);
497    status_t err = mSurfaceTexture->setTransform(transform);
498    return err;
499}
500
501int SurfaceTextureClient::setBuffersTimestamp(int64_t timestamp)
502{
503    LOGV("SurfaceTextureClient::setBuffersTimestamp");
504    Mutex::Autolock lock(mMutex);
505    mTimestamp = timestamp;
506    return NO_ERROR;
507}
508
509void SurfaceTextureClient::freeAllBuffers() {
510    for (int i = 0; i < NUM_BUFFER_SLOTS; i++) {
511        mSlots[i] = 0;
512    }
513}
514
515// ----------------------------------------------------------------------
516// the lock/unlock APIs must be used from the same thread
517
518static status_t copyBlt(
519        const sp<GraphicBuffer>& dst,
520        const sp<GraphicBuffer>& src,
521        const Region& reg)
522{
523    // src and dst with, height and format must be identical. no verification
524    // is done here.
525    status_t err;
526    uint8_t const * src_bits = NULL;
527    err = src->lock(GRALLOC_USAGE_SW_READ_OFTEN, reg.bounds(), (void**)&src_bits);
528    LOGE_IF(err, "error locking src buffer %s", strerror(-err));
529
530    uint8_t* dst_bits = NULL;
531    err = dst->lock(GRALLOC_USAGE_SW_WRITE_OFTEN, reg.bounds(), (void**)&dst_bits);
532    LOGE_IF(err, "error locking dst buffer %s", strerror(-err));
533
534    Region::const_iterator head(reg.begin());
535    Region::const_iterator tail(reg.end());
536    if (head != tail && src_bits && dst_bits) {
537        const size_t bpp = bytesPerPixel(src->format);
538        const size_t dbpr = dst->stride * bpp;
539        const size_t sbpr = src->stride * bpp;
540
541        while (head != tail) {
542            const Rect& r(*head++);
543            ssize_t h = r.height();
544            if (h <= 0) continue;
545            size_t size = r.width() * bpp;
546            uint8_t const * s = src_bits + (r.left + src->stride * r.top) * bpp;
547            uint8_t       * d = dst_bits + (r.left + dst->stride * r.top) * bpp;
548            if (dbpr==sbpr && size==sbpr) {
549                size *= h;
550                h = 1;
551            }
552            do {
553                memcpy(d, s, size);
554                d += dbpr;
555                s += sbpr;
556            } while (--h > 0);
557        }
558    }
559
560    if (src_bits)
561        src->unlock();
562
563    if (dst_bits)
564        dst->unlock();
565
566    return err;
567}
568
569// ----------------------------------------------------------------------------
570
571status_t SurfaceTextureClient::lock(
572        ANativeWindow_Buffer* outBuffer, ARect* inOutDirtyBounds)
573{
574    if (mLockedBuffer != 0) {
575        LOGE("Surface::lock failed, already locked");
576        return INVALID_OPERATION;
577    }
578
579    if (!mConnectedToCpu) {
580        int err = SurfaceTextureClient::connect(NATIVE_WINDOW_API_CPU);
581        if (err) {
582            return err;
583        }
584        // we're intending to do software rendering from this point
585        setUsage(GRALLOC_USAGE_SW_READ_OFTEN | GRALLOC_USAGE_SW_WRITE_OFTEN);
586    }
587
588    ANativeWindowBuffer* out;
589    status_t err = dequeueBuffer(&out);
590    LOGE_IF(err, "dequeueBuffer failed (%s)", strerror(-err));
591    if (err == NO_ERROR) {
592        sp<GraphicBuffer> backBuffer(GraphicBuffer::getSelf(out));
593        err = lockBuffer(backBuffer.get());
594        LOGE_IF(err, "lockBuffer (handle=%p) failed (%s)",
595                backBuffer->handle, strerror(-err));
596        if (err == NO_ERROR) {
597            const Rect bounds(backBuffer->width, backBuffer->height);
598
599            Region newDirtyRegion;
600            if (inOutDirtyBounds) {
601                newDirtyRegion.set(static_cast<Rect const&>(*inOutDirtyBounds));
602                newDirtyRegion.andSelf(bounds);
603            } else {
604                newDirtyRegion.set(bounds);
605            }
606
607            // figure out if we can copy the frontbuffer back
608            const sp<GraphicBuffer>& frontBuffer(mPostedBuffer);
609            const bool canCopyBack = (frontBuffer != 0 &&
610                    backBuffer->width  == frontBuffer->width &&
611                    backBuffer->height == frontBuffer->height &&
612                    backBuffer->format == frontBuffer->format);
613
614            if (canCopyBack) {
615                // copy the area that is invalid and not repainted this round
616                const Region copyback(mOldDirtyRegion.subtract(newDirtyRegion));
617                if (!copyback.isEmpty())
618                    copyBlt(backBuffer, frontBuffer, copyback);
619            } else {
620                // if we can't copy-back anything, modify the user's dirty
621                // region to make sure they redraw the whole buffer
622                newDirtyRegion.set(bounds);
623            }
624
625            // keep track of the are of the buffer that is "clean"
626            // (ie: that will be redrawn)
627            mOldDirtyRegion = newDirtyRegion;
628
629            if (inOutDirtyBounds) {
630                *inOutDirtyBounds = newDirtyRegion.getBounds();
631            }
632
633            void* vaddr;
634            status_t res = backBuffer->lock(
635                    GRALLOC_USAGE_SW_READ_OFTEN | GRALLOC_USAGE_SW_WRITE_OFTEN,
636                    newDirtyRegion.bounds(), &vaddr);
637
638            LOGW_IF(res, "failed locking buffer (handle = %p)",
639                    backBuffer->handle);
640
641            mLockedBuffer = backBuffer;
642            outBuffer->width  = backBuffer->width;
643            outBuffer->height = backBuffer->height;
644            outBuffer->stride = backBuffer->stride;
645            outBuffer->format = backBuffer->format;
646            outBuffer->bits   = vaddr;
647        }
648    }
649    return err;
650}
651
652status_t SurfaceTextureClient::unlockAndPost()
653{
654    if (mLockedBuffer == 0) {
655        LOGE("Surface::unlockAndPost failed, no locked buffer");
656        return INVALID_OPERATION;
657    }
658
659    status_t err = mLockedBuffer->unlock();
660    LOGE_IF(err, "failed unlocking buffer (%p)", mLockedBuffer->handle);
661
662    err = queueBuffer(mLockedBuffer.get());
663    LOGE_IF(err, "queueBuffer (handle=%p) failed (%s)",
664            mLockedBuffer->handle, strerror(-err));
665
666    mPostedBuffer = mLockedBuffer;
667    mLockedBuffer = 0;
668    return err;
669}
670
671}; // namespace android
672