208cb07724
this situation happened when the last buffer needed to be resized (or allocated, the first time). the assumption was that the buffer was in use by SF itself as the current buffer (obviously, this assumption made no sense when the buffer had never been allocated, btw). the system would wait until some other buffer became the "front" buffer. we fix this problem by entirely removing the requirement that the buffer being resized cannot be the front buffer. instead, we just allocate a new buffer and replace the front buffer by the new one. the downside is that this uses more memory (an extra buffer) for a brief amount of time while the old buffer is being reallocated and before it has actually been replaced. Change-Id: I022e4621209474ceb1c671b23deb4188eaaa7285
636 lines
18 KiB
C++
636 lines
18 KiB
C++
/*
|
|
* Copyright (C) 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 LOG_TAG "SharedBufferStack"
|
|
|
|
#include <stdint.h>
|
|
#include <sys/types.h>
|
|
|
|
#include <utils/Debug.h>
|
|
#include <utils/Log.h>
|
|
#include <utils/threads.h>
|
|
|
|
#include <private/surfaceflinger/SharedBufferStack.h>
|
|
|
|
#include <ui/Rect.h>
|
|
#include <ui/Region.h>
|
|
|
|
#define DEBUG_ATOMICS 0
|
|
|
|
namespace android {
|
|
// ----------------------------------------------------------------------------
|
|
|
|
SharedClient::SharedClient()
|
|
: lock(Mutex::SHARED), cv(Condition::SHARED)
|
|
{
|
|
}
|
|
|
|
SharedClient::~SharedClient() {
|
|
}
|
|
|
|
|
|
// these functions are used by the clients
|
|
status_t SharedClient::validate(size_t i) const {
|
|
if (uint32_t(i) >= uint32_t(SharedBufferStack::NUM_LAYERS_MAX))
|
|
return BAD_INDEX;
|
|
return surfaces[i].status;
|
|
}
|
|
|
|
// ----------------------------------------------------------------------------
|
|
|
|
|
|
SharedBufferStack::SharedBufferStack()
|
|
{
|
|
}
|
|
|
|
void SharedBufferStack::init(int32_t i)
|
|
{
|
|
inUse = -2;
|
|
status = NO_ERROR;
|
|
identity = i;
|
|
}
|
|
|
|
status_t SharedBufferStack::setCrop(int buffer, const Rect& crop)
|
|
{
|
|
if (uint32_t(buffer) >= NUM_BUFFER_MAX)
|
|
return BAD_INDEX;
|
|
|
|
buffers[buffer].crop.l = uint16_t(crop.left);
|
|
buffers[buffer].crop.t = uint16_t(crop.top);
|
|
buffers[buffer].crop.r = uint16_t(crop.right);
|
|
buffers[buffer].crop.b = uint16_t(crop.bottom);
|
|
return NO_ERROR;
|
|
}
|
|
|
|
status_t SharedBufferStack::setDirtyRegion(int buffer, const Region& dirty)
|
|
{
|
|
if (uint32_t(buffer) >= NUM_BUFFER_MAX)
|
|
return BAD_INDEX;
|
|
|
|
FlatRegion& reg(buffers[buffer].dirtyRegion);
|
|
if (dirty.isEmpty()) {
|
|
reg.count = 0;
|
|
return NO_ERROR;
|
|
}
|
|
|
|
size_t count;
|
|
Rect const* r = dirty.getArray(&count);
|
|
if (count > FlatRegion::NUM_RECT_MAX) {
|
|
const Rect bounds(dirty.getBounds());
|
|
reg.count = 1;
|
|
reg.rects[0].l = uint16_t(bounds.left);
|
|
reg.rects[0].t = uint16_t(bounds.top);
|
|
reg.rects[0].r = uint16_t(bounds.right);
|
|
reg.rects[0].b = uint16_t(bounds.bottom);
|
|
} else {
|
|
reg.count = count;
|
|
for (size_t i=0 ; i<count ; i++) {
|
|
reg.rects[i].l = uint16_t(r[i].left);
|
|
reg.rects[i].t = uint16_t(r[i].top);
|
|
reg.rects[i].r = uint16_t(r[i].right);
|
|
reg.rects[i].b = uint16_t(r[i].bottom);
|
|
}
|
|
}
|
|
return NO_ERROR;
|
|
}
|
|
|
|
Region SharedBufferStack::getDirtyRegion(int buffer) const
|
|
{
|
|
Region res;
|
|
if (uint32_t(buffer) >= NUM_BUFFER_MAX)
|
|
return res;
|
|
|
|
const FlatRegion& reg(buffers[buffer].dirtyRegion);
|
|
if (reg.count > FlatRegion::NUM_RECT_MAX)
|
|
return res;
|
|
|
|
if (reg.count == 1) {
|
|
const Rect r(
|
|
reg.rects[0].l,
|
|
reg.rects[0].t,
|
|
reg.rects[0].r,
|
|
reg.rects[0].b);
|
|
res.set(r);
|
|
} else {
|
|
for (size_t i=0 ; i<reg.count ; i++) {
|
|
const Rect r(
|
|
reg.rects[i].l,
|
|
reg.rects[i].t,
|
|
reg.rects[i].r,
|
|
reg.rects[i].b);
|
|
res.orSelf(r);
|
|
}
|
|
}
|
|
return res;
|
|
}
|
|
|
|
// ----------------------------------------------------------------------------
|
|
|
|
SharedBufferBase::SharedBufferBase(SharedClient* sharedClient,
|
|
int surface, int32_t identity)
|
|
: mSharedClient(sharedClient),
|
|
mSharedStack(sharedClient->surfaces + surface),
|
|
mIdentity(identity)
|
|
{
|
|
}
|
|
|
|
SharedBufferBase::~SharedBufferBase()
|
|
{
|
|
}
|
|
|
|
status_t SharedBufferBase::getStatus() const
|
|
{
|
|
SharedBufferStack& stack( *mSharedStack );
|
|
return stack.status;
|
|
}
|
|
|
|
int32_t SharedBufferBase::getIdentity() const
|
|
{
|
|
SharedBufferStack& stack( *mSharedStack );
|
|
return stack.identity;
|
|
}
|
|
|
|
size_t SharedBufferBase::getFrontBuffer() const
|
|
{
|
|
SharedBufferStack& stack( *mSharedStack );
|
|
return size_t( stack.head );
|
|
}
|
|
|
|
String8 SharedBufferBase::dump(char const* prefix) const
|
|
{
|
|
const size_t SIZE = 1024;
|
|
char buffer[SIZE];
|
|
String8 result;
|
|
SharedBufferStack& stack( *mSharedStack );
|
|
snprintf(buffer, SIZE,
|
|
"%s[ head=%2d, available=%2d, queued=%2d ] "
|
|
"reallocMask=%08x, inUse=%2d, identity=%d, status=%d",
|
|
prefix, stack.head, stack.available, stack.queued,
|
|
stack.reallocMask, stack.inUse, stack.identity, stack.status);
|
|
result.append(buffer);
|
|
result.append("\n");
|
|
return result;
|
|
}
|
|
|
|
status_t SharedBufferBase::waitForCondition(const ConditionBase& condition)
|
|
{
|
|
const SharedBufferStack& stack( *mSharedStack );
|
|
SharedClient& client( *mSharedClient );
|
|
const nsecs_t TIMEOUT = s2ns(1);
|
|
const int identity = mIdentity;
|
|
|
|
Mutex::Autolock _l(client.lock);
|
|
while ((condition()==false) &&
|
|
(stack.identity == identity) &&
|
|
(stack.status == NO_ERROR))
|
|
{
|
|
status_t err = client.cv.waitRelative(client.lock, TIMEOUT);
|
|
// handle errors and timeouts
|
|
if (CC_UNLIKELY(err != NO_ERROR)) {
|
|
if (err == TIMED_OUT) {
|
|
if (condition()) {
|
|
LOGE("waitForCondition(%s) timed out (identity=%d), "
|
|
"but condition is true! We recovered but it "
|
|
"shouldn't happen." , condition.name(), stack.identity);
|
|
break;
|
|
} else {
|
|
LOGW("waitForCondition(%s) timed out "
|
|
"(identity=%d, status=%d). "
|
|
"CPU may be pegged. trying again.", condition.name(),
|
|
stack.identity, stack.status);
|
|
}
|
|
} else {
|
|
LOGE("waitForCondition(%s) error (%s) ",
|
|
condition.name(), strerror(-err));
|
|
return err;
|
|
}
|
|
}
|
|
}
|
|
return (stack.identity != mIdentity) ? status_t(BAD_INDEX) : stack.status;
|
|
}
|
|
// ============================================================================
|
|
// conditions and updates
|
|
// ============================================================================
|
|
|
|
SharedBufferClient::DequeueCondition::DequeueCondition(
|
|
SharedBufferClient* sbc) : ConditionBase(sbc) {
|
|
}
|
|
bool SharedBufferClient::DequeueCondition::operator()() const {
|
|
return stack.available > 0;
|
|
}
|
|
|
|
SharedBufferClient::LockCondition::LockCondition(
|
|
SharedBufferClient* sbc, int buf) : ConditionBase(sbc), buf(buf) {
|
|
}
|
|
bool SharedBufferClient::LockCondition::operator()() const {
|
|
// NOTE: if stack.head is messed up, we could crash the client
|
|
// or cause some drawing artifacts. This is okay, as long as it is
|
|
// limited to the client.
|
|
return (buf != stack.index[stack.head] ||
|
|
(stack.queued > 0 && stack.inUse != buf));
|
|
}
|
|
|
|
// ----------------------------------------------------------------------------
|
|
|
|
SharedBufferClient::QueueUpdate::QueueUpdate(SharedBufferBase* sbb)
|
|
: UpdateBase(sbb) {
|
|
}
|
|
ssize_t SharedBufferClient::QueueUpdate::operator()() {
|
|
android_atomic_inc(&stack.queued);
|
|
return NO_ERROR;
|
|
}
|
|
|
|
SharedBufferClient::UndoDequeueUpdate::UndoDequeueUpdate(SharedBufferBase* sbb)
|
|
: UpdateBase(sbb) {
|
|
}
|
|
ssize_t SharedBufferClient::UndoDequeueUpdate::operator()() {
|
|
android_atomic_inc(&stack.available);
|
|
return NO_ERROR;
|
|
}
|
|
|
|
SharedBufferServer::UnlockUpdate::UnlockUpdate(
|
|
SharedBufferBase* sbb, int lockedBuffer)
|
|
: UpdateBase(sbb), lockedBuffer(lockedBuffer) {
|
|
}
|
|
ssize_t SharedBufferServer::UnlockUpdate::operator()() {
|
|
if (stack.inUse != lockedBuffer) {
|
|
LOGE("unlocking %d, but currently locked buffer is %d "
|
|
"(identity=%d, token=%d)",
|
|
lockedBuffer, stack.inUse,
|
|
stack.identity, stack.token);
|
|
return BAD_VALUE;
|
|
}
|
|
android_atomic_write(-1, &stack.inUse);
|
|
return NO_ERROR;
|
|
}
|
|
|
|
SharedBufferServer::RetireUpdate::RetireUpdate(
|
|
SharedBufferBase* sbb, int numBuffers)
|
|
: UpdateBase(sbb), numBuffers(numBuffers) {
|
|
}
|
|
ssize_t SharedBufferServer::RetireUpdate::operator()() {
|
|
int32_t head = stack.head;
|
|
if (uint32_t(head) >= SharedBufferStack::NUM_BUFFER_MAX)
|
|
return BAD_VALUE;
|
|
|
|
// Preventively lock the current buffer before updating queued.
|
|
android_atomic_write(stack.index[head], &stack.inUse);
|
|
|
|
// Decrement the number of queued buffers
|
|
int32_t queued;
|
|
do {
|
|
queued = stack.queued;
|
|
if (queued == 0) {
|
|
return NOT_ENOUGH_DATA;
|
|
}
|
|
} while (android_atomic_cmpxchg(queued, queued-1, &stack.queued));
|
|
|
|
// lock the buffer before advancing head, which automatically unlocks
|
|
// the buffer we preventively locked upon entering this function
|
|
|
|
head = (head + 1) % numBuffers;
|
|
android_atomic_write(stack.index[head], &stack.inUse);
|
|
|
|
// head is only modified here, so we don't need to use cmpxchg
|
|
android_atomic_write(head, &stack.head);
|
|
|
|
// now that head has moved, we can increment the number of available buffers
|
|
android_atomic_inc(&stack.available);
|
|
return head;
|
|
}
|
|
|
|
SharedBufferServer::StatusUpdate::StatusUpdate(
|
|
SharedBufferBase* sbb, status_t status)
|
|
: UpdateBase(sbb), status(status) {
|
|
}
|
|
|
|
ssize_t SharedBufferServer::StatusUpdate::operator()() {
|
|
android_atomic_write(status, &stack.status);
|
|
return NO_ERROR;
|
|
}
|
|
|
|
// ============================================================================
|
|
|
|
SharedBufferClient::SharedBufferClient(SharedClient* sharedClient,
|
|
int surface, int num, int32_t identity)
|
|
: SharedBufferBase(sharedClient, surface, identity),
|
|
mNumBuffers(num), tail(0), undoDequeueTail(0)
|
|
{
|
|
SharedBufferStack& stack( *mSharedStack );
|
|
tail = computeTail();
|
|
queued_head = stack.head;
|
|
}
|
|
|
|
int32_t SharedBufferClient::computeTail() const
|
|
{
|
|
SharedBufferStack& stack( *mSharedStack );
|
|
return (mNumBuffers + stack.head - stack.available + 1) % mNumBuffers;
|
|
}
|
|
|
|
ssize_t SharedBufferClient::dequeue()
|
|
{
|
|
SharedBufferStack& stack( *mSharedStack );
|
|
|
|
if (stack.head == tail && stack.available == mNumBuffers) {
|
|
LOGW("dequeue: tail=%d, head=%d, avail=%d, queued=%d",
|
|
tail, stack.head, stack.available, stack.queued);
|
|
}
|
|
|
|
RWLock::AutoRLock _rd(mLock);
|
|
|
|
const nsecs_t dequeueTime = systemTime(SYSTEM_TIME_THREAD);
|
|
|
|
//LOGD("[%d] about to dequeue a buffer",
|
|
// mSharedStack->identity);
|
|
DequeueCondition condition(this);
|
|
status_t err = waitForCondition(condition);
|
|
if (err != NO_ERROR)
|
|
return ssize_t(err);
|
|
|
|
// NOTE: 'stack.available' is part of the conditions, however
|
|
// decrementing it, never changes any conditions, so we don't need
|
|
// to do this as part of an update.
|
|
if (android_atomic_dec(&stack.available) == 0) {
|
|
LOGW("dequeue probably called from multiple threads!");
|
|
}
|
|
|
|
undoDequeueTail = tail;
|
|
int dequeued = stack.index[tail];
|
|
tail = ((tail+1 >= mNumBuffers) ? 0 : tail+1);
|
|
LOGD_IF(DEBUG_ATOMICS, "dequeued=%d, tail++=%d, %s",
|
|
dequeued, tail, dump("").string());
|
|
|
|
mDequeueTime[dequeued] = dequeueTime;
|
|
|
|
return dequeued;
|
|
}
|
|
|
|
status_t SharedBufferClient::undoDequeue(int buf)
|
|
{
|
|
RWLock::AutoRLock _rd(mLock);
|
|
|
|
// TODO: we can only undo the previous dequeue, we should
|
|
// enforce that in the api
|
|
UndoDequeueUpdate update(this);
|
|
status_t err = updateCondition( update );
|
|
if (err == NO_ERROR) {
|
|
tail = undoDequeueTail;
|
|
}
|
|
return err;
|
|
}
|
|
|
|
status_t SharedBufferClient::lock(int buf)
|
|
{
|
|
RWLock::AutoRLock _rd(mLock);
|
|
|
|
SharedBufferStack& stack( *mSharedStack );
|
|
LockCondition condition(this, buf);
|
|
status_t err = waitForCondition(condition);
|
|
return err;
|
|
}
|
|
|
|
status_t SharedBufferClient::queue(int buf)
|
|
{
|
|
RWLock::AutoRLock _rd(mLock);
|
|
|
|
SharedBufferStack& stack( *mSharedStack );
|
|
|
|
queued_head = (queued_head + 1) % mNumBuffers;
|
|
stack.index[queued_head] = buf;
|
|
|
|
QueueUpdate update(this);
|
|
status_t err = updateCondition( update );
|
|
LOGD_IF(DEBUG_ATOMICS, "queued=%d, %s", buf, dump("").string());
|
|
|
|
const nsecs_t now = systemTime(SYSTEM_TIME_THREAD);
|
|
stack.stats.totalTime = ns2us(now - mDequeueTime[buf]);
|
|
return err;
|
|
}
|
|
|
|
bool SharedBufferClient::needNewBuffer(int buf) const
|
|
{
|
|
SharedBufferStack& stack( *mSharedStack );
|
|
const uint32_t mask = 1<<(31-buf);
|
|
return (android_atomic_and(~mask, &stack.reallocMask) & mask) != 0;
|
|
}
|
|
|
|
status_t SharedBufferClient::setCrop(int buf, const Rect& crop)
|
|
{
|
|
SharedBufferStack& stack( *mSharedStack );
|
|
return stack.setCrop(buf, crop);
|
|
}
|
|
|
|
status_t SharedBufferClient::setDirtyRegion(int buf, const Region& reg)
|
|
{
|
|
SharedBufferStack& stack( *mSharedStack );
|
|
return stack.setDirtyRegion(buf, reg);
|
|
}
|
|
|
|
status_t SharedBufferClient::setBufferCount(
|
|
int bufferCount, const SetBufferCountCallback& ipc)
|
|
{
|
|
SharedBufferStack& stack( *mSharedStack );
|
|
if (uint32_t(bufferCount) >= SharedBufferStack::NUM_BUFFER_MAX)
|
|
return BAD_VALUE;
|
|
|
|
if (uint32_t(bufferCount) < SharedBufferStack::NUM_BUFFER_MIN)
|
|
return BAD_VALUE;
|
|
|
|
RWLock::AutoWLock _wr(mLock);
|
|
|
|
status_t err = ipc(bufferCount);
|
|
if (err == NO_ERROR) {
|
|
mNumBuffers = bufferCount;
|
|
queued_head = (stack.head + stack.queued) % mNumBuffers;
|
|
}
|
|
return err;
|
|
}
|
|
|
|
// ----------------------------------------------------------------------------
|
|
|
|
SharedBufferServer::SharedBufferServer(SharedClient* sharedClient,
|
|
int surface, int num, int32_t identity)
|
|
: SharedBufferBase(sharedClient, surface, identity),
|
|
mNumBuffers(num)
|
|
{
|
|
mSharedStack->init(identity);
|
|
mSharedStack->token = surface;
|
|
mSharedStack->head = num-1;
|
|
mSharedStack->available = num;
|
|
mSharedStack->queued = 0;
|
|
mSharedStack->reallocMask = 0;
|
|
memset(mSharedStack->buffers, 0, sizeof(mSharedStack->buffers));
|
|
for (int i=0 ; i<num ; i++) {
|
|
mBufferList.add(i);
|
|
mSharedStack->index[i] = i;
|
|
}
|
|
}
|
|
|
|
SharedBufferServer::~SharedBufferServer()
|
|
{
|
|
}
|
|
|
|
ssize_t SharedBufferServer::retireAndLock()
|
|
{
|
|
RWLock::AutoRLock _l(mLock);
|
|
|
|
RetireUpdate update(this, mNumBuffers);
|
|
ssize_t buf = updateCondition( update );
|
|
if (buf >= 0) {
|
|
if (uint32_t(buf) >= SharedBufferStack::NUM_BUFFER_MAX)
|
|
return BAD_VALUE;
|
|
SharedBufferStack& stack( *mSharedStack );
|
|
buf = stack.index[buf];
|
|
LOGD_IF(DEBUG_ATOMICS && buf>=0, "retire=%d, %s",
|
|
int(buf), dump("").string());
|
|
}
|
|
return buf;
|
|
}
|
|
|
|
status_t SharedBufferServer::unlock(int buf)
|
|
{
|
|
UnlockUpdate update(this, buf);
|
|
status_t err = updateCondition( update );
|
|
return err;
|
|
}
|
|
|
|
void SharedBufferServer::setStatus(status_t status)
|
|
{
|
|
if (status < NO_ERROR) {
|
|
StatusUpdate update(this, status);
|
|
updateCondition( update );
|
|
}
|
|
}
|
|
|
|
status_t SharedBufferServer::reallocateAll()
|
|
{
|
|
RWLock::AutoRLock _l(mLock);
|
|
|
|
SharedBufferStack& stack( *mSharedStack );
|
|
uint32_t mask = mBufferList.getMask();
|
|
android_atomic_or(mask, &stack.reallocMask);
|
|
return NO_ERROR;
|
|
}
|
|
|
|
status_t SharedBufferServer::reallocateAllExcept(int buffer)
|
|
{
|
|
RWLock::AutoRLock _l(mLock);
|
|
|
|
SharedBufferStack& stack( *mSharedStack );
|
|
BufferList temp(mBufferList);
|
|
temp.remove(buffer);
|
|
uint32_t mask = temp.getMask();
|
|
android_atomic_or(mask, &stack.reallocMask);
|
|
return NO_ERROR;
|
|
}
|
|
|
|
int32_t SharedBufferServer::getQueuedCount() const
|
|
{
|
|
SharedBufferStack& stack( *mSharedStack );
|
|
return stack.queued;
|
|
}
|
|
|
|
Region SharedBufferServer::getDirtyRegion(int buf) const
|
|
{
|
|
SharedBufferStack& stack( *mSharedStack );
|
|
return stack.getDirtyRegion(buf);
|
|
}
|
|
|
|
/*
|
|
* NOTE: this is not thread-safe on the server-side, meaning
|
|
* 'head' cannot move during this operation. The client-side
|
|
* can safely operate an usual.
|
|
*
|
|
*/
|
|
status_t SharedBufferServer::resize(int newNumBuffers)
|
|
{
|
|
if (uint32_t(newNumBuffers) >= SharedBufferStack::NUM_BUFFER_MAX)
|
|
return BAD_VALUE;
|
|
|
|
RWLock::AutoWLock _l(mLock);
|
|
|
|
// for now we're not supporting shrinking
|
|
const int numBuffers = mNumBuffers;
|
|
if (newNumBuffers < numBuffers)
|
|
return BAD_VALUE;
|
|
|
|
SharedBufferStack& stack( *mSharedStack );
|
|
const int extra = newNumBuffers - numBuffers;
|
|
|
|
// read the head, make sure it's valid
|
|
int32_t head = stack.head;
|
|
if (uint32_t(head) >= SharedBufferStack::NUM_BUFFER_MAX)
|
|
return BAD_VALUE;
|
|
|
|
int base = numBuffers;
|
|
int32_t avail = stack.available;
|
|
int tail = head - avail + 1;
|
|
|
|
if (tail >= 0) {
|
|
int8_t* const index = const_cast<int8_t*>(stack.index);
|
|
const int nb = numBuffers - head;
|
|
memmove(&index[head + extra], &index[head], nb);
|
|
base = head;
|
|
// move head 'extra' ahead, this doesn't impact stack.index[head];
|
|
stack.head = head + extra;
|
|
}
|
|
stack.available += extra;
|
|
|
|
// fill the new free space with unused buffers
|
|
BufferList::const_iterator curr(mBufferList.free_begin());
|
|
for (int i=0 ; i<extra ; i++) {
|
|
stack.index[base+i] = *curr;
|
|
mBufferList.add(*curr);
|
|
++curr;
|
|
}
|
|
|
|
mNumBuffers = newNumBuffers;
|
|
return NO_ERROR;
|
|
}
|
|
|
|
SharedBufferStack::Statistics SharedBufferServer::getStats() const
|
|
{
|
|
SharedBufferStack& stack( *mSharedStack );
|
|
return stack.stats;
|
|
}
|
|
|
|
// ---------------------------------------------------------------------------
|
|
status_t SharedBufferServer::BufferList::add(int value)
|
|
{
|
|
if (uint32_t(value) >= mCapacity)
|
|
return BAD_VALUE;
|
|
uint32_t mask = 1<<(31-value);
|
|
if (mList & mask)
|
|
return ALREADY_EXISTS;
|
|
mList |= mask;
|
|
return NO_ERROR;
|
|
}
|
|
|
|
status_t SharedBufferServer::BufferList::remove(int value)
|
|
{
|
|
if (uint32_t(value) >= mCapacity)
|
|
return BAD_VALUE;
|
|
uint32_t mask = 1<<(31-value);
|
|
if (!(mList & mask))
|
|
return NAME_NOT_FOUND;
|
|
mList &= ~mask;
|
|
return NO_ERROR;
|
|
}
|
|
|
|
|
|
// ---------------------------------------------------------------------------
|
|
}; // namespace android
|