Currently, Chromium stores segmented data in a SharedBuffer and appends
to SkRWBuffer one segment at a time:
const char* segment = 0;
for (size_t length = data->getSomeData(segment, m_rwBuffer->size());
length; length = data->getSomeData(segment, m_rwBuffer->size())) {
m_rwBuffer->append(segment, length, remaining);
}
This can yield a bunch of just-above-4k allocations => wasted RAM due to
internal fragmentation.
Ideally, we'd want a SkRWBuffer::reserve(size_t bytes) API, but the
current internals don't support that trivially.
Alternatively, the caller can pass a reserve hint at append() time.
BUG=chromium:651698
R=scroggo@google.com,reed@google.com
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2385803002
Review-Url: https://codereview.chromium.org/2385803002
Do not call SkBufferHead::validate in SkROBuffer's destructor, which
may be called in a separate thread from SkRWBuffer::append. validate()
reads SkBufferBlock::fUsed, and append() writes to it, resulting in
a data race.
Update some comments to be more clear about how it is safe to use
these classes across threads.
Test the readers in separate threads.
In addition, make sure it is safe to create a reader even when no
data has been appended. Add tests for this case.
Mark a parameter to SkBufferHead::validate() as const, reflecting
its use.
BUG=chromium:601578
BUG=chromium:605479
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1871953002
Review URL: https://codereview.chromium.org/1871953002
Do not call SkBufferHead::validate in SkROBuffer's destructor, which
may be called in a separate thread from SkRWBuffer::append. validate()
reads SkBufferBlock::fUsed, and append() writes to it, resulting in
a data race.
Update some comments to be more clear about how it is safe to use
these classes across threads.
Test the readers in separate threads.
In addition, make sure it is safe to create a reader even when no
data has been appended. Add tests for this case.
Mark a parameter to SkBufferHead::validate() as const, reflecting
its use.
BUG=chromium:601578
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1871953002
Review URL: https://codereview.chromium.org/1871953002
