RGBCube/serenity
1
Fork 0
mirror of https://github.com/RGBCube/serenity synced 2025-07-27 12:07:45 +00:00
Code Issues Activity Actions

LibCore: Make BufferedHelper::read() block at most once per read

Browse source 
The previous method could block multiple times, leading to a completely
stuck/deadlocked read() call, and it could also consume data without
telling the user about it, which is Not A Good Thing ™️.
This patch makes it block at most once, and fixes loading HTTP pages
with LibHTTP :^)
This commit is contained in:
Ali Mohammad Pur 2022-02-08 15:01:09 +03:30 • committed by Andreas Kling
parent 17a3dd23f4
commit d3c25b8ea2
1 changed files with 22 additions and 16 deletions
Download patch file Download diff file Expand all files Collapse all files

36
Userland/Libraries/LibCore/Stream.h
View file

@ -521,6 +521,10 @@ public:
if (!buffer.size()) if (!buffer.size())
return Error::from_errno(ENOBUFS); return Error::from_errno(ENOBUFS);
// Fill the internal buffer if it has run dry.
if (m_buffered_size == 0)
TRY(populate_read_buffer());
// Let's try to take all we can from the buffer first. // Let's try to take all we can from the buffer first.
size_t buffer_nread = 0; size_t buffer_nread = 0;
if (m_buffered_size > 0) { if (m_buffered_size > 0) {
@ -539,22 +543,9 @@ public:
m_buffered_size -= amount_to_take; m_buffered_size -= amount_to_take;
} }
// If the buffer satisfied the request, then we need not continue.
if (buffer_nread == buffer.size()) {
return buffer_nread; return buffer_nread;
} }
// Otherwise, let's try an extra read just in case there's something
// in our receive buffer.
auto stream_nread = TRY(stream().read(buffer.slice(buffer_nread)));
// Fill the internal buffer if it has run dry.
if (m_buffered_size == 0)
TRY(populate_read_buffer());
return buffer_nread + stream_nread;
}
// Reads into the buffer until \n is encountered. // Reads into the buffer until \n is encountered.
// The size of the Bytes object is the maximum amount of bytes that will be // The size of the Bytes object is the maximum amount of bytes that will be
// read. Returns the amount of bytes read. // read. Returns the amount of bytes read.
@ -703,8 +694,23 @@ private:
return ReadonlyBytes {}; return ReadonlyBytes {};
auto fillable_slice = m_buffer.span().slice(m_buffered_size); auto fillable_slice = m_buffer.span().slice(m_buffered_size);
auto nread = TRY(stream().read(fillable_slice)); size_t nread = 0;
m_buffered_size += nread; do {
auto result = stream().read(fillable_slice);
if (result.is_error()) {
if (!result.error().is_errno())
return result.error();
if (result.error().code() == EINTR)
continue;
if (result.error().code() == EAGAIN)
break;
return result.error();
}
auto read_size = result.value();
m_buffered_size += read_size;
nread += read_size;
break;
} while (true);
return fillable_slice.slice(0, nread); return fillable_slice.slice(0, nread);
} }