mirrors/ladybird
0
0
Fork 0
mirror of https://github.com/LadybirdBrowser/ladybird.git synced 2025-07-29 12:19:54 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions 9

LibCore: Atomically ref-count SharedSingleProducerCircularQueue guts

Browse source 
This fixes two race conditions and ASAN crashes in the test for the
same.

The first comes from destroying the internals struct, which was
previously using the standard, thread-unsafe RefCounted CRTP. The
second is from destroying the name, which is secretly another
RefCounted object, in a thread-unsafe manner.
This commit is contained in:
Andrew Kaster 2025-05-24 04:29:58 -06:00 • committed by Andrew Kaster
commit 228211205a
Notes: github-actions[bot] 2025-05-24 12:53:21 +00:00
1 changed files with 9 additions and 9 deletions
Download patch file Download diff file Expand all files Collapse all files

18
Libraries/LibCore/SharedCircularQueue.h
View file

@ -7,6 +7,7 @@
#pragma once
#include <AK/AtomicRefCounted.h>
#include <AK/BuiltinWrappers.h>
#include <AK/ByteString.h>
#include <AK/Debug.h>
@ -162,22 +163,24 @@ private:
};
class RefCountedSharedMemorySPCQ
: public RefCounted<RefCountedSharedMemorySPCQ>
: public AtomicRefCounted<RefCountedSharedMemorySPCQ>
, public AnonymousBuffer {
friend class SharedSingleProducerCircularQueue;
public:
SharedMemorySPCQ* m_queue;
ByteString m_name;
~RefCountedSharedMemorySPCQ()
{
dbgln_if(SHARED_QUEUE_DEBUG, "destructed SSPCQ at {:p}, shared mem: {:p}", this, m_queue);
dbgln_if(SHARED_QUEUE_DEBUG, "destructed SSPCQ at {:p} named {}, shared mem: {:p}", this, m_name, m_queue);
}
private:
RefCountedSharedMemorySPCQ(AnonymousBuffer anon_buf, SharedMemorySPCQ* shared_queue)
RefCountedSharedMemorySPCQ(AnonymousBuffer anon_buf, SharedMemorySPCQ* shared_queue, ByteString name)
: AnonymousBuffer(anon_buf)
, m_queue(shared_queue)
, m_name(move(name))
{
}
};
@ -188,19 +191,16 @@ private:
return Error::from_string_literal("Unexpected error when creating shared queue from raw memory");
auto name = ByteString::formatted("SharedSingleProducerCircularQueue@{:x}", anon_buf.fd());
dbgln_if(SHARED_QUEUE_DEBUG, "successfully mmapped {} at {:p}", name, shared_queue);
auto ref_counted = new (nothrow) RefCountedSharedMemorySPCQ(anon_buf, shared_queue);
return SharedSingleProducerCircularQueue<T, Size> { move(name), adopt_ref(*ref_counted) };
auto ref_counted = new (nothrow) RefCountedSharedMemorySPCQ(anon_buf, shared_queue, move(name));
return SharedSingleProducerCircularQueue<T, Size> { adopt_ref(*ref_counted) };
}
SharedSingleProducerCircularQueue(ByteString name, RefPtr<RefCountedSharedMemorySPCQ> queue)
SharedSingleProducerCircularQueue(RefPtr<RefCountedSharedMemorySPCQ> queue)
: m_queue(queue)
, m_name(move(name))
{
}
RefPtr<RefCountedSharedMemorySPCQ> m_queue;
ByteString m_name {};
};
}