It says dillo uses threads for DNS querying and reading local files, and signal driven I/O for TCP connections. When the socket gets ready for transmission, the data is sent using g_io_channel_write. But I can't not find the place where g_io_channel_write is invoked in the code. In previous posts I see "When using threads and mutexes (pthreads), thread scheduling is done by a third thread or by the kernel (depends upon the implementation), and it is preemptive. Now, the address space may be shared, so the need for mutexes arise, and because of both reasons, performance is degraded. Using a pseudo-thread (CCC thread), doesn't require scheduling by an external process or by the kernel. All is done in the same process, but there's no preemption." But I do find a thread is spawned in "a_IO_write_chunk()". Would you please tell me the reason? What does pseudo-thread mean? Is such thread spawned in "a_IO_write_chunk()" pseudo-thread? Thanks a lot!