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path: root/qemu-coroutine-io.c
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2012-06-11rewrite iov_send_recv() and move it to iov.cMichael Tokarev
Make it much more understandable, add a missing iov_cnt argument (number of iovs in the iov), and add comments to it. The new implementation has been extensively tested by splitting a large buffer into many small randomly-sized chunks, sending it over socket to another, slow process and verifying the receiving data is the same. Also add a unit test for iov_send_recv(), sending/ receiving data between two processes over a socketpair using random vectors and random sizes. Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2012-06-11cleanup qemu_co_sendv(), qemu_co_recvv() and friendsMichael Tokarev
The same as for non-coroutine versions in previous patches: rename arguments to be more obvious, change type of arguments from int to size_t where appropriate, and use common code for send and receive paths (with one extra argument) since these are exactly the same. Use common iov_send_recv() directly. qemu_co_sendv(), qemu_co_recvv(), and qemu_co_recv() are now trivial #define's merely adding one extra arg. qemu_co_sendv() and qemu_co_recvv() callers are converted to different argument order and extra `iov_cnt' argument. Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2012-06-11rename qemu_sendv to iov_send, change proto and move declarations to iov.hMichael Tokarev
Rename arguments and use size_t for sizes instead of int, from int qemu_sendv(int sockfd, struct iovec *iov, int len, int iov_offset) to ssize_t iov_send(int sockfd, struct iovec *iov, size_t offset, size_t bytes) The main motivation was to make it clear that length and offset are in _bytes_, not in iov elements: it was very confusing before, because all standard functions which deals with iovecs expects number of iovs, not bytes, even the fact that struct iovec has iov_len and iov_ prefix does not help. With "bytes" and "offset", especially since they're now size_t, it is much more explicit. Also change the return type to be ssize_t instead of int. This also changes it to match other iov-related functons, but not _quite_: there's still no argument indicating where iovec ends, ie, no iov_cnt parameter as used in iov_size() and friends. If will be added in subsequent patch/rewrite. All callers of qemu_sendv() and qemu_recvv() and related, like qemu_co_sendv() and qemu_co_recvv(), were checked to verify that it is safe to use unsigned datatype instead of int. Note that the order of arguments is changed to: offset and bytes (len and iov_offset) are swapped with each other. This is to make them consistent with very similar functions from qemu_iovec family, where offset always follows qiov, to mean the place in it to start from. Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2011-12-22sheepdog: move coroutine send/recv function to generic codePaolo Bonzini
Outside coroutines, avoid busy waiting on EAGAIN by temporarily making the socket blocking. The API of qemu_recvv/qemu_sendv is slightly different from do_readv/do_writev because they do not handle coroutines. It returns the number of bytes written before encountering an EAGAIN. The specificity of yielding on EAGAIN is entirely in qemu-coroutine.c. Reviewed-by: MORITA Kazutaka <morita.kazutaka@lab.ntt.co.jp> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>