| Message ID | 1331430564-32745-6-git-send-email-mjt@msgid.tls.msk.ru |
|---|---|
| State | New |
| Headers | show |
Il 11/03/2012 02:49, Michael Tokarev ha scritto: > Rename do_sendv_recvv() to qemu_sendv_recvv(), > change its last arg (do_send) from int to bool, > export it in qemu-common.h, and made the two > callers of it (qemu_sendv() and qemu_recvv()) > to be trivial #defines just adding 5th arg. GCC is smart and knows how to do tail calls in many cases. Thus, I don't see very much the point of this patch. Paolo
On 11.03.2012 19:00, Paolo Bonzini wrote: > Il 11/03/2012 02:49, Michael Tokarev ha scritto: >> Rename do_sendv_recvv() to qemu_sendv_recvv(), >> change its last arg (do_send) from int to bool, >> export it in qemu-common.h, and made the two >> callers of it (qemu_sendv() and qemu_recvv()) >> to be trivial #defines just adding 5th arg. > > GCC is smart and knows how to do tail calls in many cases. Thus, I > don't see very much the point of this patch. The point is to allow qemu_sendv_recvv() to be used directly, see the next patch [PATCHv2 6/7] cleanup qemu_co_sendv(), qemu_co_recvv() and friends for an example, and see my previous attempt to address all this with bdrv_* methods where reads and writes are implemented in common functions and are split back on layer boundary, just to go to a common routine on the next layer. Or worse yet, repeating exactly the same code like in this 6/7 patch for qemu_co_recvv() and qemu_co_sendv(). It is not about tail calls at all. Thanks, /mjt
diff --git a/cutils.c b/cutils.c index b3b9cfb..b6f8eb8 100644 --- a/cutils.c +++ b/cutils.c @@ -419,8 +419,8 @@ int qemu_parse_fd(const char *param) * The first `offset' bytes in the iovec buffer are skipped and next * `bytes' bytes are used. */ -static int do_sendv_recvv(int sockfd, struct iovec *iov, size_t offset, size_t bytes, - int do_sendv) +int qemu_sendv_recvv(int sockfd, struct iovec *iov, size_t offset, size_t bytes, + bool do_sendv) { int ret, iovlen; size_t diff; @@ -499,14 +499,3 @@ static int do_sendv_recvv(int sockfd, struct iovec *iov, size_t offset, size_t b last_iov->iov_len += diff; return ret; } - -int qemu_recvv(int sockfd, struct iovec *iov, size_t offset, size_t bytes) -{ - return do_sendv_recvv(sockfd, iov, offset, bytes, 0); -} - -int qemu_sendv(int sockfd, struct iovec *iov, size_t offset, size_t bytes) -{ - return do_sendv_recvv(sockfd, iov, offset, bytes, 1); -} - diff --git a/qemu-common.h b/qemu-common.h index bb75dd3..b8190e9 100644 --- a/qemu-common.h +++ b/qemu-common.h @@ -199,8 +199,18 @@ int qemu_pipe(int pipefd[2]); #define qemu_recv(sockfd, buf, len, flags) recv(sockfd, buf, len, flags) #endif -int qemu_recvv(int sockfd, struct iovec *iov, size_t offset, size_t bytes); -int qemu_sendv(int sockfd, struct iovec *iov, size_t offset, size_t bytes); +/** + * Send or receive data from/to an (optionally partial) iovec. + * Instead of processing whole iovector, this routine can process + * not more than a specified number of bytes, and start not at + * the beginning of iovec but at byte position `offset'. + */ +int qemu_sendv_recvv(int sockfd, struct iovec *iov, + size_t offset, size_t bytes, bool do_sendv); +#define qemu_recvv(sockfd, iov, offset, bytes) \ + qemu_sendv_recvv(sockfd, iov, offset, bytes, false) +#define qemu_sendv(sockfd, iov, offset, bytes) \ + qemu_sendv_recvv(sockfd, iov, offset, bytes, true) /* Error handling. */
Rename do_sendv_recvv() to qemu_sendv_recvv(), change its last arg (do_send) from int to bool, export it in qemu-common.h, and made the two callers of it (qemu_sendv() and qemu_recvv()) to be trivial #defines just adding 5th arg. qemu_sendv_recvv() will be used later. Signed-off-by: Michael Tokarev <mjt@tls.msk.ru> --- cutils.c | 15 ++------------- qemu-common.h | 14 ++++++++++++-- 2 files changed, 14 insertions(+), 15 deletions(-)