[Qemu-devel] [PATCHv2 6/7] cleanup qemu_co_sendv(), qemu_co_recvv() and friends

[Michael 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 qemu_sendv_recvv() directly.
Also constify buf arg of qemu_co_send().

qemu_co_sendv(), qemu_co_recvv(), and qemu_co_recv() are now
trivial #define's merely adding one extra arg.  qemu_co_send()
is an inline function due to `buf' arg de-constification.

qemu_co_sendv() and qemu_co_recvv() callers are converted to
different argument order.

Signed-off-by: Michael Tokarev <address@hidden>
---
 block/nbd.c         |    4 +-
 block/sheepdog.c    |    6 ++--
 qemu-common.h       |   38 +++++++++++-----------
 qemu-coroutine-io.c |   83 +++++++++++++-------------------------------------
 4 files changed, 46 insertions(+), 85 deletions(-)

diff --git a/block/nbd.c b/block/nbd.c
index 161b299..9919acc 100644
--- a/block/nbd.c
+++ b/block/nbd.c
@@ -194,7 +194,7 @@ static int nbd_co_send_request(BDRVNBDState *s, struct 
nbd_request *request,
                             nbd_have_request, NULL, s);
     rc = nbd_send_request(s->sock, request);
     if (rc != -1 && iov) {
-        ret = qemu_co_sendv(s->sock, iov, request->len, offset);
+        ret = qemu_co_sendv(s->sock, iov, offset, request->len);
         if (ret != request->len) {
             errno = -EIO;
             rc = -1;
@@ -221,7 +221,7 @@ static void nbd_co_receive_reply(BDRVNBDState *s, struct 
nbd_request *request,
         reply->error = EIO;
     } else {
         if (iov && reply->error == 0) {
-            ret = qemu_co_recvv(s->sock, iov, request->len, offset);
+            ret = qemu_co_recvv(s->sock, iov, offset, request->len);
             if (ret != request->len) {
                 reply->error = EIO;
             }
diff --git a/block/sheepdog.c b/block/sheepdog.c
index 00276f6f..fed436b 100644
--- a/block/sheepdog.c
+++ b/block/sheepdog.c
@@ -657,8 +657,8 @@ static void coroutine_fn aio_read_response(void *opaque)
         }
         break;
     case AIOCB_READ_UDATA:
-        ret = qemu_co_recvv(fd, acb->qiov->iov, rsp.data_length,
-                            aio_req->iov_offset);
+        ret = qemu_co_recvv(fd, acb->qiov->iov, aio_req->iov_offset,
+                            rsp.data_length);
         if (ret < 0) {
             error_report("failed to get the data, %s", strerror(errno));
             goto out;
@@ -924,7 +924,7 @@ static int coroutine_fn add_aio_request(BDRVSheepdogState 
*s, AIOReq *aio_req,
     }
 
     if (wlen) {
-        ret = qemu_co_sendv(s->fd, iov, wlen, aio_req->iov_offset);
+        ret = qemu_co_sendv(s->fd, iov, aio_req->iov_offset, wlen);
         if (ret < 0) {
             qemu_co_mutex_unlock(&s->lock);
             error_report("failed to send a data, %s", strerror(errno));
diff --git a/qemu-common.h b/qemu-common.h
index b8190e9..110ec06 100644
--- a/qemu-common.h
+++ b/qemu-common.h
@@ -306,31 +306,31 @@ struct qemu_work_item {
 void qemu_init_vcpu(void *env);
 #endif
 
-/**
- * Sends an iovec (or optionally a part of it) down a socket, yielding
- * when the socket is full.
- */
-int qemu_co_sendv(int sockfd, struct iovec *iov,
-                  int len, int iov_offset);
-
-/**
- * Receives data into an iovec (or optionally into a part of it) from
- * a socket, yielding when there is no data in the socket.
- */
-int qemu_co_recvv(int sockfd, struct iovec *iov,
-                  int len, int iov_offset);
-
 
 /**
- * Sends a buffer down a socket, yielding when the socket is full.
+ * Sends a (part of) iovec down a socket, yielding when the socket is full, or
+ * Receives data into a (part of) iovec from a socket,
+ * yielding when there is no data in the socket.
+ * The same interface as qemu_sendv_recvv(), with added yielding.
+ * XXX should mark these as coroutine_fn
  */
-int qemu_co_send(int sockfd, void *buf, int len);
+int qemu_co_sendv_recvv(int sockfd, struct iovec *iov,
+                       size_t offset, size_t bytes, bool do_send);
+#define qemu_co_recvv(sockfd, iov, offset, bytes) \
+  qemu_co_sendv_recvv(sockfd, iov, offset, bytes, false)
+#define qemu_co_sendv(sockfd, iov, offset, bytes) \
+  qemu_co_sendv_recvv(sockfd, iov, offset, bytes, true)
 
 /**
- * Receives data into a buffer from a socket, yielding when there
- * is no data in the socket.
+ * The same as above, but with just a single buffer
  */
-int qemu_co_recv(int sockfd, void *buf, int len);
+int qemu_co_send_recv(int sockfd, void *buf, size_t bytes, bool do_send);
+#define qemu_co_recv(sockfd, buf, bytes) \
+  qemu_co_send_recv(sockfd, buf, bytes, false)
+static inline int qemu_co_send(int sockfd, const void *buf, size_t bytes)
+{
+    return qemu_co_send_recv(sockfd, (void*)buf, bytes, true);
+}
 
 
 typedef struct QEMUIOVector {
diff --git a/qemu-coroutine-io.c b/qemu-coroutine-io.c
index df8ff21..75a4117 100644
--- a/qemu-coroutine-io.c
+++ b/qemu-coroutine-io.c
@@ -26,71 +26,32 @@
 #include "qemu_socket.h"
 #include "qemu-coroutine.h"
 
-int coroutine_fn qemu_co_recvv(int sockfd, struct iovec *iov,
-                               int len, int iov_offset)
+int coroutine_fn
+qemu_co_sendv_recvv(int sockfd, struct iovec *iov,
+                       size_t offset, size_t bytes, bool do_send)
 {
-    int total = 0;
+    size_t done = 0;
     int ret;
-    while (len) {
-        ret = qemu_recvv(sockfd, iov, iov_offset + total, len);
-        if (ret < 0) {
-            if (errno == EAGAIN) {
-                qemu_coroutine_yield();
-                continue;
-            }
-            if (total == 0) {
-                total = -1;
-            }
-            break;
-        }
-        if (ret == 0) {
-            break;
-        }
-        total += ret, len -= ret;
+    while (done < bytes) {
+        ret = qemu_sendv_recvv(sockfd, iov, offset + done, bytes - done, 
do_send);
+       if (ret > 0) {
+           done += ret;
+       } else if (!ret) {
+           break;
+       } else if (errno == EAGAIN) {
+           qemu_coroutine_yield();
+       } else if (done == 0) {
+           return -1;
+       } else {
+           break;
+       }
     }
-
-    return total;
-}
-
-int coroutine_fn qemu_co_sendv(int sockfd, struct iovec *iov,
-                               int len, int iov_offset)
-{
-    int total = 0;
-    int ret;
-    while (len) {
-        ret = qemu_sendv(sockfd, iov, iov_offset + total, len);
-        if (ret < 0) {
-            if (errno == EAGAIN) {
-                qemu_coroutine_yield();
-                continue;
-            }
-            if (total == 0) {
-                total = -1;
-            }
-            break;
-        }
-        total += ret, len -= ret;
-    }
-
-    return total;
+    return done;
 }
 
-int coroutine_fn qemu_co_recv(int sockfd, void *buf, int len)
+int coroutine_fn
+qemu_co_send_recv(int sockfd, void *buf, size_t bytes, bool do_send)
 {
-    struct iovec iov;
-
-    iov.iov_base = buf;
-    iov.iov_len = len;
-
-    return qemu_co_recvv(sockfd, &iov, len, 0);
-}
-
-int coroutine_fn qemu_co_send(int sockfd, void *buf, int len)
-{
-    struct iovec iov;
-
-    iov.iov_base = buf;
-    iov.iov_len = len;
-
-    return qemu_co_sendv(sockfd, &iov, len, 0);
+    struct iovec iov = { buf, bytes };
+    return qemu_co_sendv_recvv(sockfd, &iov, 0, bytes, do_send);
 }
-- 
1.7.9.1