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authorDaniel P. Berrange <berrange@redhat.com>2015-09-01 14:48:02 +0100
committerDaniel P. Berrange <berrange@redhat.com>2015-10-20 14:59:04 +0100
commit10817bf09d5f8cb22711fb0ee8d8da49f6f05f89 (patch)
tree735f6b70cedecd57843b9108cb68e2359e147e0c /util/qemu-coroutine-io.c
parent57cb38b3833c5215131b983f181b26d6ba9b8d35 (diff)
coroutine: move into libqemuutil.a library
The coroutine files are currently referenced by the block-obj-y variable. The coroutine functionality though is already used by more than just the block code. eg migration code uses coroutine yield. In the future the I/O channel code will also use the coroutine yield functionality. Since the coroutine code is nicely self-contained it can be easily built as part of the libqemuutil.a library, making it widely available. The headers are also moved into include/qemu, instead of the include/block directory, since they are now part of the util codebase, and the impl was never in the block/ directory either. Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Diffstat (limited to 'util/qemu-coroutine-io.c')
-rw-r--r--util/qemu-coroutine-io.c91
1 files changed, 91 insertions, 0 deletions
diff --git a/util/qemu-coroutine-io.c b/util/qemu-coroutine-io.c
new file mode 100644
index 0000000000..e1eae7331e
--- /dev/null
+++ b/util/qemu-coroutine-io.c
@@ -0,0 +1,91 @@
+/*
+ * Coroutine-aware I/O functions
+ *
+ * Copyright (C) 2009-2010 Nippon Telegraph and Telephone Corporation.
+ * Copyright (c) 2011, Red Hat, Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+#include "qemu-common.h"
+#include "qemu/sockets.h"
+#include "qemu/coroutine.h"
+#include "qemu/iov.h"
+#include "qemu/main-loop.h"
+
+ssize_t coroutine_fn
+qemu_co_sendv_recvv(int sockfd, struct iovec *iov, unsigned iov_cnt,
+ size_t offset, size_t bytes, bool do_send)
+{
+ size_t done = 0;
+ ssize_t ret;
+ int err;
+ while (done < bytes) {
+ ret = iov_send_recv(sockfd, iov, iov_cnt,
+ offset + done, bytes - done, do_send);
+ if (ret > 0) {
+ done += ret;
+ } else if (ret < 0) {
+ err = socket_error();
+ if (err == EAGAIN || err == EWOULDBLOCK) {
+ qemu_coroutine_yield();
+ } else if (done == 0) {
+ return -err;
+ } else {
+ break;
+ }
+ } else if (ret == 0 && !do_send) {
+ /* write (send) should never return 0.
+ * read (recv) returns 0 for end-of-file (-data).
+ * In both cases there's little point retrying,
+ * but we do for write anyway, just in case */
+ break;
+ }
+ }
+ return done;
+}
+
+ssize_t coroutine_fn
+qemu_co_send_recv(int sockfd, void *buf, size_t bytes, bool do_send)
+{
+ struct iovec iov = { .iov_base = buf, .iov_len = bytes };
+ return qemu_co_sendv_recvv(sockfd, &iov, 1, 0, bytes, do_send);
+}
+
+typedef struct {
+ Coroutine *co;
+ int fd;
+} FDYieldUntilData;
+
+static void fd_coroutine_enter(void *opaque)
+{
+ FDYieldUntilData *data = opaque;
+ qemu_set_fd_handler(data->fd, NULL, NULL, NULL);
+ qemu_coroutine_enter(data->co, NULL);
+}
+
+void coroutine_fn yield_until_fd_readable(int fd)
+{
+ FDYieldUntilData data;
+
+ assert(qemu_in_coroutine());
+ data.co = qemu_coroutine_self();
+ data.fd = fd;
+ qemu_set_fd_handler(fd, fd_coroutine_enter, NULL, &data);
+ qemu_coroutine_yield();
+}