iohandlers: Add enable/disable_write_fd_handler() functions

These will be used to provide a cleaner API for the nonblocking case.

Signed-off-by: Amit Shah <amit.shah@redhat.com>

2 files changed, 38 insertions, 0 deletions

diff --git a/iohandler.c b/iohandler.c
index 2b824218e5..8e6628ba9b 100644
--- a/iohandler.c
+++ b/iohandler.c
@@ -44,6 +44,41 @@ typedef struct IOHandlerRecord {
 static QLIST_HEAD(, IOHandlerRecord) io_handlers =
     QLIST_HEAD_INITIALIZER(io_handlers);
 
+static IOHandlerRecord *find_iohandler(int fd)
+{
+    IOHandlerRecord *ioh;
+
+    QLIST_FOREACH(ioh, &io_handlers, next) {
+        if (ioh->fd == fd) {
+            return ioh;
+        }
+    }
+    return NULL;
+}
+
+void enable_write_fd_handler(int fd, IOHandler *fd_write)
+{
+    IOHandlerRecord *ioh;
+
+    ioh = find_iohandler(fd);
+    if (!ioh) {
+        return;
+    }
+
+    ioh->fd_write = fd_write;
+}
+
+void disable_write_fd_handler(int fd)
+{
+    IOHandlerRecord *ioh;
+
+    ioh = find_iohandler(fd);
+    if (!ioh) {
+        return;
+    }
+
+    ioh->fd_write = NULL;
+}
 
 /* XXX: fd_read_poll should be suppressed, but an API change is
    necessary in the character devices to suppress fd_can_read(). */
diff --git a/qemu-char.h b/qemu-char.h
index d326834cb1..c1071e6964 100644
--- a/qemu-char.h
+++ b/qemu-char.h
@@ -117,6 +117,9 @@ size_t qemu_chr_mem_osize(const CharDriverState *chr);
 
 /* async I/O support */
 
+void enable_write_fd_handler(int fd, IOHandler *fd_write);
+void disable_write_fd_handler(int fd);
+
 int qemu_set_fd_handler2(int fd,
                          IOCanReadHandler *fd_read_poll,
                          IOHandler *fd_read,