Introduce a new iohandler api that doesn't have multiple callbacks.
Instead, a single callback and a mask of events that got set will be
passed on to the handler. This will ease our transition to a poll()
interface instead of the current select() that happens on the fds.
Signed-off-by: Amit Shah<address@hidden>
---
iohandler.h | 28 +++++++++++
vl.c | 144 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 172 insertions(+), 0 deletions(-)
create mode 100644 iohandler.h
diff --git a/iohandler.h b/iohandler.h
new file mode 100644
index 0000000..6553835
--- /dev/null
+++ b/iohandler.h
@@ -0,0 +1,28 @@
+/*
+ * Declarations for iohandler functions
+ *
+ * Copyright Red Hat, Inc. 2011
+ * Copyright Amit Shah<address@hidden> 2011
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2. See
+ * the COPYING file in the top-level directory.
+ */
+
+#ifndef _QEMU_IOHANDLER_H
+#define _QEMU_IOHANDLER_H
+
+/* iohandler masks */
+#define IOH_MASK_CAN_READ (1U<< 0)
+#define IOH_MASK_READ (1U<< 1)
+#define IOH_MASK_WRITE (1U<< 2)
+
+typedef int IOAllHandler(void *opaque, unsigned int mask);
+
+int assign_iohandler(int fd, IOAllHandler *handler, unsigned int mask,
+ void *opaque);
+int remove_iohandler(int fd);
+int update_fd_mask(int fd, unsigned int mask);
+int get_fd_mask(int fd, unsigned int *mask);
+
+
+#endif /* _QEMU_IOHANDLER_H */
diff --git a/vl.c b/vl.c
index e248ec4..9dabee2 100644
--- a/vl.c
+++ b/vl.c
@@ -2,6 +2,8 @@
* QEMU System Emulator
*
* Copyright (c) 2003-2008 Fabrice Bellard
+ * Copyright (C) 2011 Red Hat, Inc.
+ * Copyright (C) 2011 Amit Shah,<address@hidden>
*
* Permission is hereby granted, free of charge, to any person obtaining a
copy
* of this software and associated documentation files (the "Software"), to
deal
@@ -136,6 +138,7 @@ int main(int argc, char **argv)
#include "gdbstub.h"
#include "qemu-timer.h"
#include "qemu-char.h"
+#include "iohandler.h"
#include "cache-utils.h"
#include "block.h"
#include "blockdev.h"
@@ -1030,6 +1033,8 @@ typedef struct IOHandlerRecord {
IOCanReadHandler *fd_read_poll;
IOHandler *fd_read;
IOHandler *fd_write;
+ IOAllHandler *fd_iohandler;
+ unsigned int mask;
int deleted;
void *opaque;
/* temporary data */
@@ -1040,6 +1045,97 @@ typedef struct IOHandlerRecord {
static QLIST_HEAD(, IOHandlerRecord) io_handlers_old =
QLIST_HEAD_INITIALIZER(io_handlers_old);
+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;
+}
+
+static int update_iohandler_mask(IOHandlerRecord *ioh, unsigned int mask)
+{
+ assert(ioh);
+
+ ioh->mask = mask;
+ return 0;
+}
+
+/*
+ * Updates the mask for the fd. Returns 0 on success.
+ */
+int update_fd_mask(int fd, unsigned int mask)
+{
+ IOHandlerRecord *ioh;
+
+ ioh = find_iohandler(fd);
+ if (!ioh) {
+ return -1;
+ }
+
+ return update_iohandler_mask(ioh, mask);
+}
+
+/*
+ * Populates the mask registered in *mask. Only valid if return value
+ * is 0.
+ */
+int get_fd_mask(int fd, unsigned int *mask)
+{
+ IOHandlerRecord *ioh;
+
+ ioh = find_iohandler(fd);
+ if (!ioh) {
+ return -1;
+ }
+ *mask = ioh->mask;
+
+ return 0;
+}
+
+/*
+ * Assign an iohandler to an fd. Can also be used to update the mask
+ * or handler or the opaque pointer and also to delete the iohandler.
+ * Returns 0 on success.
+ */
+int assign_iohandler(int fd, IOAllHandler *handler, unsigned int mask,
+ void *opaque)
+{
+ IOHandlerRecord *ioh;
+
+ ioh = find_iohandler(fd);
+
+ if (!handler) {
+ if (ioh) {
+ ioh->deleted = 1;
+ }
+ return 0;
+ }
+
+ if (!ioh) {
+ ioh = qemu_mallocz(sizeof(IOHandlerRecord));
+ QLIST_INSERT_HEAD(&io_handlers, ioh, next);
+ ioh->fd = fd;
+ }
+ ioh->fd_iohandler = handler;
+ ioh->opaque = opaque;
+ update_iohandler_mask(ioh, mask);
+ ioh->deleted = 0;
+
+ return 0;
+}
+
+int remove_iohandler(int fd)
+{
+ return assign_iohandler(fd, NULL, 0, NULL);
+}
/* XXX: fd_read_poll should be suppressed, but an API change is
necessary in the character devices to suppress fd_can_read(). */
@@ -1363,6 +1459,26 @@ void main_loop_wait(int nonblocking)
nfds = ioh->fd;
}
}
+ QLIST_FOREACH(ioh,&io_handlers, next) {
+ if (ioh->deleted) {
+ continue;
+ }
+ if (ioh->mask& IOH_MASK_READ&&
+ (!(ioh->mask& IOH_MASK_CAN_READ) ||
+ (ioh->fd_iohandler(ioh->opaque, IOH_MASK_CAN_READ) != 0))) {
+
+ FD_SET(ioh->fd,&rfds);
+ if (ioh->fd> nfds) {
+ nfds = ioh->fd;
+ }
+ }
+ if (ioh->mask& IOH_MASK_WRITE) {
+ FD_SET(ioh->fd,&wfds);
+ if (ioh->fd> nfds) {
+ nfds = ioh->fd;
+ }
+ }
+ }
tv.tv_sec = timeout / 1000;
tv.tv_usec = (timeout % 1000) * 1000;
@@ -1389,6 +1505,34 @@ void main_loop_wait(int nonblocking)
qemu_free(ioh);
}
}
+ QLIST_FOREACH_SAFE(ioh,&io_handlers, next, pioh) {
+ unsigned int mask;
+
+ mask = 0;
+ if (!ioh->deleted) {
+ if (FD_ISSET(ioh->fd,&rfds)) {
+ mask |= IOH_MASK_READ;
+ }
+ if (FD_ISSET(ioh->fd,&wfds)) {
+ mask |= IOH_MASK_WRITE;
+ }
+ }
+ /*
+ * Strip out flags the caller didn't ask for -- shouldn't
+ * happen since we set rfds and wfds based on the value of
+ * ioh->mask anyway.
+ */
+ mask&= ioh->mask;
+ if (mask) {
+ ioh->fd_iohandler(ioh->opaque, mask);
+ }
+ /* Do this last in case the handler marked it for deletion */
+ if (ioh->deleted) {
+ QLIST_REMOVE(ioh, next);
+ qemu_free(ioh);
+ continue;
+ }
+ }
}
slirp_select_poll(&rfds,&wfds,&xfds, (ret< 0));