On Sun, Jun 17, 2007 at 10:52:55PM +0100, Daniel P. Berrange wrote:
> The following patch adds a qemud/event.c & qemud/event.h file providing a
> general purpose event loop built around poll. Users register file handles
> and associated callbacks, and / or timers. The qemud.c file is changed to
> make use of these APIs for dealing with server, client, and VM file handles
> and/or sockets. This decouples much of the QEMU VM I/O code from the main
> qemud.c daemon code.
>
> qemud/event.c | 311 +++++++++++++++++++++++++++++++++++++++++
> qemud/event.h | 13 +
> qemud/Makefile.am | 3
> qemud/qemud.c | 401 +++++++++++++++++++++++++++++-------------------------
> qemud/remote.c | 5
> 5 files changed, 546 insertions(+), 187 deletions(-)
As I understand taht patch could be applied alone without disturbing
operations, right ?
> diff -r 93de958458cb qemud/Makefile.am
> --- a/qemud/Makefile.am Fri Jun 15 14:27:39 2007 +0000
> +++ b/qemud/Makefile.am Sun Jun 17 16:26:41 2007 -0400
> @@ -16,7 +16,8 @@ libvirt_qemud_SOURCES = \
> buf.c buf.h \
> protocol.h protocol.c \
> remote_protocol.h remote_protocol.c \
> - remote.c
> + remote.c \
> + event.c event.h
> #-D_XOPEN_SOURCE=600 -D_XOPEN_SOURCE_EXTENDED=1 -D_POSIX_C_SOURCE=199506L
> libvirt_qemud_CFLAGS = \
> -I$(top_srcdir)/include -I$(top_builddir)/include $(LIBXML_CFLAGS) \
> diff -r 93de958458cb qemud/event.c
> --- /dev/null Thu Jan 01 00:00:00 1970 +0000
> +++ b/qemud/event.c Sun Jun 17 16:26:34 2007 -0400
> @@ -0,0 +1,311 @@
In general a severe lack of comment, I assume it's an early review version.
> +int virEventAddHandle(int fd, int events, virEventHandleCallback cb, void *opaque) {
> + struct virEventHandle *tmp;
> +
> + printf("Add handle %d %d %p %p\n", fd, events, cb, opaque);
> + tmp = realloc(eventLoop.handles, sizeof(struct virEventHandle) * (eventLoop.nhandles+1));
> + if (!tmp) {
> + return -1;
> + }
Hum, realloc( , n+1) always leave me with a unpleasant feeling. I really
prefer a current usage size, an allocated size and growing by doubling the
block only when needed.
> + eventLoop.handles = tmp;
> +
> + eventLoop.handles[eventLoop.nhandles].fd = fd;
> + eventLoop.handles[eventLoop.nhandles].events = events;
> + eventLoop.handles[eventLoop.nhandles].cb = cb;
> + eventLoop.handles[eventLoop.nhandles].opaque = opaque;
> + eventLoop.handles[eventLoop.nhandles].deleted = 0;
> +
> + eventLoop.nhandles++;
> +
> + return 0;
> +}
> +
> +int virEventRemoveHandle(int fd) {
> + int i;
> + printf("Remove handle %d\n", fd);
> + for (i = eventLoop.nhandles-1 ; i >= 0 ; i--) {
> + if (eventLoop.handles[i].fd == fd) {
> + printf("mark delete %d\n", i);
> + eventLoop.handles[i].deleted = 1;
> + return 0;
> + }
> + }
> + return -1;
> +}
> +
> +
> +int virEventAddTimeout(int timeout, virEventTimeoutCallback cb, void *opaque) {
> + struct virEventTimeout *tmp;
> + struct timeval tv;
> +
> + if (gettimeofday(&tv, NULL) < 0) {
> + return -1;
> + }
> +
> + tmp = realloc(eventLoop.timeouts, sizeof(struct virEventTimeout) * (eventLoop.ntimeouts+1));
> + if (!tmp) {
> + return -1;
> + }
> + eventLoop.timeouts = tmp;
> +
> + eventLoop.timeouts[eventLoop.ntimeouts].timer = nextTimer++;
> + eventLoop.timeouts[eventLoop.ntimeouts].timeout = timeout;
> + eventLoop.timeouts[eventLoop.ntimeouts].cb = cb;
> + eventLoop.timeouts[eventLoop.ntimeouts].opaque = opaque;
> + eventLoop.timeouts[eventLoop.ntimeouts].deleted = 0;
> + eventLoop.timeouts[eventLoop.ntimeouts].expiresAt =
> + (((unsigned long long)tv.tv_sec)*1000) +
> + (((unsigned long long)tv.tv_usec)/1000);
> +
> + eventLoop.ntimeouts++;
> +
> + return 0;
> +}
> +
> +int virEventRemoveTimeout(int timer) {
> + int i;
> + for (i = eventLoop.ntimeouts-1 ; i >=0 ; i--) {
> + if (eventLoop.timeouts[i].timer == timer) {
> + eventLoop.timeouts[i].deleted = 1;
> + return 0;
> + }
> + }
> + return -1;
> +}
> +
> +
> +static int virEventCalculateTimeout(int *timeout) {
> + unsigned long long then = 0;
> + int i;
> +
> + /* Figure out if we need a timeout */
> + for (i = 0 ; i < eventLoop.ntimeouts ; i++) {
> + if (then == 0 ||
> + eventLoop.timeouts[i].expiresAt < then)
> + then = eventLoop.timeouts[i].expiresAt;
> + }
> +
> + /* Calculate how long we should wait for a timeout if needed */
> + if (then > 0) {
> + struct timeval tv;
> +
> + if (gettimeofday(&tv, NULL) < 0) {
> + return -1;
> + }
> +
> + *timeout = then -
> + ((((unsigned long long)tv.tv_sec)*1000) +
> + (((unsigned long long)tv.tv_usec)/1000));
> +
> + if (*timeout < 0)
> + *timeout = 1;
> + } else {
> + *timeout = -1;
> + }
> +
> + return 0;
> +}
> +
> +static struct pollfd *virEventMakePollFDs(void) {
> + struct pollfd *fds;
> + int i;
> +
> + /* Setup the poll file handle data structs */
> + if (!(fds = malloc(sizeof(struct pollfd)*eventLoop.nhandles)))
> + return NULL;
> +
> + for (i = 0 ; i < eventLoop.nhandles ; i++) {
> + fds[i].fd = eventLoop.handles[i].fd;
> + fds[i].events = eventLoop.handles[i].events;
> + fds[i].revents = 0;
> + printf("Wait for %d %d\n", eventLoop.handles[i].fd, eventLoop.handles[i].events);
> + }
[...]
same here
> +
> +static int virEventCleanupTimeouts(void) {
> + int i;
> + for (i = 0 ; i < eventLoop.ntimeouts ; ) {
> + struct virEventTimeout *tmp;
> + if (!eventLoop.handles[i].deleted) {
> + i++;
> + continue;
> + }
> +
> + if ((i+1) < eventLoop.ntimeouts) {
> + memmove(eventLoop.timeouts+i,
> + eventLoop.timeouts+i+1,
> + sizeof(struct virEventTimeout)*(eventLoop.ntimeouts-(i+1)));
> + }
> +
> + tmp = realloc(eventLoop.timeouts, sizeof(struct virEventTimeout) * (eventLoop.ntimeouts-1));
> + if (!tmp) {
> + return -1;
> + }
> + eventLoop.timeouts = tmp;
> + eventLoop.ntimeouts--;
> + }
> + return 0;
> +}
realloc( -1); in a loop, I would rather realloc at the end or just keep
a maximum allocated block and realloc to maxtimeouts / 2 only if
ntimeouts < (maxtimeouts / 2) -1)
> +static int virEventCleanupHandles(void) {
[...]
> + tmp = realloc(eventLoop.handles, sizeof(struct virEventHandle) * (eventLoop.nhandles-1));
> + if (!tmp) {
> + return -1;
> + }
> + eventLoop.handles = tmp;
> + eventLoop.nhandles--;
> + }
> + return 0;
> +}
Same here
> +int virEventRunOnce(void) {
> + struct pollfd *fds;
> + int ret, timeout;
> +
> + if (!(fds = virEventMakePollFDs()))
> + return -1;
> +
> + if (virEventCalculateTimeout(&timeout) < 0) {
> + free(fds);
> + return -1;
> + }
> +
> + retry:
> + printf("Poll on %d handles %p timeout %d\n", eventLoop.nhandles, fds, timeout);
> + ret = poll(fds, eventLoop.nhandles, timeout);
> + printf("Poll got %d event\n", ret);
> + if (ret < 0) {
> + if (errno == EINTR) {
> + goto retry;
> + }
> + free(fds);
> + return -1;
> + }
> + if (virEventDispatchTimeouts() < 0) {
> + free(fds);
> + return -1;
> + }
> +
> + if (ret > 0 &&
> + virEventDispatchHandles(fds) < 0) {
> + free(fds);
> + return -1;
> + }
> + free(fds);
> +
> + if (virEventCleanupTimeouts() < 0)
> + return -1;
> +
> + if (virEventCleanupHandles() < 0)
> + return -1;
> +
> + return 0;
> +}
...
> diff -r 93de958458cb qemud/event.h
> --- /dev/null Thu Jan 01 00:00:00 1970 +0000
> +++ b/qemud/event.h Sun Jun 17 16:26:34 2007 -0400
> @@ -0,0 +1,13 @@
> +
> +
> +typedef void (*virEventHandleCallback)(int fd, int events, void *opaque);
> +
> +int virEventAddHandle(int fd, int events, virEventHandleCallback cb, void *opaque);
> +int virEventRemoveHandle(int fd);
> +
> +typedef void (*virEventTimeoutCallback)(int timer, void *opaque);
> +
> +int virEventAddTimeout(int timeout, virEventTimeoutCallback cb, void *opaque);
> +int virEventRemoveTimeout(int timer);
> +
> +int virEventRunOnce(void);
> diff -r 93de958458cb qemud/qemud.c
> --- a/qemud/qemud.c Fri Jun 15 14:27:39 2007 +0000
> +++ b/qemud/qemud.c Sun Jun 17 17:37:07 2007 -0400
> @@ -61,6 +61,7 @@
> #include "driver.h"
> #include "conf.h"
> #include "iptables.h"
> +#include "event.h"
>
> static int godaemon = 0; /* -d: Be a daemon */
> static int verbose = 0; /* -v: Verbose mode */
> @@ -109,6 +110,13 @@ static void sig_handler(int sig) {
> }
> errno = origerrno;
> }
> +
> +static void qemudDispatchVMEvent(int fd, int events, void *opaque);
> +static void qemudDispatchClientEvent(int fd, int events, void *opaque);
> +static void qemudDispatchServerEvent(int fd, int events, void *opaque);
> +static int qemudRegisterClientEvent(struct qemud_server *server,
> + struct qemud_client *client,
> + int remove);
>
> static int
> remoteInitializeGnuTLS (void)
> @@ -184,8 +192,10 @@ remoteInitializeGnuTLS (void)
> return 0;
> }
>
> -static int qemudDispatchSignal(struct qemud_server *server)
> -{
> +static void qemudDispatchSignalEvent(int fd ATTRIBUTE_UNUSED,
> + int events ATTRIBUTE_UNUSED,
> + void *opaque) {
> + struct qemud_server *server = (struct qemud_server *)opaque;
> unsigned char sigc;
> struct qemud_vm *vm;
> struct qemud_network *network;
> @@ -194,7 +204,7 @@ static int qemudDispatchSignal(struct qe
> if (read(server->sigread, &sigc, 1) != 1) {
> qemudLog(QEMUD_ERR, "Failed to read from signal pipe: %s",
> strerror(errno));
> - return -1;
> + return;
> }
>
> ret = 0;
> @@ -266,7 +276,8 @@ static int qemudDispatchSignal(struct qe
> break;
> }
>
> - return ret;
> + if (ret != 0)
> + server->shutdown = 1;
> }
is asynchronous error handling really better there ?
> static int qemudSetCloseExec(int fd) {
> @@ -474,19 +485,16 @@ static int qemudListenUnix(struct qemud_
> }
[...]
> diff -r 93de958458cb qemud/remote.c
> --- a/qemud/remote.c Fri Jun 15 14:27:39 2007 +0000
> +++ b/qemud/remote.c Sun Jun 17 16:26:54 2007 -0400
> @@ -691,7 +691,7 @@ remoteDispatchDomainGetInfo (struct qemu
> remoteDispatchError (client, req, "domain not found");
> return -2;
> }
> -
> + printf("------------------------------------- %d %s\n", dom->id, dom->name);
I assume those are debugging left over, right ?
> if (virDomainGetInfo (dom, &info) == -1)
> return -1;
>
> @@ -862,7 +862,7 @@ remoteDispatchDomainLookupById (struct q
>
> dom = virDomainLookupByID (client->conn, args->id);
> if (dom == NULL) return -1;
> -
> + printf("******************Loopu %d %s\n", dom->id, dom->name);
> make_nonnull_domain (&ret->dom, dom);
>
> return 0;
> @@ -1539,6 +1539,7 @@ get_nonnull_domain (virConnectPtr conn,
> /* Should we believe the domain.id sent by the client? Maybe
> * this should be a check rather than an assignment? XXX
> */
> + printf("********************* %d\n", domain.id);
> if (dom) dom->id = domain.id;
> return dom;
> }
My main concern is lack of comments and the allocation stategy,
Daniel
--
Red Hat Virtualization group http://redhat.com/virtualization/
Daniel Veillard | virtualization library http://libvirt.org/
veillard@xxxxxxxxxx | libxml GNOME XML XSLT toolkit http://xmlsoft.org/
http://veillard.com/ | Rpmfind RPM search engine http://rpmfind.net/