|
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCH 4 of 9 v2] libxl: introduce libxl__wait_for_device_state
On Fri, 2011-11-18 at 11:59 +0000, Roger Pau Monne wrote:
> # HG changeset patch
> # User Roger Pau Monne <roger.pau@xxxxxxxxxxxxx>
> # Date 1321609740 -3600
> # Node ID a77bba3717402fdf24a72d028ae0f3d482e6f427
> # Parent ec94a7e4983ad6338db20fa0777a85507b582607
> libxl: introduce libxl__wait_for_device_state
>
> This is a generic function, that waits for xs watches to reach a
> certain state and then executes the passed helper function. Removed
> wait_for_dev_destroy and used this new function instead. This
> function will also be used by future patches that need to wait for
> the initialization of devices before executing hotplug scripts.
>
> Signed-off-by: Roger Pau Monne <roger.pau@xxxxxxxxxxxxx>
Acked-by: Ian Campbell <ian.campbell@xxxxxxxxxx>
> diff -r ec94a7e4983a -r a77bba371740 tools/libxl/libxl_device.c
> --- a/tools/libxl/libxl_device.c Fri Nov 18 10:46:54 2011 +0100
> +++ b/tools/libxl/libxl_device.c Fri Nov 18 10:49:00 2011 +0100
> @@ -370,7 +370,9 @@ int libxl__device_disk_dev_number(const
> * Returns 0 if a device is removed, ERROR_* if an error
> * or timeout occurred.
> */
> -static int wait_for_dev_destroy(libxl__gc *gc, struct timeval *tv)
> +int libxl__wait_for_device_state(libxl__gc *gc, struct timeval *tv,
> + int state,
> + libxl__device_state_handler handler)
> {
> libxl_ctx *ctx = libxl__gc_owner(gc);
> int nfds, rc;
> @@ -395,17 +397,14 @@ start:
> default:
> l1 = xs_read_watch(ctx->xsh, &n);
> if (l1 != NULL) {
> - char *state = libxl__xs_read(gc, XBT_NULL,
> + char *sstate = libxl__xs_read(gc, XBT_NULL,
> l1[XS_WATCH_PATH]);
> - if (!state || atoi(state) == 6) {
> - xs_unwatch(ctx->xsh, l1[0], l1[1]);
> - xs_rm(ctx->xsh, XBT_NULL, l1[XS_WATCH_TOKEN]);
> - LIBXL__LOG(ctx, LIBXL__LOG_DEBUG,
> - "Destroyed device backend at %s",
> - l1[XS_WATCH_TOKEN]);
> - rc = 0;
> + if (!sstate || atoi(sstate) == state) {
> + /* Call handler function if present */
> + if (handler)
> + rc = handler(gc, l1, sstate);
> } else {
> - /* State is not "disconnected", continue waiting... */
> + /* State is different than expected, continue waiting...
> */
> goto start;
> }
> free(l1);
> @@ -418,6 +417,23 @@ start:
> }
>
> /*
> + * Handler function for device destruction to be passed to
> + * libxl__wait_for_device_state
> + */
> +static int destroy_device(libxl__gc *gc, char **l1, char *state)
> +{
> + libxl_ctx *ctx = libxl__gc_owner(gc);
> +
> + xs_unwatch(ctx->xsh, l1[0], l1[1]);
> + xs_rm(ctx->xsh, XBT_NULL, l1[XS_WATCH_TOKEN]);
> + LIBXL__LOG(ctx, LIBXL__LOG_DEBUG,
> + "Destroyed device backend at %s",
> + l1[XS_WATCH_TOKEN]);
> +
> + return 0;
> +}
> +
> +/*
> * Returns 0 (device already destroyed) or 1 (caller must
> * wait_for_dev_destroy) on success, ERROR_* on fail.
> */
> @@ -458,7 +474,7 @@ retry_transaction:
> struct timeval tv;
> tv.tv_sec = LIBXL_DESTROY_TIMEOUT;
> tv.tv_usec = 0;
> - rc = wait_for_dev_destroy(gc, &tv);
> + rc = libxl__wait_for_device_state(gc, &tv, 6, destroy_device);
> if (rc < 0) /* an error or timeout occurred, clear watches */
> xs_unwatch(ctx->xsh, state_path, be_path);
> xs_rm(ctx->xsh, XBT_NULL, libxl__device_frontend_path(gc, dev));
> @@ -566,7 +582,7 @@ int libxl__devices_destroy(libxl__gc *gc
> tv.tv_sec = LIBXL_DESTROY_TIMEOUT;
> tv.tv_usec = 0;
> while (n_watches > 0) {
> - if (wait_for_dev_destroy(gc, &tv) < 0) {
> + if (libxl__wait_for_device_state(gc, &tv, 6, destroy_device) <
> 0) {
> /* function returned ERROR_* */
> break;
> } else {
> diff -r ec94a7e4983a -r a77bba371740 tools/libxl/libxl_internal.h
> --- a/tools/libxl/libxl_internal.h Fri Nov 18 10:46:54 2011 +0100
> +++ b/tools/libxl/libxl_internal.h Fri Nov 18 10:49:00 2011 +0100
> @@ -20,6 +20,7 @@
> #include <stdint.h>
> #include <stdarg.h>
> #include <stdlib.h>
> +#include <sys/time.h>
>
> #include <xs.h>
> #include <xenctrl.h>
> @@ -252,6 +253,31 @@ _hidden int libxl__device_destroy(libxl_
> _hidden int libxl__devices_destroy(libxl__gc *gc, uint32_t domid, int force);
> _hidden int libxl__wait_for_backend(libxl__gc *gc, char *be_path, char
> *state);
>
> +/* Handler for the libxl__wait_for_device_state callback */
> +/*
> + * libxl__device_state_handler - Handler for the libxl__wait_for_device_state
> + * gc: allocation pool
> + * l1: array containing the path and token
> + * state: string that contains the state of the device
> + *
> + * Returns 0 on success, and < 0 on error.
> + */
> +typedef int libxl__device_state_handler(libxl__gc *gc, char **l1, char
> *state);
> +
> +/*
> + * libxl__wait_for_device_state - waits a given time for a device to
> + * reach a given state
> + * gc: allocation pool
> + * tv: timeval struct containing the maximum time to wait
> + * state: state to wait for
> + * handler: callback function to execute when state is reached
> + *
> + * Returns 0 on success, and < 0 on error.
> + */
> +_hidden int libxl__wait_for_device_state(libxl__gc *gc, struct timeval *tv,
> + int state,
> + libxl__device_state_handler
> handler);
> +
> /*
> * libxl__try_phy_backend - Check if there's support for the passed
> * type of file using the PHY backend
>
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@xxxxxxxxxxxxxxxxxxx
> http://lists.xensource.com/xen-devel
_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel
|
 |
Lists.xenproject.org is hosted with RackSpace, monitoring our |