Your advice was taken and implemented, sending changes in the next version.
On Thu, Sep 27, 2018 at 2:48 PM Marc-André Lureau <
marcandre.lur...@gmail.com> wrote:
> Hi
>
> On Thu, Sep 27, 2018 at 11:41 AM Bishara AbuHattoum <bish...@daynix.com>
> wrote:
> >
> > Currently whenever the qemu-ga's service doesn't find the virtio-serial
> > the run_agent() loops in a QGA_RETRY_INTERVAL (default 5 seconds)
> > intervals and try to restart the qemu-ga which causes a synchronous loop.
> > Changed to wait and listen for the serial events by registering for
> > notifications a proper serial event handler that deals with events:
> > DBT_DEVICEARRIVAL indicates that the device has been inserted
> and
> > is available
> > DBT_DEVICEREMOVECOMPLETE indicates that the devive has been removed
> > Which allow us to determine when the channel path is available for the
> > qemu-ga to restart.
> >
> > Signed-off-by: Bishara AbuHattoum <bish...@daynix.com>
> > Signed-off-by: Sameeh Jubran <sam...@daynix.com>
>
> looks good overall,
>
> > ---
> > qga/main.c | 101 +++++++++++++++++++++++++++++++++++++++++++-
> > qga/service-win32.h | 4 ++
> > 2 files changed, 104 insertions(+), 1 deletion(-)
> >
> > diff --git a/qga/main.c b/qga/main.c
> > index 6a152eb3a7..215dcb36f1 100644
> > --- a/qga/main.c
> > +++ b/qga/main.c
> > @@ -34,6 +34,7 @@
> > #include "qemu/systemd.h"
> > #include "qemu-version.h"
> > #ifdef _WIN32
> > +#include <dbt.h>
> > #include "qga/service-win32.h"
> > #include "qga/vss-win32.h"
> > #endif
> > @@ -101,6 +102,8 @@ struct GAState {
> > bool logging_enabled;
> > #ifdef _WIN32
> > GAService service;
> > + HANDLE channel_available_event;
> > + HANDLE stop_event;
> > #endif
> > bool delimit_response;
> > bool frozen;
> > @@ -137,6 +140,7 @@ static const char *ga_freeze_whitelist[] = {
> > #ifdef _WIN32
> > DWORD WINAPI service_ctrl_handler(DWORD ctrl, DWORD type, LPVOID data,
> > LPVOID ctx);
> > +DWORD WINAPI handle_serial_device_events(DWORD type, LPVOID data);
> > VOID WINAPI service_main(DWORD argc, TCHAR *argv[]);
> > #endif
> > static int run_agent(GAState *s);
> > @@ -729,6 +733,36 @@ static gboolean channel_init(GAState *s, const
> gchar *method, const gchar *path,
> > }
> >
> > #ifdef _WIN32
> > +DWORD WINAPI handle_serial_device_events(DWORD type, LPVOID data)
> > +{
> > + DWORD ret = NO_ERROR;
> > + PDEV_BROADCAST_HDR broadcast_header = (PDEV_BROADCAST_HDR)data;
> > +
> > + if (broadcast_header->dbch_devicetype ==
> DBT_DEVTYP_DEVICEINTERFACE) {
> > + switch (type) {
> > + /* Device inserted */
> > + case DBT_DEVICEARRIVAL:
> > + /* Start QEMU-ga's service */
> > + if (!SetEvent(ga_state->channel_available_event)) {
> > + ret = GetLastError();
> > + }
> > + break;
> > + /* Device removed */
> > + case DBT_DEVICEQUERYREMOVE:
> > + case DBT_DEVICEREMOVEPENDING:
> > + case DBT_DEVICEREMOVECOMPLETE:
> > + /* Stop QEMU-ga's service */
> > + if (!ResetEvent(ga_state->channel_available_event)) {
> > + ret = GetLastError();
> > + }
> > + break;
> > + default:
> > + ret = ERROR_CALL_NOT_IMPLEMENTED;
> > + }
> > + }
> > + return ret;
> > +}
> > +
> > DWORD WINAPI service_ctrl_handler(DWORD ctrl, DWORD type, LPVOID data,
> > LPVOID ctx)
> > {
> > @@ -740,9 +774,13 @@ DWORD WINAPI service_ctrl_handler(DWORD ctrl, DWORD
> type, LPVOID data,
> > case SERVICE_CONTROL_STOP:
> > case SERVICE_CONTROL_SHUTDOWN:
> > quit_handler(SIGTERM);
> > + SetEvent(ga_state->stop_event);
> > service->status.dwCurrentState = SERVICE_STOP_PENDING;
> > SetServiceStatus(service->status_handle, &service->status);
> > break;
> > + case SERVICE_CONTROL_DEVICEEVENT:
> > + handle_serial_device_events(type, data);
> > + break;
> >
> > default:
> > ret = ERROR_CALL_NOT_IMPLEMENTED;
> > @@ -769,10 +807,25 @@ VOID WINAPI service_main(DWORD argc, TCHAR *argv[])
> > service->status.dwServiceSpecificExitCode = NO_ERROR;
> > service->status.dwCheckPoint = 0;
> > service->status.dwWaitHint = 0;
> > + DEV_BROADCAST_DEVICEINTERFACE notification_filter;
> > + ZeroMemory(¬ification_filter, sizeof(notification_filter));
> > + notification_filter.dbcc_devicetype = DBT_DEVTYP_DEVICEINTERFACE;
> > + notification_filter.dbcc_size =
> sizeof(DEV_BROADCAST_DEVICEINTERFACE);
> > + notification_filter.dbcc_classguid = GUID_VIOSERIAL_PORT;
> > +
> > + service->device_notification_handle =
> > + RegisterDeviceNotification(service->status_handle,
> > + ¬ification_filter, DEVICE_NOTIFY_SERVICE_HANDLE);
> > + if (!service->device_notification_handle) {
> > + g_critical("Failed to register device notification handle!\n");
> > + return;
> > + }
> > SetServiceStatus(service->status_handle, &service->status);
> > + ResetEvent(ga_state->stop_event);
> >
> > run_agent(ga_state);
> >
> > + UnregisterDeviceNotification(service->device_notification_handle);
> > service->status.dwCurrentState = SERVICE_STOPPED;
> > SetServiceStatus(service->status_handle, &service->status);
> > }
> > @@ -1360,12 +1413,32 @@ static GAState *initialize_agent(GAConfig
> *config, int socket_activation)
> >
> > s->config = config;
> > s->socket_activation = socket_activation;
> > +
> > +#ifdef _WIN32
> > + s->channel_available_event = CreateEvent(NULL, TRUE, FALSE,
> > +
> TEXT("ChannelAvailableEvent"));
> > + if (s->channel_available_event == NULL) {
> > + g_critical("CreateEvent failed");
> > + return NULL;
> > + }
> > + s->stop_event = CreateEvent(NULL, TRUE, FALSE,
> > + TEXT("StopEvent"));
> > + if (s->stop_event == NULL) {
> > + g_critical("CreateEvent failed");
> > + return NULL;
> > + }
> > +#endif
> > +
> > ga_state = s;
> > return s;
> > }
> >
> > static void cleanup_agent(GAState *s)
> > {
> > +#ifdef _WIN32
> > + CloseHandle(s->channel_available_event);
> > + CloseHandle(s->stop_event);
> > +#endif
> > if (s->command_state) {
> > ga_command_state_cleanup_all(s->command_state);
> > ga_command_state_free(s->command_state);
> > @@ -1397,6 +1470,32 @@ static int run_agent_once(GAState *s)
> > return EXIT_SUCCESS;
> > }
> >
> > +static void wait_for_channel_availability(GAState *s)
> > +{
> > + g_warning("waiting for channel path...");
> > +#ifndef _WIN32
> > + sleep(QGA_RETRY_INTERVAL);
> > +#else
> > + DWORD dwWaitResult;
> > +
> > + HANDLE lpHandles[2] = { s->channel_available_event, s->stop_event };
> > +
> > + dwWaitResult = WaitForMultipleObjects(2, lpHandles, false,
> INFINITE);
> > +
> > + switch (dwWaitResult) {
> > + case WAIT_OBJECT_0:
> > + break;
> > + case (WAIT_OBJECT_0 + 1):
> > + g_warning("service stopped");
> > + break;
>
> Given that both events do basically the same thing, you could use one
> called generically "wakeup".
>
> Alternatively, you could wait on the main_loop (manual iteration), and
> call g_main_context_wakeup() to avoid the extra events altogether (I
> think).
>
>
>
> > + case WAIT_TIMEOUT:
> > + break;
> > + default:
> > + g_critical("WaitForMultipleObjects failed");
> > + }
> > +#endif
> > +}
> > +
> > static int run_agent(GAState *s)
> > {
> > int ret = EXIT_SUCCESS;
> > @@ -1407,7 +1506,7 @@ static int run_agent(GAState *s)
> > ret = run_agent_once(s);
> > if (s->config->retry_path && !s->force_exit) {
> > g_warning("agent stopped unexpectedly, restarting...");
> > - sleep(QGA_RETRY_INTERVAL);
> > + wait_for_channel_availability(s);
> > }
> > } while (s->config->retry_path && !s->force_exit);
> >
> > diff --git a/qga/service-win32.h b/qga/service-win32.h
> > index 89e99dfede..7b16d69b57 100644
> > --- a/qga/service-win32.h
> > +++ b/qga/service-win32.h
> > @@ -20,9 +20,13 @@
> > #define QGA_SERVICE_NAME "qemu-ga"
> > #define QGA_SERVICE_DESCRIPTION "Enables integration with QEMU machine
> emulator and virtualizer."
> >
> > +static const GUID GUID_VIOSERIAL_PORT = { 0x6fde7521, 0x1b65, 0x48ae,
> > +{ 0xb6, 0x28, 0x80, 0xbe, 0x62, 0x1, 0x60, 0x26 } };
> > +
> > typedef struct GAService {
> > SERVICE_STATUS status;
> > SERVICE_STATUS_HANDLE status_handle;
> > + HDEVNOTIFY device_notification_handle;
> > } GAService;
> >
> > int ga_install_service(const char *path, const char *logfile,
> > --
> > 2.17.0
> >
> >
>
>
> --
> Marc-André Lureau
>
