diff options
Diffstat (limited to 'src/modules/reserve-monitor.c')
| -rw-r--r-- | src/modules/reserve-monitor.c | 267 |
1 files changed, 267 insertions, 0 deletions
diff --git a/src/modules/reserve-monitor.c b/src/modules/reserve-monitor.c new file mode 100644 index 0000000..70de870 --- /dev/null +++ b/src/modules/reserve-monitor.c @@ -0,0 +1,267 @@ +/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: t -*-*/ + +/*** + Copyright 2009 Lennart Poettering + + Permission is hereby granted, free of charge, to any person + obtaining a copy of this software and associated documentation files + (the "Software"), to deal in the Software without restriction, + including without limitation the rights to use, copy, modify, merge, + publish, distribute, sublicense, and/or sell copies of the Software, + and to permit persons to whom the Software is furnished to do so, + subject to the following conditions: + + The above copyright notice and this permission notice shall be + included in all copies or substantial portions of the Software. + + THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS + BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN + ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + SOFTWARE. +***/ + +#include <string.h> +#include <unistd.h> +#include <errno.h> +#include <stdlib.h> +#include <stdio.h> +#include <assert.h> + +#include "reserve-monitor.h" +#include "reserve.h" + +struct rm_monitor { + int ref; + + char *device_name; + char *service_name; + char *match; + + DBusConnection *connection; + + unsigned busy:1; + unsigned filtering:1; + unsigned matching:1; + + rm_change_cb_t change_cb; + void *userdata; +}; + +#define SERVICE_PREFIX "org.freedesktop.ReserveDevice1." + +#define SERVICE_FILTER \ + "type='signal'," \ + "sender='" DBUS_SERVICE_DBUS "'," \ + "interface='" DBUS_INTERFACE_DBUS "'," \ + "member='NameOwnerChanged'," \ + "arg0='%s'" + +static unsigned get_busy( + DBusConnection *c, + const char *name_owner) { + + const char *un; + + if (!name_owner || !*name_owner) + return FALSE; + + /* If we ourselves own the device, then don't consider this 'busy' */ + if ((un = dbus_bus_get_unique_name(c))) + if (strcmp(name_owner, un) == 0) + return FALSE; + + return TRUE; +} + +static DBusHandlerResult filter_handler( + DBusConnection *c, + DBusMessage *s, + void *userdata) { + + rm_monitor *m; + DBusError error; + + dbus_error_init(&error); + + m = userdata; + assert(m->ref >= 1); + + if (dbus_message_is_signal(s, "org.freedesktop.DBus", "NameOwnerChanged")) { + const char *name, *old, *new; + + if (!dbus_message_get_args( + s, + &error, + DBUS_TYPE_STRING, &name, + DBUS_TYPE_STRING, &old, + DBUS_TYPE_STRING, &new, + DBUS_TYPE_INVALID)) + goto invalid; + + if (strcmp(name, m->service_name) == 0) { + unsigned old_busy = m->busy; + + m->busy = get_busy(c, new); + + if (m->busy != old_busy && m->change_cb) { + m->ref++; + m->change_cb(m); + rm_release(m); + } + } + } + +invalid: + dbus_error_free(&error); + + return DBUS_HANDLER_RESULT_NOT_YET_HANDLED; +} + +int rm_watch( + rm_monitor **_m, + DBusConnection *connection, + const char *device_name, + rm_change_cb_t change_cb, + DBusError *error) { + + rm_monitor *m = NULL; + char *name_owner; + int r; + DBusError _error; + + if (!error) + error = &_error; + + dbus_error_init(error); + + if (!_m) + return -EINVAL; + + if (!connection) + return -EINVAL; + + if (!device_name) + return -EINVAL; + + if (!(m = calloc(sizeof(rm_monitor), 1))) + return -ENOMEM; + + m->ref = 1; + + if (!(m->device_name = strdup(device_name))) { + r = -ENOMEM; + goto fail; + } + + m->connection = dbus_connection_ref(connection); + m->change_cb = change_cb; + + if (!(m->service_name = malloc(sizeof(SERVICE_PREFIX) + strlen(device_name)))) { + r = -ENOMEM; + goto fail; + } + sprintf(m->service_name, SERVICE_PREFIX "%s", m->device_name); + + if (!(dbus_connection_add_filter(m->connection, filter_handler, m, NULL))) { + r = -ENOMEM; + goto fail; + } + + m->filtering = 1; + + if (!(m->match = malloc(sizeof(SERVICE_FILTER) - 2 + strlen(m->service_name)))) { + r = -ENOMEM; + goto fail; + } + + sprintf(m->match, SERVICE_FILTER, m->service_name); + dbus_bus_add_match(m->connection, m->match, error); + + if (dbus_error_is_set(error)) { + r = -EIO; + goto fail; + } + + m->matching = 1; + + if ((r = rd_dbus_get_name_owner(m->connection, m->service_name, &name_owner, error)) < 0) + goto fail; + + m->busy = get_busy(m->connection, name_owner); + free(name_owner); + + *_m = m; + return 0; + +fail: + if (&_error == error) + dbus_error_free(&_error); + + if (m) + rm_release(m); + + return r; +} + +void rm_release(rm_monitor *m) { + if (!m) + return; + + assert(m->ref > 0); + + if (--m->ref > 0) + return; + + if (m->matching) + dbus_bus_remove_match( + m->connection, + m->match, + NULL); + + if (m->filtering) + dbus_connection_remove_filter( + m->connection, + filter_handler, + m); + + free(m->device_name); + free(m->service_name); + free(m->match); + + if (m->connection) + dbus_connection_unref(m->connection); + + free(m); +} + +int rm_busy(rm_monitor *m) { + if (!m) + return -EINVAL; + + assert(m->ref > 0); + + return m->busy; +} + +void rm_set_userdata(rm_monitor *m, void *userdata) { + + if (!m) + return; + + assert(m->ref > 0); + m->userdata = userdata; +} + +void* rm_get_userdata(rm_monitor *m) { + + if (!m) + return NULL; + + assert(m->ref > 0); + + return m->userdata; +} |