bus: introduce concept of "const" properties

This way we have four kinds of properties:

a) those which are constant as long as an object exists
b) those which can change and PropertiesChange messages with contents are generated
c) those which can change and where the PropertesChange merely includes invalidation
d) those which can change but for which no events are generated

Clients (through code generators run on the introspection XML) can thus
aggressively cache a, b, c, with only d excluded.

diff --git a/TODO b/TODO
index 3a00eb12cfb17e47321b8ff0e8ad3ea0ffddea20..de5738e2ace2a1b0d82c7840c7e4a7a3f07e6d58 100644 (file)
--- a/TODO
+++ b/TODO
@@ -118,11 +118,18 @@ Features:
   - support "const" properties as flag
   - add API to clone sd_bus_message objects
   - SD_BUS_COMMENT() macro for inclusion in vtables, syntax inspired by gdbus
   - support "const" properties as flag
   - add API to clone sd_bus_message objects
   - SD_BUS_COMMENT() macro for inclusion in vtables, syntax inspired by gdbus

+  - systemd-bus-proxyd needs to synthesize NameLost/NameAcquired

   - kdbus: matches against source or destination pids for an "strace -p"-like feel. Problem: The PID info needs to be available in userspace too...
   - kdbus: we need a way to figure out whether there's currently an activator for a name that is already activated
   - longer term:
     * priority queues
     * priority inheritance
   - kdbus: matches against source or destination pids for an "strace -p"-like feel. Problem: The PID info needs to be available in userspace too...
   - kdbus: we need a way to figure out whether there's currently an activator for a name that is already activated
   - longer term:
     * priority queues
     * priority inheritance

+  - move to siphash for bloom filter
+  - dbus spec updates:
+       - kdbus mapping
+       - NameLost/NameAcquired obsolete
+       - GVariant
+       - "const" properties

 
 * sd-event
   - allow multiple signal handlers per signal?
 
 * sd-event
   - allow multiple signal handlers per signal?

diff --git a/src/libsystemd-bus/bus-introspect.c b/src/libsystemd-bus/bus-introspect.c
index 4d5c25a23fdc34bddb5b230902140728bba6f5ac..d528ab2a04b1fe826dc71a15c7b2d15578a19c4b 100644 (file)
--- a/src/libsystemd-bus/bus-introspect.c
+++ b/src/libsystemd-bus/bus-introspect.c
@@ -82,10 +82,12 @@ static void introspect_write_flags(struct introspect *i, int type, int flags) {
                 fputs("   <annotation name=\"org.freedesktop.DBus.Method.NoReply\" value=\"true\"/>\n", i->f);
 
         if (type == _SD_BUS_VTABLE_PROPERTY || type == _SD_BUS_VTABLE_WRITABLE_PROPERTY) {
                 fputs("   <annotation name=\"org.freedesktop.DBus.Method.NoReply\" value=\"true\"/>\n", i->f);
 
         if (type == _SD_BUS_VTABLE_PROPERTY || type == _SD_BUS_VTABLE_WRITABLE_PROPERTY) {

-                if (!(flags & SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE))
-                        fputs("   <annotation name=\"org.freedesktop.DBus.Property.EmitsChangedSignal\" value=\"false\"/>\n", i->f);
-                else if (flags & SD_BUS_VTABLE_PROPERTY_INVALIDATE_ONLY)
+                if (flags & SD_BUS_VTABLE_PROPERTY_CONST)
+                        fputs("   <annotation name=\"org.freedesktop.DBus.Property.EmitsChangedSignal\" value=\"const\"/>\n", i->f);
+                else if (flags & SD_BUS_VTABLE_PROPERTY_EMITS_INVALIDATION)

                         fputs("   <annotation name=\"org.freedesktop.DBus.Property.EmitsChangedSignal\" value=\"invalidates\"/>\n", i->f);
                         fputs("   <annotation name=\"org.freedesktop.DBus.Property.EmitsChangedSignal\" value=\"invalidates\"/>\n", i->f);

+                else if (!(flags & SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE))
+                        fputs("   <annotation name=\"org.freedesktop.DBus.Property.EmitsChangedSignal\" value=\"false\"/>\n", i->f);

         }
 
         if (!i->trusted &&
         }
 
         if (!i->trusted &&

diff --git a/src/libsystemd-bus/bus-objects.c b/src/libsystemd-bus/bus-objects.c
index c3889b794948b9486d82542c476448f3f8744470..e468025a8189f293e6db77896968096d161edbc5 100644 (file)
--- a/src/libsystemd-bus/bus-objects.c
+++ b/src/libsystemd-bus/bus-objects.c
@@ -1680,7 +1680,7 @@ static int add_object_vtable_internal(
                             !signature_is_valid(strempty(v->x.method.signature), false) ||
                             !signature_is_valid(strempty(v->x.method.result), false) ||
                             !(v->x.method.handler || (isempty(v->x.method.signature) && isempty(v->x.method.result))) ||
                             !signature_is_valid(strempty(v->x.method.signature), false) ||
                             !signature_is_valid(strempty(v->x.method.result), false) ||
                             !(v->x.method.handler || (isempty(v->x.method.signature) && isempty(v->x.method.result))) ||

-                            v->flags & (SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE|SD_BUS_VTABLE_PROPERTY_INVALIDATE_ONLY)) {
+                            v->flags & (SD_BUS_VTABLE_PROPERTY_CONST|SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE|SD_BUS_VTABLE_PROPERTY_EMITS_INVALIDATION)) {

                                 r = -EINVAL;
                                 goto fail;
                         }
                                 r = -EINVAL;
                                 goto fail;
                         }


@@ -1722,13 +1722,12 @@ static int add_object_vtable_internal(
                             !signature_is_single(v->x.property.signature, false) ||
                             !(v->x.property.get || bus_type_is_basic(v->x.property.signature[0]) || streq(v->x.property.signature, "as")) ||
                             v->flags & SD_BUS_VTABLE_METHOD_NO_REPLY ||
                             !signature_is_single(v->x.property.signature, false) ||
                             !(v->x.property.get || bus_type_is_basic(v->x.property.signature[0]) || streq(v->x.property.signature, "as")) ||
                             v->flags & SD_BUS_VTABLE_METHOD_NO_REPLY ||

-                            (v->flags & SD_BUS_VTABLE_PROPERTY_INVALIDATE_ONLY && !(v->flags & SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE)) ||
+                            (!!(v->flags & SD_BUS_VTABLE_PROPERTY_CONST) + !!(v->flags & SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE) + !!(v->flags & SD_BUS_VTABLE_PROPERTY_EMITS_INVALIDATION)) > 1 ||

                             (v->flags & SD_BUS_VTABLE_UNPRIVILEGED && v->type == _SD_BUS_VTABLE_PROPERTY)) {
                                 r = -EINVAL;
                                 goto fail;
                         }
 
                             (v->flags & SD_BUS_VTABLE_UNPRIVILEGED && v->type == _SD_BUS_VTABLE_PROPERTY)) {
                                 r = -EINVAL;
                                 goto fail;
                         }
 

-

                         m = new0(struct vtable_member, 1);
                         if (!m) {
                                 r = -ENOMEM;
                         m = new0(struct vtable_member, 1);
                         if (!m) {
                                 r = -ENOMEM;


@@ -2013,9 +2012,10 @@ static int emit_properties_changed_on_interface(
                         if (c != v->parent)
                                 continue;
 
                         if (c != v->parent)
                                 continue;
 

-                        assert_return(v->vtable->flags & SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE, -EDOM);
+                        assert_return(v->vtable->flags & SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE ||
+                                      v->vtable->flags & SD_BUS_VTABLE_PROPERTY_EMITS_INVALIDATION, -EDOM);

 
 

-                        if (v->vtable->flags & SD_BUS_VTABLE_PROPERTY_INVALIDATE_ONLY) {
+                        if (v->vtable->flags & SD_BUS_VTABLE_PROPERTY_EMITS_INVALIDATION) {

                                 has_invalidating = true;
                                 continue;
                         }
                                 has_invalidating = true;
                                 continue;
                         }


@@ -2084,7 +2084,7 @@ static int emit_properties_changed_on_interface(
                                 assert_se(v = hashmap_get(bus->vtable_properties, &key));
                                 assert(c == v->parent);
 
                                 assert_se(v = hashmap_get(bus->vtable_properties, &key));
                                 assert(c == v->parent);
 

-                                if (!(v->vtable->flags & SD_BUS_VTABLE_PROPERTY_INVALIDATE_ONLY))
+                                if (!(v->vtable->flags & SD_BUS_VTABLE_PROPERTY_EMITS_INVALIDATION))

                                         continue;
 
                                 r = sd_bus_message_append(m, "s", *property);
                                         continue;
 
                                 r = sd_bus_message_append(m, "s", *property);

diff --git a/src/libsystemd-bus/test-bus-introspect.c b/src/libsystemd-bus/test-bus-introspect.c
index 574479dd6ced409d1418b51cc9a8427830322a6a..67b6461f30e5f9423df9a22265a0da47dd432990 100644 (file)
--- a/src/libsystemd-bus/test-bus-introspect.c
+++ b/src/libsystemd-bus/test-bus-introspect.c
@@ -41,7 +41,8 @@ static const sd_bus_vtable vtable[] = {
         SD_BUS_WRITABLE_PROPERTY("AProperty", "s", prop_get, prop_set, 0, 0),
         SD_BUS_PROPERTY("AReadOnlyDeprecatedProperty", "(ut)", prop_get, 0, SD_BUS_VTABLE_DEPRECATED),
         SD_BUS_PROPERTY("ChangingProperty", "t", prop_get, 0, SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE),
         SD_BUS_WRITABLE_PROPERTY("AProperty", "s", prop_get, prop_set, 0, 0),
         SD_BUS_PROPERTY("AReadOnlyDeprecatedProperty", "(ut)", prop_get, 0, SD_BUS_VTABLE_DEPRECATED),
         SD_BUS_PROPERTY("ChangingProperty", "t", prop_get, 0, SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE),

-        SD_BUS_PROPERTY("Invalidating", "t", prop_get, 0, SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE|SD_BUS_VTABLE_PROPERTY_INVALIDATE_ONLY),
+        SD_BUS_PROPERTY("Invalidating", "t", prop_get, 0, SD_BUS_VTABLE_PROPERTY_EMITS_INVALIDATION),
+        SD_BUS_PROPERTY("Constant", "t", prop_get, 0, SD_BUS_VTABLE_PROPERTY_CONST),

         SD_BUS_VTABLE_END
 };
 
         SD_BUS_VTABLE_END
 };
 

diff --git a/src/systemd/sd-bus-vtable.h b/src/systemd/sd-bus-vtable.h
index cc029eb1a7c44dbbb87f3e7b8411cdb278876926..a03221502a175b7019197bd7baef5901b0cbd59c 100644 (file)
--- a/src/systemd/sd-bus-vtable.h
+++ b/src/systemd/sd-bus-vtable.h
@@ -40,13 +40,14 @@ enum {
 };
 
 enum {
 };
 
 enum {

-        SD_BUS_VTABLE_DEPRECATED               = 1ULL << 0,
-        SD_BUS_VTABLE_METHOD_NO_REPLY          = 1ULL << 1,
-        SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE    = 1ULL << 2,
-        SD_BUS_VTABLE_PROPERTY_INVALIDATE_ONLY = 1ULL << 3,
-        SD_BUS_VTABLE_UNPRIVILEGED             = 1ULL << 4,
-        SD_BUS_VTABLE_HIDDEN                   = 1ULL << 5,
-        _SD_BUS_VTABLE_CAPABILITY_MASK         = 0xFFFFULL << 40
+        SD_BUS_VTABLE_DEPRECATED                   = 1ULL << 0,
+        SD_BUS_VTABLE_HIDDEN                       = 1ULL << 1,
+        SD_BUS_VTABLE_UNPRIVILEGED                 = 1ULL << 2,
+        SD_BUS_VTABLE_METHOD_NO_REPLY              = 1ULL << 3,
+        SD_BUS_VTABLE_PROPERTY_CONST               = 1ULL << 4,
+        SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE        = 1ULL << 5,
+        SD_BUS_VTABLE_PROPERTY_EMITS_INVALIDATION  = 1ULL << 6,
+        _SD_BUS_VTABLE_CAPABILITY_MASK             = 0xFFFFULL << 40

 };
 
 #define SD_BUS_VTABLE_CAPABILITY(x) ((uint64_t) (((x)+1) & 0xFFFF) << 40)
 };
 
 #define SD_BUS_VTABLE_CAPABILITY(x) ((uint64_t) (((x)+1) & 0xFFFF) << 40)