salsa/
event.rs

1use crate::Revision;
2use crate::key::DatabaseKeyIndex;
3use crate::sync::thread::{self, ThreadId};
4
5/// The `Event` struct identifies various notable things that can
6/// occur during salsa execution. Instances of this struct are given
7/// to `salsa_event`.
8#[derive(Debug)]
9pub struct Event {
10    /// The id of the thread that triggered the event.
11    pub thread_id: ThreadId,
12
13    /// What sort of event was it.
14    pub kind: EventKind,
15}
16
17impl Event {
18    pub fn new(kind: EventKind) -> Self {
19        Self {
20            thread_id: thread::current().id(),
21            kind,
22        }
23    }
24}
25
26/// An enum identifying the various kinds of events that can occur.
27#[derive(Debug)]
28pub enum EventKind {
29    /// Occurs when we found that all inputs to a memoized value are
30    /// up-to-date and hence the value can be re-used without
31    /// executing the closure.
32    ///
33    /// Executes before the "re-used" value is returned.
34    DidValidateMemoizedValue {
35        /// The database-key for the affected value. Implements `Debug`.
36        database_key: DatabaseKeyIndex,
37    },
38
39    /// Indicates that another thread (with id `other_thread_id`) is processing the
40    /// given query (`database_key`), so we will block until they
41    /// finish.
42    ///
43    /// Executes after we have registered with the other thread but
44    /// before they have answered us.
45    WillBlockOn {
46        /// The id of the thread we will block on.
47        other_thread_id: ThreadId,
48
49        /// The database-key for the affected value. Implements `Debug`.
50        database_key: DatabaseKeyIndex,
51    },
52
53    /// Indicates that the function for this query will be executed.
54    /// This is either because it has never executed before or because
55    /// its inputs may be out of date.
56    WillExecute {
57        /// The database-key for the affected value. Implements `Debug`.
58        database_key: DatabaseKeyIndex,
59    },
60
61    /// Salsa starts a new fixpoint iteration for the cycle with `database_key` as its
62    /// outermost cycle.
63    WillIterateCycle {
64        /// The database-key for the cycle head. Implements `Debug`.
65        database_key: DatabaseKeyIndex,
66        iteration: u8,
67    },
68
69    /// Salsa completed a fixpoint iteration for the cycle with `database_key` as its
70    /// outermost cycle.
71    DidFinalizeCycle {
72        database_key: DatabaseKeyIndex,
73        iteration: u8,
74    },
75
76    /// Indicates that `unwind_if_cancelled` was called and salsa will check if
77    /// the current revision has been cancelled.
78    WillCheckCancellation,
79
80    /// Indicates that one [`Handle`](`crate::Handle`) has set the cancellation flag.
81    /// When other active handles execute salsa methods, they will observe this flag
82    /// and panic with a sentinel value of type [`Cancelled`](`crate::Cancelled`).
83    DidSetCancellationFlag,
84
85    /// Discovered that a query used to output a given output but no longer does.
86    WillDiscardStaleOutput {
87        /// Key for the query that is executing and which no longer outputs the given value.
88        execute_key: DatabaseKeyIndex,
89
90        /// Key for the query that is no longer output
91        output_key: DatabaseKeyIndex,
92    },
93
94    /// Tracked structs or memoized data were discarded (freed).
95    DidDiscard {
96        /// Value being discarded.
97        key: DatabaseKeyIndex,
98    },
99
100    /// Discarded accumulated data from a given fn
101    DidDiscardAccumulated {
102        /// The key of the fn that accumulated results
103        executor_key: DatabaseKeyIndex,
104
105        /// Accumulator that was accumulated into
106        accumulator: DatabaseKeyIndex,
107    },
108
109    /// Indicates that a value was newly interned.
110    DidInternValue {
111        // The key of the interned value.
112        key: DatabaseKeyIndex,
113
114        // The revision the value was interned in.
115        revision: Revision,
116    },
117
118    /// Indicates that a value was interned by reusing an existing slot.
119    DidReuseInternedValue {
120        // The key of the interned value.
121        key: DatabaseKeyIndex,
122
123        // The revision the value was interned in.
124        revision: Revision,
125    },
126
127    /// Indicates that a previously interned value was read in a new revision.
128    DidValidateInternedValue {
129        // The key of the interned value.
130        key: DatabaseKeyIndex,
131
132        // The revision the value was interned in.
133        revision: Revision,
134    },
135}
salsa/event.rs

salsa/
event.rs
