wgpu_core/lock/
rank.rs

1//! Ranks for `wgpu-core` locks, restricting acquisition order.
2//!
3//! See [`LockRank`].
4
5/// The rank of a lock.
6///
7/// Each [`Mutex`], [`RwLock`], and [`SnatchLock`] in `wgpu-core` has been
8/// assigned a *rank*: a node in the DAG defined at the bottom of
9/// `wgpu-core/src/lock/rank.rs`. The rank of the most recently
10/// acquired lock you are still holding determines which locks you may
11/// attempt to acquire next.
12///
13/// When you create a lock in `wgpu-core`, you must specify its rank
14/// by passing in a [`LockRank`] value. This module declares a
15/// pre-defined set of ranks to cover everything in `wgpu-core`, named
16/// after the type in which they occur, and the name of the type's
17/// field that is a lock. For example, [`CommandBuffer::data`] is a
18/// `Mutex`, and its rank here is the constant
19/// [`COMMAND_BUFFER_DATA`].
20///
21/// Building with `RUSTFLAGS="--cfg wgpu_validate_locks"`, replaces the
22/// lock implementation in `lock::vanilla` with in `lock::ranked`, which
23/// checks that the observed sequences of lock acquisition respect the
24/// ordering defined here.
25///
26/// TODO(<https://github.com/gfx-rs/wgpu/issues/5572>): Resolve invalid
27/// acquisitions of DEVICE_COMMAND_INDICES followed by COMMAND_BUFFER_DATA.
28///
29/// [`Mutex`]: wgpu_sync::Mutex
30/// [`RwLock`]: wgpu_sync::RwLock
31/// [`SnatchLock`]: crate::snatch::SnatchLock
32/// [`CommandBuffer::data`]: crate::command::CommandBuffer::data
33#[derive(Debug, Copy, Clone)]
34pub struct LockRank {
35    /// The bit representing this lock.
36    ///
37    /// There should only be a single bit set in this value.
38    pub(super) bit: LockRankSet,
39
40    /// A bitmask of permitted successor ranks.
41    ///
42    /// If `rank` is the rank of the most recently acquired lock we
43    /// are still holding, then `rank.followers` is the mask of
44    /// locks we are allowed to acquire next.
45    ///
46    /// The `define_lock_ranks!` macro ensures that there are no
47    /// cycles in the graph of lock ranks and their followers.
48    pub(super) followers: LockRankSet,
49}
50
51/// Define a set of lock ranks, and each rank's permitted successors.
52macro_rules! define_lock_ranks {
53    {
54        $(
55            $( #[ $attr:meta ] )*
56            rank $name:ident $member:literal followed by { $( $follower:ident ),* $(,)? }
57        )*
58    } => {
59        // An enum that assigns a unique number to each rank.
60        #[allow(non_camel_case_types, clippy::upper_case_acronyms)]
61        enum LockRankNumber { $( $name, )* }
62
63        bitflags::bitflags! {
64            #[derive(Debug, Copy, Clone, Eq, PartialEq)]
65            /// A bitflags type representing a set of lock ranks.
66            pub struct LockRankSet: u64 {
67                $(
68                    const $name = 1 << (LockRankNumber:: $name as u64);
69                )*
70            }
71        }
72
73        impl LockRankSet {
74            pub fn member_name(self) -> &'static str {
75                match self {
76                    $(
77                        LockRankSet:: $name => $member,
78                    )*
79                    _ => "<unrecognized LockRankSet bit>",
80                }
81            }
82
83            #[cfg_attr(not(feature = "observe_locks"), allow(dead_code))]
84            pub fn const_name(self) -> &'static str {
85                match self {
86                    $(
87                        LockRankSet:: $name => stringify!($name),
88                    )*
89                    _ => "<unrecognized LockRankSet bit>",
90                }
91            }
92        }
93
94        $(
95            // If there is any cycle in the ranking, the initializers
96            // for `followers` will be cyclic, and rustc will give us
97            // an error message explaining the cycle.
98            $( #[ $attr ] )*
99            pub const $name: LockRank = LockRank {
100                bit: LockRankSet:: $name,
101                followers: LockRankSet::empty() $( .union($follower.bit) )*,
102            };
103        )*
104    }
105}
106
107define_lock_ranks! {
108    // Non-leaf ranks, in topological order.
109    rank INSTANCE_DEVICES "InstanceDevices" followed by {
110        DEVICE_SNATCHABLE_LOCK,
111        QUEUE_PENDING_WRITES,
112        DEVICE_TRACKERS,
113        QUEUE_LIFE_TRACKER,
114        BUFFER_BIND_GROUPS,
115        DEVICE_TRACE,
116        TEXTURE_BIND_GROUPS,
117        TEXTURE_CLEAR_MODE,
118        TEXTURE_VIEWS,
119        DEVICE_DEFERRED_DESTROY,
120        DEVICE_LOST_CLOSURE,
121    }
122    rank DEVICE_SNATCHABLE_LOCK "Device::snatchable_lock" followed by {
123        BUFFER_MAP_STATE,
124        COMMAND_BUFFER_DATA,
125        DEVICE_COMMAND_INDICES,
126        QUEUE_PENDING_WRITES,
127        DEVICE_TRACKERS,
128        QUEUE_LIFE_TRACKER,
129        BLAS_COMPACTION_STATE,
130        COMMAND_ALLOCATOR_FREE_ENCODERS,
131        BUFFER_BIND_GROUPS,
132        BUFFER_INITIALIZATION_STATUS,
133        BUFFER_POOL,
134        DEVICE_LOST_CLOSURE,
135        DEVICE_TRACE,
136        DEVICE_USAGE_SCOPES,
137        QUERY_SET_INITIALIZED_SLOTS,
138        SHARED_TRACKER_INDEX_ALLOCATOR_INNER,
139        TEXTURE_BIND_GROUPS,
140        TEXTURE_CLEAR_MODE,
141        TEXTURE_INITIALIZATION_STATUS,
142        TEXTURE_VIEWS,
143    }
144    rank DEVICE_COMMAND_INDICES "Device::command_indices" followed by {
145        COMMAND_BUFFER_DATA,
146        BUFFER_MAP_STATE,
147        BUFFER_POOL,
148        DEVICE_TRACKERS,
149        QUEUE_PENDING_WRITES,
150        QUEUE_LIFE_TRACKER,
151        BLAS_COMPACTION_STATE,
152        BLAS_BUILT_INDEX,
153        COMMAND_ALLOCATOR_FREE_ENCODERS,
154        DEVICE_DEFERRED_DESTROY,
155        DEVICE_TRACE,
156        QUERY_SET_INITIALIZED_SLOTS,
157        RESOURCE_POOL_INNER,
158        SHARED_TRACKER_INDEX_ALLOCATOR_INNER,
159        TEXTURE_CLEAR_MODE,
160        TLAS_BUILT_INDEX,
161        TLAS_DEPENDENCIES,
162    }
163    rank COMMAND_BUFFER_DATA "CommandBuffer::data" followed by {
164        BUFFER_MAP_STATE,
165        COMMAND_ALLOCATOR_FREE_ENCODERS,
166        BLAS_COMPACTION_STATE,
167        BUFFER_POOL,
168        DEVICE_TRACE,
169        DEVICE_USAGE_SCOPES,
170        SHARED_TRACKER_INDEX_ALLOCATOR_INNER,
171    }
172    rank QUEUE_PENDING_WRITES "Queue::pending_writes" followed by {
173        BUFFER_MAP_STATE,
174        DEVICE_TRACKERS,
175        COMMAND_ALLOCATOR_FREE_ENCODERS,
176        BUFFER_INITIALIZATION_STATUS,
177        TEXTURE_INITIALIZATION_STATUS,
178        SHARED_TRACKER_INDEX_ALLOCATOR_INNER,
179    }
180    rank DEVICE_TRACKERS "Device::trackers" followed by {
181        BUFFER_BIND_GROUPS,
182        BUFFER_INITIALIZATION_STATUS,
183        DEVICE_DEFERRED_DESTROY,
184        TEXTURE_BIND_GROUPS,
185        TEXTURE_CLEAR_MODE,
186        TEXTURE_INITIALIZATION_STATUS,
187        TEXTURE_VIEWS,
188    }
189    rank QUEUE_LIFE_TRACKER "Queue::life_tracker" followed by {
190        BLAS_COMPACTION_STATE,
191        BUFFER_MAP_STATE,
192        COMMAND_ALLOCATOR_FREE_ENCODERS,
193        BUFFER_INITIALIZATION_STATUS,
194        BUFFER_POOL,
195        DEVICE_DEFERRED_DESTROY,
196        DEVICE_TRACE,
197        RESOURCE_POOL_INNER,
198        SHARED_TRACKER_INDEX_ALLOCATOR_INNER,
199        TEXTURE_CLEAR_MODE,
200    }
201    rank BLAS_COMPACTION_STATE "Blas::compaction_state" followed by {
202        BLAS_BUILT_INDEX,
203    }
204    rank BUFFER_MAP_STATE "Buffer::map_state" followed by {
205        BUFFER_INITIALIZATION_STATUS,
206        DEVICE_TRACE,
207        SHARED_TRACKER_INDEX_ALLOCATOR_INNER,
208    }
209    rank COMMAND_ALLOCATOR_FREE_ENCODERS "CommandAllocator::free_encoders" followed by {
210        SHARED_TRACKER_INDEX_ALLOCATOR_INNER,
211    }
212    rank TLAS_BUILT_INDEX "Tlas::built_index" followed by {
213        TLAS_DEPENDENCIES,
214    }
215    rank TLAS_DEPENDENCIES "Tlas::dependencies" followed by {
216        BLAS_BUILT_INDEX,
217    }
218
219    // Leaf ranks reachable from the graph above, alphabetical.
220    rank BLAS_BUILT_INDEX "Blas::built_index" followed by { }
221    rank BUFFER_BIND_GROUPS "Buffer::bind_groups" followed by { }
222    rank BUFFER_INITIALIZATION_STATUS "Buffer::initialization_status" followed by { }
223    rank BUFFER_POOL "BufferPool::buffers" followed by { }
224    rank DEVICE_DEFERRED_DESTROY "Device::deferred_destroy" followed by { }
225    rank DEVICE_LOST_CLOSURE "Device::device_lost_closure" followed by { }
226    rank DEVICE_TRACE "Device::trace" followed by { }
227    rank DEVICE_USAGE_SCOPES "Device::usage_scopes" followed by { }
228    rank QUERY_SET_INITIALIZED_SLOTS "QuerySet::initialized_slots" followed by { }
229    rank RESOURCE_POOL_INNER "ResourcePool::inner" followed by { }
230    rank SHARED_TRACKER_INDEX_ALLOCATOR_INNER "SharedTrackerIndexAllocator::inner" followed by { }
231    rank TEXTURE_BIND_GROUPS "Texture::bind_groups" followed by { }
232    rank TEXTURE_CLEAR_MODE "Texture::clear_mode" followed by { }
233    rank TEXTURE_INITIALIZATION_STATUS "Texture::initialization_status" followed by { }
234    rank TEXTURE_VIEWS "Texture::views" followed by { }
235
236    // Ranks not connected to the graph, alphabetical.
237    rank SURFACE_PRESENTATION "Surface::presentation" followed by { }
238
239    #[cfg(test)]
240    rank PAWN "pawn" followed by { ROOK, BISHOP }
241    #[cfg(test)]
242    rank ROOK "rook" followed by { KNIGHT }
243    #[cfg(test)]
244    rank KNIGHT "knight" followed by { }
245    #[cfg(test)]
246    rank BISHOP "bishop" followed by { }
247}
wgpu_core/lock/rank.rs

wgpu_core/lock/
rank.rs
