| use rustc_data_structures::fingerprint::Fingerprint; |
| use rustc_data_structures::fx::{FxHashMap, FxHashSet}; |
| use rustc_data_structures::profiling::QueryInvocationId; |
| use rustc_data_structures::sharded::{self, Sharded}; |
| use rustc_data_structures::stable_hasher::{HashStable, StableHasher}; |
| use rustc_data_structures::sync::{AtomicU32, AtomicU64, Lock, Lrc, Ordering}; |
| use rustc_data_structures::unlikely; |
| use rustc_errors::Diagnostic; |
| use rustc_index::vec::{Idx, IndexVec}; |
| |
| use parking_lot::{Condvar, Mutex}; |
| use smallvec::{smallvec, SmallVec}; |
| use std::collections::hash_map::Entry; |
| use std::env; |
| use std::hash::Hash; |
| use std::marker::PhantomData; |
| use std::mem; |
| use std::sync::atomic::Ordering::Relaxed; |
| |
| use super::debug::EdgeFilter; |
| use super::prev::PreviousDepGraph; |
| use super::query::DepGraphQuery; |
| use super::serialized::{SerializedDepGraph, SerializedDepNodeIndex}; |
| use super::{DepContext, DepKind, DepNode, WorkProductId}; |
| |
| #[derive(Clone)] |
| pub struct DepGraph<K: DepKind> { |
| data: Option<Lrc<DepGraphData<K>>>, |
| |
| /// This field is used for assigning DepNodeIndices when running in |
| /// non-incremental mode. Even in non-incremental mode we make sure that |
| /// each task has a `DepNodeIndex` that uniquely identifies it. This unique |
| /// ID is used for self-profiling. |
| virtual_dep_node_index: Lrc<AtomicU32>, |
| } |
| |
| rustc_index::newtype_index! { |
| pub struct DepNodeIndex { .. } |
| } |
| |
| impl DepNodeIndex { |
| pub const INVALID: DepNodeIndex = DepNodeIndex::MAX; |
| } |
| |
| impl std::convert::From<DepNodeIndex> for QueryInvocationId { |
| #[inline] |
| fn from(dep_node_index: DepNodeIndex) -> Self { |
| QueryInvocationId(dep_node_index.as_u32()) |
| } |
| } |
| |
| #[derive(PartialEq)] |
| pub enum DepNodeColor { |
| Red, |
| Green(DepNodeIndex), |
| } |
| |
| impl DepNodeColor { |
| pub fn is_green(self) -> bool { |
| match self { |
| DepNodeColor::Red => false, |
| DepNodeColor::Green(_) => true, |
| } |
| } |
| } |
| |
| struct DepGraphData<K: DepKind> { |
| /// The new encoding of the dependency graph, optimized for red/green |
| /// tracking. The `current` field is the dependency graph of only the |
| /// current compilation session: We don't merge the previous dep-graph into |
| /// current one anymore. |
| current: CurrentDepGraph<K>, |
| |
| /// The dep-graph from the previous compilation session. It contains all |
| /// nodes and edges as well as all fingerprints of nodes that have them. |
| previous: PreviousDepGraph<K>, |
| |
| colors: DepNodeColorMap, |
| |
| /// A set of loaded diagnostics that is in the progress of being emitted. |
| emitting_diagnostics: Mutex<FxHashSet<DepNodeIndex>>, |
| |
| /// Used to wait for diagnostics to be emitted. |
| emitting_diagnostics_cond_var: Condvar, |
| |
| /// When we load, there may be `.o` files, cached MIR, or other such |
| /// things available to us. If we find that they are not dirty, we |
| /// load the path to the file storing those work-products here into |
| /// this map. We can later look for and extract that data. |
| previous_work_products: FxHashMap<WorkProductId, WorkProduct>, |
| |
| dep_node_debug: Lock<FxHashMap<DepNode<K>, String>>, |
| } |
| |
| pub fn hash_result<HashCtxt, R>(hcx: &mut HashCtxt, result: &R) -> Option<Fingerprint> |
| where |
| R: HashStable<HashCtxt>, |
| { |
| let mut stable_hasher = StableHasher::new(); |
| result.hash_stable(hcx, &mut stable_hasher); |
| |
| Some(stable_hasher.finish()) |
| } |
| |
| impl<K: DepKind> DepGraph<K> { |
| pub fn new( |
| prev_graph: PreviousDepGraph<K>, |
| prev_work_products: FxHashMap<WorkProductId, WorkProduct>, |
| ) -> DepGraph<K> { |
| let prev_graph_node_count = prev_graph.node_count(); |
| |
| DepGraph { |
| data: Some(Lrc::new(DepGraphData { |
| previous_work_products: prev_work_products, |
| dep_node_debug: Default::default(), |
| current: CurrentDepGraph::new(prev_graph_node_count), |
| emitting_diagnostics: Default::default(), |
| emitting_diagnostics_cond_var: Condvar::new(), |
| previous: prev_graph, |
| colors: DepNodeColorMap::new(prev_graph_node_count), |
| })), |
| virtual_dep_node_index: Lrc::new(AtomicU32::new(0)), |
| } |
| } |
| |
| pub fn new_disabled() -> DepGraph<K> { |
| DepGraph { data: None, virtual_dep_node_index: Lrc::new(AtomicU32::new(0)) } |
| } |
| |
| /// Returns `true` if we are actually building the full dep-graph, and `false` otherwise. |
| #[inline] |
| pub fn is_fully_enabled(&self) -> bool { |
| self.data.is_some() |
| } |
| |
| pub fn query(&self) -> DepGraphQuery<K> { |
| let data = self.data.as_ref().unwrap().current.data.lock(); |
| let nodes: Vec<_> = data.iter().map(|n| n.node).collect(); |
| let mut edges = Vec::new(); |
| for (from, edge_targets) in data.iter().map(|d| (d.node, &d.edges)) { |
| for &edge_target in edge_targets.iter() { |
| let to = data[edge_target].node; |
| edges.push((from, to)); |
| } |
| } |
| |
| DepGraphQuery::new(&nodes[..], &edges[..]) |
| } |
| |
| pub fn assert_ignored(&self) { |
| if let Some(..) = self.data { |
| K::read_deps(|task_deps| { |
| assert!(task_deps.is_none(), "expected no task dependency tracking"); |
| }) |
| } |
| } |
| |
| pub fn with_ignore<OP, R>(&self, op: OP) -> R |
| where |
| OP: FnOnce() -> R, |
| { |
| K::with_deps(None, op) |
| } |
| |
| /// Starts a new dep-graph task. Dep-graph tasks are specified |
| /// using a free function (`task`) and **not** a closure -- this |
| /// is intentional because we want to exercise tight control over |
| /// what state they have access to. In particular, we want to |
| /// prevent implicit 'leaks' of tracked state into the task (which |
| /// could then be read without generating correct edges in the |
| /// dep-graph -- see the [rustc dev guide] for more details on |
| /// the dep-graph). To this end, the task function gets exactly two |
| /// pieces of state: the context `cx` and an argument `arg`. Both |
| /// of these bits of state must be of some type that implements |
| /// `DepGraphSafe` and hence does not leak. |
| /// |
| /// The choice of two arguments is not fundamental. One argument |
| /// would work just as well, since multiple values can be |
| /// collected using tuples. However, using two arguments works out |
| /// to be quite convenient, since it is common to need a context |
| /// (`cx`) and some argument (e.g., a `DefId` identifying what |
| /// item to process). |
| /// |
| /// For cases where you need some other number of arguments: |
| /// |
| /// - If you only need one argument, just use `()` for the `arg` |
| /// parameter. |
| /// - If you need 3+ arguments, use a tuple for the |
| /// `arg` parameter. |
| /// |
| /// [rustc dev guide]: https://rustc-dev-guide.rust-lang.org/incremental-compilation.html |
| pub fn with_task<Ctxt: DepContext<DepKind = K>, A, R>( |
| &self, |
| key: DepNode<K>, |
| cx: Ctxt, |
| arg: A, |
| task: fn(Ctxt, A) -> R, |
| hash_result: impl FnOnce(&mut Ctxt::StableHashingContext, &R) -> Option<Fingerprint>, |
| ) -> (R, DepNodeIndex) { |
| self.with_task_impl( |
| key, |
| cx, |
| arg, |
| false, |
| task, |
| |_key| { |
| Some(TaskDeps { |
| #[cfg(debug_assertions)] |
| node: Some(_key), |
| reads: SmallVec::new(), |
| read_set: Default::default(), |
| phantom_data: PhantomData, |
| }) |
| }, |
| |data, key, fingerprint, task| data.complete_task(key, task.unwrap(), fingerprint), |
| hash_result, |
| ) |
| } |
| |
| fn with_task_impl<Ctxt: DepContext<DepKind = K>, A, R>( |
| &self, |
| key: DepNode<K>, |
| cx: Ctxt, |
| arg: A, |
| no_tcx: bool, |
| task: fn(Ctxt, A) -> R, |
| create_task: fn(DepNode<K>) -> Option<TaskDeps<K>>, |
| finish_task_and_alloc_depnode: fn( |
| &CurrentDepGraph<K>, |
| DepNode<K>, |
| Fingerprint, |
| Option<TaskDeps<K>>, |
| ) -> DepNodeIndex, |
| hash_result: impl FnOnce(&mut Ctxt::StableHashingContext, &R) -> Option<Fingerprint>, |
| ) -> (R, DepNodeIndex) { |
| if let Some(ref data) = self.data { |
| let task_deps = create_task(key).map(Lock::new); |
| |
| // In incremental mode, hash the result of the task. We don't |
| // do anything with the hash yet, but we are computing it |
| // anyway so that |
| // - we make sure that the infrastructure works and |
| // - we can get an idea of the runtime cost. |
| let mut hcx = cx.create_stable_hashing_context(); |
| |
| let result = if no_tcx { |
| task(cx, arg) |
| } else { |
| K::with_deps(task_deps.as_ref(), || task(cx, arg)) |
| }; |
| |
| let current_fingerprint = hash_result(&mut hcx, &result); |
| |
| let dep_node_index = finish_task_and_alloc_depnode( |
| &data.current, |
| key, |
| current_fingerprint.unwrap_or(Fingerprint::ZERO), |
| task_deps.map(|lock| lock.into_inner()), |
| ); |
| |
| let print_status = cfg!(debug_assertions) && cx.debug_dep_tasks(); |
| |
| // Determine the color of the new DepNode. |
| if let Some(prev_index) = data.previous.node_to_index_opt(&key) { |
| let prev_fingerprint = data.previous.fingerprint_by_index(prev_index); |
| |
| let color = if let Some(current_fingerprint) = current_fingerprint { |
| if current_fingerprint == prev_fingerprint { |
| if print_status { |
| eprintln!("[task::green] {:?}", key); |
| } |
| DepNodeColor::Green(dep_node_index) |
| } else { |
| if print_status { |
| eprintln!("[task::red] {:?}", key); |
| } |
| DepNodeColor::Red |
| } |
| } else { |
| if print_status { |
| eprintln!("[task::unknown] {:?}", key); |
| } |
| // Mark the node as Red if we can't hash the result |
| DepNodeColor::Red |
| }; |
| |
| debug_assert!( |
| data.colors.get(prev_index).is_none(), |
| "DepGraph::with_task() - Duplicate DepNodeColor \ |
| insertion for {:?}", |
| key |
| ); |
| |
| data.colors.insert(prev_index, color); |
| } else { |
| if print_status { |
| eprintln!("[task::new] {:?}", key); |
| } |
| } |
| |
| (result, dep_node_index) |
| } else { |
| (task(cx, arg), self.next_virtual_depnode_index()) |
| } |
| } |
| |
| /// Executes something within an "anonymous" task, that is, a task the |
| /// `DepNode` of which is determined by the list of inputs it read from. |
| pub fn with_anon_task<OP, R>(&self, dep_kind: K, op: OP) -> (R, DepNodeIndex) |
| where |
| OP: FnOnce() -> R, |
| { |
| if let Some(ref data) = self.data { |
| let task_deps = Lock::new(TaskDeps::default()); |
| |
| let result = K::with_deps(Some(&task_deps), op); |
| let task_deps = task_deps.into_inner(); |
| |
| let dep_node_index = data.current.complete_anon_task(dep_kind, task_deps); |
| (result, dep_node_index) |
| } else { |
| (op(), self.next_virtual_depnode_index()) |
| } |
| } |
| |
| /// Executes something within an "eval-always" task which is a task |
| /// that runs whenever anything changes. |
| pub fn with_eval_always_task<Ctxt: DepContext<DepKind = K>, A, R>( |
| &self, |
| key: DepNode<K>, |
| cx: Ctxt, |
| arg: A, |
| task: fn(Ctxt, A) -> R, |
| hash_result: impl FnOnce(&mut Ctxt::StableHashingContext, &R) -> Option<Fingerprint>, |
| ) -> (R, DepNodeIndex) { |
| self.with_task_impl( |
| key, |
| cx, |
| arg, |
| false, |
| task, |
| |_| None, |
| |data, key, fingerprint, _| data.alloc_node(key, smallvec![], fingerprint), |
| hash_result, |
| ) |
| } |
| |
| #[inline] |
| pub fn read(&self, v: DepNode<K>) { |
| if let Some(ref data) = self.data { |
| let map = data.current.node_to_node_index.get_shard_by_value(&v).lock(); |
| if let Some(dep_node_index) = map.get(&v).copied() { |
| std::mem::drop(map); |
| data.read_index(dep_node_index); |
| } else { |
| panic!("DepKind {:?} should be pre-allocated but isn't.", v.kind) |
| } |
| } |
| } |
| |
| #[inline] |
| pub fn read_index(&self, dep_node_index: DepNodeIndex) { |
| if let Some(ref data) = self.data { |
| data.read_index(dep_node_index); |
| } |
| } |
| |
| #[inline] |
| pub fn dep_node_index_of(&self, dep_node: &DepNode<K>) -> DepNodeIndex { |
| self.data |
| .as_ref() |
| .unwrap() |
| .current |
| .node_to_node_index |
| .get_shard_by_value(dep_node) |
| .lock() |
| .get(dep_node) |
| .cloned() |
| .unwrap() |
| } |
| |
| #[inline] |
| pub fn dep_node_exists(&self, dep_node: &DepNode<K>) -> bool { |
| if let Some(ref data) = self.data { |
| data.current |
| .node_to_node_index |
| .get_shard_by_value(&dep_node) |
| .lock() |
| .contains_key(dep_node) |
| } else { |
| false |
| } |
| } |
| |
| #[inline] |
| pub fn fingerprint_of(&self, dep_node_index: DepNodeIndex) -> Fingerprint { |
| let data = self.data.as_ref().expect("dep graph enabled").current.data.lock(); |
| data[dep_node_index].fingerprint |
| } |
| |
| pub fn prev_fingerprint_of(&self, dep_node: &DepNode<K>) -> Option<Fingerprint> { |
| self.data.as_ref().unwrap().previous.fingerprint_of(dep_node) |
| } |
| |
| #[inline] |
| pub fn prev_dep_node_index_of(&self, dep_node: &DepNode<K>) -> SerializedDepNodeIndex { |
| self.data.as_ref().unwrap().previous.node_to_index(dep_node) |
| } |
| |
| /// Checks whether a previous work product exists for `v` and, if |
| /// so, return the path that leads to it. Used to skip doing work. |
| pub fn previous_work_product(&self, v: &WorkProductId) -> Option<WorkProduct> { |
| self.data.as_ref().and_then(|data| data.previous_work_products.get(v).cloned()) |
| } |
| |
| /// Access the map of work-products created during the cached run. Only |
| /// used during saving of the dep-graph. |
| pub fn previous_work_products(&self) -> &FxHashMap<WorkProductId, WorkProduct> { |
| &self.data.as_ref().unwrap().previous_work_products |
| } |
| |
| #[inline(always)] |
| pub fn register_dep_node_debug_str<F>(&self, dep_node: DepNode<K>, debug_str_gen: F) |
| where |
| F: FnOnce() -> String, |
| { |
| let dep_node_debug = &self.data.as_ref().unwrap().dep_node_debug; |
| |
| if dep_node_debug.borrow().contains_key(&dep_node) { |
| return; |
| } |
| let debug_str = debug_str_gen(); |
| dep_node_debug.borrow_mut().insert(dep_node, debug_str); |
| } |
| |
| pub fn dep_node_debug_str(&self, dep_node: DepNode<K>) -> Option<String> { |
| self.data.as_ref()?.dep_node_debug.borrow().get(&dep_node).cloned() |
| } |
| |
| pub fn edge_deduplication_data(&self) -> Option<(u64, u64)> { |
| if cfg!(debug_assertions) { |
| let current_dep_graph = &self.data.as_ref().unwrap().current; |
| |
| Some(( |
| current_dep_graph.total_read_count.load(Relaxed), |
| current_dep_graph.total_duplicate_read_count.load(Relaxed), |
| )) |
| } else { |
| None |
| } |
| } |
| |
| pub fn serialize(&self) -> SerializedDepGraph<K> { |
| let data = self.data.as_ref().unwrap().current.data.lock(); |
| |
| let fingerprints: IndexVec<SerializedDepNodeIndex, _> = |
| data.iter().map(|d| d.fingerprint).collect(); |
| let nodes: IndexVec<SerializedDepNodeIndex, _> = data.iter().map(|d| d.node).collect(); |
| |
| let total_edge_count: usize = data.iter().map(|d| d.edges.len()).sum(); |
| |
| let mut edge_list_indices = IndexVec::with_capacity(nodes.len()); |
| let mut edge_list_data = Vec::with_capacity(total_edge_count); |
| |
| for (current_dep_node_index, edges) in data.iter_enumerated().map(|(i, d)| (i, &d.edges)) { |
| let start = edge_list_data.len() as u32; |
| // This should really just be a memcpy :/ |
| edge_list_data.extend(edges.iter().map(|i| SerializedDepNodeIndex::new(i.index()))); |
| let end = edge_list_data.len() as u32; |
| |
| debug_assert_eq!(current_dep_node_index.index(), edge_list_indices.len()); |
| edge_list_indices.push((start, end)); |
| } |
| |
| debug_assert!(edge_list_data.len() <= u32::MAX as usize); |
| debug_assert_eq!(edge_list_data.len(), total_edge_count); |
| |
| SerializedDepGraph { nodes, fingerprints, edge_list_indices, edge_list_data } |
| } |
| |
| pub fn node_color(&self, dep_node: &DepNode<K>) -> Option<DepNodeColor> { |
| if let Some(ref data) = self.data { |
| if let Some(prev_index) = data.previous.node_to_index_opt(dep_node) { |
| return data.colors.get(prev_index); |
| } else { |
| // This is a node that did not exist in the previous compilation |
| // session, so we consider it to be red. |
| return Some(DepNodeColor::Red); |
| } |
| } |
| |
| None |
| } |
| |
| /// Try to read a node index for the node dep_node. |
| /// A node will have an index, when it's already been marked green, or when we can mark it |
| /// green. This function will mark the current task as a reader of the specified node, when |
| /// a node index can be found for that node. |
| pub fn try_mark_green_and_read<Ctxt: DepContext<DepKind = K>>( |
| &self, |
| tcx: Ctxt, |
| dep_node: &DepNode<K>, |
| ) -> Option<(SerializedDepNodeIndex, DepNodeIndex)> { |
| self.try_mark_green(tcx, dep_node).map(|(prev_index, dep_node_index)| { |
| debug_assert!(self.is_green(&dep_node)); |
| self.read_index(dep_node_index); |
| (prev_index, dep_node_index) |
| }) |
| } |
| |
| pub fn try_mark_green<Ctxt: DepContext<DepKind = K>>( |
| &self, |
| tcx: Ctxt, |
| dep_node: &DepNode<K>, |
| ) -> Option<(SerializedDepNodeIndex, DepNodeIndex)> { |
| debug_assert!(!dep_node.kind.is_eval_always()); |
| |
| // Return None if the dep graph is disabled |
| let data = self.data.as_ref()?; |
| |
| // Return None if the dep node didn't exist in the previous session |
| let prev_index = data.previous.node_to_index_opt(dep_node)?; |
| |
| match data.colors.get(prev_index) { |
| Some(DepNodeColor::Green(dep_node_index)) => Some((prev_index, dep_node_index)), |
| Some(DepNodeColor::Red) => None, |
| None => { |
| // This DepNode and the corresponding query invocation existed |
| // in the previous compilation session too, so we can try to |
| // mark it as green by recursively marking all of its |
| // dependencies green. |
| self.try_mark_previous_green(tcx, data, prev_index, &dep_node) |
| .map(|dep_node_index| (prev_index, dep_node_index)) |
| } |
| } |
| } |
| |
| /// Try to mark a dep-node which existed in the previous compilation session as green. |
| fn try_mark_previous_green<Ctxt: DepContext<DepKind = K>>( |
| &self, |
| tcx: Ctxt, |
| data: &DepGraphData<K>, |
| prev_dep_node_index: SerializedDepNodeIndex, |
| dep_node: &DepNode<K>, |
| ) -> Option<DepNodeIndex> { |
| debug!("try_mark_previous_green({:?}) - BEGIN", dep_node); |
| |
| #[cfg(not(parallel_compiler))] |
| { |
| debug_assert!( |
| !data |
| .current |
| .node_to_node_index |
| .get_shard_by_value(dep_node) |
| .lock() |
| .contains_key(dep_node) |
| ); |
| debug_assert!(data.colors.get(prev_dep_node_index).is_none()); |
| } |
| |
| // We never try to mark eval_always nodes as green |
| debug_assert!(!dep_node.kind.is_eval_always()); |
| |
| debug_assert_eq!(data.previous.index_to_node(prev_dep_node_index), *dep_node); |
| |
| let prev_deps = data.previous.edge_targets_from(prev_dep_node_index); |
| |
| let mut current_deps = SmallVec::new(); |
| |
| for &dep_dep_node_index in prev_deps { |
| let dep_dep_node_color = data.colors.get(dep_dep_node_index); |
| |
| match dep_dep_node_color { |
| Some(DepNodeColor::Green(node_index)) => { |
| // This dependency has been marked as green before, we are |
| // still fine and can continue with checking the other |
| // dependencies. |
| debug!( |
| "try_mark_previous_green({:?}) --- found dependency {:?} to \ |
| be immediately green", |
| dep_node, |
| data.previous.index_to_node(dep_dep_node_index) |
| ); |
| current_deps.push(node_index); |
| } |
| Some(DepNodeColor::Red) => { |
| // We found a dependency the value of which has changed |
| // compared to the previous compilation session. We cannot |
| // mark the DepNode as green and also don't need to bother |
| // with checking any of the other dependencies. |
| debug!( |
| "try_mark_previous_green({:?}) - END - dependency {:?} was \ |
| immediately red", |
| dep_node, |
| data.previous.index_to_node(dep_dep_node_index) |
| ); |
| return None; |
| } |
| None => { |
| let dep_dep_node = &data.previous.index_to_node(dep_dep_node_index); |
| |
| // We don't know the state of this dependency. If it isn't |
| // an eval_always node, let's try to mark it green recursively. |
| if !dep_dep_node.kind.is_eval_always() { |
| debug!( |
| "try_mark_previous_green({:?}) --- state of dependency {:?} \ |
| is unknown, trying to mark it green", |
| dep_node, dep_dep_node |
| ); |
| |
| let node_index = self.try_mark_previous_green( |
| tcx, |
| data, |
| dep_dep_node_index, |
| dep_dep_node, |
| ); |
| if let Some(node_index) = node_index { |
| debug!( |
| "try_mark_previous_green({:?}) --- managed to MARK \ |
| dependency {:?} as green", |
| dep_node, dep_dep_node |
| ); |
| current_deps.push(node_index); |
| continue; |
| } |
| } |
| |
| // We failed to mark it green, so we try to force the query. |
| debug!( |
| "try_mark_previous_green({:?}) --- trying to force \ |
| dependency {:?}", |
| dep_node, dep_dep_node |
| ); |
| if tcx.try_force_from_dep_node(dep_dep_node) { |
| let dep_dep_node_color = data.colors.get(dep_dep_node_index); |
| |
| match dep_dep_node_color { |
| Some(DepNodeColor::Green(node_index)) => { |
| debug!( |
| "try_mark_previous_green({:?}) --- managed to \ |
| FORCE dependency {:?} to green", |
| dep_node, dep_dep_node |
| ); |
| current_deps.push(node_index); |
| } |
| Some(DepNodeColor::Red) => { |
| debug!( |
| "try_mark_previous_green({:?}) - END - \ |
| dependency {:?} was red after forcing", |
| dep_node, dep_dep_node |
| ); |
| return None; |
| } |
| None => { |
| if !tcx.has_errors_or_delayed_span_bugs() { |
| panic!( |
| "try_mark_previous_green() - Forcing the DepNode \ |
| should have set its color" |
| ) |
| } else { |
| // If the query we just forced has resulted in |
| // some kind of compilation error, we cannot rely on |
| // the dep-node color having been properly updated. |
| // This means that the query system has reached an |
| // invalid state. We let the compiler continue (by |
| // returning `None`) so it can emit error messages |
| // and wind down, but rely on the fact that this |
| // invalid state will not be persisted to the |
| // incremental compilation cache because of |
| // compilation errors being present. |
| debug!( |
| "try_mark_previous_green({:?}) - END - \ |
| dependency {:?} resulted in compilation error", |
| dep_node, dep_dep_node |
| ); |
| return None; |
| } |
| } |
| } |
| } else { |
| // The DepNode could not be forced. |
| debug!( |
| "try_mark_previous_green({:?}) - END - dependency {:?} \ |
| could not be forced", |
| dep_node, dep_dep_node |
| ); |
| return None; |
| } |
| } |
| } |
| } |
| |
| // If we got here without hitting a `return` that means that all |
| // dependencies of this DepNode could be marked as green. Therefore we |
| // can also mark this DepNode as green. |
| |
| // There may be multiple threads trying to mark the same dep node green concurrently |
| |
| let dep_node_index = { |
| // Copy the fingerprint from the previous graph, |
| // so we don't have to recompute it |
| let fingerprint = data.previous.fingerprint_by_index(prev_dep_node_index); |
| |
| // We allocating an entry for the node in the current dependency graph and |
| // adding all the appropriate edges imported from the previous graph |
| data.current.intern_node(*dep_node, current_deps, fingerprint) |
| }; |
| |
| // ... emitting any stored diagnostic ... |
| |
| // FIXME: Store the fact that a node has diagnostics in a bit in the dep graph somewhere |
| // Maybe store a list on disk and encode this fact in the DepNodeState |
| let diagnostics = tcx.load_diagnostics(prev_dep_node_index); |
| |
| #[cfg(not(parallel_compiler))] |
| debug_assert!( |
| data.colors.get(prev_dep_node_index).is_none(), |
| "DepGraph::try_mark_previous_green() - Duplicate DepNodeColor \ |
| insertion for {:?}", |
| dep_node |
| ); |
| |
| if unlikely!(!diagnostics.is_empty()) { |
| self.emit_diagnostics(tcx, data, dep_node_index, prev_dep_node_index, diagnostics); |
| } |
| |
| // ... and finally storing a "Green" entry in the color map. |
| // Multiple threads can all write the same color here |
| data.colors.insert(prev_dep_node_index, DepNodeColor::Green(dep_node_index)); |
| |
| debug!("try_mark_previous_green({:?}) - END - successfully marked as green", dep_node); |
| Some(dep_node_index) |
| } |
| |
| /// Atomically emits some loaded diagnostics. |
| /// This may be called concurrently on multiple threads for the same dep node. |
| #[cold] |
| #[inline(never)] |
| fn emit_diagnostics<Ctxt: DepContext<DepKind = K>>( |
| &self, |
| tcx: Ctxt, |
| data: &DepGraphData<K>, |
| dep_node_index: DepNodeIndex, |
| prev_dep_node_index: SerializedDepNodeIndex, |
| diagnostics: Vec<Diagnostic>, |
| ) { |
| let mut emitting = data.emitting_diagnostics.lock(); |
| |
| if data.colors.get(prev_dep_node_index) == Some(DepNodeColor::Green(dep_node_index)) { |
| // The node is already green so diagnostics must have been emitted already |
| return; |
| } |
| |
| if emitting.insert(dep_node_index) { |
| // We were the first to insert the node in the set so this thread |
| // must emit the diagnostics and signal other potentially waiting |
| // threads after. |
| mem::drop(emitting); |
| |
| // Promote the previous diagnostics to the current session. |
| tcx.store_diagnostics(dep_node_index, diagnostics.clone().into()); |
| |
| let handle = tcx.diagnostic(); |
| |
| for diagnostic in diagnostics { |
| handle.emit_diagnostic(&diagnostic); |
| } |
| |
| // Mark the node as green now that diagnostics are emitted |
| data.colors.insert(prev_dep_node_index, DepNodeColor::Green(dep_node_index)); |
| |
| // Remove the node from the set |
| data.emitting_diagnostics.lock().remove(&dep_node_index); |
| |
| // Wake up waiters |
| data.emitting_diagnostics_cond_var.notify_all(); |
| } else { |
| // We must wait for the other thread to finish emitting the diagnostic |
| |
| loop { |
| data.emitting_diagnostics_cond_var.wait(&mut emitting); |
| if data.colors.get(prev_dep_node_index) == Some(DepNodeColor::Green(dep_node_index)) |
| { |
| break; |
| } |
| } |
| } |
| } |
| |
| // Returns true if the given node has been marked as green during the |
| // current compilation session. Used in various assertions |
| pub fn is_green(&self, dep_node: &DepNode<K>) -> bool { |
| self.node_color(dep_node).map(|c| c.is_green()).unwrap_or(false) |
| } |
| |
| // This method loads all on-disk cacheable query results into memory, so |
| // they can be written out to the new cache file again. Most query results |
| // will already be in memory but in the case where we marked something as |
| // green but then did not need the value, that value will never have been |
| // loaded from disk. |
| // |
| // This method will only load queries that will end up in the disk cache. |
| // Other queries will not be executed. |
| pub fn exec_cache_promotions<Ctxt: DepContext<DepKind = K>>(&self, tcx: Ctxt) { |
| let _prof_timer = tcx.profiler().generic_activity("incr_comp_query_cache_promotion"); |
| |
| let data = self.data.as_ref().unwrap(); |
| for prev_index in data.colors.values.indices() { |
| match data.colors.get(prev_index) { |
| Some(DepNodeColor::Green(_)) => { |
| let dep_node = data.previous.index_to_node(prev_index); |
| tcx.try_load_from_on_disk_cache(&dep_node); |
| } |
| None | Some(DepNodeColor::Red) => { |
| // We can skip red nodes because a node can only be marked |
| // as red if the query result was recomputed and thus is |
| // already in memory. |
| } |
| } |
| } |
| } |
| |
| fn next_virtual_depnode_index(&self) -> DepNodeIndex { |
| let index = self.virtual_dep_node_index.fetch_add(1, Relaxed); |
| DepNodeIndex::from_u32(index) |
| } |
| } |
| |
| /// A "work product" is an intermediate result that we save into the |
| /// incremental directory for later re-use. The primary example are |
| /// the object files that we save for each partition at code |
| /// generation time. |
| /// |
| /// Each work product is associated with a dep-node, representing the |
| /// process that produced the work-product. If that dep-node is found |
| /// to be dirty when we load up, then we will delete the work-product |
| /// at load time. If the work-product is found to be clean, then we |
| /// will keep a record in the `previous_work_products` list. |
| /// |
| /// In addition, work products have an associated hash. This hash is |
| /// an extra hash that can be used to decide if the work-product from |
| /// a previous compilation can be re-used (in addition to the dirty |
| /// edges check). |
| /// |
| /// As the primary example, consider the object files we generate for |
| /// each partition. In the first run, we create partitions based on |
| /// the symbols that need to be compiled. For each partition P, we |
| /// hash the symbols in P and create a `WorkProduct` record associated |
| /// with `DepNode::CodegenUnit(P)`; the hash is the set of symbols |
| /// in P. |
| /// |
| /// The next time we compile, if the `DepNode::CodegenUnit(P)` is |
| /// judged to be clean (which means none of the things we read to |
| /// generate the partition were found to be dirty), it will be loaded |
| /// into previous work products. We will then regenerate the set of |
| /// symbols in the partition P and hash them (note that new symbols |
| /// may be added -- for example, new monomorphizations -- even if |
| /// nothing in P changed!). We will compare that hash against the |
| /// previous hash. If it matches up, we can reuse the object file. |
| #[derive(Clone, Debug, RustcEncodable, RustcDecodable)] |
| pub struct WorkProduct { |
| pub cgu_name: String, |
| /// Saved file associated with this CGU. |
| pub saved_file: Option<String>, |
| } |
| |
| #[derive(Clone)] |
| struct DepNodeData<K> { |
| node: DepNode<K>, |
| edges: EdgesVec, |
| fingerprint: Fingerprint, |
| } |
| |
| /// `CurrentDepGraph` stores the dependency graph for the current session. |
| /// It will be populated as we run queries or tasks. |
| /// |
| /// The nodes in it are identified by an index (`DepNodeIndex`). |
| /// The data for each node is stored in its `DepNodeData`, found in the `data` field. |
| /// |
| /// We never remove nodes from the graph: they are only added. |
| /// |
| /// This struct uses two locks internally. The `data` and `node_to_node_index` fields are |
| /// locked separately. Operations that take a `DepNodeIndex` typically just access |
| /// the data field. |
| /// |
| /// The only operation that must manipulate both locks is adding new nodes, in which case |
| /// we first acquire the `node_to_node_index` lock and then, once a new node is to be inserted, |
| /// acquire the lock on `data.` |
| pub(super) struct CurrentDepGraph<K> { |
| data: Lock<IndexVec<DepNodeIndex, DepNodeData<K>>>, |
| node_to_node_index: Sharded<FxHashMap<DepNode<K>, DepNodeIndex>>, |
| |
| /// Used to trap when a specific edge is added to the graph. |
| /// This is used for debug purposes and is only active with `debug_assertions`. |
| #[allow(dead_code)] |
| forbidden_edge: Option<EdgeFilter>, |
| |
| /// Anonymous `DepNode`s are nodes whose IDs we compute from the list of |
| /// their edges. This has the beneficial side-effect that multiple anonymous |
| /// nodes can be coalesced into one without changing the semantics of the |
| /// dependency graph. However, the merging of nodes can lead to a subtle |
| /// problem during red-green marking: The color of an anonymous node from |
| /// the current session might "shadow" the color of the node with the same |
| /// ID from the previous session. In order to side-step this problem, we make |
| /// sure that anonymous `NodeId`s allocated in different sessions don't overlap. |
| /// This is implemented by mixing a session-key into the ID fingerprint of |
| /// each anon node. The session-key is just a random number generated when |
| /// the `DepGraph` is created. |
| anon_id_seed: Fingerprint, |
| |
| /// These are simple counters that are for profiling and |
| /// debugging and only active with `debug_assertions`. |
| total_read_count: AtomicU64, |
| total_duplicate_read_count: AtomicU64, |
| } |
| |
| impl<K: DepKind> CurrentDepGraph<K> { |
| fn new(prev_graph_node_count: usize) -> CurrentDepGraph<K> { |
| use std::time::{SystemTime, UNIX_EPOCH}; |
| |
| let duration = SystemTime::now().duration_since(UNIX_EPOCH).unwrap(); |
| let nanos = duration.as_secs() * 1_000_000_000 + duration.subsec_nanos() as u64; |
| let mut stable_hasher = StableHasher::new(); |
| nanos.hash(&mut stable_hasher); |
| |
| let forbidden_edge = if cfg!(debug_assertions) { |
| match env::var("RUST_FORBID_DEP_GRAPH_EDGE") { |
| Ok(s) => match EdgeFilter::new(&s) { |
| Ok(f) => Some(f), |
| Err(err) => panic!("RUST_FORBID_DEP_GRAPH_EDGE invalid: {}", err), |
| }, |
| Err(_) => None, |
| } |
| } else { |
| None |
| }; |
| |
| // Pre-allocate the dep node structures. We over-allocate a little so |
| // that we hopefully don't have to re-allocate during this compilation |
| // session. The over-allocation is 2% plus a small constant to account |
| // for the fact that in very small crates 2% might not be enough. |
| let new_node_count_estimate = (prev_graph_node_count * 102) / 100 + 200; |
| |
| CurrentDepGraph { |
| data: Lock::new(IndexVec::with_capacity(new_node_count_estimate)), |
| node_to_node_index: Sharded::new(|| { |
| FxHashMap::with_capacity_and_hasher( |
| new_node_count_estimate / sharded::SHARDS, |
| Default::default(), |
| ) |
| }), |
| anon_id_seed: stable_hasher.finish(), |
| forbidden_edge, |
| total_read_count: AtomicU64::new(0), |
| total_duplicate_read_count: AtomicU64::new(0), |
| } |
| } |
| |
| fn complete_task( |
| &self, |
| node: DepNode<K>, |
| task_deps: TaskDeps<K>, |
| fingerprint: Fingerprint, |
| ) -> DepNodeIndex { |
| self.alloc_node(node, task_deps.reads, fingerprint) |
| } |
| |
| fn complete_anon_task(&self, kind: K, task_deps: TaskDeps<K>) -> DepNodeIndex { |
| debug_assert!(!kind.is_eval_always()); |
| |
| let mut hasher = StableHasher::new(); |
| |
| // The dep node indices are hashed here instead of hashing the dep nodes of the |
| // dependencies. These indices may refer to different nodes per session, but this isn't |
| // a problem here because we that ensure the final dep node hash is per session only by |
| // combining it with the per session random number `anon_id_seed`. This hash only need |
| // to map the dependencies to a single value on a per session basis. |
| task_deps.reads.hash(&mut hasher); |
| |
| let target_dep_node = DepNode { |
| kind, |
| |
| // Fingerprint::combine() is faster than sending Fingerprint |
| // through the StableHasher (at least as long as StableHasher |
| // is so slow). |
| hash: self.anon_id_seed.combine(hasher.finish()), |
| }; |
| |
| self.intern_node(target_dep_node, task_deps.reads, Fingerprint::ZERO) |
| } |
| |
| fn alloc_node( |
| &self, |
| dep_node: DepNode<K>, |
| edges: EdgesVec, |
| fingerprint: Fingerprint, |
| ) -> DepNodeIndex { |
| debug_assert!( |
| !self.node_to_node_index.get_shard_by_value(&dep_node).lock().contains_key(&dep_node) |
| ); |
| self.intern_node(dep_node, edges, fingerprint) |
| } |
| |
| fn intern_node( |
| &self, |
| dep_node: DepNode<K>, |
| edges: EdgesVec, |
| fingerprint: Fingerprint, |
| ) -> DepNodeIndex { |
| match self.node_to_node_index.get_shard_by_value(&dep_node).lock().entry(dep_node) { |
| Entry::Occupied(entry) => *entry.get(), |
| Entry::Vacant(entry) => { |
| let mut data = self.data.lock(); |
| let dep_node_index = DepNodeIndex::new(data.len()); |
| data.push(DepNodeData { node: dep_node, edges, fingerprint }); |
| entry.insert(dep_node_index); |
| dep_node_index |
| } |
| } |
| } |
| } |
| |
| impl<K: DepKind> DepGraphData<K> { |
| #[inline(never)] |
| fn read_index(&self, source: DepNodeIndex) { |
| K::read_deps(|task_deps| { |
| if let Some(task_deps) = task_deps { |
| let mut task_deps = task_deps.lock(); |
| let task_deps = &mut *task_deps; |
| if cfg!(debug_assertions) { |
| self.current.total_read_count.fetch_add(1, Relaxed); |
| } |
| |
| // As long as we only have a low number of reads we can avoid doing a hash |
| // insert and potentially allocating/reallocating the hashmap |
| let new_read = if task_deps.reads.len() < TASK_DEPS_READS_CAP { |
| task_deps.reads.iter().all(|other| *other != source) |
| } else { |
| task_deps.read_set.insert(source) |
| }; |
| if new_read { |
| task_deps.reads.push(source); |
| if task_deps.reads.len() == TASK_DEPS_READS_CAP { |
| // Fill `read_set` with what we have so far so we can use the hashset next |
| // time |
| task_deps.read_set.extend(task_deps.reads.iter().copied()); |
| } |
| |
| #[cfg(debug_assertions)] |
| { |
| if let Some(target) = task_deps.node { |
| let data = self.current.data.lock(); |
| if let Some(ref forbidden_edge) = self.current.forbidden_edge { |
| let source = data[source].node; |
| if forbidden_edge.test(&source, &target) { |
| panic!("forbidden edge {:?} -> {:?} created", source, target) |
| } |
| } |
| } |
| } |
| } else if cfg!(debug_assertions) { |
| self.current.total_duplicate_read_count.fetch_add(1, Relaxed); |
| } |
| } |
| }) |
| } |
| } |
| |
| /// The capacity of the `reads` field `SmallVec` |
| const TASK_DEPS_READS_CAP: usize = 8; |
| type EdgesVec = SmallVec<[DepNodeIndex; TASK_DEPS_READS_CAP]>; |
| |
| pub struct TaskDeps<K> { |
| #[cfg(debug_assertions)] |
| node: Option<DepNode<K>>, |
| reads: EdgesVec, |
| read_set: FxHashSet<DepNodeIndex>, |
| phantom_data: PhantomData<DepNode<K>>, |
| } |
| |
| impl<K> Default for TaskDeps<K> { |
| fn default() -> Self { |
| Self { |
| #[cfg(debug_assertions)] |
| node: None, |
| reads: EdgesVec::new(), |
| read_set: FxHashSet::default(), |
| phantom_data: PhantomData, |
| } |
| } |
| } |
| |
| // A data structure that stores Option<DepNodeColor> values as a contiguous |
| // array, using one u32 per entry. |
| struct DepNodeColorMap { |
| values: IndexVec<SerializedDepNodeIndex, AtomicU32>, |
| } |
| |
| const COMPRESSED_NONE: u32 = 0; |
| const COMPRESSED_RED: u32 = 1; |
| const COMPRESSED_FIRST_GREEN: u32 = 2; |
| |
| impl DepNodeColorMap { |
| fn new(size: usize) -> DepNodeColorMap { |
| DepNodeColorMap { values: (0..size).map(|_| AtomicU32::new(COMPRESSED_NONE)).collect() } |
| } |
| |
| #[inline] |
| fn get(&self, index: SerializedDepNodeIndex) -> Option<DepNodeColor> { |
| match self.values[index].load(Ordering::Acquire) { |
| COMPRESSED_NONE => None, |
| COMPRESSED_RED => Some(DepNodeColor::Red), |
| value => { |
| Some(DepNodeColor::Green(DepNodeIndex::from_u32(value - COMPRESSED_FIRST_GREEN))) |
| } |
| } |
| } |
| |
| fn insert(&self, index: SerializedDepNodeIndex, color: DepNodeColor) { |
| self.values[index].store( |
| match color { |
| DepNodeColor::Red => COMPRESSED_RED, |
| DepNodeColor::Green(index) => index.as_u32() + COMPRESSED_FIRST_GREEN, |
| }, |
| Ordering::Release, |
| ) |
| } |
| } |
