src/librustc_data_structures/profiling.rs

   1 use std::error::Error;
   2 use std::fs;
   3 use std::mem::{self, Discriminant};
   4 use std::path::Path;
   5 use std::process;
   6 use std::sync::Arc;
   7 use std::thread::ThreadId;
   8 use std::u32;
   9
  10 use measureme::StringId;
  11
  12 /// MmapSerializatioSink is faster on macOS and Linux
  13 /// but FileSerializationSink is faster on Windows
  14 #[cfg(not(windows))]
  15 type SerializationSink = measureme::MmapSerializationSink;
  16 #[cfg(windows)]
  17 type SerializationSink = measureme::FileSerializationSink;
  18
  19 type Profiler = measureme::Profiler<SerializationSink>;
  20
  21 pub trait QueryName: Sized + Copy {
  22     fn discriminant(self) -> Discriminant<Self>;
  23     fn as_str(self) -> &'static str;
  24 }
  25
  26 #[derive(Clone, Copy, Debug, PartialEq, Eq, Ord, PartialOrd)]
  27 pub enum ProfileCategory {
  28     Parsing,
  29     Expansion,
  30     TypeChecking,
  31     BorrowChecking,
  32     Codegen,
  33     Linking,
  34     Other,
  35 }
  36
  37 bitflags::bitflags! {
  38     struct EventFilter: u32 {
  39         const GENERIC_ACTIVITIES = 1 << 0;
  40         const QUERY_PROVIDERS    = 1 << 1;
  41         const QUERY_CACHE_HITS   = 1 << 2;
  42         const QUERY_BLOCKED      = 1 << 3;
  43         const INCR_CACHE_LOADS   = 1 << 4;
  44
  45         const DEFAULT = Self::GENERIC_ACTIVITIES.bits |
  46                         Self::QUERY_PROVIDERS.bits |
  47                         Self::QUERY_BLOCKED.bits |
  48                         Self::INCR_CACHE_LOADS.bits;
  49
  50         // empty() and none() aren't const-fns unfortunately
  51         const NONE = 0;
  52         const ALL  = !Self::NONE.bits;
  53     }
  54 }
  55
  56 const EVENT_FILTERS_BY_NAME: &[(&str, EventFilter)] = &[
  57     ("none", EventFilter::NONE),
  58     ("all", EventFilter::ALL),
  59     ("generic-activity", EventFilter::GENERIC_ACTIVITIES),
  60     ("query-provider", EventFilter::QUERY_PROVIDERS),
  61     ("query-cache-hit", EventFilter::QUERY_CACHE_HITS),
  62     ("query-blocked", EventFilter::QUERY_BLOCKED),
  63     ("incr-cache-load", EventFilter::INCR_CACHE_LOADS),
  64 ];
  65
  66 fn thread_id_to_u32(tid: ThreadId) -> u32 {
  67     unsafe { mem::transmute::<ThreadId, u64>(tid) as u32 }
  68 }
  69
  70 /// A reference to the SelfProfiler. It can be cloned and sent across thread
  71 /// boundaries at will.
  72 #[derive(Clone)]
  73 pub struct SelfProfilerRef {
  74     // This field is `None` if self-profiling is disabled for the current
  75     // compilation session.
  76     profiler: Option<Arc<SelfProfiler>>,
  77
  78     // We store the filter mask directly in the reference because that doesn't
  79     // cost anything and allows for filtering with checking if the profiler is
  80     // actually enabled.
  81     event_filter_mask: EventFilter,
  82 }
  83
  84 impl SelfProfilerRef {
  85     pub fn new(profiler: Option<Arc<SelfProfiler>>) -> SelfProfilerRef {
  86         // If there is no SelfProfiler then the filter mask is set to NONE,
  87         // ensuring that nothing ever tries to actually access it.
  88         let event_filter_mask =
  89             profiler.as_ref().map(|p| p.event_filter_mask).unwrap_or(EventFilter::NONE);
  90
  91         SelfProfilerRef { profiler, event_filter_mask }
  92     }
  93
  94     // This shim makes sure that calls only get executed if the filter mask
  95     // lets them pass. It also contains some trickery to make sure that
  96     // code is optimized for non-profiling compilation sessions, i.e. anything
  97     // past the filter check is never inlined so it doesn't clutter the fast
  98     // path.
  99     #[inline(always)]
 100     fn exec<F>(&self, event_filter: EventFilter, f: F) -> TimingGuard<'_>
 101     where
 102         F: for<'a> FnOnce(&'a SelfProfiler) -> TimingGuard<'a>,
 103     {
 104         #[inline(never)]
 105         fn cold_call<F>(profiler_ref: &SelfProfilerRef, f: F) -> TimingGuard<'_>
 106         where
 107             F: for<'a> FnOnce(&'a SelfProfiler) -> TimingGuard<'a>,
 108         {
 109             let profiler = profiler_ref.profiler.as_ref().unwrap();
 110             f(&**profiler)
 111         }
 112
 113         if unlikely!(self.event_filter_mask.contains(event_filter)) {
 114             cold_call(self, f)
 115         } else {
 116             TimingGuard::none()
 117         }
 118     }
 119
 120     /// Start profiling a generic activity. Profiling continues until the
 121     /// TimingGuard returned from this call is dropped.
 122     #[inline(always)]
 123     pub fn generic_activity(&self, event_id: &str) -> TimingGuard<'_> {
 124         self.exec(EventFilter::GENERIC_ACTIVITIES, |profiler| {
 125             let event_id = profiler.profiler.alloc_string(event_id);
 126             TimingGuard::start(profiler, profiler.generic_activity_event_kind, event_id)
 127         })
 128     }
 129
 130     /// Start profiling a query provider. Profiling continues until the
 131     /// TimingGuard returned from this call is dropped.
 132     #[inline(always)]
 133     pub fn query_provider(&self, query_name: impl QueryName) -> TimingGuard<'_> {
 134         self.exec(EventFilter::QUERY_PROVIDERS, |profiler| {
 135             let event_id = SelfProfiler::get_query_name_string_id(query_name);
 136             TimingGuard::start(profiler, profiler.query_event_kind, event_id)
 137         })
 138     }
 139
 140     /// Record a query in-memory cache hit.
 141     #[inline(always)]
 142     pub fn query_cache_hit(&self, query_name: impl QueryName) {
 143         self.instant_query_event(
 144             |profiler| profiler.query_cache_hit_event_kind,
 145             query_name,
 146             EventFilter::QUERY_CACHE_HITS,
 147         );
 148     }
 149
 150     /// Start profiling a query being blocked on a concurrent execution.
 151     /// Profiling continues until the TimingGuard returned from this call is
 152     /// dropped.
 153     #[inline(always)]
 154     pub fn query_blocked(&self, query_name: impl QueryName) -> TimingGuard<'_> {
 155         self.exec(EventFilter::QUERY_BLOCKED, |profiler| {
 156             let event_id = SelfProfiler::get_query_name_string_id(query_name);
 157             TimingGuard::start(profiler, profiler.query_blocked_event_kind, event_id)
 158         })
 159     }
 160
 161     /// Start profiling how long it takes to load a query result from the
 162     /// incremental compilation on-disk cache. Profiling continues until the
 163     /// TimingGuard returned from this call is dropped.
 164     #[inline(always)]
 165     pub fn incr_cache_loading(&self, query_name: impl QueryName) -> TimingGuard<'_> {
 166         self.exec(EventFilter::INCR_CACHE_LOADS, |profiler| {
 167             let event_id = SelfProfiler::get_query_name_string_id(query_name);
 168             TimingGuard::start(profiler, profiler.incremental_load_result_event_kind, event_id)
 169         })
 170     }
 171
 172     #[inline(always)]
 173     fn instant_query_event(
 174         &self,
 175         event_kind: fn(&SelfProfiler) -> StringId,
 176         query_name: impl QueryName,
 177         event_filter: EventFilter,
 178     ) {
 179         drop(self.exec(event_filter, |profiler| {
 180             let event_id = SelfProfiler::get_query_name_string_id(query_name);
 181             let thread_id = thread_id_to_u32(std::thread::current().id());
 182
 183             profiler.profiler.record_instant_event(event_kind(profiler), event_id, thread_id);
 184
 185             TimingGuard::none()
 186         }));
 187     }
 188
 189     pub fn register_queries(&self, f: impl FnOnce(&SelfProfiler)) {
 190         if let Some(profiler) = &self.profiler {
 191             f(&profiler)
 192         }
 193     }
 194 }
 195
 196 pub struct SelfProfiler {
 197     profiler: Profiler,
 198     event_filter_mask: EventFilter,
 199     query_event_kind: StringId,
 200     generic_activity_event_kind: StringId,
 201     incremental_load_result_event_kind: StringId,
 202     query_blocked_event_kind: StringId,
 203     query_cache_hit_event_kind: StringId,
 204 }
 205
 206 impl SelfProfiler {
 207     pub fn new(
 208         output_directory: &Path,
 209         crate_name: Option<&str>,
 210         event_filters: &Option<Vec<String>>,
 211     ) -> Result<SelfProfiler, Box<dyn Error>> {
 212         fs::create_dir_all(output_directory)?;
 213
 214         let crate_name = crate_name.unwrap_or("unknown-crate");
 215         let filename = format!("{}-{}.rustc_profile", crate_name, process::id());
 216         let path = output_directory.join(&filename);
 217         let profiler = Profiler::new(&path)?;
 218
 219         let query_event_kind = profiler.alloc_string("Query");
 220         let generic_activity_event_kind = profiler.alloc_string("GenericActivity");
 221         let incremental_load_result_event_kind = profiler.alloc_string("IncrementalLoadResult");
 222         let query_blocked_event_kind = profiler.alloc_string("QueryBlocked");
 223         let query_cache_hit_event_kind = profiler.alloc_string("QueryCacheHit");
 224
 225         let mut event_filter_mask = EventFilter::empty();
 226
 227         if let Some(ref event_filters) = *event_filters {
 228             let mut unknown_events = vec![];
 229             for item in event_filters {
 230                 if let Some(&(_, mask)) =
 231                     EVENT_FILTERS_BY_NAME.iter().find(|&(name, _)| name == item)
 232                 {
 233                     event_filter_mask |= mask;
 234                 } else {
 235                     unknown_events.push(item.clone());
 236                 }
 237             }
 238
 239             // Warn about any unknown event names
 240             if unknown_events.len() > 0 {
 241                 unknown_events.sort();
 242                 unknown_events.dedup();
 243
 244                 warn!(
 245                     "Unknown self-profiler events specified: {}. Available options are: {}.",
 246                     unknown_events.join(", "),
 247                     EVENT_FILTERS_BY_NAME
 248                         .iter()
 249                         .map(|&(name, _)| name.to_string())
 250                         .collect::<Vec<_>>()
 251                         .join(", ")
 252                 );
 253             }
 254         } else {
 255             event_filter_mask = EventFilter::DEFAULT;
 256         }
 257
 258         Ok(SelfProfiler {
 259             profiler,
 260             event_filter_mask,
 261             query_event_kind,
 262             generic_activity_event_kind,
 263             incremental_load_result_event_kind,
 264             query_blocked_event_kind,
 265             query_cache_hit_event_kind,
 266         })
 267     }
 268
 269     fn get_query_name_string_id(query_name: impl QueryName) -> StringId {
 270         let discriminant =
 271             unsafe { mem::transmute::<Discriminant<_>, u64>(query_name.discriminant()) };
 272
 273         StringId::reserved(discriminant as u32)
 274     }
 275
 276     pub fn register_query_name(&self, query_name: impl QueryName) {
 277         let id = SelfProfiler::get_query_name_string_id(query_name);
 278         self.profiler.alloc_string_with_reserved_id(id, query_name.as_str());
 279     }
 280 }
 281
 282 #[must_use]
 283 pub struct TimingGuard<'a>(Option<measureme::TimingGuard<'a, SerializationSink>>);
 284
 285 impl<'a> TimingGuard<'a> {
 286     #[inline]
 287     pub fn start(
 288         profiler: &'a SelfProfiler,
 289         event_kind: StringId,
 290         event_id: StringId,
 291     ) -> TimingGuard<'a> {
 292         let thread_id = thread_id_to_u32(std::thread::current().id());
 293         let raw_profiler = &profiler.profiler;
 294         let timing_guard =
 295             raw_profiler.start_recording_interval_event(event_kind, event_id, thread_id);
 296         TimingGuard(Some(timing_guard))
 297     }
 298
 299     #[inline]
 300     pub fn none() -> TimingGuard<'a> {
 301         TimingGuard(None)
 302     }
 303 }