c-p-a: add counters to control-plane-agent (#1630)

Issue #1616 describes the need to add event counters to the
`control-plane-agent` task. In particular, it's desirable to have
counters of each IPC event and MGS message received by the
`control-plane-agent` task. This commit uses the ringbuf counters added
in #1621 and the `#[count(children)]` attribute added in this branch to
generate counters from `control-plane-agent`'s MGS message events.

lib/ringbuf/macros/src/lib.rs

@@ -6,8 +6,11 @@ extern crate proc_macro;
 use proc_macro::TokenStream;
 use proc_macro2::{Ident, Span};
 use quote::{quote, ToTokens};
-use syn::{parse_macro_input, DeriveInput, parse::{Parse, ParseStream}};
-
+use syn::{
+    parse::{Parse, ParseStream},
+    parse_macro_input, DeriveInput,
+};
+
 /// Derives an implementation of the `ringbuf::Count` trait for the annotated
 /// `enum` type.
 ///
@@ -69,10 +72,10 @@ fn gen_count_impl(input: DeriveInput) -> Result<impl ToTokens, syn::Error> {
                 VariantAttr::Skip => {
                     any_skipped = true;
                     continue 'variants;
-                },
+                }
                 VariantAttr::Children => {
                     count_children = Some(attr);
-                },
+                }
             }
         }
 
@@ -131,7 +134,8 @@ fn gen_count_impl(input: DeriveInput) -> Result<impl ToTokens, syn::Error> {
                 #[doc = " has been recorded by this ringbuf."]
                 pub #ident: core::sync::atomic::AtomicU32
             });
-            field_inits.push(quote! { #ident: core::sync::atomic::AtomicU32::new(0) });
+            field_inits
+                .push(quote! { #ident: core::sync::atomic::AtomicU32::new(0) });
         }
     }
 
@@ -201,7 +205,6 @@ impl Parse for VariantAttr {
     }
 }
 
-
 fn counts_ty(ident: &Ident) -> Ident {
     Ident::new(&format!("{ident}Counts"), Span::call_site())
 }

task/control-plane-agent/src/main.rs

@@ -15,7 +15,7 @@ use idol_runtime::{
     ClientError, Leased, LenLimit, NotificationHandler, RequestError,
 };
 use mutable_statics::mutable_statics;
-use ringbuf::{ringbuf, ringbuf_entry};
+use ringbuf::{counted_ringbuf, ringbuf_entry};
 use task_control_plane_agent_api::MAX_INSTALLINATOR_IMAGE_ID_LEN;
 use task_control_plane_agent_api::{
     BarcodeParseError, ControlPlaneAgentError, UartClient, VpdIdentity,
@@ -48,18 +48,30 @@ task_slot!(SYS, sys);
 #[allow(dead_code)] // Not all cases are used by all variants
 #[derive(Debug, Clone, Copy, PartialEq, ringbuf::Count)]
 enum Log {
+    #[count(skip)]
     Empty,
     BarcodeParseError(BarcodeParseError),
     Rx(UdpMetadata),
     SendError(SendError),
+    #[count(children)]
     MgsMessage(MgsMessage),
-    UsartTxFull { remaining: usize },
+    UsartTxFull {
+        remaining: usize,
+    },
     UsartRxOverrun,
-    UsartRxBufferDataDropped { num_bytes: u64 },
-    SerialConsoleSend { buffered: usize },
-    UpdatePartial { bytes_written: u32 },
+    UsartRxBufferDataDropped {
+        num_bytes: u64,
+    },
+    SerialConsoleSend {
+        buffered: usize,
+    },
+    UpdatePartial {
+        bytes_written: u32,
+    },
     UpdateComplete,
-    HostFlashSectorsErased { num_sectors: usize },
+    HostFlashSectorsErased {
+        num_sectors: usize,
+    },
     ExpectedRspTimeout,
     RotReset(SprotError),
     SprotCabooseSize(u32),
@@ -72,7 +84,7 @@ enum Log {
 // `Log` enum above (which itself is only used by our ringbuf logs). The MGS
 // protocol is defined in the `gateway-messages` crate (which is shared with
 // MGS proper and other tools like `sp-sim` in the omicron repository).
-#[derive(Debug, Clone, Copy, PartialEq)]
+#[derive(Debug, Clone, Copy, PartialEq, ringbuf::Count)]
 enum MgsMessage {
     Discovery,
     IgnitionState {