Replace arcstr cache with weak hash set of arc str

Cargo.toml

@@ -64,7 +64,6 @@ tui-prompts = "0.5.0"
 unicode-segmentation = "1.11.0"
 unicode-width = "0.1.12"
 serial_test = { version = "3.1.1", features = ["file_locks"] }
-arcstr = { version = "1.2.0", features = ["serde"] }
 clap_complete = "4.5.2"
 regex-cursor = { version = "0.1.4", default-features = false }
 shell-words = "1.1.0"
@@ -78,12 +77,15 @@ libbpf-rs = { version = "0.24.6", optional = true, default-features = false }
 # libbpf-sys exists here because we want to control its features
 libbpf-sys = { version = "1", optional = true, default-features = false }
 libseccomp = { version = "0.3.0", optional = true }
+weak-table = { version = "0.3.2", default-features = false, features = ["ahash"] }
+rand = "0.8.5"
 # tui-prompts = { version = "0.3.11", path = "../../contrib/tui-prompts" }
 # tui-popup = { version = "0.3.0", path = "../../contrib/tui-popup" }
 
 [dev-dependencies]
 assert_cmd = "2.0.14"
 predicates = "3.1.0"
+
 rstest = "0.24.0"
 tracing-test = "0.2.4"
 
@@ -126,3 +128,7 @@ path = "fixtures/empty-argv.rs"
 name = "corrupted-envp"
 path = "fixtures/corrupted-envp.rs"
 
+
+[[bin]]
+name = "exec-stress"
+path = "fixtures/exec-stress.rs"

fixtures/exec-stress.rs

@@ -0,0 +1,33 @@
+use std::ffi::CString;
+
+use nix::unistd::execv;
+use rand::{distributions::Alphanumeric, Rng};
+
+// A stress test.
+// It will exec itself with random strings as arguments for n times
+fn main() {
+  let mut args = std::env::args().skip(1);
+  let n: u64 = args
+    .next()
+    .expect("missing n")
+    .parse()
+    .expect("cannot parse n");
+  if n == 0 {
+    // nix::sys::signal::raise(nix::sys::signal::SIGSTOP);
+    return;
+  }
+  let mut rand_args = vec![
+    CString::new("Hello").unwrap(),
+    CString::new((n - 1).to_string()).unwrap(),
+  ];
+  rand_args.extend((0..10).map(|_| unsafe {
+    CString::from_vec_unchecked(
+      rand::thread_rng()
+        .sample_iter(&Alphanumeric)
+        .take(512)
+        .chain(Some(0))
+        .collect::<Vec<u8>>(),
+    )
+  }));
+  execv(c"/proc/self/exe", &rand_args).unwrap();
+}

src/bpf.rs

@@ -13,12 +13,12 @@ use std::{
   process,
   sync::{
     atomic::{AtomicBool, Ordering},
-    Arc, OnceLock, RwLock,
+    Arc, LazyLock, RwLock,
   },
   time::Duration,
 };
 
-use arcstr::ArcStr;
+use crate::cache::ArcStr;
 use color_eyre::{eyre::eyre, Section};
 use enumflags2::{BitFlag, BitFlags};
 use event::EventStorage;
@@ -818,11 +818,10 @@ fn utf8_lossy_cow_from_bytes_with_nul(data: &[u8]) -> Cow<str> {
 }
 
 fn cached_cow(cow: Cow<str>) -> ArcStr {
-  let cache = CACHE.get_or_init(|| Arc::new(RwLock::new(StringCache::new())));
   match cow {
-    Cow::Borrowed(s) => cache.write().unwrap().get_or_insert(s),
-    Cow::Owned(s) => cache.write().unwrap().get_or_insert_owned(s),
+    Cow::Borrowed(s) => CACHE.write().unwrap().get_or_insert(s),
+    Cow::Owned(s) => CACHE.write().unwrap().get_or_insert_owned(s),
   }
 }
 
-static CACHE: OnceLock<Arc<RwLock<StringCache>>> = OnceLock::new();
+static CACHE: LazyLock<RwLock<StringCache>> = LazyLock::new(|| RwLock::new(StringCache::new()));