5 files changed, 63 insertions, 64 deletions

diff --git a/Cargo.lock b/Cargo.lock
index 4b94aa8a3..f45085921 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -40,20 +40,6 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
 name = "backtrace"
-version = "0.2.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-dependencies = [
- "backtrace-sys 0.1.31 (registry+https://github.com/rust-lang/crates.io-index)",
- "cfg-if 0.1.9 (registry+https://github.com/rust-lang/crates.io-index)",
- "dbghelp-sys 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "kernel32-sys 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
- "libc 0.2.62 (registry+https://github.com/rust-lang/crates.io-index)",
- "rustc-demangle 0.1.16 (registry+https://github.com/rust-lang/crates.io-index)",
- "winapi 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)",
-]
-
-[[package]]
-name = "backtrace"
 version = "0.3.34"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
@@ -288,15 +274,6 @@ dependencies = [
 ]
 
 [[package]]
-name = "cpuprofiler"
-version = "0.0.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-dependencies = [
- "error-chain 0.5.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "lazy_static 0.2.11 (registry+https://github.com/rust-lang/crates.io-index)",
-]
-
-[[package]]
 name = "crossbeam"
 version = "0.7.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -366,15 +343,6 @@ dependencies = [
 ]
 
 [[package]]
-name = "dbghelp-sys"
-version = "0.2.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-dependencies = [
- "winapi 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)",
- "winapi-build 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
-]
-
-[[package]]
 name = "derive-new"
 version = "0.5.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -440,14 +408,6 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
 name = "error-chain"
-version = "0.5.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-dependencies = [
- "backtrace 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)",
-]
-
-[[package]]
-name = "error-chain"
 version = "0.12.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
@@ -768,11 +728,6 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
 name = "lazy_static"
-version = "0.2.11"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-
-[[package]]
-name = "lazy_static"
 version = "1.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
@@ -1351,7 +1306,6 @@ name = "ra_prof"
 version = "0.1.0"
 dependencies = [
  "backtrace 0.3.34 (registry+https://github.com/rust-lang/crates.io-index)",
- "cpuprofiler 0.0.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "itertools 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "jemalloc-ctl 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "jemallocator 0.3.2 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -2199,7 +2153,6 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum arrayvec 0.4.11 (registry+https://github.com/rust-lang/crates.io-index)" = "b8d73f9beda665eaa98ab9e4f7442bd4e7de6652587de55b2525e52e29c1b0ba"
 "checksum atty 0.2.13 (registry+https://github.com/rust-lang/crates.io-index)" = "1803c647a3ec87095e7ae7acfca019e98de5ec9a7d01343f611cf3152ed71a90"
 "checksum autocfg 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)" = "22130e92352b948e7e82a49cdb0aa94f2211761117f29e052dd397c1ac33542b"
-"checksum backtrace 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)" = "346d7644f0b5f9bc73082d3b2236b69a05fd35cce0cfa3724e184e6a5c9e2a2f"
 "checksum backtrace 0.3.34 (registry+https://github.com/rust-lang/crates.io-index)" = "b5164d292487f037ece34ec0de2fcede2faa162f085dd96d2385ab81b12765ba"
 "checksum backtrace-sys 0.1.31 (registry+https://github.com/rust-lang/crates.io-index)" = "82a830b4ef2d1124a711c71d263c5abdc710ef8e907bd508c88be475cebc422b"
 "checksum base64 0.10.1 (registry+https://github.com/rust-lang/crates.io-index)" = "0b25d992356d2eb0ed82172f5248873db5560c4721f564b13cb5193bda5e668e"
@@ -2226,7 +2179,6 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum clicolors-control 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)" = "73abfd4c73d003a674ce5d2933fca6ce6c42480ea84a5ffe0a2dc39ed56300f9"
 "checksum cloudabi 0.0.3 (registry+https://github.com/rust-lang/crates.io-index)" = "ddfc5b9aa5d4507acaf872de71051dfd0e309860e88966e1051e462a077aac4f"
 "checksum console 0.7.7 (registry+https://github.com/rust-lang/crates.io-index)" = "8ca57c2c14b8a2bf3105bc9d15574aad80babf6a9c44b1058034cdf8bd169628"
-"checksum cpuprofiler 0.0.3 (registry+https://github.com/rust-lang/crates.io-index)" = "33f07976bb6821459632d7a18d97ccca005cb5c552f251f822c7c1781c1d7035"
 "checksum crossbeam 0.7.2 (registry+https://github.com/rust-lang/crates.io-index)" = "2d818a4990769aac0c7ff1360e233ef3a41adcb009ebb2036bf6915eb0f6b23c"
 "checksum crossbeam-channel 0.3.9 (registry+https://github.com/rust-lang/crates.io-index)" = "c8ec7fcd21571dc78f96cc96243cab8d8f035247c3efd16c687be154c3fa9efa"
 "checksum crossbeam-deque 0.6.3 (registry+https://github.com/rust-lang/crates.io-index)" = "05e44b8cf3e1a625844d1750e1f7820da46044ff6d28f4d43e455ba3e5bb2c13"
@@ -2234,7 +2186,6 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum crossbeam-epoch 0.7.2 (registry+https://github.com/rust-lang/crates.io-index)" = "fedcd6772e37f3da2a9af9bf12ebe046c0dfe657992377b4df982a2b54cd37a9"
 "checksum crossbeam-queue 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "7c979cd6cfe72335896575c6b5688da489e420d36a27a0b9eb0c73db574b4a4b"
 "checksum crossbeam-utils 0.6.6 (registry+https://github.com/rust-lang/crates.io-index)" = "04973fa96e96579258a5091af6003abde64af786b860f18622b82e026cca60e6"
-"checksum dbghelp-sys 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "97590ba53bcb8ac28279161ca943a924d1fd4a8fb3fa63302591647c4fc5b850"
 "checksum derive-new 0.5.7 (registry+https://github.com/rust-lang/crates.io-index)" = "c3fd04571b29c91cfbe1e7c9a228e069ac8635f180ffb4ccd6a6907617ee8bb0"
 "checksum deunicode 0.4.3 (registry+https://github.com/rust-lang/crates.io-index)" = "850878694b7933ca4c9569d30a34b55031b9b139ee1fc7b94a527c4ef960d690"
 "checksum difference 2.0.0 (registry+https://github.com/rust-lang/crates.io-index)" = "524cbf6897b527295dff137cec09ecf3a05f4fddffd7dfcd1585403449e74198"
@@ -2246,7 +2197,6 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum ena 0.13.0 (registry+https://github.com/rust-lang/crates.io-index)" = "3dc01d68e08ca384955a3aeba9217102ca1aa85b6e168639bf27739f1d749d87"
 "checksum encode_unicode 0.3.5 (registry+https://github.com/rust-lang/crates.io-index)" = "90b2c9496c001e8cb61827acdefad780795c42264c137744cae6f7d9e3450abd"
 "checksum error-chain 0.12.1 (registry+https://github.com/rust-lang/crates.io-index)" = "3ab49e9dcb602294bc42f9a7dfc9bc6e936fca4418ea300dbfb84fe16de0b7d9"
-"checksum error-chain 0.5.0 (registry+https://github.com/rust-lang/crates.io-index)" = "bd5c82c815138e278b8dcdeffc49f27ea6ffb528403e9dea4194f2e3dd40b143"
 "checksum failure 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)" = "795bd83d3abeb9220f257e597aa0080a508b27533824adf336529648f6abf7e2"
 "checksum failure_derive 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)" = "ea1063915fd7ef4309e222a5a07cf9c319fb9c7836b1f89b85458672dbb127e1"
 "checksum fake-simd 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "e88a8acf291dafb59c2d96e8f59828f3838bb1a70398823ade51a84de6a6deed"
@@ -2284,7 +2234,6 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum join_to_string 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)" = "4dc7a5290e8c2606ce2be49f456d50f69173cb96d1541e4f66e34ac8b331a98f"
 "checksum kernel32-sys 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)" = "7507624b29483431c0ba2d82aece8ca6cdba9382bff4ddd0f7490560c056098d"
 "checksum lalrpop-intern 0.15.1 (registry+https://github.com/rust-lang/crates.io-index)" = "cc4fd87be4a815fd373e02773983940f0d75fb26fde8c098e9e45f7af03154c0"
-"checksum lazy_static 0.2.11 (registry+https://github.com/rust-lang/crates.io-index)" = "76f033c7ad61445c5b347c7382dd1237847eb1bce590fe50365dcb33d546be73"
 "checksum lazy_static 1.3.0 (registry+https://github.com/rust-lang/crates.io-index)" = "bc5729f27f159ddd61f4df6228e827e86643d4d3e7c32183cb30a1c08f604a14"
 "checksum lazycell 1.2.1 (registry+https://github.com/rust-lang/crates.io-index)" = "b294d6fa9ee409a054354afc4352b0b9ef7ca222c69b8812cbea9e7d2bf3783f"
 "checksum libc 0.2.62 (registry+https://github.com/rust-lang/crates.io-index)" = "34fcd2c08d2f832f376f4173a231990fa5aef4e99fb569867318a227ef4c06ba"
diff --git a/crates/ra_cli/Cargo.toml b/crates/ra_cli/Cargo.toml
index 970cb1f82..9c2ebdad2 100644
--- a/crates/ra_cli/Cargo.toml
+++ b/crates/ra_cli/Cargo.toml
@@ -18,5 +18,5 @@ ra_db = { path = "../ra_db" }
 
 [dependencies.ra_prof]
 path = "../ra_prof"
-# features = [ "cpuprofiler" ]
+# features = [ "cpu_profiler" ]
 # features = [ "jemalloc" ]
diff --git a/crates/ra_prof/Cargo.toml b/crates/ra_prof/Cargo.toml
index 84dcc9813..d35adeeeb 100644
--- a/crates/ra_prof/Cargo.toml
+++ b/crates/ra_prof/Cargo.toml
@@ -9,10 +9,9 @@ publish = false
 once_cell = "0.2.0"
 itertools = "0.8.0"
 backtrace = "0.3.28"
-cpuprofiler = { version = "0.0.3", optional = true }
 jemallocator = { version = "0.3.2", optional = true }
 jemalloc-ctl = { version = "0.3.2", optional = true }
 
-
 [features]
 jemalloc = [ "jemallocator", "jemalloc-ctl" ]
+cpu_profiler = []
diff --git a/crates/ra_prof/src/google_cpu_profiler.rs b/crates/ra_prof/src/google_cpu_profiler.rs
new file mode 100644
index 000000000..db865c65b
--- /dev/null
+++ b/crates/ra_prof/src/google_cpu_profiler.rs
@@ -0,0 +1,39 @@
+//! https://github.com/gperftools/gperftools
+
+use std::{
+    ffi::CString,
+    os::raw::c_char,
+    path::Path,
+    sync::atomic::{AtomicUsize, Ordering},
+};
+
+#[link(name = "profiler")]
+#[allow(non_snake_case)]
+extern "C" {
+    fn ProfilerStart(fname: *const c_char) -> i32;
+    fn ProfilerStop();
+}
+
+static PROFILER_STATE: AtomicUsize = AtomicUsize::new(OFF);
+const OFF: usize = 0;
+const ON: usize = 1;
+const PENDING: usize = 2;
+
+pub fn start(path: &Path) {
+    if PROFILER_STATE.compare_and_swap(OFF, PENDING, Ordering::SeqCst) != OFF {
+        panic!("profiler already started");
+    }
+    let path = CString::new(path.display().to_string()).unwrap();
+    if unsafe { ProfilerStart(path.as_ptr()) } == 0 {
+        panic!("profiler failed to start")
+    }
+    assert!(PROFILER_STATE.compare_and_swap(PENDING, ON, Ordering::SeqCst) == PENDING);
+}
+
+pub fn stop() {
+    if PROFILER_STATE.compare_and_swap(ON, PENDING, Ordering::SeqCst) != ON {
+        panic!("profiler is not started")
+    }
+    unsafe { ProfilerStop() };
+    assert!(PROFILER_STATE.compare_and_swap(PENDING, OFF, Ordering::SeqCst) == PENDING);
+}
diff --git a/crates/ra_prof/src/lib.rs b/crates/ra_prof/src/lib.rs
index 6d44fef33..d32a289be 100644
--- a/crates/ra_prof/src/lib.rs
+++ b/crates/ra_prof/src/lib.rs
@@ -1,4 +1,6 @@
 mod memory_usage;
+#[cfg(feature = "cpu_profiler")]
+mod google_cpu_profiler;
 
 use std::{
     cell::RefCell,
@@ -268,25 +270,35 @@ impl Drop for Scope {
     }
 }
 
-/// A wrapper around https://github.com/AtheMathmo/cpuprofiler
+/// A wrapper around google_cpu_profiler.
 ///
-/// It can be used to capture sampling profiles of sections of code.
-/// It is not exactly out-of-the-box, as it relies on gperftools.
-/// See the docs for the crate for more!
+/// Usage:
+/// 1. Install gpref_tools (https://github.com/gperftools/gperftools), probably packaged with your Linux distro.
+/// 2. Build with `cpu_profiler` feature.
+/// 3. Tun the code, the *raw* output would be in the `./out.profile` file.
+/// 4. Install pprof for visualization (https://github.com/google/pprof).
+/// 5. Use something like `pprof -svg target/release/ra_cli ./out.profile` to see the results.
+///
+/// For example, here's how I run profiling on NixOS:
+///
+/// ```bash
+/// $ nix-shell -p gperftools --run \
+///     'cargo run --release -p ra_cli -- parse < ~/projects/rustbench/parser.rs > /dev/null'
+/// ```
 #[derive(Debug)]
 pub struct CpuProfiler {
     _private: (),
 }
 
 pub fn cpu_profiler() -> CpuProfiler {
-    #[cfg(feature = "cpuprofiler")]
+    #[cfg(feature = "cpu_profiler")]
     {
-        cpuprofiler::PROFILER.lock().unwrap().start("./out.profile").unwrap();
+        google_cpu_profiler::start("./out.profile".as_ref())
     }
 
-    #[cfg(not(feature = "cpuprofiler"))]
+    #[cfg(not(feature = "cpu_profiler"))]
     {
-        eprintln!("cpuprofiler feature is disabled")
+        eprintln!("cpu_profiler feature is disabled")
     }
 
     CpuProfiler { _private: () }
@@ -294,9 +306,9 @@ pub fn cpu_profiler() -> CpuProfiler {
 
 impl Drop for CpuProfiler {
     fn drop(&mut self) {
-        #[cfg(feature = "cpuprofiler")]
+        #[cfg(feature = "cpu_profiler")]
         {
-            cpuprofiler::PROFILER.lock().unwrap().stop().unwrap();
+            google_cpu_profiler::stop()
         }
     }
 }