From ba0f2dbdf79cc34cbd52bcb4374cbcd8ccea7e8f Mon Sep 17 00:00:00 2001
From: Simonas Kazlauskas <git@kazlauskas.me>
Date: Sun, 14 Jan 2024 04:12:15 +0200
Subject: [PATCH] =?UTF-8?q?client:=20support=20`not(manual-lifetime)`=20mo?=
 =?UTF-8?q?de=20after=20all=E2=80=A6?=
MIME-Version: 1.0
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---
 tracing-tracy/Cargo.toml  |  2 ++
 tracy-client/Cargo.toml   |  3 ++-
 tracy-client/src/state.rs | 33 +++++++++++++++++++++------------
 3 files changed, 25 insertions(+), 13 deletions(-)

diff --git a/tracing-tracy/Cargo.toml b/tracing-tracy/Cargo.toml
index 268782f..f992d4b 100644
--- a/tracing-tracy/Cargo.toml
+++ b/tracing-tracy/Cargo.toml
@@ -46,6 +46,8 @@ only-localhost = ["client/only-localhost"]
 sampling = ["client/sampling"]
 system-tracing = ["client/system-tracing"]
 callstack-inlines = ["client/callstack-inlines"]
+manual-lifetime = ["client/manual-lifetime"]
+delayed-init = ["client/delayed-init"]
 
 [package.metadata.docs.rs]
 rustdoc-args = ["--cfg", "tracing_tracy_docs"]
diff --git a/tracy-client/Cargo.toml b/tracy-client/Cargo.toml
index 16c1d2f..062192b 100644
--- a/tracy-client/Cargo.toml
+++ b/tracy-client/Cargo.toml
@@ -39,7 +39,6 @@ path = "../tracy-client-sys"
 package = "tracy-client-sys"
 version = ">=0.21.2, <0.23.0" # AUTO-UPDATE
 default-features = false
-features = ["manual-lifetime", "delayed-init"]
 
 [target.'cfg(loom)'.dependencies.loom]
 version = "0.7"
@@ -60,6 +59,8 @@ only-localhost = ["sys/only-localhost"]
 sampling = ["sys/sampling"]
 system-tracing = ["sys/system-tracing"]
 callstack-inlines = ["sys/callstack-inlines"]
+manual-lifetime = ["sys/manual-lifetime"]
+delayed-init = ["sys/delayed-init"]
 
 [package.metadata.docs.rs]
 rustdoc-args = ["--cfg", "tracy_client_docs"]
diff --git a/tracy-client/src/state.rs b/tracy-client/src/state.rs
index 59453e0..c945cff 100644
--- a/tracy-client/src/state.rs
+++ b/tracy-client/src/state.rs
@@ -1,4 +1,5 @@
 use crate::Client;
+#[cfg(all(feature = "enable", feature = "manual-lifetime"))]
 use std::sync::atomic::Ordering;
 
 /// Enabling `Tracy` when it is already enabled, or Disabling when it is already disabled will
@@ -26,7 +27,7 @@ use std::sync::atomic::Ordering;
 ///
 /// All that seems like a major pain to implement, and so we’ll punt on disabling entirely until
 /// somebody comes with a good use-case warranting that sort of complexity.
-#[cfg(feature = "enable")]
+#[cfg(all(feature = "enable", feature = "manual-lifetime"))]
 #[cfg(not(loom))]
 static CLIENT_STATE: std::sync::atomic::AtomicUsize = std::sync::atomic::AtomicUsize::new(0);
 #[cfg(loom)]
@@ -35,16 +36,16 @@ loom::lazy_static! {
         loom::sync::atomic::AtomicUsize::new(0);
 }
 
-#[cfg(feature = "enable")]
+#[cfg(all(feature = "enable", feature = "manual-lifetime"))]
 const STATE_STEP: usize = 1; // Move forward by 1 step in the FSM
-#[cfg(feature = "enable")]
+#[cfg(all(feature = "enable", feature = "manual-lifetime"))]
 const STATE_DISABLED: usize = 0;
-#[cfg(feature = "enable")]
+#[cfg(all(feature = "enable", feature = "manual-lifetime"))]
 const STATE_ENABLING: usize = STATE_DISABLED + STATE_STEP;
-#[cfg(feature = "enable")]
+#[cfg(all(feature = "enable", feature = "manual-lifetime"))]
 const STATE_ENABLED: usize = STATE_ENABLING + STATE_STEP;
 
-#[cfg(feature = "enable")]
+#[cfg(all(feature = "enable", feature = "manual-lifetime"))]
 #[inline(always)]
 fn spin_loop() {
     #[cfg(loom)]
@@ -64,7 +65,10 @@ impl Client {
     /// The underlying client implementation will be started up only if it wasn't already running
     /// yet.
     ///
-    /// Note that there currently isn't a mechanism to stop the client once it has been started.
+    /// Note that when the `manual-lifetime` feature is used, it is a responsibility of the user
+    /// to stop `tracy` using the [`sys::___tracy_shutdown_profiler`] function. Keep in mind that
+    /// at the time this function is called there can be no other invocations to the tracy
+    /// profiler, even from other threads (or you may get a crash!)
     ///
     /// # Example
     ///
@@ -75,7 +79,7 @@ impl Client {
     /// // }
     /// ```
     pub fn start() -> Self {
-        #[cfg(feature = "enable")]
+        #[cfg(all(feature = "enable", feature = "manual-lifetime"))]
         {
             let mut old_state = CLIENT_STATE.load(Ordering::Relaxed);
             loop {
@@ -120,7 +124,7 @@ impl Client {
                 }
             }
         }
-        #[cfg(not(feature = "enable"))]
+        #[cfg(not(all(feature = "enable", feature = "manual-lifetime")))]
         Client(())
     }
 
@@ -136,10 +140,15 @@ impl Client {
 
     /// Is the client already running?
     pub fn is_running() -> bool {
-        #[cfg(feature = "enable")]
-        return CLIENT_STATE.load(Ordering::Relaxed) == STATE_ENABLED;
+        #![allow(unreachable_code)]
         #[cfg(not(feature = "enable"))]
-        return true;
+        return true; // If the client is disabled, produce a "no-op" one so that users don’t need
+                     // to wory about conditional use of the instrumentation in their own code.
+        #[cfg(not(feature = "manual-lifetime"))]
+        return true; // The client is started in life-before-main (or upon first use in case of
+                     // `delayed-init`
+        #[cfg(feature = "manual-lifetime")]
+        return CLIENT_STATE.load(Ordering::Relaxed) == STATE_ENABLED;
     }
 }