From 58a1719c983e9901bb3762966e9a25ea3251d248 Mon Sep 17 00:00:00 2001
From: Stephan Dilly <dilly.stephan@gmail.com>
Date: Sat, 18 Jul 2020 13:57:08 +0200
Subject: [PATCH] fix problems with spawning too many async tasks underload
 (#196)

---
 asyncgit/src/commit_files.rs | 16 +++++++++++-----
 asyncgit/src/diff.rs         |  5 +++--
 asyncgit/src/revlog.rs       |  4 +++-
 asyncgit/src/status.rs       |  5 +++--
 asyncgit/src/tags.rs         |  5 +++--
 5 files changed, 23 insertions(+), 12 deletions(-)

diff --git a/asyncgit/src/commit_files.rs b/asyncgit/src/commit_files.rs
index e837c453..265b38ee 100644
--- a/asyncgit/src/commit_files.rs
+++ b/asyncgit/src/commit_files.rs
@@ -57,7 +57,7 @@ impl AsyncCommitFiles {
 
         {
             let current = self.current.lock()?;
-            if let Some(ref c) = *current {
+            if let Some(c) = &*current {
                 if c.0 == id {
                     return Ok(());
                 }
@@ -68,9 +68,9 @@ impl AsyncCommitFiles {
         let sender = self.sender.clone();
         let arc_pending = Arc::clone(&self.pending);
 
-        rayon_core::spawn(move || {
-            arc_pending.fetch_add(1, Ordering::Relaxed);
+        self.pending.fetch_add(1, Ordering::Relaxed);
 
+        rayon_core::spawn(move || {
             Self::fetch_helper(id, arc_current)
                 .expect("failed to fetch");
 
@@ -92,9 +92,15 @@ impl AsyncCommitFiles {
     ) -> Result<()> {
         let res = sync::get_commit_files(CWD, id)?;
 
+        log::trace!(
+            "get_commit_files: {} ({})",
+            id.to_string(),
+            res.len()
+        );
+
         {
-            let mut last = arc_current.lock()?;
-            *last = Some(Request(id, res));
+            let mut current = arc_current.lock()?;
+            *current = Some(Request(id, res));
         }
 
         Ok(())
diff --git a/asyncgit/src/diff.rs b/asyncgit/src/diff.rs
index f149d104..7dd02ffd 100644
--- a/asyncgit/src/diff.rs
+++ b/asyncgit/src/diff.rs
@@ -109,9 +109,10 @@ impl AsyncDiff {
         let arc_last = Arc::clone(&self.last);
         let sender = self.sender.clone();
         let arc_pending = Arc::clone(&self.pending);
-        rayon_core::spawn(move || {
-            arc_pending.fetch_add(1, Ordering::Relaxed);
 
+        self.pending.fetch_add(1, Ordering::Relaxed);
+
+        rayon_core::spawn(move || {
             let notify = AsyncDiff::get_diff_helper(
                 params,
                 arc_last,
diff --git a/asyncgit/src/revlog.rs b/asyncgit/src/revlog.rs
index 281b3f09..3c78aa90 100644
--- a/asyncgit/src/revlog.rs
+++ b/asyncgit/src/revlog.rs
@@ -117,16 +117,18 @@ impl AsyncLog {
         let arc_pending = Arc::clone(&self.pending);
         let arc_background = Arc::clone(&self.background);
 
+        self.pending.store(true, Ordering::Relaxed);
+
         rayon_core::spawn(move || {
             scope_time!("async::revlog");
 
-            arc_pending.store(true, Ordering::Relaxed);
             AsyncLog::fetch_helper(
                 arc_current,
                 arc_background,
                 &sender,
             )
             .expect("failed to fetch");
+
             arc_pending.store(false, Ordering::Relaxed);
 
             Self::notify(&sender);
diff --git a/asyncgit/src/status.rs b/asyncgit/src/status.rs
index 80baf472..75ffb69d 100644
--- a/asyncgit/src/status.rs
+++ b/asyncgit/src/status.rs
@@ -116,9 +116,10 @@ impl AsyncStatus {
         let arc_pending = Arc::clone(&self.pending);
         let status_type = params.status_type;
         let include_untracked = params.include_untracked;
-        rayon_core::spawn(move || {
-            arc_pending.fetch_add(1, Ordering::Relaxed);
 
+        self.pending.fetch_add(1, Ordering::Relaxed);
+
+        rayon_core::spawn(move || {
             Self::fetch_helper(
                 status_type,
                 include_untracked,
diff --git a/asyncgit/src/tags.rs b/asyncgit/src/tags.rs
index 20999c69..f23b54af 100644
--- a/asyncgit/src/tags.rs
+++ b/asyncgit/src/tags.rs
@@ -74,9 +74,10 @@ impl AsyncTags {
         let arc_last = Arc::clone(&self.last);
         let sender = self.sender.clone();
         let arc_pending = Arc::clone(&self.pending);
-        rayon_core::spawn(move || {
-            arc_pending.fetch_add(1, Ordering::Relaxed);
 
+        self.pending.fetch_add(1, Ordering::Relaxed);
+
+        rayon_core::spawn(move || {
             let notify = AsyncTags::getter(arc_last)
                 .expect("error getting tags");