From b1062207435dcc67e2cfd6b0c90cc796b67fe30d Mon Sep 17 00:00:00 2001
From: Nikita Sivukhin <sivukhin@turso.tech>
Date: Thu, 18 Sep 2025 01:35:22 +0400
Subject: [PATCH] main thread in browser can't execute parking - so we use
 parking lot in spin-lock style for that target

---
 core/storage/wal.rs | 34 ++++++++++++++++++++++++++++++++--
 1 file changed, 32 insertions(+), 2 deletions(-)

diff --git a/core/storage/wal.rs b/core/storage/wal.rs
index 3edf3f6d5..d6b111172 100644
--- a/core/storage/wal.rs
+++ b/core/storage/wal.rs
@@ -1639,11 +1639,41 @@ impl WalFile {
     }
 
     fn get_shared_mut(&self) -> parking_lot::RwLockWriteGuard<'_, WalFileShared> {
-        self.shared.write()
+        // WASM in browser main thread doesn't have a way to "park" a thread
+        // so, we spin way here instead of calling blocking lock
+        #[cfg(target_family = "wasm")]
+        {
+            loop {
+                let Some(lock) = self.shared.try_write() else {
+                    std::hint::spin_loop();
+                    continue;
+                };
+                return lock;
+            }
+        }
+        #[cfg(not(target_family = "wasm"))]
+        {
+            self.shared.write()
+        }
     }
 
     fn get_shared(&self) -> parking_lot::RwLockReadGuard<'_, WalFileShared> {
-        self.shared.read()
+        // WASM in browser main thread doesn't have a way to "park" a thread
+        // so, we spin way here instead of calling blocking lock
+        #[cfg(target_family = "wasm")]
+        {
+            loop {
+                let Some(lock) = self.shared.try_read() else {
+                    std::hint::spin_loop();
+                    continue;
+                };
+                return lock;
+            }
+        }
+        #[cfg(not(target_family = "wasm"))]
+        {
+            self.shared.read()
+        }
     }
 
     fn complete_append_frame(&mut self, page_id: u64, frame_id: u64, checksums: (u32, u32)) {