From 8e16c57eb39ea5d31139950154482e63b496a460 Mon Sep 17 00:00:00 2001
From: Yulong Wang <7679871+fs-eire@users.noreply.github.com>
Date: Thu, 12 Mar 2026 23:00:54 -0700
Subject: [PATCH] emdawnwebgpu: Add runtimeKeepalive for device.lost handler

The device.lost handler in emwgpuAdapterRequestDevice is wrapped in
callUserCallback(), which calls maybeExit() after the callback executes.
When runtimeKeepaliveCounter is 0 (common for --no-entry WASM modules),
maybeExit() triggers _exit(0), setting ABORT=true. This causes all
subsequent callUserCallback() invocations to silently drop their
callbacks, breaking any WebGPU operations that follow (e.g.,
requestAdapter for a new session).

Fix by adding runtimeKeepalivePush() before the device.lost promise
setup, and runtimeKeepalivePop() after callUserCallback() returns
inside the .then() handler. This ensures the runtime stays alive
during the callback and maybeExit() sees counter >= 1.

The pop is placed after callUserCallback (not before) because
callUserCallback internally calls maybeExit() - if the pop happened
first, the counter would be 0 during maybeExit, still triggering the
premature exit.

Bug: onnxruntime#27427
---
 third_party/emdawnwebgpu/pkg/webgpu/src/library_webgpu.js | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/third_party/emdawnwebgpu/pkg/webgpu/src/library_webgpu.js b/third_party/emdawnwebgpu/pkg/webgpu/src/library_webgpu.js
index 590d4cb2d2a..61b07f616b6 100644
--- a/third_party/emdawnwebgpu/pkg/webgpu/src/library_webgpu.js
+++ b/third_party/emdawnwebgpu/pkg/webgpu/src/library_webgpu.js
@@ -909,7 +909,9 @@ var LibraryWebGPU = {
 #if ASSERTIONS
         assert(deviceLostFutureId);
 #endif
-        // Don't keepalive here, because this isn't guaranteed to ever happen.
+        // Keep the runtime alive until device.lost resolves, to prevent
+        // maybeExit() from triggering premature ABORT during callUserCallback.
+        {{{ runtimeKeepalivePush() }}}
         WebGPU.Internals.futureInsert(deviceLostFutureId, device.lost.then((info) => {
           // If the runtime has exited, avoid calling callUserCallback as it
           // will print an error (e.g. if the device got freed during shutdown).
@@ -925,6 +927,7 @@ var LibraryWebGPU = {
               {{{ gpu.passAsPointer('messagePtr') }}});
             stackRestore(sp);
           });
+          {{{ runtimeKeepalivePop() }}}
         }));
 
         // Set up uncaptured error handlers.