From 8d69852785540512dc499578872b41118b513d82 Mon Sep 17 00:00:00 2001
From: Ryan Houdek <Sonicadvance1@gmail.com>
Date: Mon, 24 Aug 2026 18:56:40 -0700
Subject: [PATCH] unittests/FEXLinuxTests: Fixes race condition in
 signal_sra_state

This was using a one second alarm which could catch the JIT while it is
still busy. Instead wait for it to let an alarm thread that it is ready,
then tgkill the thread. This removes the race that this was hitting.
---
 .../tests/signal/signal_sra_state.32.cpp      | 21 +++++++++++++++----
 1 file changed, 17 insertions(+), 4 deletions(-)

diff --git a/unittests/FEXLinuxTests/tests/signal/signal_sra_state.32.cpp b/unittests/FEXLinuxTests/tests/signal/signal_sra_state.32.cpp
index 9fab97028..3c175d19f 100644
--- a/unittests/FEXLinuxTests/tests/signal/signal_sra_state.32.cpp
+++ b/unittests/FEXLinuxTests/tests/signal/signal_sra_state.32.cpp
@@ -1,14 +1,16 @@
 #include <catch2/catch_test_macros.hpp>
 
+#include <atomic>
 #include <signal.h>
 #include <stdint.h>
 #include <stdio.h>
 #include <string.h>
 #include <unistd.h>
+#include <thread>
 
 #pragma GCC diagnostic ignored "-Wattributes"
 
-constexpr static uint32_t xmm_values[8][4] = {
+__attribute__((aligned(16))) constexpr static uint32_t xmm_values[8][4] = {
   {0x00000001, 0x00000002, 0x00000003, 0x00000004}, {0x00000011, 0x00000012, 0x00000013, 0x00000014},
   {0x00000021, 0x00000022, 0x00000023, 0x00000024}, {0x00000031, 0x00000032, 0x00000033, 0x00000034},
   {0x00000041, 0x00000042, 0x00000043, 0x00000044}, {0x00000051, 0x00000052, 0x00000053, 0x00000054},
@@ -19,6 +21,8 @@ constexpr static uint32_t xmm_values[8][4] = {
 static uint32_t results[4 + 32] __attribute__((aligned(16)));
 static volatile int alarm_fired = 0;
 
+static std::atomic<uint32_t> test_ready {};
+
 extern "C" void ContinueAfterSignal();
 
 static void SignalHandler(int signal, siginfo_t* siginfo, void* context) {
@@ -62,6 +66,7 @@ __attribute__((nocf_check)) static void LoadRegsLoopAndStore() {
     movaps xmm6, [%[v]+96]
     movaps xmm7, [%[v]+112]
 
+    mov %[test_ready], ecx
     mov eax, %[alarm]
     test eax, eax
     jz .Lloop
@@ -79,11 +84,17 @@ __attribute__((nocf_check)) static void LoadRegsLoopAndStore() {
     movaps [%[res]+96], xmm5
     movaps [%[res]+112], xmm6
     movaps [%[res]+128], xmm7
-  )" ::[v] "r"(xmm_values),
-                 [alarm] "m"(alarm_fired), [res] "r"(results)
+  )" ::[v] "r"(&xmm_values),
+                 [alarm] "m"(alarm_fired), [res] "r"(results), [test_ready] "m"(test_ready)
                  : "memory", "cc", "eax", "ecx", "edx");
 }
 
+static void AlarmThread(int thread_to_alarm) {
+  while (!test_ready.load())
+    ;
+  tgkill(::getpid(), thread_to_alarm, SIGALRM);
+}
+
 TEST_CASE("Signals: Register state preserved across async signal with SRA") {
   struct sigaction act {};
   act.sa_sigaction = SignalHandler;
@@ -93,7 +104,7 @@ TEST_CASE("Signals: Register state preserved across async signal with SRA") {
   alarm_fired = 0;
   memset(results, 0, sizeof(results));
 
-  alarm(1);
+  std::thread t(AlarmThread, ::gettid());
   LoadRegsLoopAndStore();
 
   REQUIRE(alarm_fired == 1);
@@ -110,4 +121,6 @@ TEST_CASE("Signals: Register state preserved across async signal with SRA") {
       CHECK(val == xmm_values[i][j]);
     }
   }
+
+  t.join();
 }