From 342deb5a64d5e4f49c0bb91d8411ee28f552d0b1 Mon Sep 17 00:00:00 2001
From: Ben Doherty <bendoherty@google.com>
Date: Fri, 12 Nov 2021 09:52:58 -0800
Subject: [PATCH] speed up under ThreadSanitizer (#4842)

---
 libs/utils/include/utils/Condition.h |  2 +-
 libs/utils/include/utils/Mutex.h     |  2 +-
 libs/utils/include/utils/SpinLock.h  |  4 ++--
 libs/utils/include/utils/compiler.h  | 22 ++++++++++++----------
 4 files changed, 16 insertions(+), 14 deletions(-)

diff --git a/libs/utils/include/utils/Condition.h b/libs/utils/include/utils/Condition.h
index 97c7161dbc..2ed2c07fc6 100644
--- a/libs/utils/include/utils/Condition.h
+++ b/libs/utils/include/utils/Condition.h
@@ -17,7 +17,7 @@
 #ifndef TNT_UTILS_CONDITION_H
 #define TNT_UTILS_CONDITION_H
 
-#if defined(__linux__) && !defined(__SANITIZE_THREAD__)
+#if defined(__linux__)
 #include <utils/linux/Condition.h>
 #else
 #include <utils/generic/Condition.h>
diff --git a/libs/utils/include/utils/Mutex.h b/libs/utils/include/utils/Mutex.h
index ac03fd2123..8d12d748e1 100644
--- a/libs/utils/include/utils/Mutex.h
+++ b/libs/utils/include/utils/Mutex.h
@@ -17,7 +17,7 @@
 #ifndef TNT_UTILS_MUTEX_H
 #define TNT_UTILS_MUTEX_H
 
-#if defined(__linux__) && !defined(__SANITIZE_THREAD__)
+#if defined(__linux__)
 #include <utils/linux/Mutex.h>
 #else
 #include <utils/generic/Mutex.h>
diff --git a/libs/utils/include/utils/SpinLock.h b/libs/utils/include/utils/SpinLock.h
index 79e4ec4322..e7ce00afac 100644
--- a/libs/utils/include/utils/SpinLock.h
+++ b/libs/utils/include/utils/SpinLock.h
@@ -75,8 +75,8 @@ private:
 };
 } // namespace details
 
-#if defined(__SANITIZE_THREAD__)
-// Unfortunately TSAN doesn't support homegrown synchronization primitives
+#if UTILS_HAS_SANITIZE_THREAD
+// Active spins with atomics slow down execution too much under ThreadSanitizer.
 using SpinLock = Mutex;
 #elif defined(__ARM_ARCH_7A__)
 // We've had problems with  "wfe" on some ARM-V7 devices, causing spurious SIGILL
diff --git a/libs/utils/include/utils/compiler.h b/libs/utils/include/utils/compiler.h
index 28e6cf963c..8c3551b1a0 100644
--- a/libs/utils/include/utils/compiler.h
+++ b/libs/utils/include/utils/compiler.h
@@ -65,19 +65,21 @@
 #endif
 
 #define UTILS_NO_SANITIZE_THREAD
-#if defined(__has_feature)
-#    if __has_feature(thread_sanitizer)
-#        undef UTILS_NO_SANITIZE_THREAD
-#        define UTILS_NO_SANITIZE_THREAD __attribute__((no_sanitize("thread")))
-#    endif
+#if __has_feature(thread_sanitizer)
+#undef UTILS_NO_SANITIZE_THREAD
+#define UTILS_NO_SANITIZE_THREAD __attribute__((no_sanitize("thread")))
+#endif
+
+#define UTILS_HAS_SANITIZE_THREAD 0
+#if __has_feature(thread_sanitizer) || defined(__SANITIZE_THREAD__)
+#undef UTILS_HAS_SANITIZE_THREAD
+#define UTILS_HAS_SANITIZE_THREAD 1
 #endif
 
 #define UTILS_HAS_SANITIZE_MEMORY 0
-#if defined(__has_feature)
-#    if __has_feature(memory_sanitizer)
-#        undef UTILS_HAS_SANITIZE_MEMORY
-#        define UTILS_HAS_SANITIZE_MEMORY 1
-#    endif
+#if __has_feature(memory_sanitizer)
+#undef UTILS_HAS_SANITIZE_MEMORY
+#define UTILS_HAS_SANITIZE_MEMORY 1
 #endif
 
 /*