[compiler-rt] 5dd29d9 - Fix xray fdr mode to allow multiple flushes

[Dean Michael Berris via llvm-commits]

Author: Todd Lipcon
Date: 2021-02-10T12:57:24+11:00
New Revision: 5dd29d9922ad0c1e7c82f118444ccde7f2ae9aef

URL: https://github.com/llvm/llvm-project/commit/5dd29d9922ad0c1e7c82f118444ccde7f2ae9aef
DIFF: https://github.com/llvm/llvm-project/commit/5dd29d9922ad0c1e7c82f118444ccde7f2ae9aef.diff

LOG: Fix xray fdr mode to allow multiple flushes

Reviewed By: dberris

Differential Revision: https://reviews.llvm.org/D96382

Added: 
    

Modified: 
    compiler-rt/lib/xray/xray_fdr_logging.cpp
    compiler-rt/test/xray/TestCases/Posix/fdr-reinit.cpp

Removed: 
    


################################################################################
diff  --git a/compiler-rt/lib/xray/xray_fdr_logging.cpp b/compiler-rt/lib/xray/xray_fdr_logging.cpp
index 16ce483502f0..799814f437f9 100644
--- a/compiler-rt/lib/xray/xray_fdr_logging.cpp
+++ b/compiler-rt/lib/xray/xray_fdr_logging.cpp
@@ -284,13 +284,12 @@ XRayLogFlushStatus fdrLoggingFlush() XRAY_NEVER_INSTRUMENT {
     return XRayLogFlushStatus::XRAY_LOG_NOT_FLUSHING;
   }
 
-  s32 Result = XRayLogFlushStatus::XRAY_LOG_NOT_FLUSHING;
-  if (!atomic_compare_exchange_strong(&LogFlushStatus, &Result,
-                                      XRayLogFlushStatus::XRAY_LOG_FLUSHING,
-                                      memory_order_release)) {
+  if (atomic_exchange(&LogFlushStatus, XRayLogFlushStatus::XRAY_LOG_FLUSHING,
+                      memory_order_release) ==
+      XRayLogFlushStatus::XRAY_LOG_FLUSHING) {
     if (Verbosity())
-      Report("Not flushing log, implementation is still finalizing.\n");
-    return static_cast<XRayLogFlushStatus>(Result);
+      Report("Not flushing log, implementation is still flushing.\n");
+    return XRayLogFlushStatus::XRAY_LOG_NOT_FLUSHING;
   }
 
   if (BQ == nullptr) {

diff  --git a/compiler-rt/test/xray/TestCases/Posix/fdr-reinit.cpp b/compiler-rt/test/xray/TestCases/Posix/fdr-reinit.cpp
index dc9888d6e48a..a8f2608f02be 100644
--- a/compiler-rt/test/xray/TestCases/Posix/fdr-reinit.cpp
+++ b/compiler-rt/test/xray/TestCases/Posix/fdr-reinit.cpp
@@ -49,21 +49,23 @@ int main(int argc, char *argv[]) {
   auto flush_status = __xray_log_flushLog();
   assert(flush_status == XRayLogFlushStatus::XRAY_LOG_FLUSHED);
 
-  // Without doing anything else, we should re-initialize.
-  init_status = __xray_log_init_mode("xray-fdr", kConfig);
-  assert(init_status == XRayLogInitStatus::XRAY_LOG_INITIALIZED);
+  for (auto trial = 0; trial < 3; trial++) {
+    // Without doing anything else, we should re-initialize.
+    init_status = __xray_log_init_mode("xray-fdr", kConfig);
+    assert(init_status == XRayLogInitStatus::XRAY_LOG_INITIALIZED);
 
-  // Then we spin for a bit again calling func() enough times.
-  for (auto i = 0; i < 1 << 20; ++i)
-    func();
+    // Then we spin for a bit again calling func() enough times.
+    for (auto i = 0; i < 1 << 20; ++i)
+      func();
 
-  // Then immediately finalize the implementation.
-  finalize_status = __xray_log_finalize();
-  assert(finalize_status == XRayLogInitStatus::XRAY_LOG_FINALIZED);
+    // Then immediately finalize the implementation.
+    finalize_status = __xray_log_finalize();
+    assert(finalize_status == XRayLogInitStatus::XRAY_LOG_FINALIZED);
 
-  // Once we're here, we should then flush.
-  flush_status = __xray_log_flushLog();
-  assert(flush_status == XRayLogFlushStatus::XRAY_LOG_FLUSHED);
+    // Once we're here, we should then flush.
+    flush_status = __xray_log_flushLog();
+    assert(flush_status == XRayLogFlushStatus::XRAY_LOG_FLUSHED);
+  }
 
   // Finally, we should signal the sibling thread to stop.
   keep_going.clear(std::memory_order_release);