[tsan] Turn lit test deadlocks into failures (OS X)

[kubamracek]

Summary

Several tests currently deadlock when the lit test suite is run on OS X. At this point, I'd like to turn them into failures so we can actually have a buildbot running the tests.

One class of deadlocks is when using fork/vfork – if something fails within the fork interceptor, an external symbolizer is spawned using fork() again and that deadlock with the original fork. Let's disable the symbolizer in these tests (none of them actually rely on the symbolizer).

Second class of deadlocks is when having a very fast timer (ITIMER_PROF, tv_usec = 10) and spawning new threads. Apparently, a thread receives a signal at a very early initialization stage, which deadlocks again. I don't have a solution for this yet, so I think we should just make the test simply fail on OS X.

[dvyukov]

test/tsan/signal_reset.cc

44 ↗

(On Diff #39531)

There is some infrastructure in lit for this.

Tsan only disables for particular hardware now:
longjmp.cc:// XFAIL: mips64
longjmp.cc:// XFAIL: aarch64

but asan disables tests for operating systems:
test/asan/TestCases/log-path_test.cc:// XFAIL: android
test/asan/TestCases/log-path_test.cc:// XFAIL: win32

maybe it also works for tsan tests?

[kubamracek]

XFAILs don't work for deadlocked tests. XFAIL still runs the tests, but they'll never finish.

[ismailp]

I've go fork tests working by disabling interceptors for it. It's fused with another commit in my history, so I can't be precise. But...

--- a/lib/tsan/rtl/tsan_interceptors.cc
+++ b/lib/tsan/rtl/tsan_interceptors.cc
@@ -2112,7 +2307,15 @@ TSAN_INTERCEPTOR(int, fork, int fake) {
     return REAL(fork)(fake);
   SCOPED_INTERCEPTOR_RAW(fork, fake);
   ForkBefore(thr, pc);
+#if !SANITIZER_MAC
   int pid = REAL(fork)(fake);
+#else
+  int pid = -1;
+  {
+    ScopedIgnoreInterceptors ignore;
+    pid = REAL(fork)(fake);
+  }
+#endif
   if (pid == 0) {
     // child
     ForkChildAfter(thr, pc);

may fix the problem.

[samsonov]

In D14443#283736, @kubabrecka wrote:

XFAILs don't work for deadlocked tests. XFAIL still runs the tests, but they'll never finish.

Try UNSUPPORTED:

[kubamracek]

I didn't know about "UNSUPPORTED", thanks! Changed the patch to use it.

[samsonov]

LGTM

compiler-rt/trunk/test/tsan/fork_atexit.cc

 // RUN: %clangxx_tsan -O1 %s -o %t && TSAN_OPTIONS="atexit_sleep_ms=50" %run %t 2>&1 | FileCheck %s
+// UNSUPPORTED: darwin
 #include <pthread.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <unistd.h>
 #include <sys/types.h>
 #include <sys/wait.h>
 
 void foo() {

compiler-rt/trunk/test/tsan/fork_deadlock.cc

 // RUN: %clangxx_tsan -O1 %s -o %t && TSAN_OPTIONS="atexit_sleep_ms=50" %run %t 2>&1 | FileCheck %s
+// UNSUPPORTED: darwin
 #include "test.h"
 #include <errno.h>
 #include <sys/types.h>
 #include <sys/wait.h>
 
 int counter;
 
 static void *incrementer(void *p) {

compiler-rt/trunk/test/tsan/fork_multithreaded.cc

 // RUN: %clangxx_tsan -O1 %s -o %t && %run %t 2>&1 | FileCheck %s -check-prefix=CHECK-DIE
 // RUN: %clangxx_tsan -O1 %s -o %t && TSAN_OPTIONS="die_after_fork=0" %run %t 2>&1 | FileCheck %s -check-prefix=CHECK-NODIE
+// UNSUPPORTED: darwin
 #include "test.h"
 #include <errno.h>
 #include <sys/types.h>
 #include <sys/wait.h>
 
 static void *sleeper(void *p) {
   sleep(10);  // not intended to exit during test
   return 0;

compiler-rt/trunk/test/tsan/fork_multithreaded3.cc

 // RUN: %clangxx_tsan -O1 %s -o %t && %run %t 2>&1 | FileCheck %s
+// UNSUPPORTED: darwin
 #include <stdlib.h>
 #include <stdio.h>
 #include <errno.h>
 #include <pthread.h>
 #include <unistd.h>
 #include <sys/types.h>
 #include <sys/wait.h>
 

compiler-rt/trunk/test/tsan/signal_reset.cc

 // RUN: %clangxx_tsan -O1 %s -o %t && %run %t 2>&1 | FileCheck %s
+// UNSUPPORTED: darwin
 #include <pthread.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <signal.h>
 #include <sys/types.h>
 #include <sys/time.h>
 #include <unistd.h>
 #include <errno.h>

compiler-rt/trunk/test/tsan/signal_sync.cc

 // RUN: %clang_tsan -O1 %s -o %t && %run %t 2>&1 | FileCheck %s
+// UNSUPPORTED: darwin
 #include "test.h"
 #include <signal.h>
 #include <sys/types.h>
 #include <sys/time.h>
 #include <errno.h>
 
 volatile int X;
 

compiler-rt/trunk/test/tsan/signal_thread.cc

 // RUN: %clangxx_tsan -O1 %s -o %t && %run %t 2>&1 | FileCheck %s
+// UNSUPPORTED: darwin
 #include <pthread.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <signal.h>
 #include <sys/types.h>
 #include <sys/time.h>
 #include <unistd.h>
 #include <errno.h>

compiler-rt/trunk/test/tsan/vfork.cc

 // RUN: %clangxx_tsan -O1 %s -o %t && %run %t 2>&1 | FileCheck %s
+// UNSUPPORTED: darwin
 #include <pthread.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <unistd.h>
 #include <sys/types.h>
 
 int fds[2];
 int X;