tsan: add new mutex annotations

There are several problems with the current annotations (AnnotateRWLockCreate and friends):
- they don't fully support deadlock detection (we need a hook _before_ mutex lock)
- they don't support insertion of random artificial delays to perturb execution (again we need a hook _before_ mutex lock)
- they don't support setting extended mutex attributes like read/write reentrancy (only "linker init" was bolted on)
- they don't support setting mutex attributes if a mutex don't have a "constructor" (e.g. static, Java, Go mutexes)
- they don't ignore synchronization inside of lock/unlock operations which leads to slowdown and false negatives
The new annotations solve of the above problems. See tsan_interface.h for the interface specification and comments.

Reviewed in https://reviews.llvm.org/D31093



git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@298809 91177308-0d34-0410-b5e6-96231b3b80d8

4 files changed, 195 insertions, 0 deletions

diff --git a/test/tsan/custom_mutex.h b/test/tsan/custom_mutex.h
new file mode 100644
index 000000000..675ad59b3
--- /dev/null
+++ b/test/tsan/custom_mutex.h
@@ -0,0 +1,91 @@
+#include "test.h"
+#include <atomic>
+#include <vector>
+#include <sanitizer/tsan_interface.h>
+
+// A very primitive mutex annotated with tsan annotations.
+class Mutex {
+ public:
+  Mutex(bool prof = true)
+      : prof_(prof)
+      , locked_(false)
+      , seq_(0) {
+    __tsan_mutex_create(this, 0);
+  }
+
+  ~Mutex() {
+    __tsan_mutex_destroy(this, 0);
+  }
+
+  void Lock() {
+    __tsan_mutex_pre_lock(this, 0);
+    LockImpl();
+    __tsan_mutex_post_lock(this, 0, 0);
+  }
+
+  bool TryLock() {
+    __tsan_mutex_pre_lock(this, __tsan_mutex_try_lock);
+    bool ok = TryLockImpl();
+    __tsan_mutex_post_lock(this, __tsan_mutex_try_lock |
+        (ok ? 0 : __tsan_mutex_try_lock_failed), 0);
+    return ok;
+  }
+
+  void Unlock() {
+    __tsan_mutex_pre_unlock(this, 0);
+    UnlockImpl();
+    __tsan_mutex_post_unlock(this, 0);
+  }
+
+  void Wait() {
+    for (int seq = seq_; seq == seq_;) {
+      Unlock();
+      usleep(100);
+      Lock();
+    }
+  }
+
+  void Broadcast() {
+    __tsan_mutex_pre_signal(this, 0);
+    LockImpl(false);
+    seq_++;
+    UnlockImpl();
+    __tsan_mutex_post_signal(this, 0);
+  }
+
+ private:
+  const bool prof_;
+  std::atomic<bool> locked_;
+  int seq_;
+
+  // This models mutex profiling subsystem.
+  static Mutex prof_mu_;
+  static int prof_data_;
+
+  void LockImpl(bool prof = true) {
+    while (!TryLockImpl())
+      usleep(100);
+    if (prof && prof_)
+      Prof();
+  }
+
+  bool TryLockImpl() {
+    return !locked_.exchange(true);
+  }
+
+  void UnlockImpl() {
+    locked_.store(false);
+  }
+
+  void Prof() {
+      // This happens inside of mutex lock annotations.
+      __tsan_mutex_pre_divert(this, 0);
+      prof_mu_.Lock();
+      prof_data_++;
+      prof_mu_.Unlock();
+      __tsan_mutex_post_divert(this, 0);
+  }
+};
+
+Mutex Mutex::prof_mu_(false);
+int Mutex::prof_data_;
diff --git a/test/tsan/custom_mutex0.cc b/test/tsan/custom_mutex0.cc
new file mode 100644
index 000000000..4079c72a1
--- /dev/null
+++ b/test/tsan/custom_mutex0.cc
@@ -0,0 +1,31 @@
+// RUN: %clangxx_tsan -O1 %s -o %t && %run %t 2>&1 | FileCheck %s
+#include "custom_mutex.h"
+
+// Test that custom annoations provide normal mutex synchronization
+// (no race reports for properly protected critical sections).
+
+Mutex mu;
+long data;
+
+void *thr(void *arg) {
+  barrier_wait(&barrier);
+  mu.Lock();
+  data++;
+  mu.Unlock();
+  return 0;
+}
+
+int main() {
+  barrier_init(&barrier, 2);
+  pthread_t th;
+  pthread_create(&th, 0, thr, 0);
+  barrier_wait(&barrier);
+  mu.Lock();
+  data++;
+  mu.Unlock();
+  pthread_join(th, 0);
+  fprintf(stderr, "DONE\n");
+  return 0;
+}
+
+// CHECK: DONE
diff --git a/test/tsan/custom_mutex1.cc b/test/tsan/custom_mutex1.cc
new file mode 100644
index 000000000..ec7294ccd
--- /dev/null
+++ b/test/tsan/custom_mutex1.cc
@@ -0,0 +1,39 @@
+// RUN: %clangxx_tsan -O1 %s -o %t && %deflake %run %t 2>&1 | FileCheck %s
+#include "custom_mutex.h"
+
+// Test that failed TryLock does not induce parasitic synchronization.
+
+Mutex mu;
+long data;
+
+void *thr(void *arg) {
+  mu.Lock();
+  data++;
+  mu.Unlock();
+  mu.Lock();
+  barrier_wait(&barrier);
+  barrier_wait(&barrier);
+  mu.Unlock();
+  return 0;
+}
+
+int main() {
+  barrier_init(&barrier, 2);
+  pthread_t th;
+  pthread_create(&th, 0, thr, 0);
+  barrier_wait(&barrier);
+  if (mu.TryLock()) {
+    fprintf(stderr, "TryLock succeeded, should not\n");
+    exit(0);
+  }
+  data++;
+  barrier_wait(&barrier);
+  pthread_join(th, 0);
+  fprintf(stderr, "DONE\n");
+  return 0;
+}
+
+// CHECK: ThreadSanitizer: data race
+// CHECK-NEXT:   Write of size 8 at {{.*}} by main thread:
+// CHECK-NEXT:     #0 main {{.*}}custom_mutex1.cc:29
+// CHECK: DONE
diff --git a/test/tsan/custom_mutex2.cc b/test/tsan/custom_mutex2.cc
new file mode 100644
index 000000000..217b44466
--- /dev/null
+++ b/test/tsan/custom_mutex2.cc
@@ -0,0 +1,34 @@
+// RUN: %clangxx_tsan -O1 %s -o %t && %deflake %run %t 2>&1 | FileCheck %s
+#include "custom_mutex.h"
+
+// Test that Broadcast does not induce parasitic synchronization.
+
+Mutex mu;
+long data;
+
+void *thr(void *arg) {
+  barrier_wait(&barrier);
+  mu.Lock();
+  data++;
+  mu.Unlock();
+  data++;
+  mu.Broadcast();
+  return 0;
+}
+
+int main() {
+  barrier_init(&barrier, 2);
+  pthread_t th;
+  pthread_create(&th, 0, thr, 0);
+  mu.Lock();
+  barrier_wait(&barrier);
+  while (data == 0)
+    mu.Wait();
+  mu.Unlock();
+  pthread_join(th, 0);
+  fprintf(stderr, "DONE\n");
+  return 0;
+}
+
+// CHECK: ThreadSanitizer: data race
+// CHECK: DONE