1 files changed, 163 insertions, 0 deletions
diff --git a/xpcom/tests/gtest/TestDeadlockDetectorScalability.cpp b/xpcom/tests/gtest/TestDeadlockDetectorScalability.cpp
new file mode 100644
index 0000000000..40519f43ed
--- /dev/null
+++ b/xpcom/tests/gtest/TestDeadlockDetectorScalability.cpp
@@ -0,0 +1,163 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+ * vim: sw=2 ts=4 et :
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+// Avoid DMD-specific parts of MOZ_DEFINE_MALLOC_SIZE_OF
+#undef MOZ_DMD
+
+#include "nsIMemoryReporter.h"
+#include "mozilla/Mutex.h"
+
+#include "gtest/gtest.h"
+
+//-----------------------------------------------------------------------------
+
+static void AllocLockRecurseUnlockFree(int i) {
+  if (0 == i) return;
+
+  mozilla::Mutex* lock = new mozilla::Mutex("deadlockDetector.scalability.t1");
+  {
+    mozilla::MutexAutoLock _(*lock);
+    AllocLockRecurseUnlockFree(i - 1);
+  }
+  delete lock;
+}
+
+// This test creates a resource dependency chain N elements long, then
+// frees all the resources in the chain.
+TEST(DeadlockDetectorScalability, LengthNDepChain)
+{
+  const int N = 1 << 14;  // 16K
+  AllocLockRecurseUnlockFree(N);
+  ASSERT_TRUE(true);
+}
+
+//-----------------------------------------------------------------------------
+
+// This test creates a single lock that is ordered < N resources, then
+// repeatedly exercises this order k times.
+//
+// NB: It takes a minute or two to run so it is disabled by default.
+TEST(DeadlockDetectorScalability, DISABLED_OneLockNDeps)
+{
+  // NB: Using a larger test size to stress our traversal logic.
+  const int N = 1 << 17;  // 131k
+  const int K = 100;
+
+  mozilla::Mutex* lock =
+      new mozilla::Mutex("deadlockDetector.scalability.t2.master");
+  mozilla::Mutex** locks = new mozilla::Mutex*[N];
+  if (!locks) MOZ_CRASH("couldn't allocate lock array");
+
+  for (int i = 0; i < N; ++i)
+    locks[i] = new mozilla::Mutex("deadlockDetector.scalability.t2.dep");
+
+  // establish orders
+  {
+    mozilla::MutexAutoLock m(*lock);
+    for (int i = 0; i < N; ++i) mozilla::MutexAutoLock s(*locks[i]);
+  }
+
+  // exercise order check
+  {
+    mozilla::MutexAutoLock m(*lock);
+    for (int i = 0; i < K; ++i)
+      for (int j = 0; j < N; ++j) mozilla::MutexAutoLock s(*locks[i]);
+  }
+
+  for (int i = 0; i < N; ++i) delete locks[i];
+  delete[] locks;
+
+  ASSERT_TRUE(true);
+}
+
+//-----------------------------------------------------------------------------
+
+// This test creates N resources and adds the theoretical maximum number
+// of dependencies, O(N^2).  It then repeats that sequence of
+// acquisitions k times.  Finally, all resources are freed.
+//
+// It's very difficult to perform well on this test.  It's put forth as a
+// challenge problem.
+
+TEST(DeadlockDetectorScalability, MaxDepsNsq)
+{
+  const int N = 1 << 10;  // 1k
+  const int K = 10;
+
+  mozilla::Mutex** locks = new mozilla::Mutex*[N];
+  if (!locks) MOZ_CRASH("couldn't allocate lock array");
+
+  for (int i = 0; i < N; ++i)
+    locks[i] = new mozilla::Mutex("deadlockDetector.scalability.t3");
+
+  for (int i = 0; i < N; ++i) {
+    mozilla::MutexAutoLock al1(*locks[i]);
+    for (int j = i + 1; j < N; ++j) mozilla::MutexAutoLock al2(*locks[j]);
+  }
+
+  for (int i = 0; i < K; ++i) {
+    for (int j = 0; j < N; ++j) {
+      mozilla::MutexAutoLock al1(*locks[j]);
+      for (int k = j + 1; k < N; ++k) mozilla::MutexAutoLock al2(*locks[k]);
+    }
+  }
+
+  for (int i = 0; i < N; ++i) delete locks[i];
+  delete[] locks;
+
+  ASSERT_TRUE(true);
+}
+
+//-----------------------------------------------------------------------------
+
+// This test creates a single lock that is ordered < N resources. The
+// resources are allocated, exercised K times, and deallocated one at
+// a time.
+
+TEST(DeadlockDetectorScalability, OneLockNDepsUsedSeveralTimes)
+{
+  const size_t N = 1 << 17;  // 131k
+  const size_t K = 3;
+
+  // Create master lock.
+  mozilla::Mutex* lock_1 =
+      new mozilla::Mutex("deadlockDetector.scalability.t4.master");
+  for (size_t n = 0; n < N; n++) {
+    // Create child lock.
+    mozilla::Mutex* lock_2 =
+        new mozilla::Mutex("deadlockDetector.scalability.t4.child");
+
+    // First lock the master.
+    mozilla::MutexAutoLock m(*lock_1);
+
+    // Now lock and unlock the child a few times.
+    for (size_t k = 0; k < K; k++) {
+      mozilla::MutexAutoLock c(*lock_2);
+    }
+
+    // Destroy the child lock.
+    delete lock_2;
+  }
+
+  // Cleanup the master lock.
+  delete lock_1;
+
+  ASSERT_TRUE(true);
+}
+
+//-----------------------------------------------------------------------------
+
+MOZ_DEFINE_MALLOC_SIZE_OF(DeadlockDetectorMallocSizeOf)
+
+// This is a simple test that exercises the deadlock detector memory reporting
+// functionality.
+TEST(DeadlockDetectorScalability, SizeOf)
+{
+  size_t memory_used = mozilla::BlockingResourceBase::SizeOfDeadlockDetector(
+      DeadlockDetectorMallocSizeOf);
+
+  ASSERT_GT(memory_used, size_t(0));
+}