From 5abf9bb1cad9982d13ee5091b62a498b6bae8669 Mon Sep 17 00:00:00 2001
From: Dmitry Vyukov <dvyukov@google.com>
Date: Wed, 12 Jul 2017 12:34:12 +0000
Subject: [PATCH] tsan: give debug names to dense allocators

Improves crash message on dense alloc overflow.
Allows to understand what alloc overflowed.

llvm-svn: 307780
---
 compiler-rt/lib/tsan/rtl/tsan_dense_alloc.h | 11 ++++++++---
 compiler-rt/lib/tsan/rtl/tsan_rtl.cc        |  3 ++-
 compiler-rt/lib/tsan/rtl/tsan_sync.cc       |  4 +++-
 3 files changed, 13 insertions(+), 5 deletions(-)

diff --git a/compiler-rt/lib/tsan/rtl/tsan_dense_alloc.h b/compiler-rt/lib/tsan/rtl/tsan_dense_alloc.h
index e9815c90a953..16dbdf391085 100644
--- a/compiler-rt/lib/tsan/rtl/tsan_dense_alloc.h
+++ b/compiler-rt/lib/tsan/rtl/tsan_dense_alloc.h
@@ -39,7 +39,7 @@ class DenseSlabAlloc {
   typedef DenseSlabAllocCache Cache;
   typedef typename Cache::IndexT IndexT;
 
-  DenseSlabAlloc() {
+  explicit DenseSlabAlloc(const char *name) {
     // Check that kL1Size and kL2Size are sane.
     CHECK_EQ(kL1Size & (kL1Size - 1), 0);
     CHECK_EQ(kL2Size & (kL2Size - 1), 0);
@@ -49,6 +49,7 @@ class DenseSlabAlloc {
     internal_memset(map_, 0, sizeof(map_));
     freelist_ = 0;
     fillpos_ = 0;
+    name_ = name;
   }
 
   ~DenseSlabAlloc() {
@@ -96,15 +97,19 @@ class DenseSlabAlloc {
   SpinMutex mtx_;
   IndexT freelist_;
   uptr fillpos_;
+  const char *name_;
 
   void Refill(Cache *c) {
     SpinMutexLock lock(&mtx_);
     if (freelist_ == 0) {
       if (fillpos_ == kL1Size) {
-        Printf("ThreadSanitizer: DenseSlabAllocator overflow. Dying.\n");
+        Printf("ThreadSanitizer: %s overflow (%zu*%zu). Dying.\n",
+            name_, kL1Size, kL2Size);
         Die();
       }
-      T *batch = (T*)MmapOrDie(kL2Size * sizeof(T), "DenseSlabAllocator");
+      VPrintf(2, "ThreadSanitizer: growing %s: %zu out of %zu*%zu\n",
+          name_, fillpos_, kL1Size, kL2Size);
+      T *batch = (T*)MmapOrDie(kL2Size * sizeof(T), name_);
       // Reserve 0 as invalid index.
       IndexT start = fillpos_ == 0 ? 1 : 0;
       for (IndexT i = start; i < kL2Size; i++) {
diff --git a/compiler-rt/lib/tsan/rtl/tsan_rtl.cc b/compiler-rt/lib/tsan/rtl/tsan_rtl.cc
index fa60f3247c38..a01525302b02 100644
--- a/compiler-rt/lib/tsan/rtl/tsan_rtl.cc
+++ b/compiler-rt/lib/tsan/rtl/tsan_rtl.cc
@@ -104,7 +104,8 @@ Context::Context()
   , racy_stacks(MBlockRacyStacks)
   , racy_addresses(MBlockRacyAddresses)
   , fired_suppressions_mtx(MutexTypeFired, StatMtxFired)
-  , fired_suppressions(8) {
+  , fired_suppressions(8)
+  , clock_alloc("clock allocator") {
 }
 
 // The objects are allocated in TLS, so one may rely on zero-initialization.
diff --git a/compiler-rt/lib/tsan/rtl/tsan_sync.cc b/compiler-rt/lib/tsan/rtl/tsan_sync.cc
index 4cc3cb89c34f..44ae558fa1b2 100644
--- a/compiler-rt/lib/tsan/rtl/tsan_sync.cc
+++ b/compiler-rt/lib/tsan/rtl/tsan_sync.cc
@@ -53,7 +53,9 @@ void SyncVar::Reset(Processor *proc) {
   }
 }
 
-MetaMap::MetaMap() {
+MetaMap::MetaMap()
+    : block_alloc_("heap block allocator")
+    , sync_alloc_("sync allocator") {
   atomic_store(&uid_gen_, 0, memory_order_relaxed);
 }