[compiler-rt] r201405 - [sanitizer] add iterators to bit vectors; make bit vector operations use little stack; add common flag 'detect_deadlocks'
Kostya Serebryany
kcc at google.com
Fri Feb 14 04:08:23 PST 2014
Author: kcc
Date: Fri Feb 14 06:08:23 2014
New Revision: 201405
URL: http://llvm.org/viewvc/llvm-project?rev=201405&view=rev
Log:
[sanitizer] add iterators to bit vectors; make bit vector operations use little stack; add common flag 'detect_deadlocks'
Modified:
compiler-rt/trunk/lib/sanitizer_common/sanitizer_bitvector.h
compiler-rt/trunk/lib/sanitizer_common/sanitizer_bvgraph.h
compiler-rt/trunk/lib/sanitizer_common/sanitizer_deadlock_detector.h
compiler-rt/trunk/lib/sanitizer_common/sanitizer_flags.cc
compiler-rt/trunk/lib/sanitizer_common/sanitizer_flags.h
compiler-rt/trunk/lib/sanitizer_common/tests/sanitizer_bitvector_test.cc
compiler-rt/trunk/lib/sanitizer_common/tests/sanitizer_bvgraph_test.cc
Modified: compiler-rt/trunk/lib/sanitizer_common/sanitizer_bitvector.h
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/sanitizer_common/sanitizer_bitvector.h?rev=201405&r1=201404&r2=201405&view=diff
==============================================================================
--- compiler-rt/trunk/lib/sanitizer_common/sanitizer_bitvector.h (original)
+++ compiler-rt/trunk/lib/sanitizer_common/sanitizer_bitvector.h Fri Feb 14 06:08:23 2014
@@ -72,6 +72,21 @@ class BasicBitVector {
// Returns true if 'this' intersects with 'v'.
bool intersectsWith(const BasicBitVector &v) const { return bits_ & v.bits_; }
+ // for (BasicBitVector<>::Iterator it(bv); it.hasNext();) {
+ // uptr idx = it.next();
+ // use(idx);
+ // }
+ class Iterator {
+ public:
+ Iterator() { }
+ explicit Iterator(const BasicBitVector &bv) : bv_(bv) {}
+ bool hasNext() const { return !bv_.empty(); }
+ uptr next() { return bv_.getAndClearFirstOne(); }
+ void clear() { bv_.clear(); }
+ private:
+ BasicBitVector bv_;
+ };
+
private:
basic_int_t mask(uptr idx) const {
CHECK_LT(idx, size());
@@ -109,7 +124,7 @@ class TwoLevelBitVector {
}
}
- bool empty() {
+ bool empty() const {
for (uptr i = 0; i < kLevel1Size; i++)
if (!l1_[i].empty())
return false;
@@ -226,6 +241,60 @@ class TwoLevelBitVector {
return false;
}
+ // for (TwoLevelBitVector<>::Iterator it(bv); it.hasNext();) {
+ // uptr idx = it.next();
+ // use(idx);
+ // }
+ class Iterator {
+ public:
+ Iterator() { }
+ explicit Iterator(const TwoLevelBitVector &bv) : bv_(bv), i0_(0), i1_(0) {
+ it1_.clear();
+ it2_.clear();
+ }
+
+ bool hasNext() const {
+ if (it1_.hasNext()) return true;
+ for (uptr i = i0_; i < kLevel1Size; i++)
+ if (!bv_.l1_[i].empty()) return true;
+ return false;
+ }
+
+ uptr next() {
+ // Printf("++++: %zd %zd; %d %d; size %zd\n", i0_, i1_, it1_.hasNext(),
+ // it2_.hasNext(), kSize);
+ if (!it1_.hasNext() && !it2_.hasNext()) {
+ for (; i0_ < kLevel1Size; i0_++) {
+ if (bv_.l1_[i0_].empty()) continue;
+ it1_ = typename BV::Iterator(bv_.l1_[i0_]);
+ // Printf("+i0: %zd %zd; %d %d; size %zd\n", i0_, i1_, it1_.hasNext(),
+ // it2_.hasNext(), kSize);
+ break;
+ }
+ }
+ if (!it2_.hasNext()) {
+ CHECK(it1_.hasNext());
+ i1_ = it1_.next();
+ it2_ = typename BV::Iterator(bv_.l2_[i0_][i1_]);
+ // Printf("++i1: %zd %zd; %d %d; size %zd\n", i0_, i1_, it1_.hasNext(),
+ // it2_.hasNext(), kSize);
+ }
+ CHECK(it2_.hasNext());
+ uptr i2 = it2_.next();
+ uptr res = i0_ * BV::kSize * BV::kSize + i1_ * BV::kSize + i2;
+ // Printf("+ret: %zd %zd; %d %d; size %zd; res: %zd\n", i0_, i1_,
+ // it1_.hasNext(), it2_.hasNext(), kSize, res);
+ if (!it1_.hasNext() && !it2_.hasNext())
+ i0_++;
+ return res;
+ }
+
+ private:
+ const TwoLevelBitVector &bv_;
+ uptr i0_, i1_;
+ typename BV::Iterator it1_, it2_;
+ };
+
private:
void check(uptr idx) const { CHECK_LE(idx, size()); }
Modified: compiler-rt/trunk/lib/sanitizer_common/sanitizer_bvgraph.h
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/sanitizer_common/sanitizer_bvgraph.h?rev=201405&r1=201404&r2=201405&view=diff
==============================================================================
--- compiler-rt/trunk/lib/sanitizer_common/sanitizer_bvgraph.h (original)
+++ compiler-rt/trunk/lib/sanitizer_common/sanitizer_bvgraph.h Fri Feb 14 06:08:23 2014
@@ -21,6 +21,7 @@
namespace __sanitizer {
// Directed graph of fixed size implemented as an array of bit vectors.
+// Not thread-safe, all accesses should be protected by an external lock.
template<class BV>
class BVGraph {
public:
@@ -46,7 +47,8 @@ class BVGraph {
// Returns true if there is a path from the node 'from'
// to any of the nodes in 'targets'.
bool isReachable(uptr from, const BV &targets) {
- BV to_visit, visited;
+ BV &to_visit = t1,
+ &visited = t2;
to_visit.copyFrom(v[from]);
visited.clear();
visited.setBit(from);
@@ -67,10 +69,10 @@ class BVGraph {
path[0] = from;
if (targets.getBit(from))
return 1;
- BV t;
- t.copyFrom(v[from]);
- while (!t.empty()) {
- uptr idx = t.getAndClearFirstOne();
+ // The function is recursive, so we don't want to create BV on stack.
+ // Instead of a getAndClearFirstOne loop we use the slower iterator.
+ for (typename BV::Iterator it(v[from]); it.hasNext(); ) {
+ uptr idx = it.next();
if (uptr res = findPath(idx, targets, path + 1, path_size - 1))
return res + 1;
}
@@ -83,6 +85,8 @@ class BVGraph {
CHECK_LT(idx2, size());
}
BV v[kSize];
+ // Keep temporary vectors here since we can not create large objects on stack.
+ BV t1, t2;
};
} // namespace __sanitizer
Modified: compiler-rt/trunk/lib/sanitizer_common/sanitizer_deadlock_detector.h
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/sanitizer_common/sanitizer_deadlock_detector.h?rev=201405&r1=201404&r2=201405&view=diff
==============================================================================
--- compiler-rt/trunk/lib/sanitizer_common/sanitizer_deadlock_detector.h (original)
+++ compiler-rt/trunk/lib/sanitizer_common/sanitizer_deadlock_detector.h Fri Feb 14 06:08:23 2014
@@ -65,6 +65,7 @@ class DeadlockDetectorTLS {
// and one DeadlockDetectorTLS object per evey thread.
// This class is not thread safe, all concurrent accesses should be guarded
// by an external lock.
+// Not thread-safe, all accesses should be protected by an external lock.
template <class BV>
class DeadlockDetector {
public:
@@ -115,7 +116,7 @@ class DeadlockDetector {
// Handle the lock event, return true if there is a cycle.
// FIXME: handle RW locks, recusive locks, etc.
bool onLock(DeadlockDetectorTLS *dtls, uptr cur_node) {
- BV cur_locks;
+ BV &cur_locks = t1;
cur_locks.clear();
uptr cur_idx = nodeToIndex(cur_node);
for (uptr i = 0, n = dtls->numLocks(); i < n; i++) {
@@ -163,6 +164,7 @@ class DeadlockDetector {
BV recycled_nodes_;
BVGraph<BV> g_;
uptr data_[BV::kSize];
+ BV t1; // Temporary object which we can not keep on stack.
};
} // namespace __sanitizer
Modified: compiler-rt/trunk/lib/sanitizer_common/sanitizer_flags.cc
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/sanitizer_common/sanitizer_flags.cc?rev=201405&r1=201404&r2=201405&view=diff
==============================================================================
--- compiler-rt/trunk/lib/sanitizer_common/sanitizer_flags.cc (original)
+++ compiler-rt/trunk/lib/sanitizer_common/sanitizer_flags.cc Fri Feb 14 06:08:23 2014
@@ -40,6 +40,7 @@ void SetCommonFlagsDefaults(CommonFlags
f->handle_segv = SANITIZER_NEEDS_SEGV;
f->allow_user_segv_handler = false;
f->use_sigaltstack = false;
+ f->detect_deadlocks = false;
f->clear_shadow_mmap_threshold = 64 * 1024;
}
@@ -62,6 +63,7 @@ void ParseCommonFlagsFromString(CommonFl
ParseFlag(str, &f->handle_segv, "handle_segv");
ParseFlag(str, &f->allow_user_segv_handler, "allow_user_segv_handler");
ParseFlag(str, &f->use_sigaltstack, "use_sigaltstack");
+ ParseFlag(str, &f->detect_deadlocks, "detect_deadlocks");
ParseFlag(str, &f->clear_shadow_mmap_threshold,
"clear_shadow_mmap_threshold");
Modified: compiler-rt/trunk/lib/sanitizer_common/sanitizer_flags.h
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/sanitizer_common/sanitizer_flags.h?rev=201405&r1=201404&r2=201405&view=diff
==============================================================================
--- compiler-rt/trunk/lib/sanitizer_common/sanitizer_flags.h (original)
+++ compiler-rt/trunk/lib/sanitizer_common/sanitizer_flags.h Fri Feb 14 06:08:23 2014
@@ -71,6 +71,8 @@ struct CommonFlags {
bool allow_user_segv_handler;
// If set, uses alternate stack for signal handling.
bool use_sigaltstack;
+ // If set, deadlock detection is enabled.
+ bool detect_deadlocks;
// Large shadow regions are zero-filled using mmap(NORESERVE) instead of
// memset. This is the threshold size in bytes.
uptr clear_shadow_mmap_threshold;
Modified: compiler-rt/trunk/lib/sanitizer_common/tests/sanitizer_bitvector_test.cc
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/sanitizer_common/tests/sanitizer_bitvector_test.cc?rev=201405&r1=201404&r2=201405&view=diff
==============================================================================
--- compiler-rt/trunk/lib/sanitizer_common/tests/sanitizer_bitvector_test.cc (original)
+++ compiler-rt/trunk/lib/sanitizer_common/tests/sanitizer_bitvector_test.cc Fri Feb 14 06:08:23 2014
@@ -26,12 +26,25 @@ using namespace std;
// Check the 'bv' == 's' and that the indexes go in increasing order.
+// Also check the BV::Iterator
template <class BV>
static void CheckBV(const BV &bv, const set<uptr> &s) {
BV t;
t.copyFrom(bv);
set<uptr> t_s(s);
uptr last_idx = bv.size();
+ uptr count = 0;
+ for (typename BV::Iterator it(bv); it.hasNext();) {
+ uptr idx = it.next();
+ count++;
+ if (last_idx != bv.size())
+ EXPECT_LT(last_idx, idx);
+ last_idx = idx;
+ EXPECT_TRUE(s.count(idx));
+ }
+ EXPECT_EQ(count, s.size());
+
+ last_idx = bv.size();
while (!t.empty()) {
uptr idx = t.getAndClearFirstOne();
if (last_idx != bv.size())
Modified: compiler-rt/trunk/lib/sanitizer_common/tests/sanitizer_bvgraph_test.cc
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/sanitizer_common/tests/sanitizer_bvgraph_test.cc?rev=201405&r1=201404&r2=201405&view=diff
==============================================================================
--- compiler-rt/trunk/lib/sanitizer_common/tests/sanitizer_bvgraph_test.cc (original)
+++ compiler-rt/trunk/lib/sanitizer_common/tests/sanitizer_bvgraph_test.cc Fri Feb 14 06:08:23 2014
@@ -78,21 +78,21 @@ TEST(SanitizerCommon, BVGraph) {
EXPECT_GT(num_reachable, 0);
}
-TEST(SanitizerCommon, BVGraph_isReachable) {
- typedef TwoLevelBitVector<> BV;
+template <class BV>
+void Test_isReachable() {
uptr path[5];
BVGraph<BV> g;
g.clear();
BV target;
target.clear();
- uptr t0 = 100;
+ uptr t0 = 0;
uptr t1 = g.size() - 1;
target.setBit(t0);
target.setBit(t1);
- uptr f0 = 0;
- uptr f1 = 99;
- uptr f2 = 200;
+ uptr f0 = 1;
+ uptr f1 = 2;
+ uptr f2 = g.size() / 2;
uptr f3 = g.size() - 2;
EXPECT_FALSE(g.isReachable(f0, target));
@@ -127,3 +127,10 @@ TEST(SanitizerCommon, BVGraph_isReachabl
EXPECT_TRUE(g.isReachable(f2, target));
EXPECT_TRUE(g.isReachable(f3, target));
}
+
+TEST(SanitizerCommon, BVGraph_isReachable) {
+ Test_isReachable<BasicBitVector<u8> >();
+ Test_isReachable<BasicBitVector<> >();
+ Test_isReachable<TwoLevelBitVector<> >();
+ Test_isReachable<TwoLevelBitVector<3, BasicBitVector<u8> > >();
+}
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