diff options
-rw-r--r-- | lib/scudo/standalone/CMakeLists.txt | 1 | ||||
-rw-r--r-- | lib/scudo/standalone/stats.h | 105 | ||||
-rw-r--r-- | lib/scudo/standalone/tests/CMakeLists.txt | 1 | ||||
-rw-r--r-- | lib/scudo/standalone/tests/stats_test.cc | 45 |
4 files changed, 152 insertions, 0 deletions
diff --git a/lib/scudo/standalone/CMakeLists.txt b/lib/scudo/standalone/CMakeLists.txt index 993bb9499..12461c6fb 100644 --- a/lib/scudo/standalone/CMakeLists.txt +++ b/lib/scudo/standalone/CMakeLists.txt @@ -46,6 +46,7 @@ set(SCUDO_HEADERS list.h mutex.h platform.h + stats.h vector.h) if(COMPILER_RT_HAS_SCUDO_STANDALONE) diff --git a/lib/scudo/standalone/stats.h b/lib/scudo/standalone/stats.h new file mode 100644 index 000000000..7fb9c9ed6 --- /dev/null +++ b/lib/scudo/standalone/stats.h @@ -0,0 +1,105 @@ +//===-- stats.h -------------------------------------------------*- C++ -*-===// +// +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception +// +//===----------------------------------------------------------------------===// + +#ifndef SCUDO_STATS_H_ +#define SCUDO_STATS_H_ + +#include "atomic_helpers.h" +#include "mutex.h" + +#include <string.h> + +namespace scudo { + +// Memory allocator statistics +enum StatType { StatAllocated, StatMapped, StatCount }; + +typedef uptr StatCounters[StatCount]; + +// Per-thread stats, live in per-thread cache. We use atomics so that the +// numbers themselves are consistent. But we don't use atomic_{add|sub} or a +// lock, because those are expensive operations , and we only care for the stats +// to be "somewhat" correct: eg. if we call GlobalStats::get while a thread is +// LocalStats::add'ing, this is OK, we will still get a meaningful number. +class LocalStats { +public: + void initLinkerInitialized() {} + void init() { memset(this, 0, sizeof(*this)); } + + void add(StatType I, uptr V) { + V += atomic_load_relaxed(&StatsArray[I]); + atomic_store_relaxed(&StatsArray[I], V); + } + + void sub(StatType I, uptr V) { + V = atomic_load_relaxed(&StatsArray[I]) - V; + atomic_store_relaxed(&StatsArray[I], V); + } + + void set(StatType I, uptr V) { atomic_store_relaxed(&StatsArray[I], V); } + + uptr get(StatType I) const { return atomic_load_relaxed(&StatsArray[I]); } + +private: + friend class GlobalStats; + atomic_uptr StatsArray[StatCount]; + LocalStats *Next; + LocalStats *Prev; +}; + +// Global stats, used for aggregation and querying. +class GlobalStats : public LocalStats { +public: + void initLinkerInitialized() { + Next = this; + Prev = this; + } + void init() { + memset(this, 0, sizeof(*this)); + initLinkerInitialized(); + } + + void link(LocalStats *S) { + SpinMutexLock L(&Mutex); + S->Next = Next; + S->Prev = this; + Next->Prev = S; + Next = S; + } + + void unlink(LocalStats *S) { + SpinMutexLock L(&Mutex); + S->Prev->Next = S->Next; + S->Next->Prev = S->Prev; + for (uptr I = 0; I < StatCount; I++) + add(static_cast<StatType>(I), S->get(static_cast<StatType>(I))); + } + + void get(uptr *S) const { + memset(S, 0, StatCount * sizeof(uptr)); + SpinMutexLock L(&Mutex); + const LocalStats *Stats = this; + for (;;) { + for (uptr I = 0; I < StatCount; I++) + S[I] += Stats->get(static_cast<StatType>(I)); + Stats = Stats->Next; + if (Stats == this) + break; + } + // All stats must be non-negative. + for (uptr I = 0; I < StatCount; I++) + S[I] = static_cast<sptr>(S[I]) >= 0 ? S[I] : 0; + } + +private: + mutable StaticSpinMutex Mutex; +}; + +} // namespace scudo + +#endif // SCUDO_STATS_H_ diff --git a/lib/scudo/standalone/tests/CMakeLists.txt b/lib/scudo/standalone/tests/CMakeLists.txt index 82fc923c5..908e51089 100644 --- a/lib/scudo/standalone/tests/CMakeLists.txt +++ b/lib/scudo/standalone/tests/CMakeLists.txt @@ -54,6 +54,7 @@ set(SCUDO_UNIT_TEST_SOURCES list_test.cc map_test.cc mutex_test.cc + stats_test.cc vector_test.cc scudo_unit_test_main.cc) diff --git a/lib/scudo/standalone/tests/stats_test.cc b/lib/scudo/standalone/tests/stats_test.cc new file mode 100644 index 000000000..9ed105d3d --- /dev/null +++ b/lib/scudo/standalone/tests/stats_test.cc @@ -0,0 +1,45 @@ +//===-- stats_test.cc -------------------------------------------*- C++ -*-===// +// +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception +// +//===----------------------------------------------------------------------===// + +#include "scudo/standalone/stats.h" +#include "gtest/gtest.h" + +TEST(ScudoStatsTest, LocalStats) { + scudo::LocalStats LStats; + LStats.init(); + for (scudo::uptr I = 0; I < scudo::StatCount; I++) + EXPECT_EQ(LStats.get(static_cast<scudo::StatType>(I)), 0U); + LStats.add(scudo::StatAllocated, 4096U); + EXPECT_EQ(LStats.get(scudo::StatAllocated), 4096U); + LStats.sub(scudo::StatAllocated, 4096U); + EXPECT_EQ(LStats.get(scudo::StatAllocated), 0U); + LStats.set(scudo::StatAllocated, 4096U); + EXPECT_EQ(LStats.get(scudo::StatAllocated), 4096U); +} + +TEST(ScudoStatsTest, GlobalStats) { + scudo::GlobalStats GStats; + GStats.init(); + scudo::uptr Counters[scudo::StatCount] = {}; + GStats.get(Counters); + for (scudo::uptr I = 0; I < scudo::StatCount; I++) + EXPECT_EQ(Counters[I], 0U); + scudo::LocalStats LStats; + LStats.init(); + GStats.link(&LStats); + for (scudo::uptr I = 0; I < scudo::StatCount; I++) + LStats.add(static_cast<scudo::StatType>(I), 4096U); + GStats.get(Counters); + for (scudo::uptr I = 0; I < scudo::StatCount; I++) + EXPECT_EQ(Counters[I], 4096U); + // Unlinking the local stats move numbers to the global stats. + GStats.unlink(&LStats); + GStats.get(Counters); + for (scudo::uptr I = 0; I < scudo::StatCount; I++) + EXPECT_EQ(Counters[I], 4096U); +} |