Remove Mutex dependency from MemMap
Use std::mutex to remove the dependency between MemMap and Mutex/Thread,
which depend upon Runtime. Next step towards making dexdump2 build and
run on Windows.
Bug: 22322814
Test: test-art
Change-Id: Ia6f4ef882dcef516ee83a81e965b3d744ce325b0
diff --git a/runtime/mem_map.cc b/runtime/mem_map.cc
index 19a65bb..dce56b3 100644
--- a/runtime/mem_map.cc
+++ b/runtime/mem_map.cc
@@ -70,6 +70,7 @@
return os;
}
+std::mutex* MemMap::mem_maps_lock_ = nullptr;
MemMap::Maps* MemMap::maps_ = nullptr;
#if USE_ART_LOW_4G_ALLOCATOR
@@ -139,7 +140,7 @@
// There is a suspicion that BacktraceMap::Create is occasionally missing maps. TODO: Investigate
// further.
{
- MutexLock mu(Thread::Current(), *Locks::mem_maps_lock_);
+ std::lock_guard<std::mutex> mu(*mem_maps_lock_);
for (auto& pair : *maps_) {
MemMap* const map = pair.second;
if (begin >= reinterpret_cast<uintptr_t>(map->Begin()) &&
@@ -490,7 +491,7 @@
}
// Remove it from maps_.
- MutexLock mu(Thread::Current(), *Locks::mem_maps_lock_);
+ std::lock_guard<std::mutex> mu(*mem_maps_lock_);
bool found = false;
DCHECK(maps_ != nullptr);
for (auto it = maps_->lower_bound(base_begin_), end = maps_->end();
@@ -518,7 +519,7 @@
CHECK_NE(base_size_, 0U);
// Add it to maps_.
- MutexLock mu(Thread::Current(), *Locks::mem_maps_lock_);
+ std::lock_guard<std::mutex> mu(*mem_maps_lock_);
DCHECK(maps_ != nullptr);
maps_->insert(std::make_pair(base_begin_, this));
}
@@ -637,7 +638,7 @@
}
bool MemMap::CheckNoGaps(MemMap* begin_map, MemMap* end_map) {
- MutexLock mu(Thread::Current(), *Locks::mem_maps_lock_);
+ std::lock_guard<std::mutex> mu(*mem_maps_lock_);
CHECK(begin_map != nullptr);
CHECK(end_map != nullptr);
CHECK(HasMemMap(begin_map));
@@ -656,7 +657,7 @@
}
void MemMap::DumpMaps(std::ostream& os, bool terse) {
- MutexLock mu(Thread::Current(), *Locks::mem_maps_lock_);
+ std::lock_guard<std::mutex> mu(*mem_maps_lock_);
DumpMapsLocked(os, terse);
}
@@ -747,17 +748,31 @@
}
void MemMap::Init() {
- MutexLock mu(Thread::Current(), *Locks::mem_maps_lock_);
- if (maps_ == nullptr) {
+ if (mem_maps_lock_ != nullptr) {
// dex2oat calls MemMap::Init twice since its needed before the runtime is created.
- maps_ = new Maps;
+ return;
}
+ mem_maps_lock_ = new std::mutex();
+ // Not for thread safety, but for the annotation that maps_ is GUARDED_BY(mem_maps_lock_).
+ std::lock_guard<std::mutex> mu(*mem_maps_lock_);
+ DCHECK(maps_ == nullptr);
+ maps_ = new Maps;
}
void MemMap::Shutdown() {
- MutexLock mu(Thread::Current(), *Locks::mem_maps_lock_);
- delete maps_;
- maps_ = nullptr;
+ if (mem_maps_lock_ == nullptr) {
+ // If MemMap::Shutdown is called more than once, there is no effect.
+ return;
+ }
+ {
+ // Not for thread safety, but for the annotation that maps_ is GUARDED_BY(mem_maps_lock_).
+ std::lock_guard<std::mutex> mu(*mem_maps_lock_);
+ DCHECK(maps_ != nullptr);
+ delete maps_;
+ maps_ = nullptr;
+ }
+ delete mem_maps_lock_;
+ mem_maps_lock_ = nullptr;
}
void MemMap::SetSize(size_t new_size) {
@@ -813,7 +828,7 @@
if (low_4gb && addr == nullptr) {
bool first_run = true;
- MutexLock mu(Thread::Current(), *Locks::mem_maps_lock_);
+ std::lock_guard<std::mutex> mu(*mem_maps_lock_);
for (uintptr_t ptr = next_mem_pos_; ptr < 4 * GB; ptr += kPageSize) {
// Use maps_ as an optimization to skip over large maps.
// Find the first map which is address > ptr.