ART: Speed up thread stack tracing for ANRs
Share a BacktraceMap for all threads being dumped, which speeds up
ANR dumping. Results from Nexus 9 (average of five):
Before: 0.587s
After: 0.206s
Change-Id: Ia70e0dbd39049318c02de561e7b95258d4849467
diff --git a/runtime/utils.cc b/runtime/utils.cc
index 62af380..dee4f9c 100644
--- a/runtime/utils.cc
+++ b/runtime/utils.cc
@@ -46,7 +46,9 @@
#include <sys/syscall.h>
#endif
-#include <backtrace/Backtrace.h> // For DumpNativeStack.
+// For DumpNativeStack.
+#include <backtrace/Backtrace.h>
+#include <backtrace/BacktraceMap.h>
#if defined(__linux__)
#include <linux/unistd.h>
@@ -1102,7 +1104,7 @@
}
#endif
-void DumpNativeStack(std::ostream& os, pid_t tid, const char* prefix,
+void DumpNativeStack(std::ostream& os, pid_t tid, BacktraceMap* existing_map, const char* prefix,
ArtMethod* current_method, void* ucontext_ptr) {
#if __linux__
// b/18119146
@@ -1110,7 +1112,13 @@
return;
}
- std::unique_ptr<Backtrace> backtrace(Backtrace::Create(BACKTRACE_CURRENT_PROCESS, tid));
+ BacktraceMap* map = existing_map;
+ std::unique_ptr<BacktraceMap> tmp_map;
+ if (map == nullptr) {
+ tmp_map.reset(BacktraceMap::Create(tid));
+ map = tmp_map.get();
+ }
+ std::unique_ptr<Backtrace> backtrace(Backtrace::Create(BACKTRACE_CURRENT_PROCESS, tid, map));
if (!backtrace->Unwind(0, reinterpret_cast<ucontext*>(ucontext_ptr))) {
os << prefix << "(backtrace::Unwind failed for thread " << tid << ")\n";
return;
@@ -1174,7 +1182,7 @@
}
}
#else
- UNUSED(os, tid, prefix, current_method, ucontext_ptr);
+ UNUSED(os, tid, existing_map, prefix, current_method, ucontext_ptr);
#endif
}