Merge "libbacktraceoffline: make it thread-safe." (a3e49773) · Commits · e / os / android_system_core

libbacktrace/BacktraceOffline.cpp

+18 −7

Original line number	Diff line number	Diff line
		@@ -31,6 +31,7 @@ extern "C" {
		#include <unistd.h>

		#include <memory>
		#include <mutex>
		#include <string>
		#include <vector>

		@@ -91,9 +92,6 @@ struct DebugFrameInfo {
		has_debug_frame(false), has_gnu_debugdata(false) { }
		};

		static std::unordered_map<std::string, std::unique_ptr<DebugFrameInfo>>& g_debug_frames =
		*new std::unordered_map<std::string, std::unique_ptr<DebugFrameInfo>>;

		void Space::Clear() {
		start = 0;
		end = 0;
		@@ -557,18 +555,31 @@ std::string BacktraceOffline::GetFunctionNameRaw(uintptr_t, uintptr_t* offset) {
		return "";
		}

		static std::mutex g_lock;
		static std::unordered_map<std::string, std::unique_ptr<DebugFrameInfo>>* g_debug_frames = nullptr;

		static DebugFrameInfo* ReadDebugFrameFromFile(const std::string& filename);

		DebugFrameInfo* BacktraceOffline::GetDebugFrameInFile(const std::string& filename) {
		if (cache_file_) {
		auto it = g_debug_frames.find(filename);
		if (it != g_debug_frames.end()) {
		std::lock_guard<std::mutex> lock(g_lock);
		if (g_debug_frames != nullptr) {
		auto it = g_debug_frames->find(filename);
		if (it != g_debug_frames->end()) {
		return it->second.get();
		}
		}
		}
		DebugFrameInfo* debug_frame = ReadDebugFrameFromFile(filename);
		if (cache_file_) {
		g_debug_frames.emplace(filename, std::unique_ptr<DebugFrameInfo>(debug_frame));
		std::lock_guard<std::mutex> lock(g_lock);
		if (g_debug_frames == nullptr) {
		g_debug_frames = new std::unordered_map<std::string, std::unique_ptr<DebugFrameInfo>>;
		}
		auto pair = g_debug_frames->emplace(filename, std::unique_ptr<DebugFrameInfo>(debug_frame));
		if (!pair.second) {
		debug_frame = pair.first->second.get();
		}
		}
		return debug_frame;
		}