move progress reporting to main thread

src/main.cpp

@@ -69,6 +69,7 @@ bool NextCode(std::string& buffer, size_t start) {
 }
 
 // see https://bisqwit.iki.fi/jutut/kuvat/programming_examples/cpp_thread_tutorial/ver05.cc
+// this version of the code doesn't even need to worry about synchronization
 namespace {
 	unsigned ln = 1;
 
@@ -86,15 +87,17 @@ namespace {
 		return "\r" + (m < 0 ? "\33[" + std::to_string(-m) + 'A' : std::string(m, '\n'));
 	}
 
-	std::mutex print_lock;
-
 } // namespace
 
-struct BruteThreadState {
+struct ThreadDisplayData {
-	BruteThreadState(unsigned line) : line(line) {}
+	ThreadDisplayData() { codeString.resize(8); }
 
-	void DisplayProgress(const std::string& code, std::uint32_t hash) {
+	std::uint32_t threadIndex;
-		std::lock_guard<std::mutex> lk(print_lock);
+	std::string codeString;
+	std::uint32_t codeHash;
+	bool done = false;
+
+	void DisplayProgress() {
 		struct FputcIterator {
 			using iterator_category = std::output_iterator_tag;
 			using value_type = void;
@@ -116,34 +119,51 @@ struct BruteThreadState {
 			std::FILE* file;
 		};
 
-		std::format_to(FputcIterator(stdout), "{}Thread {:2}: Trying code {}{} {}({:08x}){}", Line(line), line, Color(172), code, Color(166), hash,
+		if(!done)
-					   Reset());
+			std::format_to(FputcIterator(stdout), "{}Thread {:2}: Trying code {}{} {}({:08x}){}", Line(threadIndex), threadIndex, Color(172),
+						   codeString, Color(166), codeHash, Reset());
+		else {
+			std::format_to(FputcIterator(stdout), "{}Thread {:2}: {}Finished!{}", Line(threadIndex), threadIndex, Color(172), Reset());
+		}
 		std::fflush(stdout);
 	}
+};
+
+std::vector<ThreadDisplayData> data(26);
+
+struct BruteThreadState {
+	BruteThreadState(unsigned tid) : threadIndex(tid) {}
 
 	void BruteForce(char prefix) {
 		// for(std::uint32_t i = 8; i <= code_length; ++i) {
-		std::string test_buffer(code_length, 'a');
+		test_buffer.resize(code_length, 'a');
 		test_buffer[0] = prefix;
 
 		// test all possible combinations
 		while(true) {
 			// std::string test_buffer = RandomString(code_length, rng);
-			auto hash = SwsfScramble(test_buffer);
+			hash = SwsfScramble(test_buffer);
 			if(hash == code_hash) {
 				std::cerr << std::format("match: {} ({:08x})\n", test_buffer, hash);
 			}
 
-			DisplayProgress(test_buffer, hash);
+			memcpy(data[threadIndex].codeString.data(), test_buffer.data(), test_buffer.length());
+			data[threadIndex].codeHash = hash;
+
+			// DisplayProgress(test_buffer, hash);
 
 			if(!NextCode(test_buffer, 1))
 				break;
 		}
 		//}
+
+		data[threadIndex].done = true;
 	}
 
-   private:
+	std::string test_buffer;
-	unsigned line;
+	std::uint32_t hash;
+
+	unsigned threadIndex;
 	std::random_device rd;
 	// swbf::Xoshiro256ss rng{rd};
 };
@@ -151,17 +171,33 @@ struct BruteThreadState {
 int main() {
 	asio::io_context ioc;
 
-	asio::thread_pool pool(26);
+	asio::thread_pool pool(27);
 
-	auto line = 0u;
+	auto threadIndex = 0u;
 
 	// post worker threads to run onto the thread pool & wait for them to complete
 	for(int i = 0; i < 26; ++i)
-		asio::post(pool, [i, l = line++]() {
+		asio::post(pool, [&, i, tid = threadIndex++]() {
-			BruteThreadState state(l);
+			BruteThreadState state(tid);
+			data[tid].threadIndex = tid;
 			state.BruteForce('a' + i);
 		});
 
-	pool.join();
+	bool done = false;
+
+	while(!done) {
+		int doneIndex = 0;
+		for(auto& d : data) {
+			if(d.done)
+			  doneIndex++;
+			d.DisplayProgress();
+		}
+
+		if(doneIndex == 26) {
+			done = true;
+		}
+	}
+
+	pool.join(); // just in case!
 	return 0;
 }