From 50651c954803c1941e6ad1bb494712891c18f7d2 Mon Sep 17 00:00:00 2001
From: "Steinar H. Gunderson" <sgunderson@bigfoot.com>
Date: Thu, 5 Apr 2018 17:58:22 +0200
Subject: [PATCH] Use C++11 std::mutex and std::lock_guard instead of our RAII
 wrapper.

---
 Makefile.in   |  2 +-
 accesslog.cpp |  7 ++-----
 accesslog.h   |  3 ++-
 httpinput.cpp | 17 +++++++----------
 httpinput.h   |  4 ++--
 mutexlock.cpp | 13 -------------
 mutexlock.h   | 16 ----------------
 server.cpp    | 32 ++++++++++++++------------------
 server.h      | 14 +++++++-------
 stream.cpp    |  9 ++-------
 stream.h      |  3 ++-
 thread.cpp    |  8 ++++----
 thread.h      |  4 +++-
 udpinput.cpp  |  7 ++-----
 udpinput.h    |  4 ++--
 15 files changed, 50 insertions(+), 93 deletions(-)
 delete mode 100644 mutexlock.cpp
 delete mode 100644 mutexlock.h

diff --git a/Makefile.in b/Makefile.in
index c702ef6..0e5fb2f 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -8,7 +8,7 @@ CXXFLAGS=-Wall @CXXFLAGS@ @protobuf_CFLAGS@ @libsystemd_CFLAGS@ @libtomcrypt_CFL
 LDFLAGS=@LDFLAGS@
 LIBS=@LIBS@ @protobuf_LIBS@ @libsystemd_LIBS@ @libtomcrypt_LIBS@
 
-OBJS=main.o client.o server.o stream.o udpstream.o serverpool.o mutexlock.o input.o input_stats.o httpinput.o udpinput.o parse.o config.o acceptor.o stats.o accesslog.o thread.o util.o log.o metacube2.o sa_compare.o timespec.o state.pb.o tlse/tlse.o
+OBJS=main.o client.o server.o stream.o udpstream.o serverpool.o input.o input_stats.o httpinput.o udpinput.o parse.o config.o acceptor.o stats.o accesslog.o thread.o util.o log.o metacube2.o sa_compare.o timespec.o state.pb.o tlse/tlse.o
 
 all: cubemap
 
diff --git a/accesslog.cpp b/accesslog.cpp
index 4a54fdb..2d5eb05 100644
--- a/accesslog.cpp
+++ b/accesslog.cpp
@@ -7,25 +7,22 @@
 #include "accesslog.h"
 #include "client.h"
 #include "log.h"
-#include "mutexlock.h"
 #include "timespec.h"
 
 using namespace std;
 
 AccessLogThread::AccessLogThread()
 {
-	pthread_mutex_init(&mutex, nullptr);
 }
 
 AccessLogThread::AccessLogThread(const string &filename)
 	: filename(filename) {
-	pthread_mutex_init(&mutex, nullptr);
 }
 
 void AccessLogThread::write(const ClientStats& client)
 {
 	{
-		MutexLock lock(&mutex);
+		lock_guard<mutex> lock(mu);
 		pending_writes.push_back(client);
 	}
 	wakeup();
@@ -48,7 +45,7 @@ void AccessLogThread::do_work()
 		// Empty the queue.
 		vector<ClientStats> writes;
 		{
-			MutexLock lock(&mutex);
+			lock_guard<mutex> lock(mu);
 			swap(pending_writes, writes);
 		}
 
diff --git a/accesslog.h b/accesslog.h
index 9eae365..b6ce61c 100644
--- a/accesslog.h
+++ b/accesslog.h
@@ -7,6 +7,7 @@
 
 #include <pthread.h>
 #include <stdio.h>
+#include <mutex>
 #include <string>
 #include <vector>
 
@@ -33,7 +34,7 @@ private:
 	FILE *logfp;
 	std::string filename;
 
-	pthread_mutex_t mutex;
+	std::mutex mu;
 	std::vector<ClientStats> pending_writes;
 };
 
diff --git a/httpinput.cpp b/httpinput.cpp
index 155e0b3..05ff37c 100644
--- a/httpinput.cpp
+++ b/httpinput.cpp
@@ -20,7 +20,6 @@
 #include "httpinput.h"
 #include "log.h"
 #include "metacube2.h"
-#include "mutexlock.h"
 #include "parse.h"
 #include "serverpool.h"
 #include "state.pb.h"
@@ -51,7 +50,6 @@ HTTPInput::HTTPInput(const string &url, Input::Encoding encoding)
 	  url(url),
 	  encoding(encoding)
 {
-	pthread_mutex_init(&stats_mutex, nullptr);
 	stats.url = url;
 	stats.bytes_received = 0;
 	stats.data_bytes_received = 0;
@@ -80,7 +78,6 @@ HTTPInput::HTTPInput(const InputProto &serialized)
 	string protocol, user;
 	parse_url(url, &protocol, &user, &host, &port, &path);  // Don't care if it fails.
 
-	pthread_mutex_init(&stats_mutex, nullptr);
 	stats.url = url;
 	stats.bytes_received = serialized.bytes_received();
 	stats.data_bytes_received = serialized.data_bytes_received();
@@ -107,7 +104,7 @@ void HTTPInput::close_socket()
 		sock = -1;
 	}
 
-	MutexLock lock(&stats_mutex);
+	lock_guard<mutex> lock(stats_mutex);
 	stats.connect_time = -1;
 }
 
@@ -396,7 +393,7 @@ void HTTPInput::do_work()
 					request_bytes_sent = 0;
 				}
 
-				MutexLock lock(&stats_mutex);
+				lock_guard<mutex> lock(stats_mutex);
 				stats.connect_time = time(nullptr);
 				clock_gettime(CLOCK_MONOTONIC_COARSE, &last_activity);
 			}
@@ -566,7 +563,7 @@ void HTTPInput::do_work()
 void HTTPInput::process_data(char *ptr, size_t bytes)
 {
 	{
-		MutexLock mutex(&stats_mutex);
+		lock_guard<mutex> lock(stats_mutex);
 		stats.bytes_received += bytes;
 	}
 
@@ -645,14 +642,14 @@ void HTTPInput::process_data(char *ptr, size_t bytes)
 		// TODO: Keep metadata when sending on to other Metacube users.
 		if (flags & METACUBE_FLAGS_METADATA) {
 			{
-				MutexLock lock(&stats_mutex);
+				lock_guard<mutex> lock(stats_mutex);
 				stats.metadata_bytes_received += size;
 			}
 			process_metacube_metadata_block(hdr, pending_data.data() + sizeof(hdr), size);
 		} else {
 			// Send this block on to the servers.
 			{
-				MutexLock lock(&stats_mutex);
+				lock_guard<mutex> lock(stats_mutex);
 				stats.data_bytes_received += size;
 			}
 			char *inner_data = pending_data.data() + sizeof(metacube2_block_header);
@@ -694,7 +691,7 @@ void HTTPInput::add_destination(int stream_index)
 
 InputStats HTTPInput::get_stats() const
 {
-	MutexLock lock(&stats_mutex);
+	lock_guard<mutex> lock(stats_mutex);
 	return stats;
 }
 
@@ -725,7 +722,7 @@ void HTTPInput::process_metacube_metadata_block(const metacube2_block_header &hd
 	double elapsed = now.tv_sec - be64toh(pkt->tv_sec) +
 		1e-9 * (now.tv_nsec - long(be64toh(pkt->tv_nsec)));
 	{
-		MutexLock lock(&stats_mutex);
+		lock_guard<mutex> lock(stats_mutex);
 		stats.latency_sec = elapsed;
 	}
 }
diff --git a/httpinput.h b/httpinput.h
index ac52bfc..31819f9 100644
--- a/httpinput.h
+++ b/httpinput.h
@@ -1,8 +1,8 @@
 #ifndef _HTTPINPUT_H
 #define _HTTPINPUT_H 1
 
-#include <pthread.h>
 #include <stddef.h>
+#include <mutex>
 #include <string>
 #include <vector>
 
@@ -93,7 +93,7 @@ private:
 	int sock = -1;
 
 	// Mutex protecting <stats>.
-	mutable pthread_mutex_t stats_mutex;
+	mutable std::mutex stats_mutex;
 
 	// The current statistics for this connection. Protected by <stats_mutex>.
 	InputStats stats;
diff --git a/mutexlock.cpp b/mutexlock.cpp
deleted file mode 100644
index a1dcc6a..0000000
--- a/mutexlock.cpp
+++ /dev/null
@@ -1,13 +0,0 @@
-#include "mutexlock.h"
-
-MutexLock::MutexLock(pthread_mutex_t *mutex)
-	: mutex(mutex)
-{
-	pthread_mutex_lock(this->mutex);
-}
-
-MutexLock::~MutexLock()
-{
-	pthread_mutex_unlock(this->mutex);
-}
-
diff --git a/mutexlock.h b/mutexlock.h
deleted file mode 100644
index 0d1bc00..0000000
--- a/mutexlock.h
+++ /dev/null
@@ -1,16 +0,0 @@
-#ifndef _MUTEXLOCK_H
-#define _MUTEXLOCK_H 1
-
-#include <pthread.h>
-
-// Locks a pthread mutex, RAII-style.
-class MutexLock {
-public:
-	MutexLock(pthread_mutex_t *mutex);
-	~MutexLock();
-
-private:
-	pthread_mutex_t *mutex;
-};
-
-#endif  // !defined(_MUTEXLOCK_H)
diff --git a/server.cpp b/server.cpp
index 2ec2fe0..852ecdd 100644
--- a/server.cpp
+++ b/server.cpp
@@ -23,7 +23,6 @@
 #include "accesslog.h"
 #include "log.h"
 #include "metacube2.h"
-#include "mutexlock.h"
 #include "parse.h"
 #include "server.h"
 #include "state.pb.h"
@@ -57,9 +56,6 @@ inline bool is_earlier(timespec a, timespec b)
 
 Server::Server()
 {
-	pthread_mutex_init(&mutex, nullptr);
-	pthread_mutex_init(&queued_clients_mutex, nullptr);
-
 	epoll_fd = epoll_create(1024);  // Size argument is ignored.
 	if (epoll_fd == -1) {
 		log_perror("epoll_fd");
@@ -76,7 +72,7 @@ vector<ClientStats> Server::get_client_stats() const
 {
 	vector<ClientStats> ret;
 
-	MutexLock lock(&mutex);
+	lock_guard<mutex> lock(mu);
 	for (const auto &fd_and_client : clients) {
 		ret.push_back(fd_and_client.second.get_stats());
 	}
@@ -100,7 +96,7 @@ void Server::do_work()
 			exit(1);
 		}
 
-		MutexLock lock(&mutex);  // We release the mutex between iterations.
+		lock_guard<mutex> lock(mu);  // We release the mutex between iterations.
 	
 		process_queued_data();
 
@@ -199,7 +195,7 @@ CubemapStateProto Server::serialize()
 
 void Server::add_client_deferred(int sock, Acceptor *acceptor)
 {
-	MutexLock lock(&queued_clients_mutex);
+	lock_guard<mutex> lock(queued_clients_mutex);
 	queued_add_clients.push_back(std::make_pair(sock, acceptor));
 }
 
@@ -254,7 +250,7 @@ void Server::add_client(int sock, Acceptor *acceptor)
 
 void Server::add_client_from_serialized(const ClientProto &client)
 {
-	MutexLock lock(&mutex);
+	lock_guard<mutex> lock(mu);
 	Stream *stream;
 	int stream_index = lookup_stream_by_url(client.url());
 	if (stream_index == -1) {
@@ -313,7 +309,7 @@ int Server::lookup_stream_by_url(const string &url) const
 
 int Server::add_stream(const string &url, size_t backlog_size, size_t prebuffering_bytes, Stream::Encoding encoding, Stream::Encoding src_encoding)
 {
-	MutexLock lock(&mutex);
+	lock_guard<mutex> lock(mu);
 	stream_url_map.insert(make_pair(url, streams.size()));
 	streams.emplace_back(new Stream(url, backlog_size, prebuffering_bytes, encoding, src_encoding));
 	return streams.size() - 1;
@@ -321,7 +317,7 @@ int Server::add_stream(const string &url, size_t backlog_size, size_t prebufferi
 
 int Server::add_stream_from_serialized(const StreamProto &stream, int data_fd)
 {
-	MutexLock lock(&mutex);
+	lock_guard<mutex> lock(mu);
 	stream_url_map.insert(make_pair(stream.url(), streams.size()));
 	streams.emplace_back(new Stream(stream, data_fd));
 	return streams.size() - 1;
@@ -329,35 +325,35 @@ int Server::add_stream_from_serialized(const StreamProto &stream, int data_fd)
 	
 void Server::set_backlog_size(int stream_index, size_t new_size)
 {
-	MutexLock lock(&mutex);
+	lock_guard<mutex> lock(mu);
 	assert(stream_index >= 0 && stream_index < ssize_t(streams.size()));
 	streams[stream_index]->set_backlog_size(new_size);
 }
 
 void Server::set_prebuffering_bytes(int stream_index, size_t new_amount)
 {
-	MutexLock lock(&mutex);
+	lock_guard<mutex> lock(mu);
 	assert(stream_index >= 0 && stream_index < ssize_t(streams.size()));
 	streams[stream_index]->prebuffering_bytes = new_amount;
 }
 	
 void Server::set_encoding(int stream_index, Stream::Encoding encoding)
 {
-	MutexLock lock(&mutex);
+	lock_guard<mutex> lock(mu);
 	assert(stream_index >= 0 && stream_index < ssize_t(streams.size()));
 	streams[stream_index]->encoding = encoding;
 }
 
 void Server::set_src_encoding(int stream_index, Stream::Encoding encoding)
 {
-	MutexLock lock(&mutex);
+	lock_guard<mutex> lock(mu);
 	assert(stream_index >= 0 && stream_index < ssize_t(streams.size()));
 	streams[stream_index]->src_encoding = encoding;
 }
 	
 void Server::set_header(int stream_index, const string &http_header, const string &stream_header)
 {
-	MutexLock lock(&mutex);
+	lock_guard<mutex> lock(mu);
 	assert(stream_index >= 0 && stream_index < ssize_t(streams.size()));
 	streams[stream_index]->http_header = http_header;
 
@@ -376,7 +372,7 @@ void Server::set_header(int stream_index, const string &http_header, const strin
 	
 void Server::set_pacing_rate(int stream_index, uint32_t pacing_rate)
 {
-	MutexLock lock(&mutex);
+	lock_guard<mutex> lock(mu);
 	assert(clients.empty());
 	assert(stream_index >= 0 && stream_index < ssize_t(streams.size()));
 	streams[stream_index]->pacing_rate = pacing_rate;
@@ -384,7 +380,7 @@ void Server::set_pacing_rate(int stream_index, uint32_t pacing_rate)
 
 void Server::add_gen204(const std::string &url, const std::string &allow_origin)
 {
-	MutexLock lock(&mutex);
+	lock_guard<mutex> lock(mu);
 	assert(clients.empty());
 	ping_url_map[url] = allow_origin;
 }
@@ -978,7 +974,7 @@ void Server::change_epoll_events(Client *client, uint32_t events)
 void Server::process_queued_data()
 {
 	{
-		MutexLock lock(&queued_clients_mutex);
+		lock_guard<mutex> lock(queued_clients_mutex);
 
 		for (const pair<int, Acceptor *> &id_and_acceptor : queued_add_clients) {
 			add_client(id_and_acceptor.first, id_and_acceptor.second);
diff --git a/server.h b/server.h
index dfcac0b..68e72c4 100644
--- a/server.h
+++ b/server.h
@@ -1,7 +1,6 @@
 #ifndef _SERVER_H
 #define _SERVER_H 1
 
-#include <pthread.h>
 #include <stddef.h>
 #include <stdint.h>
 #include <sys/epoll.h>
@@ -9,6 +8,7 @@
 #include <time.h>
 #include <map>
 #include <memory>
+#include <mutex>
 #include <queue>
 #include <string>
 #include <vector>
@@ -71,24 +71,24 @@ public:
 
 private:
 	// Mutex protecting queued_add_clients.
-	// Note that if you want to hold both this and <mutex> below,
-	// you will need to take <mutex> before this one.
-	mutable pthread_mutex_t queued_clients_mutex;
+	// Note that if you want to hold both this and <mu> below,
+	// you will need to take <mu> before this one.
+	mutable std::mutex queued_clients_mutex;
 
 	// Deferred commands that should be run from the do_work() thread as soon as possible.
 	// We defer these for two reasons:
 	//
 	//  - We only want to fiddle with epoll from one thread at any given time,
 	//    and doing add_client() from the acceptor thread would violate that.
-	//  - We don't want the input thread(s) hanging on <mutex> when doing
-	//    add_data(), since they want to do add_data() rather often, and <mutex>
+	//  - We don't want the input thread(s) hanging on <mu> when doing
+	//    add_data(), since they want to do add_data() rather often, and <mu>
 	//    can be taken a lot of the time.
 	//	
 	// Protected by <queued_clients_mutex>.
 	std::vector<std::pair<int, Acceptor *>> queued_add_clients;
 
 	// All variables below this line are protected by the mutex.
-	mutable pthread_mutex_t mutex;
+	mutable std::mutex mu;
 
 	// All streams.
 	std::vector<std::unique_ptr<Stream>> streams;
diff --git a/stream.cpp b/stream.cpp
index d7a78a6..3a4ccc3 100644
--- a/stream.cpp
+++ b/stream.cpp
@@ -13,7 +13,6 @@
 
 #include "log.h"
 #include "metacube2.h"
-#include "mutexlock.h"
 #include "state.pb.h"
 #include "stream.h"
 #include "util.h"
@@ -31,8 +30,6 @@ Stream::Stream(const string &url, size_t backlog_size, size_t prebuffering_bytes
 	if (data_fd == -1) {
 		exit(1);
 	}
-
-	pthread_mutex_init(&queued_data_mutex, nullptr);
 }
 
 Stream::~Stream()
@@ -65,8 +62,6 @@ Stream::Stream(const StreamProto &serialized, int data_fd)
 		}
 		suitable_starting_points.push_back(point);
 	}
-
-	pthread_mutex_init(&queued_data_mutex, nullptr);
 }
 
 StreamProto Stream::serialize()
@@ -232,7 +227,7 @@ void Stream::add_data_deferred(const char *data, size_t bytes, uint16_t metacube
 		return;
 	}
 
-	MutexLock lock(&queued_data_mutex);
+	lock_guard<mutex> lock(queued_data_mutex);
 
 	DataElement data_element;
 	data_element.metacube_flags = metacube_flags;
@@ -271,7 +266,7 @@ void Stream::process_queued_data()
 	// Hold the lock for as short as possible, since add_data_raw() can possibly
 	// write to disk, which might disturb the input thread.
 	{
-		MutexLock lock(&queued_data_mutex);
+		lock_guard<mutex> lock(queued_data_mutex);
 		if (queued_data.empty()) {
 			return;
 		}
diff --git a/stream.h b/stream.h
index 6c757a1..17df7f3 100644
--- a/stream.h
+++ b/stream.h
@@ -9,6 +9,7 @@
 #include <sys/types.h>
 #include <sys/uio.h>
 #include <deque>
+#include <mutex>
 #include <string>
 #include <vector>
 
@@ -32,7 +33,7 @@ struct Stream {
 	// Mutex protecting <queued_data> and <queued_data_last_starting_point>.
 	// Note that if you want to hold both this and the owning server's
 	// <mutex> you will need to take <mutex> before this one.
-	mutable pthread_mutex_t queued_data_mutex;
+	mutable std::mutex queued_data_mutex;
 
 	std::string url;
 
diff --git a/thread.cpp b/thread.cpp
index 473c71a..d85be70 100644
--- a/thread.cpp
+++ b/thread.cpp
@@ -7,14 +7,14 @@
 #include <unistd.h>
 
 #include "log.h"
-#include "mutexlock.h"
 #include "thread.h"
 
+using namespace std;
+
 Thread::~Thread() {}
 
 void Thread::run()
 {
-	pthread_mutex_init(&should_stop_mutex, nullptr);
 	should_stop_status = false;
 	pthread_create(&worker_thread, nullptr, &Thread::do_work_thunk, this);
 }
@@ -22,7 +22,7 @@ void Thread::run()
 void Thread::stop()
 {
 	{
-		MutexLock lock(&should_stop_mutex);
+		lock_guard<mutex> lock(should_stop_mutex);
 		should_stop_status = true;
 	}
 	wakeup();
@@ -92,6 +92,6 @@ void Thread::wakeup()
 
 bool Thread::should_stop()
 {
-	MutexLock lock(&should_stop_mutex);
+	lock_guard<mutex> lock(should_stop_mutex);
 	return should_stop_status;
 }
diff --git a/thread.h b/thread.h
index 09e2754..46b6d39 100644
--- a/thread.h
+++ b/thread.h
@@ -4,6 +4,8 @@
 #include <signal.h>
 #include <pthread.h>
 
+#include <mutex>
+
 struct timespec;
 
 // A thread class with start/stop and signal functionality.
@@ -51,7 +53,7 @@ private:
 	pthread_t worker_thread;
 
 	// Protects should_stop_status.
-	pthread_mutex_t should_stop_mutex;
+	std::mutex should_stop_mutex;
 
 	// If this is set, the thread should return as soon as possible from do_work().
 	bool should_stop_status;
diff --git a/udpinput.cpp b/udpinput.cpp
index 93eaaa7..0035640 100644
--- a/udpinput.cpp
+++ b/udpinput.cpp
@@ -11,7 +11,6 @@
 
 #include "acceptor.h"
 #include "log.h"
-#include "mutexlock.h"
 #include "serverpool.h"
 #include "state.pb.h"
 #include "stream.h"
@@ -113,7 +112,6 @@ UDPInput::UDPInput(const string &url)
 
 	construct_header();
 
-	pthread_mutex_init(&stats_mutex, nullptr);
 	stats.url = url;
 	stats.connect_time = time(nullptr);
 }
@@ -129,7 +127,6 @@ UDPInput::UDPInput(const InputProto &serialized)
 
 	construct_header();
 
-	pthread_mutex_init(&stats_mutex, nullptr);
 	stats.url = url;
 	stats.bytes_received = serialized.bytes_received();
 	stats.data_bytes_received = serialized.data_bytes_received();
@@ -220,7 +217,7 @@ void UDPInput::do_work()
 		}
 
 		{
-			MutexLock lock(&stats_mutex);
+			lock_guard<mutex> lock(stats_mutex);
 			stats.bytes_received += ret;
 			stats.data_bytes_received += ret;
 		}
@@ -233,6 +230,6 @@ void UDPInput::do_work()
 
 InputStats UDPInput::get_stats() const
 {
-	MutexLock lock(&stats_mutex);
+	lock_guard<mutex> lock(stats_mutex);
 	return stats;
 }
diff --git a/udpinput.h b/udpinput.h
index b3f504a..4de9788 100644
--- a/udpinput.h
+++ b/udpinput.h
@@ -1,7 +1,7 @@
 #ifndef _UDPINPUT_H
 #define _UDPINPUT_H 1
 
-#include <pthread.h>
+#include <mutex>
 #include <string>
 #include <vector>
 
@@ -47,7 +47,7 @@ private:
 	char packet_buf[65536];
 
 	// Mutex protecting <stats>.
-	mutable pthread_mutex_t stats_mutex;
+	mutable std::mutex stats_mutex;
 
 	// The current statistics for this connection. Protected by <stats_mutex>.
 	InputStats stats;
-- 
2.39.2