Cosmetic improvements.
[invirt/third/libt4.git] / rpc / rpc.cc
index cd03073..7937785 100644 (file)
-/*
- The rpcc class handles client-side RPC.  Each rpcc is bound to a
- single RPC server.  The jobs of rpcc include maintaining a connection to
- server, sending RPC requests and waiting for responses, retransmissions,
- at-most-once delivery etc.
-
- The rpcs class handles the server side of RPC.  Each rpcs handles multiple
- connections from different rpcc objects.  The jobs of rpcs include accepting
- connections, dispatching requests to registered RPC handlers, at-most-once
- delivery etc.
-
- Both rpcc and rpcs use the connection class as an abstraction for the
- underlying communication channel.  To send an RPC request/reply, one calls
- connection::send() which blocks until data is sent or the connection has failed
- (thus the caller can free the buffer when send() returns).  When a
- request/reply is received, connection makes a callback into the corresponding
- rpcc or rpcs (see rpcc::got_pdu() and rpcs::got_pdu()).
-
- Thread organization:
- rpcc uses application threads to send RPC requests and blocks to receive the
- reply or error. All connections use a single PollMgr object to perform async
- socket IO.  PollMgr creates a single thread to examine the readiness of socket
- file descriptors and informs the corresponding connection whenever a socket is
- ready to be read or written.  (We use asynchronous socket IO to reduce the
- number of threads needed to manage these connections; without async IO, at
- least one thread is needed per connection to read data without blocking other
- activities.)  Each rpcs object creates one thread for listening on the server
- port and a pool of threads for executing RPC requests.  The
- thread pool allows us to control the number of threads spawned at the server
- (spawning one thread per request will hurt when the server faces thousands of
- requests).
-
- In order to delete a connection object, we must maintain a reference count.
- For rpcc,
- multiple client threads might be invoking the rpcc::call() functions and thus
- holding multiple references to the underlying connection object. For rpcs,
- multiple dispatch threads might be holding references to the same connection
- object.  A connection object is deleted only when the underlying connection is
- dead and the reference count reaches zero.
-
- The previous version of the RPC library uses pthread_cancel* routines 
- to implement the deletion of rpcc and rpcs objects. The idea is to cancel 
- all active threads that might be holding a reference to an object before 
- deleting that object. However, pthread_cancel is not robust and there are
- always bugs where outstanding references to deleted objects persist.
- This version of the RPC library does not do pthread_cancel, but explicitly 
- joins exited threads to make sure no outstanding references exist before 
- deleting objects.
-
- To delete a rpcc object safely, the users of the library must ensure that
- there are no outstanding calls on the rpcc object.
-
- To delete a rpcs object safely, we do the following in sequence: 1. stop
- accepting new incoming connections. 2. close existing active connections.
- 3.  delete the dispatch thread pool which involves waiting for current active
- RPC handlers to finish.  It is interesting how a thread pool can be deleted
- without using thread cancellation. The trick is to inject x "poison pills" for
- a thread pool of x threads. Upon getting a poison pill instead of a normal 
- task, a worker thread will exit (and thread pool destructor waits to join all
- x exited worker threads).
- */
+//
+// The rpcc class handles client-side RPC.  Each rpcc is bound to a single RPC
+// server.  The jobs of rpcc include maintaining a connection to server, sending
+// RPC requests and waiting for responses, retransmissions, at-most-once delivery
+// etc.
+//
+// The rpcs class handles the server side of RPC.  Each rpcs handles multiple
+// connections from different rpcc objects.  The jobs of rpcs include accepting
+// connections, dispatching requests to registered RPC handlers, at-most-once
+// delivery etc.
+//
+// Both rpcc and rpcs use the connection class as an abstraction for the
+// underlying communication channel.  To send an RPC request/reply, one calls
+// connection::send() which blocks until data is sent or the connection has
+// failed (thus the caller can free the buffer when send() returns).  When a
+// request/reply is received, connection makes a callback into the corresponding
+// rpcc or rpcs (see rpcc::got_pdu() and rpcs::got_pdu()).
+//
+// Thread organization:
+// rpcc uses application threads to send RPC requests and blocks to receive the
+// reply or error. All connections use a single PollMgr object to perform async
+// socket IO.  PollMgr creates a single thread to examine the readiness of socket
+// file descriptors and informs the corresponding connection whenever a socket is
+// ready to be read or written.  (We use asynchronous socket IO to reduce the
+// number of threads needed to manage these connections; without async IO, at
+// least one thread is needed per connection to read data without blocking other
+// activities.)  Each rpcs object creates one thread for listening on the server
+// port and a pool of threads for executing RPC requests.  The thread pool allows
+// us to control the number of threads spawned at the server (spawning one thread
+// per request will hurt when the server faces thousands of requests).
+//
+// In order to delete a connection object, we must maintain a reference count.
+// For rpcc, multiple client threads might be invoking the rpcc::call() functions
+// and thus holding multiple references to the underlying connection object. For
+// rpcs, multiple dispatch threads might be holding references to the same
+// connection object.  A connection object is deleted only when the underlying
+// connection is dead and the reference count reaches zero.
+//
+// This version of the RPC library explicitly joins exited threads to make sure
+// no outstanding references exist before deleting objects.
+//
+// To delete a rpcc object safely, the users of the library must ensure that
+// there are no outstanding calls on the rpcc object.
+//
+// To delete a rpcs object safely, we do the following in sequence: 1. stop
+// accepting new incoming connections. 2. close existing active connections.  3.
+// delete the dispatch thread pool which involves waiting for current active RPC
+// handlers to finish.  It is interesting how a thread pool can be deleted
+// without using thread cancellation. The trick is to inject x "poison pills" for
+// a thread pool of x threads. Upon getting a poison pill instead of a normal
+// task, a worker thread will exit (and thread pool destructor waits to join all
+// x exited worker threads).
+//
 
 #include "rpc.h"
-#include "method_thread.h"
-#include "slock.h"
 
-#include <sys/types.h>
 #include <arpa/inet.h>
 #include <netinet/tcp.h>
-#include <time.h>
 #include <netdb.h>
 #include <unistd.h>
+#include <string.h>
 
-#include "jsl_log.h"
-#include "gettime.h"
-#include "lang/verify.h"
-
-const rpcc::TO rpcc::to_max = { 120000 };
-const rpcc::TO rpcc::to_min = { 1000 };
-
-rpcc::caller::caller(unsigned int xxid, unmarshall *xun)
-: xid(xxid), un(xun), done(false)
-{
-       VERIFY(pthread_mutex_init(&m,0) == 0);
-       VERIFY(pthread_cond_init(&c, 0) == 0);
+inline void set_rand_seed() {
+    auto now = time_point_cast<nanoseconds>(steady_clock::now());
+    srandom((uint32_t)now.time_since_epoch().count()^(uint32_t)getpid());
 }
 
-rpcc::caller::~caller()
-{
-       VERIFY(pthread_mutex_destroy(&m) == 0);
-       VERIFY(pthread_cond_destroy(&c) == 0);
-}
+static sockaddr_in make_sockaddr(const string & hostandport);
 
-inline
-void set_rand_seed()
+rpcc::rpcc(const string & d) : dst_(make_sockaddr(d))
 {
-       struct timespec ts;
-       clock_gettime(CLOCK_REALTIME, &ts);
-       srandom((int)ts.tv_nsec^((int)getpid()));
-}
+    set_rand_seed();
+    clt_nonce_ = (nonce_t)random();
 
-rpcc::rpcc(sockaddr_in d, bool retrans) : 
-       dst_(d), srv_nonce_(0), bind_done_(false), xid_(1), lossytest_(0), 
-       retrans_(retrans), reachable_(true), chan_(NULL), destroy_wait_ (false), xid_rep_done_(-1)
-{
-       VERIFY(pthread_mutex_init(&m_, 0) == 0);
-       VERIFY(pthread_mutex_init(&chan_m_, 0) == 0);
-       VERIFY(pthread_cond_init(&destroy_wait_c_, 0) == 0);
-
-       if(retrans){
-               set_rand_seed();
-               clt_nonce_ = random();
-       } else {
-               // special client nonce 0 means this client does not 
-               // require at-most-once logic from the server
-               // because it uses tcp and never retries a failed connection
-               clt_nonce_ = 0;
-       }
-
-       char *loss_env = getenv("RPC_LOSSY");
-       if(loss_env != NULL){
-               lossytest_ = atoi(loss_env);
-       }
-
-       // xid starts with 1 and latest received reply starts with 0
-       xid_rep_window_.push_back(0);
-
-       jsl_log(JSL_DBG_2, "rpcc::rpcc cltn_nonce is %d lossy %d\n", 
-                       clt_nonce_, lossytest_); 
+    char *loss_env = getenv("RPC_LOSSY");
+    if (loss_env)
+        lossytest_ = atoi(loss_env);
+
+    IF_LEVEL(2) LOG("cltn_nonce is " << clt_nonce_ << " lossy " << lossytest_);
 }
 
 // IMPORTANT: destruction should happen only when no external threads
 // are blocked inside rpcc or will use rpcc in the future
-rpcc::~rpcc()
-{
-       jsl_log(JSL_DBG_2, "rpcc::~rpcc delete nonce %d channo=%d\n", 
-                       clt_nonce_, chan_?chan_->channo():-1); 
-       if(chan_){
-               chan_->closeconn();
-               chan_->decref();
-       }
-       VERIFY(calls_.size() == 0);
-       VERIFY(pthread_mutex_destroy(&m_) == 0);
-       VERIFY(pthread_mutex_destroy(&chan_m_) == 0);
-}
-
-int
-rpcc::bind(TO to)
-{
-       int r;
-       int ret = call(rpc_const::bind, 0, r, to);
-       if(ret == 0){
-               ScopedLock ml(&m_);
-               bind_done_ = true;
-               srv_nonce_ = r;
-       } else {
-               jsl_log(JSL_DBG_2, "rpcc::bind %s failed %d\n", 
-                               inet_ntoa(dst_.sin_addr), ret);
-       }
-       return ret;
+rpcc::~rpcc() {
+    cancel();
+    IF_LEVEL(2) LOG("delete nonce " << clt_nonce_ << " chan " << (chan_?(int)chan_->fd:-1));
+    chan_.reset();
+    VERIFY(calls_.size() == 0);
+}
+
+int rpcc::bind(milliseconds to) {
+    nonce_t r;
+    rpc_protocol::status ret = call_timeout(rpc_protocol::bind, to, r);
+    if (ret == 0) {
+        lock ml(m_);
+        bind_done_ = true;
+        srv_nonce_ = r;
+    } else {
+        IF_LEVEL(2) LOG("bind " << inet_ntoa(dst_.sin_addr) << " failed " << ret);
+    }
+    return ret;
 };
 
 // Cancel all outstanding calls
-void
-rpcc::cancel(void)
-{
-  ScopedLock ml(&m_);
-  printf("rpcc::cancel: force callers to fail\n");
-  std::map<int,caller*>::iterator iter;
-  for(iter = calls_.begin(); iter != calls_.end(); iter++){
-    caller *ca = iter->second;
+void rpcc::cancel(void) {
+    lock ml(m_);
+    if (calls_.size()) {
+        LOG("force callers to fail");
+        for (auto & p : calls_) {
+            caller *ca = p.second;
+
+            IF_LEVEL(2) LOG("force caller to fail");
+
+            lock cl(ca->m);
+            ca->done = true;
+            ca->intret = rpc_protocol::cancel_failure;
+            ca->c.notify_one();
+        }
 
-    jsl_log(JSL_DBG_2, "rpcc::cancel: force caller to fail\n");
+        destroy_wait_ = true;
+        while (calls_.size () > 0)
+            destroy_wait_c_.wait(ml);
+
+        LOG("done");
+    }
+}
+
+int rpcc::call1(proc_id_t proc, milliseconds to, string & rep, marshall & req) {
+
+    caller ca(0, &rep);
+    xid_t xid_rep;
     {
-      ScopedLock cl(&ca->m);
-      ca->done = true;
-      ca->intret = rpc_const::cancel_failure;
-      VERIFY(pthread_cond_signal(&ca->c) == 0);
+        lock ml(m_);
+
+        if ((proc != rpc_protocol::bind.id && !bind_done_) || (proc == rpc_protocol::bind.id && bind_done_)) {
+            IF_LEVEL(1) LOG("rpcc has not been bound to dst or binding twice");
+            return rpc_protocol::bind_failure;
+        }
+
+        if (destroy_wait_)
+            return rpc_protocol::cancel_failure;
+
+        ca.xid = xid_++;
+        calls_[ca.xid] = &ca;
+
+        req.pack_header(rpc_protocol::request_header{
+                ca.xid, proc, clt_nonce_, srv_nonce_, xid_rep_window_.front()
+                });
+        xid_rep = xid_rep_window_.front();
     }
-  }
 
-  while (calls_.size () > 0){
-    destroy_wait_ = true;
-    VERIFY(pthread_cond_wait(&destroy_wait_c_,&m_) == 0);
-  }
-  printf("rpcc::cancel: done\n");
-}
+    milliseconds curr_to = rpc::to_min;
+    auto finaldeadline = steady_clock::now() + to;
+
+    bool transmit = true;
+    shared_ptr<connection> ch;
+
+    while (1) {
+        if (transmit) {
+            get_latest_connection(ch);
+            if (ch) {
+                if (reachable_) {
+                    request forgot;
+                    {
+                        lock ml(m_);
+                        if (dup_req_.isvalid() && xid_rep_done_ > dup_req_.xid) {
+                            forgot = dup_req_;
+                            dup_req_.clear();
+                        }
+                    }
+                    if (forgot.isvalid())
+                        ch->send(forgot.buf);
+                    ch->send(req);
+                }
+                else IF_LEVEL(1) LOG("not reachable");
+                IF_LEVEL(2) LOG(clt_nonce_ << " just sent req proc " << hex << proc <<
+                                " xid " << dec << ca.xid << " clt_nonce " << clt_nonce_);
+            }
+            transmit = false; // only send once on a given channel
+        }
 
-int
-rpcc::call1(unsigned int proc, marshall &req, unmarshall &rep,
-               TO to)
-{
+        auto nextdeadline = min(steady_clock::now() + curr_to, finaldeadline);
+        curr_to *= 2;
 
-       caller ca(0, &rep);
-        int xid_rep;
-       {
-               ScopedLock ml(&m_);
-
-               if((proc != rpc_const::bind && !bind_done_) ||
-                               (proc == rpc_const::bind && bind_done_)){
-                       jsl_log(JSL_DBG_1, "rpcc::call1 rpcc has not been bound to dst or binding twice\n");
-                       return rpc_const::bind_failure;
-               }
-
-               if(destroy_wait_){
-                 return rpc_const::cancel_failure;
-               }
-
-               ca.xid = xid_++;
-               calls_[ca.xid] = &ca;
-
-               req_header h(ca.xid, proc, clt_nonce_, srv_nonce_,
-                             xid_rep_window_.front());
-               req.pack_req_header(h);
-                xid_rep = xid_rep_window_.front();
-       }
-
-       TO curr_to;
-       struct timespec now, nextdeadline, finaldeadline; 
-
-       clock_gettime(CLOCK_REALTIME, &now);
-       add_timespec(now, to.to, &finaldeadline); 
-       curr_to.to = to_min.to;
-
-       bool transmit = true;
-       connection *ch = NULL;
-
-       while (1){
-               if(transmit){
-                       get_refconn(&ch);
-                       if(ch){
-                               if(reachable_) {
-                                        request forgot;
-                                        {
-                                                ScopedLock ml(&m_);
-                                                if (dup_req_.isvalid() && xid_rep_done_ > dup_req_.xid) {
-                                                        forgot = dup_req_;
-                                                        dup_req_.clear();
-                                                }
-                                        }
-                                        if (forgot.isvalid()) 
-                                                ch->send((char *)forgot.buf.c_str(), forgot.buf.size());
-                                        ch->send(req.cstr(), req.size());
-                                }
-                               else jsl_log(JSL_DBG_1, "not reachable\n");
-                               jsl_log(JSL_DBG_2, 
-                                               "rpcc::call1 %u just sent req proc %x xid %u clt_nonce %d\n", 
-                                               clt_nonce_, proc, ca.xid, clt_nonce_); 
-                       }
-                       transmit = false; // only send once on a given channel
-               }
-
-               if(!finaldeadline.tv_sec)
-                       break;
-
-               clock_gettime(CLOCK_REALTIME, &now);
-               add_timespec(now, curr_to.to, &nextdeadline); 
-               if(cmp_timespec(nextdeadline,finaldeadline) > 0){
-                       nextdeadline = finaldeadline;
-                       finaldeadline.tv_sec = 0;
-               }
-
-               {
-                       ScopedLock cal(&ca.m);
-                       while (!ca.done){
-                               jsl_log(JSL_DBG_2, "rpcc:call1: wait\n");
-                               if(pthread_cond_timedwait(&ca.c, &ca.m,
-                                                 &nextdeadline) == ETIMEDOUT){
-                                       jsl_log(JSL_DBG_2, "rpcc::call1: timeout\n");
-                                       break;
-                               }
-                       }
-                       if(ca.done){
-                               jsl_log(JSL_DBG_2, "rpcc::call1: reply received\n");
-                               break;
-                       }
-               }
-
-               if(retrans_ && (!ch || ch->isdead())){
-                       // since connection is dead, retransmit
-                        // on the new connection 
-                       transmit = true; 
-               }
-               curr_to.to <<= 1;
-       }
-
-       { 
-                // no locking of ca.m since only this thread changes ca.xid 
-               ScopedLock ml(&m_);
-               calls_.erase(ca.xid);
-               // may need to update the xid again here, in case the
-               // packet times out before it's even sent by the channel.
-               // I don't think there's any harm in maybe doing it twice
-               update_xid_rep(ca.xid);
-
-               if(destroy_wait_){
-                 VERIFY(pthread_cond_signal(&destroy_wait_c_) == 0);
-               }
-       }
-
-        if (ca.done && lossytest_)
         {
-                ScopedLock ml(&m_);
-                if (!dup_req_.isvalid()) {
-                        dup_req_.buf.assign(req.cstr(), req.size());
-                        dup_req_.xid = ca.xid;
+            lock cal(ca.m);
+            while (!ca.done) {
+                IF_LEVEL(2) LOG("wait");
+                if (ca.c.wait_until(cal, nextdeadline) == cv_status::timeout) {
+                    IF_LEVEL(2) LOG("timeout");
+                    break;
                 }
-                if (xid_rep > xid_rep_done_)
-                        xid_rep_done_ = xid_rep;
+            }
+            if (ca.done) {
+                IF_LEVEL(2) LOG("reply received");
+                break;
+            }
         }
 
-       ScopedLock cal(&ca.m);
+        if (nextdeadline >= finaldeadline)
+            break;
+
+        // retransmit on new connection if connection is dead
+        if (!ch || ch->isdead())
+            transmit = true;
+    }
+
+    {
+        // no locking of ca.m since only this thread changes ca.xid
+        lock ml(m_);
+        calls_.erase(ca.xid);
+        // may need to update the xid again here, in case the
+        // packet times out before it's even sent by the channel.
+        // I don't think there's any harm in maybe doing it twice
+        update_xid_rep(ca.xid, ml);
+
+        if (destroy_wait_)
+            destroy_wait_c_.notify_one();
+    }
+
+    if (ca.done && lossytest_)
+    {
+        lock ml(m_);
+        if (!dup_req_.isvalid()) {
+            dup_req_.buf = req;
+            dup_req_.xid = ca.xid;
+        }
+        if (xid_rep > xid_rep_done_)
+            xid_rep_done_ = xid_rep;
+    }
 
-       jsl_log(JSL_DBG_2, 
-                       "rpcc::call1 %u call done for req proc %x xid %u %s:%d done? %d ret %d \n", 
-                       clt_nonce_, proc, ca.xid, inet_ntoa(dst_.sin_addr),
-                       ntohs(dst_.sin_port), ca.done, ca.intret);
+    lock cal(ca.m);
 
-       if(ch)
-               ch->decref();
+    IF_LEVEL(2) LOG(clt_nonce_ << " call done for req proc " << hex << proc <<
+                    " xid " << dec << ca.xid << " " << inet_ntoa(dst_.sin_addr) << ":" <<
+                    ntoh(dst_.sin_port) << " done? " << ca.done << " ret " << ca.intret);
 
-       // destruction of req automatically frees its buffer
-       return (ca.done? ca.intret : rpc_const::timeout_failure);
+    // destruction of req automatically frees its buffer
+    return (ca.done? ca.intret : rpc_protocol::timeout_failure);
 }
 
-void
-rpcc::get_refconn(connection **ch)
-{
-       ScopedLock ml(&chan_m_);
-       if(!chan_ || chan_->isdead()){
-               if(chan_)
-                       chan_->decref();
-               chan_ = connect_to_dst(dst_, this, lossytest_);
-       }
-       if(ch && chan_){
-               if(*ch){
-                       (*ch)->decref();
-               }
-               *ch = chan_;
-               (*ch)->incref();
-       }
+void rpcc::get_latest_connection(shared_ptr<connection> & ch) {
+    lock ml(chan_m_);
+    if (!chan_ || chan_->isdead())
+        chan_ = connection::to_dst(dst_, this, lossytest_);
+
+    if (chan_)
+        ch = chan_;
 }
 
-// PollMgr's thread is being used to 
-// make this upcall from connection object to rpcc. 
+// PollMgr's thread is being used to
+// make this upcall from connection object to rpcc.
 // this funtion must not block.
 //
-// this function keeps no reference for connection *c 
+// this function keeps no reference for connection *c
 bool
-rpcc::got_pdu(connection *c, char *b, int sz)
+rpcc::got_pdu(const shared_ptr<connection> &, const string & b)
 {
-       unmarshall rep(b, sz);
-       reply_header h;
-       rep.unpack_reply_header(&h);
-
-       if(!rep.ok()){
-               jsl_log(JSL_DBG_1, "rpcc:got_pdu unmarshall header failed!!!\n");
-               return true;
-       }
-
-       ScopedLock ml(&m_);
-
-       update_xid_rep(h.xid);
-
-       if(calls_.find(h.xid) == calls_.end()){
-               jsl_log(JSL_DBG_2, "rpcc::got_pdu xid %d no pending request\n", h.xid);
-               return true;
-       }
-       caller *ca = calls_[h.xid];
-
-       ScopedLock cl(&ca->m);
-       if(!ca->done){
-               ca->un->take_in(rep);
-               ca->intret = h.ret;
-               if(ca->intret < 0){
-                       jsl_log(JSL_DBG_2, "rpcc::got_pdu: RPC reply error for xid %d intret %d\n",
-                                       h.xid, ca->intret);
-               }
-               ca->done = 1;
-       }
-       VERIFY(pthread_cond_broadcast(&ca->c) == 0);
-       return true;
-}
+    unmarshall rep(b, true);
+    rpc_protocol::reply_header h;
+    rep.unpack_header(h);
 
-// assumes thread holds mutex m
-void 
-rpcc::update_xid_rep(unsigned int xid)
-{
-       std::list<unsigned int>::iterator it;
+    if (!rep.ok()) {
+        IF_LEVEL(1) LOG("unmarshall header failed!!!");
+        return true;
+    }
 
-       if(xid <= xid_rep_window_.front()){
-               return;
-       }
+    lock ml(m_);
 
-       for (it = xid_rep_window_.begin(); it != xid_rep_window_.end(); it++){
-               if(*it > xid){
-                       xid_rep_window_.insert(it, xid);
-                       goto compress;
-               }
-       }
-       xid_rep_window_.push_back(xid);
+    update_xid_rep(h.xid, ml);
 
-compress:
-       it = xid_rep_window_.begin();
-       for (it++; it != xid_rep_window_.end(); it++){
-               while (xid_rep_window_.front() + 1 == *it)
-                       xid_rep_window_.pop_front();
-       }
+    if (calls_.find(h.xid) == calls_.end()) {
+        IF_LEVEL(2) LOG("xid " << h.xid << " no pending request");
+        return true;
+    }
+    caller *ca = calls_[h.xid];
+
+    lock cl(ca->m);
+    if (!ca->done) {
+        *ca->rep = b;
+        ca->intret = h.ret;
+        if (ca->intret < 0) {
+            IF_LEVEL(2) LOG("RPC reply error for xid " << h.xid << " intret " << ca->intret);
+        }
+        ca->done = 1;
+    }
+    ca->c.notify_all();
+    return true;
 }
 
+void rpcc::update_xid_rep(xid_t xid, lock & m_lock) {
+    VERIFY(m_lock);
+    if (xid <= xid_rep_window_.front())
+        return;
 
-rpcs::rpcs(unsigned int p1, int count)
-  : port_(p1), counting_(count), curr_counts_(count), lossytest_(0), reachable_ (true)
-{
-       VERIFY(pthread_mutex_init(&procs_m_, 0) == 0);
-       VERIFY(pthread_mutex_init(&count_m_, 0) == 0);
-       VERIFY(pthread_mutex_init(&reply_window_m_, 0) == 0);
-       VERIFY(pthread_mutex_init(&conss_m_, 0) == 0);
+    for (auto it = xid_rep_window_.begin(); it != xid_rep_window_.end(); it++) {
+        if (*it > xid) {
+            xid_rep_window_.insert(it, xid);
+            goto compress;
+        }
+    }
+    xid_rep_window_.push_back(xid);
 
-       set_rand_seed();
-       nonce_ = random();
-       jsl_log(JSL_DBG_2, "rpcs::rpcs created with nonce %d\n", nonce_);
+compress:
+    auto it = xid_rep_window_.begin();
+    for (it++; it != xid_rep_window_.end(); it++) {
+        while (xid_rep_window_.front() + 1 == *it)
+            xid_rep_window_.pop_front();
+    }
+}
 
-       char *loss_env = getenv("RPC_LOSSY");
-       if(loss_env != NULL){
-               lossytest_ = atoi(loss_env);
-       }
+rpcs::rpcs(in_port_t p1) : port_(p1)
+{
+    set_rand_seed();
+    nonce_ = (nonce_t)random();
+    IF_LEVEL(2) LOG("created with nonce " << nonce_);
 
-       reg(rpc_const::bind, this, &rpcs::rpcbind);
-       dispatchpool_ = new ThrPool(6,false);
+    reg(rpc_protocol::bind, &rpcs::rpcbind, this);
+}
 
-       listener_ = new tcpsconn(this, port_, lossytest_);
+void rpcs::start() {
+    char *loss_env = getenv("RPC_LOSSY");
+    listener_.reset(new connection_listener(this, port_, loss_env ? atoi(loss_env) : 0));
 }
 
-rpcs::~rpcs()
-{
-       // must delete listener before dispatchpool
-       delete listener_;
-       delete dispatchpool_;
-       free_reply_window();
+rpcs::~rpcs() {
+    // must delete listener before dispatchpool
+    listener_ = nullptr;
+    dispatchpool_ = nullptr;
 }
 
-bool
-rpcs::got_pdu(connection *c, char *b, int sz)
-{
-        if(!reachable_){
-            jsl_log(JSL_DBG_1, "rpcss::got_pdu: not reachable\n");
-            return true;
-        }
+bool rpcs::got_pdu(const shared_ptr<connection> & c, const string & b) {
+    if (!reachable_) {
+        IF_LEVEL(1) LOG("not reachable");
+        return true;
+    }
 
-       djob_t *j = new djob_t(c, b, sz);
-       c->incref();
-       bool succ = dispatchpool_->addObjJob(this, &rpcs::dispatch, j);
-       if(!succ || !reachable_){
-               c->decref();
-               delete j;
-       }
-       return succ; 
+    return dispatchpool_->addJob(std::bind(&rpcs::dispatch, this, c, b));
 }
 
-void
-rpcs::reg1(unsigned int proc, handler *h)
-{
-       ScopedLock pl(&procs_m_);
-       VERIFY(procs_.count(proc) == 0);
-       procs_[proc] = h;
-       VERIFY(procs_.count(proc) >= 1);
-}
+void rpcs::dispatch(shared_ptr<connection> c, const string & buf) {
+    unmarshall req(buf, true);
 
-void
-rpcs::updatestat(unsigned int proc)
-{
-       ScopedLock cl(&count_m_);
-       counts_[proc]++;
-       curr_counts_--;
-       if(curr_counts_ == 0){
-               std::map<int, int>::iterator i;
-               printf("RPC STATS: ");
-               for (i = counts_.begin(); i != counts_.end(); i++){
-                       printf("%x:%d ", i->first, i->second);
-               }
-               printf("\n");
-
-               ScopedLock rwl(&reply_window_m_);
-               std::map<unsigned int,std::list<reply_t> >::iterator clt;
-
-               unsigned int totalrep = 0, maxrep = 0;
-               for (clt = reply_window_.begin(); clt != reply_window_.end(); clt++){
-                       totalrep += clt->second.size();
-                       if(clt->second.size() > maxrep)
-                               maxrep = clt->second.size();
-               }
-               jsl_log(JSL_DBG_1, "REPLY WINDOW: clients %d total reply %d max per client %d\n", 
-                        (int) reply_window_.size()-1, totalrep, maxrep);
-               curr_counts_ = counting_;
-       }
-}
+    rpc_protocol::request_header h;
+    req.unpack_header(h);
+    proc_id_t proc = h.proc;
 
-void
-rpcs::dispatch(djob_t *j)
-{
-       connection *c = j->conn;
-       unmarshall req(j->buf, j->sz);
-       delete j;
-
-       req_header h;
-       req.unpack_req_header(&h);
-       int proc = h.proc;
-
-       if(!req.ok()){
-               jsl_log(JSL_DBG_1, "rpcs:dispatch unmarshall header failed!!!\n");
-               c->decref();
-               return;
-       }
-
-       jsl_log(JSL_DBG_2,
-                       "rpcs::dispatch: rpc %u (proc %x, last_rep %u) from clt %u for srv instance %u \n",
-                       h.xid, proc, h.xid_rep, h.clt_nonce, h.srv_nonce);
-
-       marshall rep;
-       reply_header rh(h.xid,0);
-
-       // is client sending to an old instance of server?
-       if(h.srv_nonce != 0 && h.srv_nonce != nonce_){
-               jsl_log(JSL_DBG_2,
-                               "rpcs::dispatch: rpc for an old server instance %u (current %u) proc %x\n",
-                               h.srv_nonce, nonce_, h.proc);
-               rh.ret = rpc_const::oldsrv_failure;
-               rep.pack_reply_header(rh);
-               c->send(rep.cstr(),rep.size());
-               return;
-       }
-
-       handler *f;
-       // is RPC proc a registered procedure?
-       {
-               ScopedLock pl(&procs_m_);
-               if(procs_.count(proc) < 1){
-                       fprintf(stderr, "rpcs::dispatch: unknown proc %x.\n",
-                               proc);
-                       c->decref();
-                        VERIFY(0);
-                       return;
-               }
-
-               f = procs_[proc];
-       }
-
-       rpcs::rpcstate_t stat;
-       char *b1;
-       int sz1;
-
-       if(h.clt_nonce){
-               // have i seen this client before?
-               {
-                       ScopedLock rwl(&reply_window_m_);
-                       // if we don't know about this clt_nonce, create a cleanup object
-                       if(reply_window_.find(h.clt_nonce) == reply_window_.end()){
-                               VERIFY (reply_window_[h.clt_nonce].size() == 0); // create
-                reply_window_[h.clt_nonce].push_back(reply_t(-1)); // store starting reply xid
-                               jsl_log(JSL_DBG_2,
-                                               "rpcs::dispatch: new client %u xid %d chan %d, total clients %d\n", 
-                                               h.clt_nonce, h.xid, c->channo(), (int)reply_window_.size()-1);
-                       }
-               }
-
-               // save the latest good connection to the client
-               {
-                       ScopedLock rwl(&conss_m_);
-                       if(conns_.find(h.clt_nonce) == conns_.end()){
-                               c->incref();
-                               conns_[h.clt_nonce] = c;
-                       } else if(conns_[h.clt_nonce]->compare(c) < 0){
-                               conns_[h.clt_nonce]->decref();
-                               c->incref();
-                               conns_[h.clt_nonce] = c;
-                       }
-               }
-
-               stat = checkduplicate_and_update(h.clt_nonce, h.xid,
-                                                 h.xid_rep, &b1, &sz1);
-       } else {
-               // this client does not require at most once logic
-               stat = NEW;
-       }
-
-       switch (stat){
-               case NEW: // new request
-                       if(counting_){
-                               updatestat(proc);
-                       }
-
-                       rh.ret = f->fn(req, rep);
-                        if (rh.ret == rpc_const::unmarshal_args_failure) {
-                                fprintf(stderr, "rpcs::dispatch: failed to"
-                                       " unmarshall the arguments. You are"
-                                       " probably calling RPC 0x%x with wrong"
-                                       " types of arguments.\n", proc);
-                                VERIFY(0);
-                        }
-                       VERIFY(rh.ret >= 0);
-
-                       rep.pack_reply_header(rh);
-                       rep.take_buf(&b1,&sz1);
-
-                       jsl_log(JSL_DBG_2,
-                                       "rpcs::dispatch: sending and saving reply of size %d for rpc %u, proc %x ret %d, clt %u\n",
-                                       sz1, h.xid, proc, rh.ret, h.clt_nonce);
-
-                       if(h.clt_nonce > 0){
-                               // only record replies for clients that require at-most-once logic
-                               add_reply(h.clt_nonce, h.xid, b1, sz1);
-                       }
-
-                       // get the latest connection to the client
-                       {
-                               ScopedLock rwl(&conss_m_);
-                               if(c->isdead() && c != conns_[h.clt_nonce]){
-                                       c->decref();
-                                       c = conns_[h.clt_nonce];
-                                       c->incref();
-                               }
-                       }
-
-                       c->send(b1, sz1);
-                       if(h.clt_nonce == 0){
-                               // reply is not added to at-most-once window, free it
-                               free(b1);
-                       }
-                       break;
-               case INPROGRESS: // server is working on this request
-                       break;
-               case DONE: // duplicate and we still have the response
-                       c->send(b1, sz1);
-                       break;
-               case FORGOTTEN: // very old request and we don't have the response anymore
-                       jsl_log(JSL_DBG_2, "rpcs::dispatch: very old request %u from %u\n", 
-                                       h.xid, h.clt_nonce);
-                       rh.ret = rpc_const::atmostonce_failure;
-                       rep.pack_reply_header(rh);
-                       c->send(rep.cstr(),rep.size());
-                       break;
-       }
-       c->decref();
+    if (!req.ok()) {
+        IF_LEVEL(1) LOG("unmarshall header failed");
+        return;
+    }
+
+    IF_LEVEL(2) LOG("rpc " << h.xid << " (proc " << hex << proc << ", last_rep " <<
+                    dec << h.xid_rep << ") from clt " << h.clt_nonce << " for srv instance " << h.srv_nonce);
+
+    marshall rep;
+    rpc_protocol::reply_header rh{h.xid,0};
+
+    // is client sending to an old instance of server?
+    if (h.srv_nonce != 0 && h.srv_nonce != nonce_) {
+        IF_LEVEL(2) LOG("rpc for an old server instance " << h.srv_nonce <<
+                        " (current " << nonce_ << ") proc " << hex << h.proc);
+        rh.ret = rpc_protocol::oldsrv_failure;
+        rep.pack_header(rh);
+        c->send(rep);
+        return;
+    }
+
+    handler *f;
+    // is RPC proc a registered procedure?
+    {
+        lock pl(procs_m_);
+        if (procs_.count(proc) < 1) {
+            LOG("unknown proc 0x" << hex << proc << " with h.srv_nonce=" << h.srv_nonce << ", my srv_nonce=" << nonce_);
+            VERIFY(0);
+            return;
+        }
+
+        f = procs_[proc];
+    }
+
+    // have i seen this client before?
+    {
+        lock rwl(reply_window_m_);
+        // if we don't know about this clt_nonce, create a cleanup object
+        if (reply_window_.find(h.clt_nonce) == reply_window_.end()) {
+            VERIFY (reply_window_[h.clt_nonce].size() == 0); // create
+            reply_window_[h.clt_nonce].push_back(reply_t(-1)); // store starting reply xid
+            IF_LEVEL(2) LOG("new client " << h.clt_nonce << " xid " << h.xid <<
+                            " chan " << c->fd << ", total clients " << (reply_window_.size()-1));
+        }
+    }
+
+    // save the latest good connection to the client
+    {
+        lock rwl(conns_m_);
+        if (conns_.find(h.clt_nonce) == conns_.end())
+            conns_[h.clt_nonce] = c;
+        else if (conns_[h.clt_nonce]->create_time < c->create_time)
+            conns_[h.clt_nonce] = c;
+    }
+
+    string b1;
+
+    switch (check_duplicate_and_update(h.clt_nonce, h.xid, h.xid_rep, b1)) {
+        case NEW: // new request
+            rh.ret = (*f)(forward<unmarshall>(req), rep);
+            if (rh.ret == rpc_protocol::unmarshall_args_failure) {
+                LOG("failed to unmarshall the arguments. You are " <<
+                    "probably calling RPC 0x" << hex << proc << " with the wrong " <<
+                    "types of arguments.");
+                VERIFY(0);
+            }
+            VERIFY(rh.ret >= 0);
+
+            rep.pack_header(rh);
+            b1 = rep;
+
+            IF_LEVEL(2) LOG("sending and saving reply of size " << b1.size() << " for rpc " <<
+                            h.xid << ", proc " << hex << proc << " ret " << dec << rh.ret << ", clt " << h.clt_nonce);
+
+            add_reply(h.clt_nonce, h.xid, b1);
+
+            // get the latest connection to the client
+            {
+                lock rwl(conns_m_);
+                if (c->isdead())
+                    c = conns_[h.clt_nonce];
+            }
+
+            c->send(rep);
+            break;
+        case INPROGRESS: // server is working on this request
+            break;
+        case DONE: // duplicate and we still have the response
+            c->send(b1);
+            break;
+        case FORGOTTEN: // very old request and we don't have the response anymore
+            IF_LEVEL(2) LOG("very old request " << h.xid << " from " << h.clt_nonce);
+            rh.ret = rpc_protocol::atmostonce_failure;
+            rep.pack_header(rh);
+            c->send(rep);
+            break;
+    }
 }
 
 // rpcs::dispatch calls this when an RPC request arrives.
@@ -656,35 +456,32 @@ rpcs::dispatch(djob_t *j)
 // returns one of:
 //   NEW: never seen this xid before.
 //   INPROGRESS: seen this xid, and still processing it.
-//   DONE: seen this xid, previous reply returned in *b and *sz.
+//   DONE: seen this xid, previous reply returned in b.
 //   FORGOTTEN: might have seen this xid, but deleted previous reply.
-rpcs::rpcstate_t 
-rpcs::checkduplicate_and_update(unsigned int clt_nonce, unsigned int xid,
-               unsigned int xid_rep, char **b, int *sz)
+rpcs::rpcstate_t
+rpcs::check_duplicate_and_update(nonce_t clt_nonce, xid_t xid,
+        xid_t xid_rep, string & b)
 {
-       ScopedLock rwl(&reply_window_m_);
+    lock rwl(reply_window_m_);
 
-    std::list<reply_t> &l = reply_window_[clt_nonce];
+    list<reply_t> & l = reply_window_[clt_nonce];
 
     VERIFY(l.size() > 0);
     VERIFY(xid >= xid_rep);
 
-    unsigned int past_xid_rep = l.begin()->xid;
+    xid_t past_xid_rep = l.begin()->xid;
 
-    std::list<reply_t>::iterator start = l.begin(), it;
-    it = ++start;
+    list<reply_t>::iterator start = l.begin(), it = ++start;
 
-    if (past_xid_rep < xid_rep || past_xid_rep == (unsigned int)-1) {
+    if (past_xid_rep < xid_rep || past_xid_rep == -1) {
         // scan for deletion candidates
-        for (; it != l.end() && it->xid < xid_rep; it++) {
-            if (it->cb_present)
-                free(it->buf);
-        }
+        while (it != l.end() && it->xid < xid_rep)
+            it++;
         l.erase(start, it);
         l.begin()->xid = xid_rep;
     }
 
-    if (xid < past_xid_rep && past_xid_rep != (unsigned int)-1)
+    if (xid < past_xid_rep && past_xid_rep != -1)
         return FORGOTTEN;
 
     // skip non-deletion candidates
@@ -695,12 +492,10 @@ rpcs::checkduplicate_and_update(unsigned int clt_nonce, unsigned int xid,
     if (it != l.end() && it->xid == xid) {
         if (it->cb_present) {
             // return information about the remembered reply
-            *b = it->buf;
-            *sz = it->sz;
+            b = it->buf;
             return DONE;
-        } else {
-            return INPROGRESS;
         }
+        return INPROGRESS;
     } else {
         // remember that a new request has arrived
         l.insert(it, reply_t(xid));
@@ -709,379 +504,56 @@ rpcs::checkduplicate_and_update(unsigned int clt_nonce, unsigned int xid,
 }
 
 // rpcs::dispatch calls add_reply when it is sending a reply to an RPC,
-// and passes the return value in b and sz.
-// add_reply() should remember b and sz.
-// free_reply_window() and checkduplicate_and_update is responsible for 
-// calling free(b).
-void
-rpcs::add_reply(unsigned int clt_nonce, unsigned int xid,
-               char *b, int sz)
-{
-       ScopedLock rwl(&reply_window_m_);
+// and passes the return value in b.
+// add_reply() should remember b.
+void rpcs::add_reply(nonce_t clt_nonce, xid_t xid, const string & b) {
+    lock rwl(reply_window_m_);
     // remember the RPC reply value
-    std::list<reply_t> &l = reply_window_[clt_nonce];
-    std::list<reply_t>::iterator it = l.begin();
+    list<reply_t> & l = reply_window_[clt_nonce];
+    list<reply_t>::iterator it = l.begin();
     // skip to our place in the list
     for (it++; it != l.end() && it->xid < xid; it++);
     // there should already be an entry, so whine if there isn't
     if (it == l.end() || it->xid != xid) {
-        fprintf(stderr, "Could not find reply struct in add_reply");
-        l.insert(it, reply_t(xid, b, sz));
+        LOG("Could not find reply struct in add_reply");
+        l.insert(it, reply_t(xid, b));
     } else {
-        *it = reply_t(xid, b, sz);
+        *it = reply_t(xid, b);
     }
 }
 
-void
-rpcs::free_reply_window(void)
-{
-       std::map<unsigned int,std::list<reply_t> >::iterator clt;
-       std::list<reply_t>::iterator it;
-
-       ScopedLock rwl(&reply_window_m_);
-       for (clt = reply_window_.begin(); clt != reply_window_.end(); clt++){
-               for (it = clt->second.begin(); it != clt->second.end(); it++){
-                       if (it->cb_present)
-                free(it->buf);
-               }
-               clt->second.clear();
-       }
-       reply_window_.clear();
-}
-
-// rpc handler
-int 
-rpcs::rpcbind(int a, int &r)
-{
-       jsl_log(JSL_DBG_2, "rpcs::rpcbind called return nonce %u\n", nonce_);
-       r = nonce_;
-       return 0;
-}
-
-void
-marshall::rawbyte(unsigned char x)
-{
-       if(_ind >= _capa){
-               _capa *= 2;
-               VERIFY (_buf != NULL);
-               _buf = (char *)realloc(_buf, _capa);
-               VERIFY(_buf);
-       }
-       _buf[_ind++] = x;
-}
-
-void
-marshall::rawbytes(const char *p, int n)
-{
-       if((_ind+n) > _capa){
-               _capa = _capa > n? 2*_capa:(_capa+n);
-               VERIFY (_buf != NULL);
-               _buf = (char *)realloc(_buf, _capa);
-               VERIFY(_buf);
-       }
-       memcpy(_buf+_ind, p, n);
-       _ind += n;
-}
-
-marshall &
-operator<<(marshall &m, bool x)
-{
-       m.rawbyte(x);
-       return m;
-}
-
-marshall &
-operator<<(marshall &m, unsigned char x)
-{
-       m.rawbyte(x);
-       return m;
-}
-
-marshall &
-operator<<(marshall &m, char x)
-{
-       m << (unsigned char) x;
-       return m;
-}
-
-
-marshall &
-operator<<(marshall &m, unsigned short x)
-{
-       m.rawbyte((x >> 8) & 0xff);
-       m.rawbyte(x & 0xff);
-       return m;
-}
-
-marshall &
-operator<<(marshall &m, short x)
-{
-       m << (unsigned short) x;
-       return m;
-}
-
-marshall &
-operator<<(marshall &m, unsigned int x)
-{
-       // network order is big-endian
-       m.rawbyte((x >> 24) & 0xff);
-       m.rawbyte((x >> 16) & 0xff);
-       m.rawbyte((x >> 8) & 0xff);
-       m.rawbyte(x & 0xff);
-       return m;
-}
-
-marshall &
-operator<<(marshall &m, int x)
-{
-       m << (unsigned int) x;
-       return m;
-}
-
-marshall &
-operator<<(marshall &m, const std::string &s)
-{
-       m << (unsigned int) s.size();
-       m.rawbytes(s.data(), s.size());
-       return m;
-}
-
-marshall &
-operator<<(marshall &m, unsigned long long x)
-{
-       m << (unsigned int) (x >> 32);
-       m << (unsigned int) x;
-       return m;
-}
-
-void
-marshall::pack(int x)
-{
-       rawbyte((x >> 24) & 0xff);
-       rawbyte((x >> 16) & 0xff);
-       rawbyte((x >> 8) & 0xff);
-       rawbyte(x & 0xff);
-}
-
-void
-unmarshall::unpack(int *x)
-{
-       (*x) = (rawbyte() & 0xff) << 24;
-       (*x) |= (rawbyte() & 0xff) << 16;
-       (*x) |= (rawbyte() & 0xff) << 8;
-       (*x) |= rawbyte() & 0xff;
-}
-
-// take the contents from another unmarshall object
-void
-unmarshall::take_in(unmarshall &another)
-{
-       if(_buf)
-               free(_buf);
-       another.take_buf(&_buf, &_sz);
-       _ind = RPC_HEADER_SZ;
-       _ok = _sz >= RPC_HEADER_SZ?true:false;
-}
-
-bool
-unmarshall::okdone()
-{
-       if(ok() && _ind == _sz){
-               return true;
-       } else {
-               return false;
-       }
+rpc_protocol::status rpcs::rpcbind(nonce_t & r) {
+    IF_LEVEL(2) LOG("called return nonce " << nonce_);
+    r = nonce_;
+    return 0;
 }
 
-unsigned int
-unmarshall::rawbyte()
-{
-       char c = 0;
-       if(_ind >= _sz)
-               _ok = false;
-       else
-               c = _buf[_ind++];
-       return c;
-}
-
-unmarshall &
-operator>>(unmarshall &u, bool &x)
-{
-       x = (bool) u.rawbyte() ;
-       return u;
-}
-
-unmarshall &
-operator>>(unmarshall &u, unsigned char &x)
-{
-       x = (unsigned char) u.rawbyte() ;
-       return u;
-}
-
-unmarshall &
-operator>>(unmarshall &u, char &x)
-{
-       x = (char) u.rawbyte();
-       return u;
-}
-
-
-unmarshall &
-operator>>(unmarshall &u, unsigned short &x)
-{
-       x = (u.rawbyte() & 0xff) << 8;
-       x |= u.rawbyte() & 0xff;
-       return u;
-}
-
-unmarshall &
-operator>>(unmarshall &u, short &x)
-{
-       x = (u.rawbyte() & 0xff) << 8;
-       x |= u.rawbyte() & 0xff;
-       return u;
-}
-
-unmarshall &
-operator>>(unmarshall &u, unsigned int &x)
-{
-       x = (u.rawbyte() & 0xff) << 24;
-       x |= (u.rawbyte() & 0xff) << 16;
-       x |= (u.rawbyte() & 0xff) << 8;
-       x |= u.rawbyte() & 0xff;
-       return u;
-}
-
-unmarshall &
-operator>>(unmarshall &u, int &x)
-{
-       x = (u.rawbyte() & 0xff) << 24;
-       x |= (u.rawbyte() & 0xff) << 16;
-       x |= (u.rawbyte() & 0xff) << 8;
-       x |= u.rawbyte() & 0xff;
-       return u;
-}
-
-unmarshall &
-operator>>(unmarshall &u, unsigned long long &x)
-{
-       unsigned int h, l;
-       u >> h;
-       u >> l;
-       x = l | ((unsigned long long) h << 32);
-       return u;
-}
-
-unmarshall &
-operator>>(unmarshall &u, std::string &s)
-{
-       unsigned sz;
-       u >> sz;
-       if(u.ok())
-               u.rawbytes(s, sz);
-       return u;
-}
-
-void
-unmarshall::rawbytes(std::string &ss, unsigned int n)
-{
-       if((_ind+n) > (unsigned)_sz){
-               _ok = false;
-       } else {
-               std::string tmps = std::string(_buf+_ind, n);
-               swap(ss, tmps);
-               VERIFY(ss.size() == n);
-               _ind += n;
-       }
-}
-
-bool operator<(const sockaddr_in &a, const sockaddr_in &b){
-       return ((a.sin_addr.s_addr < b.sin_addr.s_addr) ||
-                       ((a.sin_addr.s_addr == b.sin_addr.s_addr) &&
-                        ((a.sin_port < b.sin_port))));
-}
-
-/*---------------auxilary function--------------*/
-void
-make_sockaddr(const char *hostandport, struct sockaddr_in *dst){
-
-       char host[200];
-       const char *localhost = "127.0.0.1";
-       const char *port = index(hostandport, ':');
-       if(port == NULL){
-               memcpy(host, localhost, strlen(localhost)+1);
-               port = hostandport;
-       } else {
-               memcpy(host, hostandport, port-hostandport);
-               host[port-hostandport] = '\0';
-               port++;
-       }
-
-       make_sockaddr(host, port, dst);
-
-}
+static sockaddr_in make_sockaddr(const string & hostandport) {
+    string host = "127.0.0.1";
+    string port = hostandport;
+    auto colon = hostandport.find(':');
+    if (colon != string::npos) {
+        host = hostandport.substr(0, colon);
+        port = hostandport.substr(colon+1);
+    }
 
-void
-make_sockaddr(const char *host, const char *port, struct sockaddr_in *dst){
-
-       in_addr_t a;
-
-       bzero(dst, sizeof(*dst));
-       dst->sin_family = AF_INET;
-
-       a = inet_addr(host);
-       if(a != INADDR_NONE){
-               dst->sin_addr.s_addr = a;
-       } else {
-               struct hostent *hp = gethostbyname(host);
-               if(hp == 0 || hp->h_length != 4){
-                       fprintf(stderr, "cannot find host name %s\n", host);
-                       exit(1);
-               }
-               dst->sin_addr.s_addr = ((struct in_addr *)(hp->h_addr))->s_addr;
-       }
-       dst->sin_port = htons(atoi(port));
-}
+    sockaddr_in dst{}; // zero initialize
+    dst.sin_family = AF_INET;
 
-int
-cmp_timespec(const struct timespec &a, const struct timespec &b)
-{
-       if(a.tv_sec > b.tv_sec)
-               return 1;
-       else if(a.tv_sec < b.tv_sec)
-               return -1;
-       else {
-               if(a.tv_nsec > b.tv_nsec)
-                       return 1;
-               else if(a.tv_nsec < b.tv_nsec)
-                       return -1;
-               else
-                       return 0;
-       }
-}
+    struct in_addr a{inet_addr(host.c_str())};
 
-void
-add_timespec(const struct timespec &a, int b, struct timespec *result)
-{
-       // convert to millisec, add timeout, convert back
-       result->tv_sec = a.tv_sec + b/1000;
-       result->tv_nsec = a.tv_nsec + (b % 1000) * 1000000;
-       VERIFY(result->tv_nsec >= 0);
-       while (result->tv_nsec > 1000000000){
-               result->tv_sec++;
-               result->tv_nsec-=1000000000;
-       }
-}
+    if (a.s_addr != INADDR_NONE)
+        dst.sin_addr.s_addr = a.s_addr;
+    else {
+        struct hostent *hp = gethostbyname(host.c_str());
 
-int
-diff_timespec(const struct timespec &end, const struct timespec &start)
-{
-       int diff = (end.tv_sec > start.tv_sec)?(end.tv_sec-start.tv_sec)*1000:0;
-       VERIFY(diff || end.tv_sec == start.tv_sec);
-       if(end.tv_nsec > start.tv_nsec){
-               diff += (end.tv_nsec-start.tv_nsec)/1000000;
-       } else {
-               diff -= (start.tv_nsec-end.tv_nsec)/1000000;
-       }
-       return diff;
+        if (!hp || hp->h_length != 4 || hp->h_addrtype != AF_INET) {
+            LOG_NONMEMBER("cannot find host name " << host);
+            exit(1);
+        }
+        memcpy(&a, hp->h_addr_list[0], sizeof(in_addr_t));
+        dst.sin_addr.s_addr = a.s_addr;
+    }
+    dst.sin_port = hton((in_port_t)stoi(port));
+    return dst;
 }