Explicit refcounting removed from connection object

[invirt/third/libt4.git] / rpc / rpc.cc

diff --git a/rpc/rpc.cc b/rpc/rpc.cc
index 62003dd..2c1f1a5 100644 (file)
--- a/rpc/rpc.cc
+++ b/rpc/rpc.cc
@@ -1,8 +1,8 @@
 /*
 /*

- 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 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
 
  The rpcs class handles the server side of RPC.  Each rpcs handles multiple
  connections from different rpcc objects.  The jobs of rpcs include accepting

@@ -11,8 +11,8 @@
 
  Both rpcc and rpcs use the connection class as an abstraction for the
  underlying communication channel.  To send an RPC request/reply, one calls
 
  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
+ 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()).
 
  request/reply is received, connection makes a callback into the corresponding
  rpcc or rpcs (see rpcc::got_pdu() and rpcs::got_pdu()).
 

@@ -25,18 +25,16 @@
  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
  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).
+ 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.
 
  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.
+ 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.
 
  This version of the RPC library explicitly joins exited threads to make sure
  no outstanding references exist before deleting objects.

@@ -45,9 +43,9 @@
  there are no outstanding calls on the rpcc object.
 
  To delete a rpcs object safely, we do the following in sequence: 1. stop
  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
+ 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
  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

@@ -63,9 +61,6 @@
 #include <netdb.h>
 #include <unistd.h>
 
 #include <netdb.h>
 #include <unistd.h>
 

-const rpcc::TO rpcc::to_max = { 120000 };
-const rpcc::TO rpcc::to_min = { 1000 };
-

 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());
 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());

@@ -75,7 +70,7 @@ static sockaddr_in make_sockaddr(const string &hostandport);
 
 rpcc::rpcc(const string & d, bool retrans) :
     dst_(make_sockaddr(d)), srv_nonce_(0), bind_done_(false), xid_(1), lossytest_(0),
 
 rpcc::rpcc(const string & d, bool retrans) :
     dst_(make_sockaddr(d)), srv_nonce_(0), bind_done_(false), xid_(1), lossytest_(0),

-    retrans_(retrans), reachable_(true), chan_(NULL), destroy_wait_ (false), xid_rep_done_(-1)
+    retrans_(retrans), reachable_(true), chan_(), destroy_wait_ (false), xid_rep_done_(-1)

 {
     if(retrans){
         set_rand_seed();
 {
     if(retrans){
         set_rand_seed();

@@ -100,15 +95,14 @@ rpcc::rpcc(const string & d, bool retrans) :
 // IMPORTANT: destruction should happen only when no external threads
 // are blocked inside rpcc or will use rpcc in the future
 rpcc::~rpcc() {
 // IMPORTANT: destruction should happen only when no external threads
 // are blocked inside rpcc or will use rpcc in the future
 rpcc::~rpcc() {

+    cancel();

     IF_LEVEL(2) LOG("delete nonce " << clt_nonce_ << " channo=" << (chan_?chan_->channo():-1));
     IF_LEVEL(2) LOG("delete nonce " << clt_nonce_ << " channo=" << (chan_?chan_->channo():-1));

-    if(chan_){
+    if(chan_)

         chan_->closeconn();
         chan_->closeconn();

-        chan_->decref();
-    }

     VERIFY(calls_.size() == 0);
 }
 
     VERIFY(calls_.size() == 0);
 }
 

-int rpcc::bind(TO to) {
+int rpcc::bind(milliseconds to) {

     unsigned int r;
     int ret = call_timeout(rpc_const::bind, to, r, 0);
     if(ret == 0){
     unsigned int r;
     int ret = call_timeout(rpc_const::bind, to, r, 0);
     if(ret == 0){

@@ -124,27 +118,29 @@ int rpcc::bind(TO to) {
 // Cancel all outstanding calls
 void rpcc::cancel(void) {
     lock ml(m_);
 // Cancel all outstanding calls
 void rpcc::cancel(void) {
     lock ml(m_);

-    LOG("force callers to fail");
-    for(auto &p : calls_){
-        caller *ca = p.second;
+    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_const::cancel_failure;
-            ca->c.notify_one();
+            IF_LEVEL(2) LOG("force caller to fail");
+            {
+                lock cl(ca->m);
+                ca->done = true;
+                ca->intret = rpc_const::cancel_failure;
+                ca->c.notify_one();
+            }

         }
         }

-    }

 
 

-    while (calls_.size () > 0){
-        destroy_wait_ = true;
-        destroy_wait_c_.wait(ml);
+        while (calls_.size () > 0){
+            destroy_wait_ = true;
+            destroy_wait_c_.wait(ml);
+        }
+        LOG("done");

     }
     }

-    LOG("done");

 }
 
 }
 

-int rpcc::call1(proc_t proc, marshall &req, string &rep, TO to) {
+int rpcc::call1(proc_t proc, marshall &req, string &rep, milliseconds to) {

 
     caller ca(0, &rep);
     int xid_rep;
 
     caller ca(0, &rep);
     int xid_rep;

@@ -168,20 +164,17 @@ int rpcc::call1(proc_t proc, marshall &req, string &rep, TO to) {
         xid_rep = xid_rep_window_.front();
     }
 
         xid_rep = xid_rep_window_.front();
     }
 

-    TO curr_to;
-    auto finaldeadline = steady_clock::now() + milliseconds(to.to),
-        nextdeadline = finaldeadline;
-
-    curr_to.to = to_min.to;
+    milliseconds curr_to = rpc::to_min;
+    auto finaldeadline = steady_clock::now() + to, nextdeadline = finaldeadline;

 
     bool transmit = true;
 
     bool transmit = true;

-    connection *ch = NULL;
+    shared_ptr<connection> ch;

 
 

-    while (1){
-        if(transmit){
-            get_refconn(&ch);
-            if(ch){
-                if(reachable_) {
+    while (1) {
+        if(transmit) {
+            get_refconn(ch);
+            if (ch) {
+                if (reachable_) {

                     request forgot;
                     {
                         lock ml(m_);
                     request forgot;
                     {
                         lock ml(m_);

@@ -204,7 +197,7 @@ int rpcc::call1(proc_t proc, marshall &req, string &rep, TO to) {
         if(finaldeadline == time_point<steady_clock>::min())
             break;
 
         if(finaldeadline == time_point<steady_clock>::min())
             break;
 

-        nextdeadline = steady_clock::now() + milliseconds(curr_to.to);
+        nextdeadline = steady_clock::now() + curr_to;

         if(nextdeadline > finaldeadline) {
             nextdeadline = finaldeadline;
             finaldeadline = time_point<steady_clock>::min();
         if(nextdeadline > finaldeadline) {
             nextdeadline = finaldeadline;
             finaldeadline = time_point<steady_clock>::min();

@@ -225,12 +218,12 @@ int rpcc::call1(proc_t proc, marshall &req, string &rep, TO to) {
             }
         }
 
             }
         }
 

-        if(retrans_ && (!ch || ch->isdead())){
+        if(retrans_ && (!ch || ch->isdead())) {

             // since connection is dead, retransmit
             // on the new connection
             transmit = true;
         }
             // since connection is dead, retransmit
             // on the new connection
             transmit = true;
         }

-        curr_to.to <<= 1;
+        curr_to *= 2;

     }
 
     {
     }
 
     {

@@ -262,31 +255,21 @@ int rpcc::call1(proc_t proc, marshall &req, string &rep, TO to) {
 
     IF_LEVEL(2) LOG(clt_nonce_ << " call done for req proc " << hex << proc <<
                     " xid " << dec << ca.xid << " " << inet_ntoa(dst_.sin_addr) << ":" <<
 
     IF_LEVEL(2) LOG(clt_nonce_ << " call done for req proc " << hex << proc <<
                     " xid " << dec << ca.xid << " " << inet_ntoa(dst_.sin_addr) << ":" <<

-                    ntohs(dst_.sin_port) << " done? " << ca.done << " ret " << ca.intret);
-
-    if(ch)
-        ch->decref();
+                    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);
 }
 
 void
 
     // destruction of req automatically frees its buffer
     return (ca.done? ca.intret : rpc_const::timeout_failure);
 }
 
 void

-rpcc::get_refconn(connection **ch)
+rpcc::get_refconn(shared_ptr<connection> & ch)

 {
     lock ml(chan_m_);
 {
     lock ml(chan_m_);

-    if(!chan_ || chan_->isdead()){
-        if(chan_)
-            chan_->decref();
+    if (!chan_ || chan_->isdead())

         chan_ = connect_to_dst(dst_, this, lossytest_);
         chan_ = connect_to_dst(dst_, this, lossytest_);

-    }
-    if(ch && chan_){
-        if(*ch){
-            (*ch)->decref();
-        }
-        *ch = chan_;
-        (*ch)->incref();
-    }
+
+    if (chan_)
+        ch = chan_;

 }
 
 // PollMgr's thread is being used to
 }
 
 // PollMgr's thread is being used to

@@ -295,7 +278,7 @@ rpcc::get_refconn(connection **ch)
 //
 // this function keeps no reference for connection *c
 bool
 //
 // this function keeps no reference for connection *c
 bool

-rpcc::got_pdu(connection *, const string & b)
+rpcc::got_pdu(const shared_ptr<connection> &, const string & b)

 {
     unmarshall rep(b, true);
     reply_header h;
 {
     unmarshall rep(b, true);
     reply_header h;

@@ -353,7 +336,7 @@ compress:
     }
 }
 
     }
 }
 

-rpcs::rpcs(unsigned int p1, size_t count)
+rpcs::rpcs(in_port_t p1, size_t count)

   : port_(p1), counting_(count), curr_counts_(count), reachable_ (true)
 {
     set_rand_seed();
   : port_(p1), counting_(count), curr_counts_(count), reachable_ (true)
 {
     set_rand_seed();

@@ -376,21 +359,14 @@ rpcs::~rpcs()
 }
 
 bool
 }
 
 bool

-rpcs::got_pdu(connection *c, const string & b)
+rpcs::got_pdu(const shared_ptr<connection> & c, const string & b)

 {
     if(!reachable_){
         IF_LEVEL(1) LOG("not reachable");
         return true;
     }
 
 {
     if(!reachable_){
         IF_LEVEL(1) LOG("not reachable");
         return true;
     }
 

-    djob_t *j = new djob_t{c, b};
-    c->incref();
-    bool succ = dispatchpool_->addJob(bind(&rpcs::dispatch, this, j));
-    if(!succ || !reachable_){
-        c->decref();
-        delete j;
-    }
-    return succ;
+    return dispatchpool_->addJob(bind(&rpcs::dispatch, this, c, b));

 }
 
 void
 }
 
 void

@@ -427,20 +403,15 @@ rpcs::updatestat(proc_t proc)
     }
 }
 
     }
 }
 

-void
-rpcs::dispatch(djob_t *j)
-{
-    connection *c = j->conn;
-    unmarshall req(j->buf, true);
-    delete j;
+void rpcs::dispatch(shared_ptr<connection> c, const string & buf) {
+    unmarshall req(buf, true);

 
     request_header h;
     req.unpack_header(h);
     proc_t proc = h.proc;
 
 
     request_header h;
     req.unpack_header(h);
     proc_t proc = h.proc;
 

-    if(!req.ok()){
-        IF_LEVEL(1) LOG("unmarshall header failed!!!");
-        c->decref();
+    if (!req.ok()) {
+        IF_LEVEL(1) LOG("unmarshall header failed");

         return;
     }
 
         return;
     }
 

@@ -466,7 +437,6 @@ rpcs::dispatch(djob_t *j)
         lock pl(procs_m_);
         if(procs_.count(proc) < 1){
             cerr << "unknown proc " << hex << proc << "." << endl;
         lock pl(procs_m_);
         if(procs_.count(proc) < 1){
             cerr << "unknown proc " << hex << proc << "." << endl;

-            c->decref();

             VERIFY(0);
             return;
         }
             VERIFY(0);
             return;
         }

@@ -492,15 +462,11 @@ rpcs::dispatch(djob_t *j)
 
         // save the latest good connection to the client
         {
 
         // save the latest good connection to the client
         {

-            lock rwl(conss_m_);
-            if(conns_.find(h.clt_nonce) == conns_.end()){
-                c->incref();
+            lock rwl(conns_m_);
+            if (conns_.find(h.clt_nonce) == conns_.end())

                 conns_[h.clt_nonce] = c;
                 conns_[h.clt_nonce] = c;

-            } else if(conns_[h.clt_nonce]->compare(c) < 0){
-                conns_[h.clt_nonce]->decref();
-                c->incref();
+            else if(conns_[h.clt_nonce]->create_time() < c->create_time())

                 conns_[h.clt_nonce] = c;
                 conns_[h.clt_nonce] = c;

-            }

         }
 
         stat = checkduplicate_and_update(h.clt_nonce, h.xid, h.xid_rep, b1);
         }
 
         stat = checkduplicate_and_update(h.clt_nonce, h.xid, h.xid_rep, b1);

@@ -537,12 +503,9 @@ rpcs::dispatch(djob_t *j)
 
             // get the latest connection to the client
             {
 
             // get the latest connection to the client
             {

-                lock rwl(conss_m_);
-                if(c->isdead() && c != conns_[h.clt_nonce]){
-                    c->decref();
+                lock rwl(conns_m_);
+                if (c->isdead())

                     c = conns_[h.clt_nonce];
                     c = conns_[h.clt_nonce];

-                    c->incref();
-                }

             }
 
             c->send(rep);
             }
 
             c->send(rep);

@@ -559,7 +522,6 @@ rpcs::dispatch(djob_t *j)
             c->send(rep);
             break;
     }
             c->send(rep);
             break;
     }

-    c->decref();

 }
 
 // rpcs::dispatch calls this when an RPC request arrives.
 }
 
 // rpcs::dispatch calls this when an RPC request arrives.

@@ -682,6 +644,6 @@ static sockaddr_in make_sockaddr(const string &host, const string &port) {
         memcpy(&a, hp->h_addr_list[0], sizeof(in_addr_t));
         dst.sin_addr.s_addr = a.s_addr;
     }
         memcpy(&a, hp->h_addr_list[0], sizeof(in_addr_t));
         dst.sin_addr.s_addr = a.s_addr;
     }

-    dst.sin_port = hton((uint16_t)stoi(port));
+    dst.sin_port = hton((in_port_t)stoi(port));

     return dst;
 }
     return dst;
 }