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authorrubidium <rubidium@openttd.org>2013-11-15 22:22:01 +0000
committerrubidium <rubidium@openttd.org>2013-11-15 22:22:01 +0000
commit18a3a569fb81f3d0b04e10ff35db6919a0285742 (patch)
treedca477723c03c220810358f0af02a606d491d08c /src/network
parentc98c41e00794db958d86104e2fbf37489ba93412 (diff)
downloadopenttd-18a3a569fb81f3d0b04e10ff35db6919a0285742.tar.xz
(svn r26005) -Fix [FS#5478]: crash when transferring savegame from server to client
Diffstat (limited to 'src/network')
-rw-r--r--src/network/network_server.cpp131
-rw-r--r--src/network/network_server.h3
2 files changed, 87 insertions, 47 deletions
diff --git a/src/network/network_server.cpp b/src/network/network_server.cpp
index bab9f4ae3..716b41744 100644
--- a/src/network/network_server.cpp
+++ b/src/network/network_server.cpp
@@ -57,30 +57,90 @@ struct PacketWriter : SaveFilter {
ServerNetworkGameSocketHandler *cs; ///< Socket we are associated with.
Packet *current; ///< The packet we're currently writing to.
size_t total_size; ///< Total size of the compressed savegame.
+ Packet *packets; ///< Packet queue of the savegame; send these "slowly" to the client.
+ ThreadMutex *mutex; ///< Mutex for making threaded saving safe.
/**
* Create the packet writer.
* @param cs The socket handler we're making the packets for.
*/
- PacketWriter(ServerNetworkGameSocketHandler *cs) : SaveFilter(NULL), cs(cs), current(NULL), total_size(0)
+ PacketWriter(ServerNetworkGameSocketHandler *cs) : SaveFilter(NULL), cs(cs), current(NULL), total_size(0), packets(NULL)
{
- this->cs->savegame_mutex = ThreadMutex::New();
+ this->mutex = ThreadMutex::New();
}
/** Make sure everything is cleaned up. */
~PacketWriter()
{
- /* Prevent double frees. */
- if (this->cs != NULL) {
- if (this->cs->savegame_mutex != NULL) this->cs->savegame_mutex->BeginCritical();
- this->cs->savegame = NULL;
- if (this->cs->savegame_mutex != NULL) this->cs->savegame_mutex->EndCritical();
-
- delete this->cs->savegame_mutex;
- this->cs->savegame_mutex = NULL;
+ if (this->mutex != NULL) this->mutex->BeginCritical();
+
+ if (this->cs != NULL && this->mutex != NULL) {
+ this->mutex->WaitForSignal();
+ }
+
+ /* This must all wait until the Destroy function is called. */
+
+ while (this->packets != NULL) {
+ Packet *p = this->packets->next;
+ delete this->packets;
+ this->packets = p;
}
delete this->current;
+
+ if (this->mutex != NULL) this->mutex->EndCritical();
+
+ delete this->mutex;
+ this->mutex = NULL;
+ }
+
+ /**
+ * Begin the destruction of this packet writer. It can happen in two ways:
+ * in the first case the client disconnected while saving the map. In this
+ * case the saving has not finished and killed this PacketWriter. In that
+ * case we simply set cs to NULL, triggering the appending to fail due to
+ * the connection problem and eventually triggering the destructor. In the
+ * second case the destructor is already called, and it is waiting for our
+ * signal which we will send. Only then the packets will be removed by the
+ * destructor.
+ */
+ void Destroy()
+ {
+ if (this->mutex != NULL) this->mutex->BeginCritical();
+
+ this->cs = NULL;
+
+ if (this->mutex != NULL) this->mutex->SendSignal();
+
+ if (this->mutex != NULL) this->mutex->EndCritical();
+ }
+
+ /**
+ * Checks whether there are packets.
+ * It's not 100% threading safe, but this is only asked for when checking
+ * whether there still is something to send. Then another call will be made
+ * to actually get the Packet, which will be the only one popping packets
+ * and thus eventually setting this on false.
+ */
+ bool HasPackets()
+ {
+ return this->packets != NULL;
+ }
+
+ /**
+ * Pop a single created packet from the queue with packets.
+ */
+ Packet *PopPacket()
+ {
+ if (this->mutex != NULL) this->mutex->BeginCritical();
+
+ Packet *p = this->packets;
+ this->packets = p->next;
+ p->next = NULL;
+
+ if (this->mutex != NULL) this->mutex->EndCritical();
+
+ return p;
}
/** Append the current packet to the queue. */
@@ -88,7 +148,7 @@ struct PacketWriter : SaveFilter {
{
if (this->current == NULL) return;
- Packet **p = &this->cs->savegame_packets;
+ Packet **p = &this->packets;
while (*p != NULL) {
p = &(*p)->next;
}
@@ -104,7 +164,7 @@ struct PacketWriter : SaveFilter {
if (this->current == NULL) this->current = new Packet(PACKET_SERVER_MAP_DATA);
- if (this->cs->savegame_mutex != NULL) this->cs->savegame_mutex->BeginCritical();
+ if (this->mutex != NULL) this->mutex->BeginCritical();
byte *bufe = buf + size;
while (buf != bufe) {
@@ -119,7 +179,7 @@ struct PacketWriter : SaveFilter {
}
}
- if (this->cs->savegame_mutex != NULL) this->cs->savegame_mutex->EndCritical();
+ if (this->mutex != NULL) this->mutex->EndCritical();
this->total_size += size;
}
@@ -129,7 +189,7 @@ struct PacketWriter : SaveFilter {
/* We want to abort the saving when the socket is closed. */
if (this->cs == NULL) SlError(STR_NETWORK_ERROR_LOSTCONNECTION);
- if (this->cs->savegame_mutex != NULL) this->cs->savegame_mutex->BeginCritical();
+ if (this->mutex != NULL) this->mutex->BeginCritical();
/* Make sure the last packet is flushed. */
this->AppendQueue();
@@ -143,7 +203,7 @@ struct PacketWriter : SaveFilter {
p->Send_uint32((uint32)this->total_size);
this->cs->NetworkTCPSocketHandler::SendPacket(p);
- if (this->cs->savegame_mutex != NULL) this->cs->savegame_mutex->EndCritical();
+ if (this->mutex != NULL) this->mutex->EndCritical();
}
};
@@ -172,9 +232,10 @@ ServerNetworkGameSocketHandler::~ServerNetworkGameSocketHandler()
if (_redirect_console_to_client == this->client_id) _redirect_console_to_client = INVALID_CLIENT_ID;
OrderBackup::ResetUser(this->client_id);
- if (this->savegame_mutex != NULL) this->savegame_mutex->BeginCritical();
- if (this->savegame != NULL) this->savegame->cs = NULL;
- if (this->savegame_mutex != NULL) this->savegame_mutex->EndCritical();
+ if (this->savegame != NULL) {
+ this->savegame->Destroy();
+ this->savegame = NULL;
+ }
/* Make sure the saving is completely cancelled.
* Yes, we need to handle the save finish as well
@@ -182,14 +243,6 @@ ServerNetworkGameSocketHandler::~ServerNetworkGameSocketHandler()
* just be requesting the map and such. */
WaitTillSaved();
ProcessAsyncSaveFinish();
-
- while (this->savegame_packets != NULL) {
- Packet *p = this->savegame_packets->next;
- delete this->savegame_packets;
- this->savegame_packets = p;
- }
-
- delete this->savegame_mutex;
}
Packet *ServerNetworkGameSocketHandler::ReceivePacket()
@@ -205,13 +258,6 @@ Packet *ServerNetworkGameSocketHandler::ReceivePacket()
return p;
}
-void ServerNetworkGameSocketHandler::SendPacket(Packet *packet)
-{
- if (this->savegame_mutex != NULL) this->savegame_mutex->BeginCritical();
- this->NetworkTCPSocketHandler::SendPacket(packet);
- if (this->savegame_mutex != NULL) this->savegame_mutex->EndCritical();
-}
-
NetworkRecvStatus ServerNetworkGameSocketHandler::CloseConnection(NetworkRecvStatus status)
{
assert(status != NETWORK_RECV_STATUS_OKAY);
@@ -556,18 +602,14 @@ NetworkRecvStatus ServerNetworkGameSocketHandler::SendMap()
}
if (this->status == STATUS_MAP) {
- if (this->savegame_mutex != NULL) this->savegame_mutex->BeginCritical();
-
bool last_packet = false;
+ bool has_packets = false;
- for (uint i = 0; i < sent_packets && this->savegame_packets != NULL; i++) {
- Packet *p = this->savegame_packets;
+ for (uint i = 0; (has_packets = this->savegame->HasPackets()) && i < sent_packets; i++) {
+ Packet *p = this->savegame->PopPacket();
last_packet = p->buffer[2] == PACKET_SERVER_MAP_DONE;
- /* Remove the packet from the savegame queue and put it in the real queue. */
- this->savegame_packets = p->next;
- p->next = NULL;
- this->NetworkTCPSocketHandler::SendPacket(p);
+ this->SendPacket(p);
if (last_packet) {
/* There is no more data, so break the for */
@@ -575,10 +617,11 @@ NetworkRecvStatus ServerNetworkGameSocketHandler::SendMap()
}
}
- if (this->savegame_mutex != NULL) this->savegame_mutex->EndCritical();
-
if (last_packet) {
/* Done reading, make sure saving is done as well */
+ this->savegame->Destroy();
+ this->savegame = NULL;
+
WaitTillSaved();
/* Set the status to DONE_MAP, no we will wait for the client
@@ -615,7 +658,7 @@ NetworkRecvStatus ServerNetworkGameSocketHandler::SendMap()
case SPS_ALL_SENT:
/* All are sent, increase the sent_packets */
- if (this->savegame_packets != NULL) sent_packets *= 2;
+ if (has_packets) sent_packets *= 2;
break;
case SPS_PARTLY_SENT:
diff --git a/src/network/network_server.h b/src/network/network_server.h
index 0fc52adf3..b0a2ec461 100644
--- a/src/network/network_server.h
+++ b/src/network/network_server.h
@@ -75,16 +75,13 @@ public:
CommandQueue outgoing_queue; ///< The command-queue awaiting delivery
int receive_limit; ///< Amount of bytes that we can receive at this moment
- Packet *savegame_packets; ///< Packet queue of the savegame; send these "slowly" to the client.
struct PacketWriter *savegame; ///< Writer used to write the savegame.
- ThreadMutex *savegame_mutex; ///< Mutex for making threaded saving safe.
NetworkAddress client_address; ///< IP-address of the client (so he can be banned)
ServerNetworkGameSocketHandler(SOCKET s);
~ServerNetworkGameSocketHandler();
virtual Packet *ReceivePacket();
- virtual void SendPacket(Packet *packet);
NetworkRecvStatus CloseConnection(NetworkRecvStatus status);
void GetClientName(char *client_name, size_t size) const;