src/socketengines/socketengine_kqueue.cpp

   1 /*       +------------------------------------+
   2  *       | Inspire Internet Relay Chat Daemon |
   3  *       +------------------------------------+
   4  *
   5  *  InspIRCd: (C) 2002-2010 InspIRCd Development Team
   6  * See: http://wiki.inspircd.org/Credits
   7  *
   8  * This program is free but copyrighted software; see
   9  *          the file COPYING for details.
  10  *
  11  * ---------------------------------------------------
  12  */
  13
  14 #include "inspircd.h"
  15 #include "exitcodes.h"
  16 #include <sys/types.h>
  17 #include <sys/event.h>
  18 #include <sys/time.h>
  19 #include "socketengine.h"
  20
  21 /** A specialisation of the SocketEngine class, designed to use FreeBSD kqueue().
  22  */
  23 class KQueueEngine : public SocketEngine
  24 {
  25 private:
  26         int EngineHandle;
  27         /** These are used by kqueue() to hold socket events
  28          */
  29         struct kevent* ke_list;
  30         /** This is a specialised time value used by kqueue()
  31          */
  32         struct timespec ts;
  33 public:
  34         /** Create a new KQueueEngine
  35          */
  36         KQueueEngine();
  37         /** Delete a KQueueEngine
  38          */
  39         virtual ~KQueueEngine();
  40         bool AddFd(EventHandler* eh, int event_mask);
  41         void OnSetEvent(EventHandler* eh, int old_mask, int new_mask);
  42         virtual void DelFd(EventHandler* eh);
  43         virtual int DispatchEvents();
  44         virtual std::string GetName();
  45         virtual void RecoverFromFork();
  46 };
  47
  48 #include <sys/sysctl.h>
  49
  50 KQueueEngine::KQueueEngine()
  51 {
  52         MAX_DESCRIPTORS = 0;
  53         int mib[2];
  54         size_t len;
  55
  56         mib[0] = CTL_KERN;
  57         mib[1] = KERN_MAXFILESPERPROC;
  58         len = sizeof(MAX_DESCRIPTORS);
  59         sysctl(mib, 2, &MAX_DESCRIPTORS, &len, NULL, 0);
  60         if (MAX_DESCRIPTORS <= 0)
  61         {
  62                 ServerInstance->Logs->Log("SOCKET", DEFAULT, "ERROR: Can't determine maximum number of open sockets!");
  63                 printf("ERROR: Can't determine maximum number of open sockets!\n");
  64                 ServerInstance->Exit(EXIT_STATUS_SOCKETENGINE);
  65         }
  66
  67         this->RecoverFromFork();
  68         ke_list = new struct kevent[GetMaxFds()];
  69         ref = new EventHandler* [GetMaxFds()];
  70         memset(ref, 0, GetMaxFds() * sizeof(EventHandler*));
  71 }
  72
  73 void KQueueEngine::RecoverFromFork()
  74 {
  75         /*
  76          * The only bad thing about kqueue is that its fd cant survive a fork and is not inherited.
  77          * BUM HATS.
  78          *
  79          */
  80         EngineHandle = kqueue();
  81         if (EngineHandle == -1)
  82         {
  83                 ServerInstance->Logs->Log("SOCKET",DEFAULT, "ERROR: Could not initialize socket engine. Your kernel probably does not have the proper features.");
  84                 ServerInstance->Logs->Log("SOCKET",DEFAULT, "ERROR: this is a fatal error, exiting now.");
  85                 printf("ERROR: Could not initialize socket engine. Your kernel probably does not have the proper features.\n");
  86                 printf("ERROR: this is a fatal error, exiting now.\n");
  87                 ServerInstance->Exit(EXIT_STATUS_SOCKETENGINE);
  88         }
  89         CurrentSetSize = 0;
  90 }
  91
  92 KQueueEngine::~KQueueEngine()
  93 {
  94         this->Close(EngineHandle);
  95         delete[] ref;
  96         delete[] ke_list;
  97 }
  98
  99 bool KQueueEngine::AddFd(EventHandler* eh, int event_mask)
 100 {
 101         int fd = eh->GetFd();
 102
 103         if ((fd < 0) || (fd > GetMaxFds() - 1))
 104                 return false;
 105
 106         if (ref[fd])
 107                 return false;
 108
 109         // We always want to read from the socket...
 110         struct kevent ke;
 111         EV_SET(&ke, fd, EVFILT_READ, EV_ADD, 0, 0, NULL);
 112
 113         int i = kevent(EngineHandle, &ke, 1, 0, 0, NULL);
 114         if (i == -1)
 115         {
 116                 ServerInstance->Logs->Log("SOCKET",DEFAULT,"Failed to add fd: %d %s",
 117                                           fd, strerror(errno));
 118                 return false;
 119         }
 120
 121         ref[fd] = eh;
 122         SocketEngine::SetEventMask(eh, event_mask);
 123         OnSetEvent(eh, 0, event_mask);
 124         CurrentSetSize++;
 125
 126         ServerInstance->Logs->Log("SOCKET",DEBUG,"New file descriptor: %d", fd);
 127         return true;
 128 }
 129
 130 void KQueueEngine::DelFd(EventHandler* eh)
 131 {
 132         int fd = eh->GetFd();
 133
 134         if ((fd < 0) || (fd > GetMaxFds() - 1))
 135         {
 136                 ServerInstance->Logs->Log("SOCKET",DEFAULT,"DelFd() on invalid fd: %d", fd);
 137                 return;
 138         }
 139
 140         struct kevent ke;
 141
 142         // First remove the write filter ignoring errors, since we can't be
 143         // sure if there are actually any write filters registered.
 144         EV_SET(&ke, eh->GetFd(), EVFILT_WRITE, EV_DELETE, 0, 0, NULL);
 145         kevent(EngineHandle, &ke, 1, 0, 0, NULL);
 146
 147         // Then remove the read filter.
 148         EV_SET(&ke, eh->GetFd(), EVFILT_READ, EV_DELETE, 0, 0, NULL);
 149         int j = kevent(EngineHandle, &ke, 1, 0, 0, NULL);
 150
 151         if (j < 0)
 152         {
 153                 ServerInstance->Logs->Log("SOCKET",DEFAULT,"Failed to remove fd: %d %s",
 154                                           fd, strerror(errno));
 155         }
 156
 157         CurrentSetSize--;
 158         ref[fd] = NULL;
 159
 160         ServerInstance->Logs->Log("SOCKET",DEBUG,"Remove file descriptor: %d", fd);
 161 }
 162
 163 void KQueueEngine::OnSetEvent(EventHandler* eh, int old_mask, int new_mask)
 164 {
 165         if ((new_mask & FD_WANT_POLL_WRITE) && !(old_mask & FD_WANT_POLL_WRITE))
 166         {
 167                 // new poll-style write
 168                 struct kevent ke;
 169                 EV_SET(&ke, eh->GetFd(), EVFILT_WRITE, EV_ADD, 0, 0, NULL);
 170                 int i = kevent(EngineHandle, &ke, 1, 0, 0, NULL);
 171                 if (i < 0) {
 172                         ServerInstance->Logs->Log("SOCKET",DEFAULT,"Failed to mark for writing: %d %s",
 173                                                   eh->GetFd(), strerror(errno));
 174                 }
 175         }
 176         else if ((old_mask & FD_WANT_POLL_WRITE) && !(new_mask & FD_WANT_POLL_WRITE))
 177         {
 178                 // removing poll-style write
 179                 struct kevent ke;
 180                 EV_SET(&ke, eh->GetFd(), EVFILT_WRITE, EV_DELETE, 0, 0, NULL);
 181                 int i = kevent(EngineHandle, &ke, 1, 0, 0, NULL);
 182                 if (i < 0) {
 183                         ServerInstance->Logs->Log("SOCKET",DEFAULT,"Failed to mark for writing: %d %s",
 184                                                   eh->GetFd(), strerror(errno));
 185                 }
 186         }
 187         if ((new_mask & (FD_WANT_FAST_WRITE | FD_WANT_SINGLE_WRITE)) && !(old_mask & (FD_WANT_FAST_WRITE | FD_WANT_SINGLE_WRITE)))
 188         {
 189                 // new one-shot write
 190                 struct kevent ke;
 191                 EV_SET(&ke, eh->GetFd(), EVFILT_WRITE, EV_ADD | EV_ONESHOT, 0, 0, NULL);
 192                 int i = kevent(EngineHandle, &ke, 1, 0, 0, NULL);
 193                 if (i < 0) {
 194                         ServerInstance->Logs->Log("SOCKET",DEFAULT,"Failed to mark for writing: %d %s",
 195                                                   eh->GetFd(), strerror(errno));
 196                 }
 197         }
 198 }
 199
 200 int KQueueEngine::DispatchEvents()
 201 {
 202         ts.tv_nsec = 0;
 203         ts.tv_sec = 1;
 204
 205         int i = kevent(EngineHandle, NULL, 0, &ke_list[0], GetMaxFds(), &ts);
 206         ServerInstance->UpdateTime();
 207
 208         TotalEvents += i;
 209
 210         for (int j = 0; j < i; j++)
 211         {
 212                 EventHandler* eh = ref[ke_list[j].ident];
 213                 if (!eh)
 214                         continue;
 215                 if (ke_list[j].flags & EV_EOF)
 216                 {
 217                         ErrorEvents++;
 218                         eh->HandleEvent(EVENT_ERROR, ke_list[j].fflags);
 219                         continue;
 220                 }
 221                 if (ke_list[j].filter == EVFILT_WRITE)
 222                 {
 223                         WriteEvents++;
 224                         /* When mask is FD_WANT_FAST_WRITE or FD_WANT_SINGLE_WRITE,
 225                          * we set a one-shot write, so we need to clear that bit
 226                          * to detect when it set again.
 227                          */
 228                         const int bits_to_clr = FD_WANT_SINGLE_WRITE | FD_WANT_FAST_WRITE | FD_WRITE_WILL_BLOCK;
 229                         SetEventMask(eh, eh->GetEventMask() & ~bits_to_clr);
 230                         eh->HandleEvent(EVENT_WRITE);
 231
 232                         if (eh != ref[ke_list[j].ident])
 233                                 // whoops, deleted out from under us
 234                                 continue;
 235                 }
 236                 if (ke_list[j].filter == EVFILT_READ)
 237                 {
 238                         ReadEvents++;
 239                         SetEventMask(eh, eh->GetEventMask() & ~FD_READ_WILL_BLOCK);
 240                         eh->HandleEvent(EVENT_READ);
 241                 }
 242         }
 243
 244         return i;
 245 }
 246
 247 std::string KQueueEngine::GetName()
 248 {
 249         return "kqueue";
 250 }
 251
 252 SocketEngine* CreateSocketEngine()
 253 {
 254         return new KQueueEngine;
 255 }