text: /* Linux epoll(2) based ae.c module
   *
   * Copyright (c) 2009-2012, Salvatore Sanfilippo <antirez at gmail dot com>
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions are met:
   *
   *   * Redistributions of source code must retain the above copyright notice,
   *     this list of conditions and the following disclaimer.
   *   * Redistributions in binary form must reproduce the above copyright
   *     notice, this list of conditions and the following disclaimer in the
   *     documentation and/or other materials provided with the distribution.
   *   * Neither the name of Redis nor the names of its contributors may be used
   *     to endorse or promote products derived from this software without
   *     specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
   * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
   * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
   * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
   * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
   * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
   * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
   * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
   * POSSIBILITY OF SUCH DAMAGE.
   */
  
  
  #include <sys/epoll.h>
  
  #include <mtcp_api.h>
  
  #include "mod.h"
  
  extern int socketnum;
  
  typedef struct aeApiState {
      int epfd;
      struct epoll_event *events;
  } aeApiState;
  
  static int aeApiCreate(aeEventLoop *eventLoop) {
      aeApiState *state = zmalloc(sizeof(aeApiState));
      
      if (!state) return -1;
      state->events = zmalloc(sizeof(struct epoll_event)*eventLoop->setsize);
      if (!state->events) {
          zfree(state);
          return -1;
      }
      socketnum = 2;
      state->epfd = epoll_create(10240); /* 1024 is just a hint for the kernel */
      if (state->epfd == -1) {
          zfree(state->events);
          zfree(state);
          return -1;
      }
      //printf("sucessful create epoll!\n");
      eventLoop->apidata = state;
      return 0;
  }
  
  static int aeApiResize(aeEventLoop *eventLoop, int setsize) {
      aeApiState *state = eventLoop->apidata;
      
      state->events = zrealloc(state->events, sizeof(struct epoll_event)*setsize);
      return 0;
  }
  
  static void aeApiFree(aeEventLoop *eventLoop) {
      aeApiState *state = eventLoop->apidata;
      
      socketnum = 2;
      close(state->epfd);
      zfree(state->events);
      zfree(state);
  }
  
  static int aeApiAddEvent(aeEventLoop *eventLoop, int fd, int mask) {
      aeApiState *state = eventLoop->apidata;
      struct epoll_event ee = {0}; /* avoid valgrind warning */
      /* If the fd was already monitored for some event, we need a MOD
       * operation. Otherwise we need an ADD operation. */
      int op = eventLoop->events[fd].mask == AE_NONE ?
      EPOLL_CTL_ADD : EPOLL_CTL_MOD;
      
      ee.events = 0;
      mask |= eventLoop->events[fd].mask; /* Merge old events */
      if (mask & AE_READABLE) ee.events |= EPOLLIN;
      if (mask & AE_WRITABLE) ee.events |= EPOLLOUT;
      ee.data.fd = fd;
      socketnum = 2;
      //printf("epollfd=%d\n",state->epfd);
      if (epoll_ctl(state->epfd,op,fd,&ee) == -1) { return -1;}   //mtcp modificaiton
      //printf("sucessful Add/mod epoll%d! fd=%d\n",state->epfd,fd);
      return 0;
  }
  
  static void aeApiDelEvent(aeEventLoop *eventLoop, int fd, int delmask) {
      aeApiState *state = eventLoop->apidata;
      struct epoll_event ee = {0}; /* avoid valgrind warning */
      int mask = eventLoop->events[fd].mask & (~delmask);
      int ret;
      ee.events = 0;
      if (mask & AE_READABLE) ee.events |= EPOLLIN;
      if (mask & AE_WRITABLE) ee.events |= EPOLLOUT;
      ee.data.fd = fd;
      socketnum = 2;
      if (mask != AE_NONE) {
          epoll_ctl(state->epfd,EPOLL_CTL_MOD,fd,&ee);
          //printf("sucessful MOD epoll%d!\n",ee.data.fd);
      } else {
          /* Note, Kernel < 2.6.9 requires a non null event pointer even for
           * EPOLL_CTL_DEL. */
          ret = epoll_ctl(state->epfd,EPOLL_CTL_DEL,fd,&ee);
          if(ret<0){socketnum = 2; close(fd);return;}
          //printf("sucessful delete epoll%d!\n",state->epfd);
      }
  }
  
  static int aeApiPoll(aeEventLoop *eventLoop, struct timeval *tvp) {
      aeApiState *state = eventLoop->apidata;
      int retval, numevents = 0;
      
      socketnum = 2;
      retval = epoll_wait(state->epfd,state->events,eventLoop->setsize,
                          tvp ? (tvp->tv_sec*1000 + tvp->tv_usec/1000) : -1);
      if (retval > 0) {
          int j;
          
          numevents = retval;
          for (j = 0; j < numevents; j++) {
              int mask = 0;
              struct epoll_event *e = state->events+j;
              
              if (e->events & EPOLLIN) mask |= AE_READABLE;
              if (e->events & EPOLLOUT) mask |= AE_WRITABLE;
              if (e->events & EPOLLERR) mask |= AE_WRITABLE;
              if (e->events & EPOLLHUP) mask |= AE_WRITABLE;
              eventLoop->fired[j].fd = e->data.fd;
              eventLoop->fired[j].mask = mask;
              
              //printf("sucessful wait e->data.fd%d\n",e->data.fd);
          }
          //printf("sucessful wait epoll!%d\n",state->epfd);
          
          //printf("sucessful wait retval%d\n",retval);
      }
      if (retval < 0) {
          if (errno != EINTR)
              perror("mtcp_epoll_wait");
      }
      return numevents;
  }
  
  static char *aeApiName(void) {
      return "epoll";
  }
  
  