peerplays-fc/vendor/udt4/src/epoll.cpp
2014-06-24 21:57:38 -04:00

367 lines
10 KiB
C++

/*****************************************************************************
Copyright (c) 2001 - 2011, The Board of Trustees of the University of Illinois.
All rights reserved.
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met:
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and the following disclaimer in the documentation
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nor the names of its contributors may be used to
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THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
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*****************************************************************************/
/*****************************************************************************
written by
Yunhong Gu, last updated 01/01/2011
*****************************************************************************/
#ifdef LINUX
#include <sys/epoll.h>
#include <unistd.h>
#endif
#include <algorithm>
#include <cerrno>
#include <cstring>
#include <iterator>
#include "common.h"
#include "epoll.h"
#include "udt.h"
using namespace std;
CEPoll::CEPoll():
m_iIDSeed(0)
{
CGuard::createMutex(m_EPollLock);
}
CEPoll::~CEPoll()
{
CGuard::releaseMutex(m_EPollLock);
}
int CEPoll::create()
{
CGuard pg(m_EPollLock);
int localid = 0;
#ifdef LINUX
localid = epoll_create(1024);
if (localid < 0)
throw CUDTException(-1, 0, errno);
#else
// on BSD, use kqueue
// on Solaris, use /dev/poll
// on Windows, select
#endif
if (++ m_iIDSeed >= 0x7FFFFFFF)
m_iIDSeed = 0;
CEPollDesc desc;
desc.m_iID = m_iIDSeed;
desc.m_iLocalID = localid;
m_mPolls[desc.m_iID] = desc;
return desc.m_iID;
}
int CEPoll::add_usock(const int eid, const UDTSOCKET& u, const int* events)
{
CGuard pg(m_EPollLock);
map<int, CEPollDesc>::iterator p = m_mPolls.find(eid);
if (p == m_mPolls.end())
throw CUDTException(5, 13);
if (!events || (*events & UDT_EPOLL_IN))
p->second.m_sUDTSocksIn.insert(u);
if (!events || (*events & UDT_EPOLL_OUT))
p->second.m_sUDTSocksOut.insert(u);
return 0;
}
int CEPoll::add_ssock(const int eid, const SYSSOCKET& s, const int* events)
{
CGuard pg(m_EPollLock);
map<int, CEPollDesc>::iterator p = m_mPolls.find(eid);
if (p == m_mPolls.end())
throw CUDTException(5, 13);
#ifdef LINUX
epoll_event ev;
memset(&ev, 0, sizeof(epoll_event));
if (NULL == events)
ev.events = EPOLLIN | EPOLLOUT | EPOLLERR;
else
{
ev.events = 0;
if (*events & UDT_EPOLL_IN)
ev.events |= EPOLLIN;
if (*events & UDT_EPOLL_OUT)
ev.events |= EPOLLOUT;
if (*events & UDT_EPOLL_ERR)
ev.events |= EPOLLERR;
}
ev.data.fd = s;
if (::epoll_ctl(p->second.m_iLocalID, EPOLL_CTL_ADD, s, &ev) < 0)
throw CUDTException();
#endif
p->second.m_sLocals.insert(s);
return 0;
}
int CEPoll::remove_usock(const int eid, const UDTSOCKET& u)
{
CGuard pg(m_EPollLock);
map<int, CEPollDesc>::iterator p = m_mPolls.find(eid);
if (p == m_mPolls.end())
throw CUDTException(5, 13);
p->second.m_sUDTSocksIn.erase(u);
p->second.m_sUDTSocksOut.erase(u);
p->second.m_sUDTSocksEx.erase(u);
return 0;
}
int CEPoll::remove_ssock(const int eid, const SYSSOCKET& s)
{
CGuard pg(m_EPollLock);
map<int, CEPollDesc>::iterator p = m_mPolls.find(eid);
if (p == m_mPolls.end())
throw CUDTException(5, 13);
#ifdef LINUX
epoll_event ev; // ev is ignored, for compatibility with old Linux kernel only.
if (::epoll_ctl(p->second.m_iLocalID, EPOLL_CTL_DEL, s, &ev) < 0)
throw CUDTException();
#endif
p->second.m_sLocals.erase(s);
return 0;
}
int CEPoll::wait(const int eid, set<UDTSOCKET>* readfds, set<UDTSOCKET>* writefds, int64_t msTimeOut, set<SYSSOCKET>* lrfds, set<SYSSOCKET>* lwfds)
{
// if all fields is NULL and waiting time is infinite, then this would be a deadlock
if (!readfds && !writefds && !lrfds && lwfds && (msTimeOut < 0))
throw CUDTException(5, 3, 0);
// Clear these sets in case the app forget to do it.
if (readfds) readfds->clear();
if (writefds) writefds->clear();
if (lrfds) lrfds->clear();
if (lwfds) lwfds->clear();
int total = 0;
int64_t entertime = CTimer::getTime();
while (true)
{
CGuard::enterCS(m_EPollLock);
map<int, CEPollDesc>::iterator p = m_mPolls.find(eid);
if (p == m_mPolls.end())
{
CGuard::leaveCS(m_EPollLock);
throw CUDTException(5, 13);
}
if (p->second.m_sUDTSocksIn.empty() && p->second.m_sUDTSocksOut.empty() && p->second.m_sLocals.empty() && (msTimeOut < 0))
{
// no socket is being monitored, this may be a deadlock
CGuard::leaveCS(m_EPollLock);
throw CUDTException(5, 3);
}
// Sockets with exceptions are returned to both read and write sets.
if ((NULL != readfds) && (!p->second.m_sUDTReads.empty() || !p->second.m_sUDTExcepts.empty()))
{
*readfds = p->second.m_sUDTReads;
for (set<UDTSOCKET>::const_iterator i = p->second.m_sUDTExcepts.begin(); i != p->second.m_sUDTExcepts.end(); ++ i)
readfds->insert(*i);
total += p->second.m_sUDTReads.size() + p->second.m_sUDTExcepts.size();
}
if ((NULL != writefds) && (!p->second.m_sUDTWrites.empty() || !p->second.m_sUDTExcepts.empty()))
{
*writefds = p->second.m_sUDTWrites;
for (set<UDTSOCKET>::const_iterator i = p->second.m_sUDTExcepts.begin(); i != p->second.m_sUDTExcepts.end(); ++ i)
writefds->insert(*i);
total += p->second.m_sUDTWrites.size() + p->second.m_sUDTExcepts.size();
}
if (lrfds || lwfds)
{
#ifdef LINUX
const int max_events = p->second.m_sLocals.size();
epoll_event ev[max_events];
int nfds = ::epoll_wait(p->second.m_iLocalID, ev, max_events, 0);
for (int i = 0; i < nfds; ++ i)
{
if ((NULL != lrfds) && (ev[i].events & EPOLLIN))
{
lrfds->insert(ev[i].data.fd);
++ total;
}
if ((NULL != lwfds) && (ev[i].events & EPOLLOUT))
{
lwfds->insert(ev[i].data.fd);
++ total;
}
}
#else
//currently "select" is used for all non-Linux platforms.
//faster approaches can be applied for specific systems in the future.
//"select" has a limitation on the number of sockets
fd_set readfds;
fd_set writefds;
FD_ZERO(&readfds);
FD_ZERO(&writefds);
for (set<SYSSOCKET>::const_iterator i = p->second.m_sLocals.begin(); i != p->second.m_sLocals.end(); ++ i)
{
if (lrfds)
FD_SET(*i, &readfds);
if (lwfds)
FD_SET(*i, &writefds);
}
timeval tv;
tv.tv_sec = 0;
tv.tv_usec = 0;
if (::select(0, &readfds, &writefds, NULL, &tv) > 0)
{
for (set<SYSSOCKET>::const_iterator i = p->second.m_sLocals.begin(); i != p->second.m_sLocals.end(); ++ i)
{
if (lrfds && FD_ISSET(*i, &readfds))
{
lrfds->insert(*i);
++ total;
}
if (lwfds && FD_ISSET(*i, &writefds))
{
lwfds->insert(*i);
++ total;
}
}
}
#endif
}
CGuard::leaveCS(m_EPollLock);
if (total > 0)
return total;
if ((msTimeOut >= 0) && (int64_t(CTimer::getTime() - entertime) >= msTimeOut * 1000LL))
throw CUDTException(6, 3, 0);
CTimer::waitForEvent();
}
return 0;
}
int CEPoll::release(const int eid)
{
CGuard pg(m_EPollLock);
map<int, CEPollDesc>::iterator i = m_mPolls.find(eid);
if (i == m_mPolls.end())
throw CUDTException(5, 13);
#ifdef LINUX
// release local/system epoll descriptor
::close(i->second.m_iLocalID);
#endif
m_mPolls.erase(i);
return 0;
}
namespace
{
void update_epoll_sets(const UDTSOCKET& uid, const set<UDTSOCKET>& watch, set<UDTSOCKET>& result, bool enable)
{
if (enable && (watch.find(uid) != watch.end()))
{
result.insert(uid);
}
else if (!enable)
{
result.erase(uid);
}
}
} // namespace
int CEPoll::update_events(const UDTSOCKET& uid, std::set<int>& eids, int events, bool enable)
{
CGuard pg(m_EPollLock);
map<int, CEPollDesc>::iterator p;
vector<int> lost;
for (set<int>::iterator i = eids.begin(); i != eids.end(); ++ i)
{
p = m_mPolls.find(*i);
if (p == m_mPolls.end())
{
lost.push_back(*i);
}
else
{
if ((events & UDT_EPOLL_IN) != 0)
update_epoll_sets(uid, p->second.m_sUDTSocksIn, p->second.m_sUDTReads, enable);
if ((events & UDT_EPOLL_OUT) != 0)
update_epoll_sets(uid, p->second.m_sUDTSocksOut, p->second.m_sUDTWrites, enable);
if ((events & UDT_EPOLL_ERR) != 0)
update_epoll_sets(uid, p->second.m_sUDTSocksEx, p->second.m_sUDTExcepts, enable);
}
}
for (vector<int>::iterator i = lost.begin(); i != lost.end(); ++ i)
eids.erase(*i);
return 0;
}