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/* |
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iom.C -- I/O multiplexor |
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|
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This program is free software; you can redistribute it and/or modify |
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it under the terms of the GNU General Public License as published by |
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the Free Software Foundation; either version 2 of the License, or |
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(at your option) any later version. |
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|
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This program is distributed in the hope that it will be useful, |
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but WITHOUT ANY WARRANTY; without even the implied warranty of |
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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GNU General Public License for more details. |
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|
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You should have received a copy of the GNU General Public License |
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along with this program; if not, write to the Free Software |
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Foundation, Inc. 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
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*/ |
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|
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#include "config.h" |
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|
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#include <sys/time.h> |
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|
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#include <algorithm> |
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#include <functional> |
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|
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#include "slog.h" |
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#include "iom.h" |
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|
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tstamp NOW; |
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bool iom_valid; |
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io_manager iom; |
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|
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inline bool earliest_first (const time_watcher *a, const time_watcher *b) |
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{ |
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return a->at > b->at; |
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} |
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|
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void time_watcher::set (tstamp when) |
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{ |
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at = when; |
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|
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if (registered) |
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iom.reschedule_time_watchers (); |
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else |
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iom.reg (this); |
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} |
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|
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void time_watcher::trigger () |
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{ |
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call (*this); |
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|
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if (registered) |
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iom.reschedule_time_watchers (); |
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else |
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iom.reg (this); |
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} |
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|
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void time_watcher::start () |
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{ |
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if (!registered) |
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iom.reg (this); |
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} |
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|
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time_watcher::~time_watcher () |
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{ |
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if (iom_valid) |
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iom.unreg (this); |
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} |
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|
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io_watcher::~io_watcher () |
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{ |
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if (iom_valid) |
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iom.unreg (this); |
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} |
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|
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void io_manager::reg (io_watcher *w) |
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{ |
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pollfd pfd; |
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|
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pfs.push_back (pfd); |
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iow.push_back (w); |
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|
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w->p = &(*(pfs.end () - 1)); |
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} |
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|
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void io_manager::unreg (io_watcher *w) |
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{ |
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if (w->p) |
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{ |
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unsigned int sz = iow.size (); |
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unsigned int i = find (iow.begin (), iow.end (), w) - iow.begin (); |
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|
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assert (i != sz); |
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|
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if (sz == 1) |
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{ |
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pfs.clear (); |
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iow.clear (); |
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} |
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else if (i == sz - 1) |
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{ |
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iow.pop_back (); |
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pfs.pop_back (); |
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} |
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else |
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{ |
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iow[i] = iow[sz - 1]; iow.pop_back (); |
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pfs[i] = pfs[sz - 1]; pfs.pop_back (); |
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} |
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|
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w->p = 0; |
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} |
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} |
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|
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void io_manager::reschedule_time_watchers () |
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{ |
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make_heap (tw.begin (), tw.end (), earliest_first); |
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} |
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|
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void io_manager::reg (time_watcher *w) |
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{ |
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w->registered = true; |
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|
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tw.push_back (w); |
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push_heap (tw.begin (), tw.end (), earliest_first); |
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} |
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|
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void io_manager::unreg (time_watcher *w) |
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{ |
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if (w->registered) |
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{ |
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unsigned int sz = tw.size (); |
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unsigned int i = find (tw.begin (), tw.end (), w) - tw.begin (); |
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|
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assert (i != sz); |
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|
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if (i != sz - 1) |
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tw[i] = tw[sz - 1]; |
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|
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tw.pop_back (); |
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reschedule_time_watchers (); |
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|
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w->registered = false; |
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} |
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} |
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|
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inline void set_now (void) |
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{ |
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struct timeval tv; |
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|
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gettimeofday (&tv, 0); |
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|
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NOW = (tstamp)tv.tv_sec + (tstamp)tv.tv_usec / 1000000; |
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} |
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|
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void io_manager::loop () |
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{ |
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set_now (); |
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|
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for (;;) |
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{ |
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while (tw[0]->at <= NOW) |
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{ |
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// remove the first watcher |
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time_watcher *w = tw[0]; |
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|
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pop_heap (tw.begin (), tw.end (), earliest_first); |
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tw.pop_back (); |
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|
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w->registered = false; |
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|
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// call it |
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w->call (*w); |
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|
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// re-add it if necessary |
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if (w->at >= 0 && !w->registered) |
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reg (w); |
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} |
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|
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int timeout = (int) ((tw[0]->at - NOW) * 1000); |
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|
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int fds = poll (&pfs[0], pfs.size (), timeout); |
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|
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set_now (); |
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|
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vector<io_watcher *>::iterator w; |
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vector<pollfd>::iterator p; |
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|
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for (w = iow.begin (), p = pfs.begin (); |
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fds > 0 && w < iow.end (); |
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++w, ++p) |
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if (p->revents) |
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{ |
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--fds; |
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(*w)->call (**w, p->revents); |
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} |
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} |
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} |
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|
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void io_manager::idle_cb (time_watcher &w) |
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{ |
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w.at = NOW + 86400; // wake up every day, for no good reason |
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} |
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|
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io_manager::io_manager () |
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{ |
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iom_valid = true; |
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|
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set_now (); |
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idle = new time_watcher (this, &io_manager::idle_cb); |
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idle->start (0); |
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} |
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|
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io_manager::~io_manager () |
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{ |
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iom_valid = false; |
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} |
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|
