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author | Michele Calgaro <michele.calgaro@yahoo.it> | 2020-12-06 19:28:06 +0900 |
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committer | Michele Calgaro <michele.calgaro@yahoo.it> | 2020-12-06 19:28:06 +0900 |
commit | 00d4f92b717fbcbed6f9eee361975d6ee5380d59 (patch) | |
tree | 043b5970d66e539e1fbf6dde03440d6569e34c4e /mcop/iomanager.cpp | |
parent | 2f53bfe61c8ee78ff36ac6c66ae714b01e407b33 (diff) | |
download | arts-00d4f92b717fbcbed6f9eee361975d6ee5380d59.tar.gz arts-00d4f92b717fbcbed6f9eee361975d6ee5380d59.zip |
Renaming of files in preparation for code style tools.
Signed-off-by: Michele Calgaro <michele.calgaro@yahoo.it>
Diffstat (limited to 'mcop/iomanager.cpp')
-rw-r--r-- | mcop/iomanager.cpp | 494 |
1 files changed, 494 insertions, 0 deletions
diff --git a/mcop/iomanager.cpp b/mcop/iomanager.cpp new file mode 100644 index 0000000..897a61c --- /dev/null +++ b/mcop/iomanager.cpp @@ -0,0 +1,494 @@ + /* + + Copyright (C) 2000 Stefan Westerfeld + stefan@space.twc.de + + This library is free software; you can redistribute it and/or + modify it under the terms of the GNU Library General Public + License as published by the Free Software Foundation; either + version 2 of the License, or (at your option) any later version. + + This library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Library General Public License for more details. + + You should have received a copy of the GNU Library General Public License + along with this library; see the file COPYING.LIB. If not, write to + the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, + Boston, MA 02110-1301, USA. + + */ +#ifdef HAVE_CONFIG_H +#include <config.h> +#endif + +#include "iomanager.h" +#include "dispatcher.h" +#include "notification.h" +#include "thread.h" +#include <stdio.h> +#include <fcntl.h> + +#ifdef HAVE_SYS_SELECT_H +#include <sys/select.h> // Needed on some systems. +#endif +// WABA: NOTE! +// sys/select.h is needed on e.g. AIX to define "fd_set". +// However, we can not include config.h in a header file. +// The right solution would be not to use "fd_set" in the +// header file but to use it only in a private datastructure +// defined in the .cpp file. + +using namespace std; +using namespace Arts; + +namespace Arts { +/* internal data structures */ +class IOWatchFD { + int _fd, _types; + IONotify *_notify; + +public: + int activeTypes; + + IOWatchFD(int fd, int types, IONotify *notify); + + inline int fd() { return _fd; }; + inline int types() { return _types; }; + inline IONotify *notify() { return _notify; }; + inline void remove(int types) { _types &= ~types; } +}; + +class TimeWatcher { + int milliseconds; + TimeNotify *_notify; + timeval nextNotify; + bool active, destroyed; + + bool earlier(const timeval& reference); +public: + TimeWatcher(int _milliseconds, TimeNotify *notify); + + inline TimeNotify *notify() { return _notify; }; + timeval advance(const timeval& currentTime); + void destroy(); +}; +} + +/* + * Enable this if you want to debug how long certain plugins / operations + * take to perform. You'll get the times between two select() calls that are + * done by the IOManager, which is equivalent to the time the input/output + * remains unserved. For apps like artsd, it gives the minimum audio latency + * users will need to specify to avoid dropouts. + */ +#undef IOMANAGER_DEBUG_LATENCY + +#ifdef IOMANAGER_DEBUG_LATENCY +static timeval iomanager_debug_latency_time = { 0, 0 }; + +static void iomanager_debug_latency_end() +{ + if(iomanager_debug_latency_time.tv_sec) + { + timeval end; + gettimeofday(&end,0); + + float diff = (end.tv_usec-iomanager_debug_latency_time.tv_usec)/1000.0 + + (end.tv_sec-iomanager_debug_latency_time.tv_sec)*1000.0; + + /* change this value if you get your screen filled up with messages */ + if(diff >= 1.5) + fprintf(stderr,"IOManager: latency for operation: %2.3f ms\n",diff); + } +} + +static void iomanager_debug_latency_start() +{ + gettimeofday(&iomanager_debug_latency_time,0); +} +#else +static inline void iomanager_debug_latency_end() +{ +} + +static inline void iomanager_debug_latency_start() +{ +} +#endif + +IOWatchFD::IOWatchFD(int fd, int types, IONotify *notify) +{ + _fd = fd; + _types = types; + _notify = notify; + activeTypes = 0; +} + +StdIOManager::StdIOManager() +{ + // force initialization of the fd_set's + fdListChanged = true; + timeListChanged = false; + level = 0; +} + +void StdIOManager::processOneEvent(bool blocking) +{ + assert(SystemThreads::the()->isMainThread()); + + level++; + + // we release and acquire the lock only on level 1 + if(level == 1) + Dispatcher::lock(); + + // notifications not carried out reentrant + if(level == 1) + NotificationManager::the()->run(); + + // FIXME: timers *could* change the file descriptors to select... + //--- + if(fdListChanged) + { + FD_ZERO(&readfds); + FD_ZERO(&writefds); + FD_ZERO(&exceptfds); + FD_ZERO(&reentrant_readfds); + FD_ZERO(&reentrant_writefds); + FD_ZERO(&reentrant_exceptfds); + + maxfd = 0; + + list<IOWatchFD *>::iterator i; + for(i = fdList.begin(); i != fdList.end(); i++) + { + IOWatchFD *w = *i; + + if(w->types() & IOType::read) FD_SET(w->fd(),&readfds); + if(w->types() & IOType::write) FD_SET(w->fd(),&writefds); + if(w->types() & IOType::except) FD_SET(w->fd(),&exceptfds); + + if(w->types() & IOType::reentrant) + { + if(w->types() & IOType::read) + FD_SET(w->fd(),&reentrant_readfds); + if(w->types() & IOType::write) + FD_SET(w->fd(),&reentrant_writefds); + if(w->types() & IOType::except) + FD_SET(w->fd(),&reentrant_exceptfds); + } + + if(w->types() && w->fd() > maxfd) maxfd = w->fd(); + } + + fdListChanged = false; + } + fd_set rfd,wfd,efd; + if(level == 1) + { + rfd = readfds; + wfd = writefds; + efd = exceptfds; + } + else + { + // watch out, this is reentrant I/O + rfd = reentrant_readfds; + wfd = reentrant_writefds; + efd = reentrant_exceptfds; + } + + /* default timeout 5 seconds */ + long selectabs; + + if(blocking) + selectabs = 5000000; + else + selectabs = 0; + + /* prepare timers - only at level 1 */ + if(level == 1 && timeList.size()) + { + struct timeval currenttime; + gettimeofday(¤ttime,0); + + list<TimeWatcher *>::iterator ti; + + timeListChanged = false; + ti = timeList.begin(); + while(ti != timeList.end()) + { + TimeWatcher *w = *ti++; + timeval timertime = w->advance(currenttime); + + // if that may happen in the next ten seconds + if(timertime.tv_sec < currenttime.tv_sec+10) + { + long timerabs = (timertime.tv_sec - currenttime.tv_sec)*1000000; + timerabs += (timertime.tv_usec - currenttime.tv_usec); + + if(timerabs < selectabs) selectabs = timerabs; + } + + if(timeListChanged) + { + ti = timeList.begin(); + timeListChanged = false; + } + } + } + + timeval select_timeout; + select_timeout.tv_sec = selectabs / 1000000; + select_timeout.tv_usec = selectabs % 1000000; + + if(level == 1) iomanager_debug_latency_end(); + + // we release and acquire the lock only on level 1 + if(level == 1) + Dispatcher::unlock(); + + int retval = select(maxfd+1,&rfd,&wfd,&efd,&select_timeout); + + // we release and acquire the lock only on level 1 + if(level == 1) + Dispatcher::lock(); + + if(level == 1) iomanager_debug_latency_start(); + + if(retval > 0) + { + /* + * the problem is, that objects that are being notified may change + * the watch list, add fds, remove fds, remove objects and whatever + * else + * + * so we can' notify them from the loop - but we can make a stack + * of "notifications to do" and send them as soon as we looked up + * in the list what to send + */ + long tonotify = 0; + + list<IOWatchFD *>::iterator i; + for(i = fdList.begin(); i != fdList.end(); i++) { + IOWatchFD *w = *i; + int match = 0; + + if(FD_ISSET(w->fd(),&rfd) && (w->types() & IOType::read)) + match |= IOType::read; + + if(FD_ISSET(w->fd(),&wfd) && (w->types() & IOType::write)) + match |= IOType::write; + + if(FD_ISSET(w->fd(),&efd) && (w->types() & IOType::except)) + match |= IOType::except; + + if((w->types() & IOType::reentrant) == 0 && level != 1) + match = 0; + + if(match) { + tonotify++; + w->activeTypes = match; + notifyStack.push(w); + } + } + + while(tonotify != 0) + { + if(!fdListChanged) + { + IOWatchFD *w = notifyStack.top(); + int activeTypes = w->activeTypes; + int fd = w->fd(); + IONotify *notify = w->notify(); + + w->activeTypes = 0; + notify->notifyIO(fd, activeTypes); + // warning: w and notify might no longer exist here + } + + notifyStack.pop(); + tonotify--; + } + } + /* handle timers - only at level 1 */ + if(level == 1 && timeList.size()) + { + struct timeval currenttime; + gettimeofday(¤ttime,0); + + list<TimeWatcher *>::iterator ti; + + timeListChanged = false; + ti = timeList.begin(); + while(ti != timeList.end()) + { + TimeWatcher *w = *ti++; + w->advance(currenttime); + if (timeListChanged) + { + ti = timeList.begin(); + timeListChanged = false; + } + } + } + + // notifications not carried out reentrant + if(level == 1) + NotificationManager::the()->run(); + + // we release and acquire the lock only on level 1 + if(level == 1) + Dispatcher::unlock(); + + level--; +} + +void StdIOManager::run() +{ + assert(SystemThreads::the()->isMainThread()); + assert(level == 0); + + // FIXME: this might not be threadsafe, as there is no lock here! + terminated = false; + while(!terminated) + processOneEvent(true); +} + +void StdIOManager::terminate() +{ + terminated = true; + Dispatcher::wakeUp(); +} + +void StdIOManager::watchFD(int fd, int types, IONotify *notify) +{ + /* + IOWatchFD *watchfd = findWatch(fd,notify); + if(watchfd) + { + watchfd->add(types); + } + else + { + fdList.push_back(new IOWatchFD(fd,types,notify)); + } + */ + + // FIXME: might want to reuse old watches + fdList.push_back(new IOWatchFD(fd,types,notify)); + fdListChanged = true; + Dispatcher::wakeUp(); +} + +void StdIOManager::remove(IONotify *notify, int types) +{ + list<IOWatchFD *>::iterator i; + + i = fdList.begin(); + + while(i != fdList.end()) + { + IOWatchFD *w = *i; + + if(w->notify() == notify) w->remove(types); + + // nothing left to watch? + if(w->types() == 0 || w->types() == IOType::reentrant) + { + i = fdList.erase(i); + delete w; // FIXME: shouldn't we have a destroy() similar + // to the one for timers + } + else i++; + } + fdListChanged = true; +} + +void StdIOManager::addTimer(int milliseconds, TimeNotify *notify) +{ + if (milliseconds == -1 && notify == 0) { + // HACK: in order to not add a virtual function to IOManager we're calling addTimer with + // magic values. This call tells the ioManager that notifications are pending and + // NotificationManager::run() should get called soon. + } else { + timeList.push_back(new TimeWatcher(milliseconds,notify)); + timeListChanged = true; + Dispatcher::wakeUp(); + } +} + +void StdIOManager::removeTimer(TimeNotify *notify) +{ + list<TimeWatcher *>::iterator i; + + i = timeList.begin(); + + while(i != timeList.end()) + { + TimeWatcher *w = *i; + + if(w->notify() == notify) + { + i = timeList.erase(i); + timeListChanged = true; + w->destroy(); + } + else i++; + } +} + +TimeWatcher::TimeWatcher(int _milliseconds, TimeNotify *notify) + : milliseconds(_milliseconds),_notify(notify),active(false),destroyed(false) +{ + gettimeofday(&nextNotify,0); + + nextNotify.tv_usec += (milliseconds%1000)*1000; + nextNotify.tv_sec += (milliseconds/1000)+(nextNotify.tv_usec/1000000); + nextNotify.tv_usec %= 1000000; +} + +timeval TimeWatcher::advance(const timeval& currentTime) +{ + active = true; + while(earlier(currentTime)) + { + nextNotify.tv_usec += (milliseconds%1000)*1000; + nextNotify.tv_sec += (milliseconds/1000)+(nextNotify.tv_usec/1000000); + nextNotify.tv_usec %= 1000000; + + _notify->notifyTime(); + + if(destroyed) + { + delete this; + + struct timeval never = { -1, 0 }; + return never; + } + } + active = false; + return nextNotify; +} + +bool TimeWatcher::earlier(const timeval& reference) +{ + if(nextNotify.tv_sec > reference.tv_sec) return false; + if(nextNotify.tv_sec < reference.tv_sec) return true; + + return (nextNotify.tv_usec < reference.tv_usec); +} + +void TimeWatcher::destroy() +{ + if(active) + { + destroyed = true; + } + else + { + delete this; + } +} |