Chris@95: /* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */
Chris@95: 
Chris@95: /*
Chris@95:     Sonic Visualiser
Chris@95:     An audio file viewer and annotation editor.
Chris@95:     Centre for Digital Music, Queen Mary, University of London.
Chris@95:     This file copyright 2006 Chris Cannam.
Chris@95:     
Chris@95:     This program is free software; you can redistribute it and/or
Chris@95:     modify it under the terms of the GNU General Public License as
Chris@95:     published by the Free Software Foundation; either version 2 of the
Chris@95:     License, or (at your option) any later version.  See the file
Chris@95:     COPYING included with this distribution for more information.
Chris@95: */
Chris@95: 
Chris@95: #include "FileReadThread.h"
Chris@95: 
Chris@95: #include <iostream>
Chris@95: 
Chris@95: FileReadThread::FileReadThread() :
Chris@95:     m_nextToken(0),
Chris@95:     m_exiting(false)
Chris@95: {
Chris@95: }
Chris@95: 
Chris@95: void
Chris@95: FileReadThread::run()
Chris@95: {
Chris@95:     m_mutex.lock();
Chris@95: 
Chris@95:     while (!m_exiting) {
Chris@95:         if (m_queue.empty()) {
Chris@95:             m_condition.wait(&m_mutex, 1000);
Chris@95:         } else {
Chris@95:             process();
Chris@95:         }
Chris@96:         notifyCancelled();
Chris@95:     }
Chris@95: 
Chris@95:     notifyCancelled();
Chris@95:     m_mutex.unlock();
Chris@95: 
Chris@95:     std::cerr << "FileReadThread::run() exiting" << std::endl;
Chris@95: }
Chris@95: 
Chris@95: void
Chris@95: FileReadThread::finish()
Chris@95: {
Chris@95:     std::cerr << "FileReadThread::finish()" << std::endl;
Chris@95: 
Chris@95:     m_mutex.lock();
Chris@95:     while (!m_queue.empty()) {
Chris@95:         m_cancelledRequests[m_queue.begin()->first] = m_queue.begin()->second;
Chris@95:         m_newlyCancelled.insert(m_queue.begin()->first);
Chris@95:         m_queue.erase(m_queue.begin());
Chris@95:     }
Chris@95: 
Chris@95:     m_exiting = true;
Chris@95:     m_mutex.unlock();
Chris@95: 
Chris@95:     m_condition.wakeAll();
Chris@95: 
Chris@95:     std::cerr << "FileReadThread::finish() exiting" << std::endl;
Chris@95: }
Chris@95: 
Chris@95: int
Chris@95: FileReadThread::request(const Request &request)
Chris@95: {
Chris@95:     m_mutex.lock();
Chris@95:     
Chris@95:     int token = m_nextToken++;
Chris@95:     m_queue[token] = request;
Chris@95: 
Chris@95:     m_mutex.unlock();
Chris@95:     m_condition.wakeAll();
Chris@95: 
Chris@95:     return token;
Chris@95: }
Chris@95: 
Chris@95: void
Chris@95: FileReadThread::cancel(int token)
Chris@95: {
Chris@95:     m_mutex.lock();
Chris@95: 
Chris@95:     if (m_queue.find(token) != m_queue.end()) {
Chris@95:         m_cancelledRequests[token] = m_queue[token];
Chris@95:         m_queue.erase(token);
Chris@95:         m_newlyCancelled.insert(token);
Chris@96:     } else if (m_readyRequests.find(token) != m_readyRequests.end()) {
Chris@96:         m_cancelledRequests[token] = m_readyRequests[token];
Chris@96:         m_readyRequests.erase(token);
Chris@96:     } else {
Chris@96:         std::cerr << "WARNING: FileReadThread::cancel: token " << token << " not found" << std::endl;
Chris@95:     }
Chris@95: 
Chris@95:     m_mutex.unlock();
Chris@96: 
Chris@96:     std::cerr << "FileReadThread::cancel(" << token << ") waking condition" << std::endl;
Chris@96: 
Chris@96:     m_condition.wakeAll();
Chris@95: }
Chris@95: 
Chris@95: bool
Chris@95: FileReadThread::isReady(int token)
Chris@95: {
Chris@95:     m_mutex.lock();
Chris@95: 
Chris@95:     bool ready = m_readyRequests.find(token) != m_readyRequests.end();
Chris@95: 
Chris@95:     m_mutex.unlock();
Chris@95:     return ready;
Chris@95: }
Chris@95: 
Chris@95: bool
Chris@95: FileReadThread::isCancelled(int token)
Chris@95: {
Chris@95:     m_mutex.lock();
Chris@95: 
Chris@95:     bool cancelled = 
Chris@95:         m_cancelledRequests.find(token) != m_cancelledRequests.end() &&
Chris@95:         m_newlyCancelled.find(token) == m_newlyCancelled.end();
Chris@95: 
Chris@95:     m_mutex.unlock();
Chris@95:     return cancelled;
Chris@95: }
Chris@95: 
Chris@95: bool
Chris@95: FileReadThread::getRequest(int token, Request &request)
Chris@95: {
Chris@95:     m_mutex.lock();
Chris@95: 
Chris@95:     bool found = false;
Chris@95: 
Chris@95:     if (m_queue.find(token) != m_queue.end()) {
Chris@95:         request = m_queue[token];
Chris@95:         found = true;
Chris@95:     } else if (m_cancelledRequests.find(token) != m_cancelledRequests.end()) {
Chris@95:         request = m_cancelledRequests[token];
Chris@95:         found = true;
Chris@95:     } else if (m_readyRequests.find(token) != m_readyRequests.end()) {
Chris@95:         request = m_readyRequests[token];
Chris@95:         found = true;
Chris@95:     }
Chris@95: 
Chris@95:     m_mutex.unlock();
Chris@95:     
Chris@95:     return found;
Chris@95: }
Chris@95: 
Chris@95: void
Chris@95: FileReadThread::done(int token)
Chris@95: {
Chris@95:     m_mutex.lock();
Chris@95: 
Chris@95:     bool found = false;
Chris@95: 
Chris@95:     if (m_cancelledRequests.find(token) != m_cancelledRequests.end()) {
Chris@95:         m_cancelledRequests.erase(token);
Chris@95:         m_newlyCancelled.erase(token);
Chris@95:         found = true;
Chris@95:     } else if (m_readyRequests.find(token) != m_readyRequests.end()) {
Chris@95:         m_readyRequests.erase(token);
Chris@95:         found = true;
Chris@95:     } else if (m_queue.find(token) != m_queue.end()) {
Chris@95:         std::cerr << "WARNING: FileReadThread::done(" << token << "): request is still in queue (wait or cancel it)" << std::endl;
Chris@95:     }
Chris@95: 
Chris@95:     m_mutex.unlock();
Chris@95: 
Chris@95:     if (!found) {
Chris@95:         std::cerr << "WARNING: FileReadThread::done(" << token << "): request not found" << std::endl;
Chris@95:     }
Chris@95: }
Chris@95: 
Chris@95: void
Chris@95: FileReadThread::process()
Chris@95: {
Chris@95:     // entered with m_mutex locked and m_queue non-empty
Chris@95: 
Chris@95:     int token = m_queue.begin()->first;
Chris@95:     Request request = m_queue.begin()->second;
Chris@95: 
Chris@95:     m_mutex.unlock();
Chris@95: 
Chris@95:     std::cerr << "FileReadThread::process: got something to do" << std::endl;
Chris@95: 
Chris@95:     bool successful = false;
Chris@95:     bool seekFailed = false;
Chris@95:     ssize_t r = 0;
Chris@95: 
Chris@95:     if (request.mutex) request.mutex->lock();
Chris@95: 
Chris@95:     if (::lseek(request.fd, request.start, SEEK_SET) == (off_t)-1) {
Chris@95:         seekFailed = true;
Chris@95:     } else {
Chris@96:         
Chris@96:         // if request.size is large, we want to avoid making a single
Chris@96:         // system call to read it all as it may block too much
Chris@96: 
Chris@96:         static const size_t blockSize = 16384;
Chris@96:         
Chris@96:         size_t size = request.size;
Chris@96:         char *destination = request.data;
Chris@96: 
Chris@96:         while (size > 0) {
Chris@96:             size_t readSize = size;
Chris@96:             if (readSize > blockSize) readSize = blockSize;
Chris@96:             ssize_t br = ::read(request.fd, destination, readSize);
Chris@96:             if (br < 0) { 
Chris@96:                 r = br;
Chris@96:                 break;
Chris@96:             } else {
Chris@96:                 r += br;
Chris@96:                 if (br < ssize_t(readSize)) break;
Chris@96:             }
Chris@96:             destination += readSize;
Chris@96:             size -= readSize;
Chris@96:         }
Chris@95:     }
Chris@95: 
Chris@95:     if (request.mutex) request.mutex->unlock();
Chris@95: 
Chris@95:     if (seekFailed) {
Chris@95:         ::perror("Seek failed");
Chris@95:         std::cerr << "ERROR: FileReadThread::process: seek to "
Chris@95:                   << request.start << " failed" << std::endl;
Chris@95:         request.size = 0;
Chris@95:     } else {
Chris@95:         if (r < 0) {
Chris@95:             ::perror("ERROR: FileReadThread::process: Read failed");
Chris@95:             request.size = 0;
Chris@95:         } else if (r < ssize_t(request.size)) {
Chris@95:             std::cerr << "WARNING: FileReadThread::process: read "
Chris@95:                       << request.size << " returned only " << r << " bytes"
Chris@95:                       << std::endl;
Chris@95:             request.size = r;
Chris@95:         } else {
Chris@95:             successful = true;
Chris@95:         }
Chris@95:     }
Chris@95:         
Chris@95:     // Check that the token hasn't been cancelled and the thread
Chris@95:     // hasn't been asked to finish
Chris@95:     
Chris@95:     m_mutex.lock();
Chris@95:         
Chris@95:     if (m_queue.find(token) != m_queue.end() && !m_exiting) {
Chris@95:         m_queue.erase(token);
Chris@95:         m_readyRequests[token] = request;
Chris@95:         m_mutex.unlock();
Chris@95:         std::cerr << "emitting" << std::endl;
Chris@95:         emit ready(token, successful);
Chris@95:         m_mutex.lock();
Chris@95:     }
Chris@95: }
Chris@95: 
Chris@95: void
Chris@95: FileReadThread::notifyCancelled()
Chris@95: {
Chris@95:     // entered with m_mutex locked
Chris@95: 
Chris@95:     while (!m_newlyCancelled.empty()) {
Chris@96: 
Chris@95:         int token = *m_newlyCancelled.begin();
Chris@96: 
Chris@96:         std::cerr << "FileReadThread::notifyCancelled: token " << token << std::endl;
Chris@96: 
Chris@95:         m_newlyCancelled.erase(token);
Chris@95:         emit cancelled(token);
Chris@95:     }
Chris@95: }
Chris@95:         
Chris@95: