Mercurial > hg > svcore
view data/fileio/FileReadThread.cpp @ 299:576be0d0d218
* Merge transform directory from sv-match-alignment branch
(the previous comment included notes for this stuff, but I missed it
in the actual merge)
* Fix crash when a transform fails to create an output model and the
thread that created the transform then deletes its input model thinking
it's no longer needed, even though the transform run thread is still
using it -- fix is to wait() on the transform before returning the
null output model
author | Chris Cannam |
---|---|
date | Fri, 28 Sep 2007 16:15:06 +0000 |
parents | 1a42221a1522 |
children | 115f60df1e4d |
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/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*- vi:set ts=8 sts=4 sw=4: */ /* Sonic Visualiser An audio file viewer and annotation editor. Centre for Digital Music, Queen Mary, University of London. This file copyright 2006 Chris Cannam. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. See the file COPYING included with this distribution for more information. */ #include "FileReadThread.h" #include "base/Profiler.h" #include <iostream> #include <unistd.h> //#define DEBUG_FILE_READ_THREAD 1 FileReadThread::FileReadThread() : m_nextToken(0), m_exiting(false) { } void FileReadThread::run() { m_mutex.lock(); while (!m_exiting) { if (m_queue.empty()) { m_condition.wait(&m_mutex, 1000); } else { process(); } notifyCancelled(); } notifyCancelled(); m_mutex.unlock(); #ifdef DEBUG_FILE_READ_THREAD std::cerr << "FileReadThread::run() exiting" << std::endl; #endif } void FileReadThread::finish() { #ifdef DEBUG_FILE_READ_THREAD std::cerr << "FileReadThread::finish()" << std::endl; #endif m_mutex.lock(); while (!m_queue.empty()) { m_cancelledRequests[m_queue.begin()->first] = m_queue.begin()->second; m_newlyCancelled.insert(m_queue.begin()->first); m_queue.erase(m_queue.begin()); } m_exiting = true; m_mutex.unlock(); m_condition.wakeAll(); #ifdef DEBUG_FILE_READ_THREAD std::cerr << "FileReadThread::finish() exiting" << std::endl; #endif } int FileReadThread::request(const Request &request) { m_mutex.lock(); int token = m_nextToken++; m_queue[token] = request; m_mutex.unlock(); m_condition.wakeAll(); return token; } void FileReadThread::cancel(int token) { m_mutex.lock(); if (m_queue.find(token) != m_queue.end()) { m_cancelledRequests[token] = m_queue[token]; m_queue.erase(token); m_newlyCancelled.insert(token); } else if (m_readyRequests.find(token) != m_readyRequests.end()) { m_cancelledRequests[token] = m_readyRequests[token]; m_readyRequests.erase(token); } else { std::cerr << "WARNING: FileReadThread::cancel: token " << token << " not found" << std::endl; } m_mutex.unlock(); #ifdef DEBUG_FILE_READ_THREAD std::cerr << "FileReadThread::cancel(" << token << ") waking condition" << std::endl; #endif m_condition.wakeAll(); } bool FileReadThread::isReady(int token) { m_mutex.lock(); bool ready = m_readyRequests.find(token) != m_readyRequests.end(); m_mutex.unlock(); return ready; } bool FileReadThread::isCancelled(int token) { m_mutex.lock(); bool cancelled = m_cancelledRequests.find(token) != m_cancelledRequests.end() && m_newlyCancelled.find(token) == m_newlyCancelled.end(); m_mutex.unlock(); return cancelled; } bool FileReadThread::getRequest(int token, Request &request) { m_mutex.lock(); bool found = false; if (m_queue.find(token) != m_queue.end()) { request = m_queue[token]; found = true; } else if (m_cancelledRequests.find(token) != m_cancelledRequests.end()) { request = m_cancelledRequests[token]; found = true; } else if (m_readyRequests.find(token) != m_readyRequests.end()) { request = m_readyRequests[token]; found = true; } m_mutex.unlock(); return found; } void FileReadThread::done(int token) { m_mutex.lock(); bool found = false; if (m_cancelledRequests.find(token) != m_cancelledRequests.end()) { m_cancelledRequests.erase(token); m_newlyCancelled.erase(token); found = true; } else if (m_readyRequests.find(token) != m_readyRequests.end()) { m_readyRequests.erase(token); found = true; } else if (m_queue.find(token) != m_queue.end()) { std::cerr << "WARNING: FileReadThread::done(" << token << "): request is still in queue (wait or cancel it)" << std::endl; } m_mutex.unlock(); if (!found) { std::cerr << "WARNING: FileReadThread::done(" << token << "): request not found" << std::endl; } } void FileReadThread::process() { // entered with m_mutex locked and m_queue non-empty #ifdef DEBUG_FILE_READ_THREAD Profiler profiler("FileReadThread::process()", true); #endif int token = m_queue.begin()->first; Request request = m_queue.begin()->second; m_mutex.unlock(); #ifdef DEBUG_FILE_READ_THREAD std::cerr << "FileReadThread::process: reading " << request.start << ", " << request.size << " on " << request.fd << std::endl; #endif bool successful = false; bool seekFailed = false; ssize_t r = 0; if (request.mutex) request.mutex->lock(); if (::lseek(request.fd, request.start, SEEK_SET) == (off_t)-1) { seekFailed = true; } else { // if request.size is large, we want to avoid making a single // system call to read it all as it may block too much static const size_t blockSize = 256 * 1024; size_t size = request.size; char *destination = request.data; while (size > 0) { size_t readSize = size; if (readSize > blockSize) readSize = blockSize; ssize_t br = ::read(request.fd, destination, readSize); if (br < 0) { r = br; break; } else { r += br; if (br < ssize_t(readSize)) break; } destination += readSize; size -= readSize; } } if (request.mutex) request.mutex->unlock(); if (seekFailed) { ::perror("Seek failed"); std::cerr << "ERROR: FileReadThread::process: seek to " << request.start << " failed" << std::endl; request.size = 0; } else { if (r < 0) { ::perror("ERROR: FileReadThread::process: Read failed"); request.size = 0; } else if (r < ssize_t(request.size)) { std::cerr << "WARNING: FileReadThread::process: read " << request.size << " returned only " << r << " bytes" << std::endl; request.size = r; usleep(100000); } else { successful = true; } } // Check that the token hasn't been cancelled and the thread // hasn't been asked to finish m_mutex.lock(); request.successful = successful; if (m_queue.find(token) != m_queue.end() && !m_exiting) { m_queue.erase(token); m_readyRequests[token] = request; #ifdef DEBUG_FILE_READ_THREAD std::cerr << "FileReadThread::process: done, marking as ready" << std::endl; #endif } else { #ifdef DEBUG_FILE_READ_THREAD std::cerr << "FileReadThread::process: request disappeared or exiting" << std::endl; #endif } } void FileReadThread::notifyCancelled() { // entered with m_mutex locked while (!m_newlyCancelled.empty()) { int token = *m_newlyCancelled.begin(); #ifdef DEBUG_FILE_READ_THREAD std::cerr << "FileReadThread::notifyCancelled: token " << token << std::endl; #endif m_newlyCancelled.erase(token); } }