fix crash when copy'ing latent plugins

[ardour.git] / libs / ardour / worker.cc

diff --git a/libs/ardour/worker.cc b/libs/ardour/worker.cc
index 67c72ffeba0b4b290865d70022148a948e92e832..f8a5e44aee06294c0c354e5d85bf110715a05270 100644 (file)
--- a/libs/ardour/worker.cc
+++ b/libs/ardour/worker.cc
@@ -1,5 +1,5 @@
 /*
-  Copyright (C) 2012 Paul Davis
+  Copyright (C) 2012-2016 Paul Davis
   Author: David Robillard
 
   This program is free software; you can redistribute it and/or modify
@@ -18,50 +18,94 @@
 */
 
 #include <stdlib.h>
+#include <unistd.h>
 
 #include "ardour/worker.h"
 #include "pbd/error.h"
 
+#include <glibmm/timer.h>
+
 namespace ARDOUR {
 
-Worker::Worker(Workee* workee, uint32_t ring_size)
+Worker::Worker(Workee* workee, uint32_t ring_size, bool threaded)
        : _workee(workee)
-       , _requests(new RingBuffer<uint8_t>(ring_size))
+       , _requests(threaded ? new RingBuffer<uint8_t>(ring_size) : NULL)
        , _responses(new RingBuffer<uint8_t>(ring_size))
        , _response((uint8_t*)malloc(ring_size))
-       , _sem(0)
+       , _sem("worker_semaphore", 0)
+       , _thread(NULL)
        , _exit(false)
-       , _thread (Glib::Threads::Thread::create(sigc::mem_fun(*this, &Worker::run)))
-{}
+       , _synchronous(!threaded)
+{
+       if (threaded) {
+               _thread = Glib::Threads::Thread::create(
+                       sigc::mem_fun(*this, &Worker::run));
+       }
+}
 
 Worker::~Worker()
 {
        _exit = true;
-       _sem.post();
-       _thread->join();
+       _sem.signal();
+       if (_thread) {
+               _thread->join();
+       }
 }
 
 bool
 Worker::schedule(uint32_t size, const void* data)
 {
+       if (_synchronous || !_requests) {
+               _workee->work(*this, size, data);
+               return true;
+       }
+       if (_requests->write_space() < size + sizeof(size)) {
+               return false;
+       }
        if (_requests->write((const uint8_t*)&size, sizeof(size)) != sizeof(size)) {
                return false;
        }
        if (_requests->write((const uint8_t*)data, size) != size) {
-               return false;  // FIXME: corruption
+               return false;
        }
-       _sem.post();
+       _sem.signal();
        return true;
 }
 
 bool
 Worker::respond(uint32_t size, const void* data)
 {
+       if (_responses->write_space() < size + sizeof(size)) {
+               return false;
+       }
        if (_responses->write((const uint8_t*)&size, sizeof(size)) != sizeof(size)) {
                return false;
        }
        if (_responses->write((const uint8_t*)data, size) != size) {
-               return false;  // FIXME: corruption
+               return false;
+       }
+       return true;
+}
+
+bool
+Worker::verify_message_completeness(RingBuffer<uint8_t>* rb)
+{
+       uint32_t read_space = rb->read_space();
+       uint32_t size;
+       RingBuffer<uint8_t>::rw_vector vec;
+       rb->get_read_vector (&vec);
+       if (vec.len[0] + vec.len[1] < sizeof(size)) {
+               return false;
+       }
+       if (vec.len[0] >= sizeof(size)) {
+               memcpy (&size, vec.buf[0], sizeof (size));
+       } else {
+               memcpy (&size, vec.buf[0], vec.len[0]);
+               memcpy (&size + vec.len[0], vec.buf[1], sizeof(size) - vec.len[0]);
+       }
+       if (read_space < size+sizeof(size)) {
+               /* message from writer is yet incomplete. respond next cycle */
+               return false;
        }
        return true;
 }
@@ -71,7 +115,12 @@ Worker::emit_responses()
 {
        uint32_t read_space = _responses->read_space();
        uint32_t size       = 0;
-       while (read_space > sizeof(size)) {
+       while (read_space >= sizeof(size)) {
+               if (!verify_message_completeness(_responses)) {
+                       /* message from writer is yet incomplete. respond next cycle */
+                       return;
+               }
+               /* read and send response */
                _responses->read((uint8_t*)&size, sizeof(size));
                _responses->read(_response, size);
                _workee->work_response(size, _response);
@@ -87,10 +136,22 @@ Worker::run()
        while (true) {
                _sem.wait();
                if (_exit) {
+                       free(buf);
                        return;
                }
 
-               uint32_t size = 0;
+               uint32_t size = _requests->read_space();
+               if (size < sizeof(size)) {
+                       PBD::error << "Worker: no work-data on ring buffer" << endmsg;
+                       continue;
+               }
+               while (!verify_message_completeness(_requests)) {
+                       Glib::usleep(2000);
+                       if (_exit) {
+                               if (buf) free(buf);
+                               return;
+                       }
+               }
                if (_requests->read((uint8_t*)&size, sizeof(size)) < sizeof(size)) {
                        PBD::error << "Worker: Error reading size from request ring"
                                   << endmsg;
@@ -99,7 +160,13 @@ Worker::run()
 
                if (size > buf_size) {
                        buf = realloc(buf, size);
-                       buf_size = size;
+                       if (buf) {
+                               buf_size = size;
+                       } else {
+                               PBD::error << "Worker: Error allocating memory"
+                                          << endmsg;
+                               buf_size = 0; // TODO: This is probably fatal
+                       }
                }
 
                if (_requests->read((uint8_t*)buf, size) < size) {
@@ -108,7 +175,7 @@ Worker::run()
                        continue;  // TODO: This is probably fatal
                }
 
-               _workee->work(size, buf);
+               _workee->work(*this, size, buf);
        }
 }