On Tue, Nov 22, 2011 at 9:02 AM, Rachel Kroll
<address@hidden> wrote:
On Nov 22, 2011, at 7:56 AM, Marcus D. Leech wrote:
> On 22/11/11 10:48 AM, Rachel Kroll wrote:
>> It's pretty easy to get wedged forever if you call lock and unlock a lot in conjunction with connect and disconnect. Sooner or later, you'll hit a race and things will get stuck.
>>
>> I have a simple reproduction case if anyone is interested. It'll hang reliably after a few dozen iterations.
>>
>>
> That's the type of information that shouldn't be withheld from this
> list, and by implication, the
> developers. Don't assume that because you've found a
> bug/unexpected-behaviour, that the developers
> know about it, and are working on a fix.
It's come up a few times in the mailing list archives. The usual solution seems to be "add more sleeps", which of course is not a fix.
Anyway, here's the reproduction case:
#include <gnuradio/gr_file_sink.h>
#include <gnuradio/gr_sig_source_f.h>
#include <gnuradio/gr_hier_block2.h>
#include <gnuradio/gr_io_signature.h>
#include <gnuradio/gr_top_block.h>
static void connect(gr_top_block_sptr block, gr_sig_source_f_sptr source,
gr_hier_block2_sptr block2) {
fprintf(stderr, "connect: calling lock, connect, unlock\n");
block->lock();
block->connect(source, 0, block2, 0);
block->unlock();
fprintf(stderr, "connect: done\n");
}
static void disconnect(gr_top_block_sptr block, gr_sig_source_f_sptr source,
gr_hier_block2_sptr block2) {
fprintf(stderr, "disconnect: calling block->lock\n");
block->lock();
fprintf(stderr, "disconnect: calling block->disconnect\n");
block->disconnect(source, 0, block2, 0);
fprintf(stderr, "disconnect: calling block->unlock\n");
block->unlock(); // It usually hangs here.
fprintf(stderr, "disconnect: done\n");
}
int main(int argc, char** argv) {
// Inner block: block to sink.
gr_hier_block2_sptr inner;
inner = gr_make_hier_block2("inner",
gr_make_io_signature(1, 1, sizeof(float)),
gr_make_io_signature(0, 0, 0));
gr_file_sink_sptr sink;
sink = gr_make_file_sink(sizeof(float), "/dev/null");
inner->connect(inner, 0, sink, 0);
// Outer block: signal source to inner block.
gr_top_block_sptr outer = gr_make_top_block("outer");
gr_sig_source_f_sptr src = "" GR_COS_WAVE,
400, .1, 0);
// Hook it up and get it going.
connect(outer, src, inner);
outer->start();
// Frob it until we die.
while (true) {
disconnect(outer, src, inner);
fprintf(stderr, "\n\n------------------------\n\n");
connect(outer, src, inner);
}
return 0;