• Joshua Niehus (78/78) Nov 20 2012 Hello,

"Joshua Niehus" <jm.niehus gmail.com> writes:

Hello,
Im starting one process in the main thread who in turn is going 
to kick off another process but has no way of passing along 
main's Tid, hence the shared(Tid) nonsense.
* This works in serial (i.e. change workUnitSize > x.length in 
mains foreach loop).
* It also works when passing the tid directly into f.run(mainTid) 
with workUnitSize == 1
But I get a crash when attempting to run in parallel with a 
"shared" tid (see below).
Any ideas how to make this work?
Thanks,
Josh

// garbage: newb playing with threads
module test;
import core.thread;
import std.concurrency, std.parallelism, std.stdio;

shared(Tid) mainTid;

struct Foo {
     void run() {
         Thread.sleep(dur!"seconds"(1));
         writeln(cast(Tid)mainTid);
         send(cast(Tid)mainTid, true);
     }
}

void someAction(Tid tid) {
     mainTid = cast(shared(Tid))tid;
}

void main() {
     Foo[] x = [Foo(), Foo(), Foo()];
     spawn( &someAction, thisTid );
     foreach(f; taskPool.parallel(x, 1)) {
         f.run();
         receiveTimeout(dur!"seconds"(3),
             (bool x) { writeln("received"); }
         );
     }
}
// exception output:
core.exception.AssertError /usr/share/dmd/src/phobos/std/concurrency.d(1007): 
null this
----------------
5   test                                0x000000010604a4ad 
_d_assert_msg + 69
6   test                                0x0000000106032523 bool 
std.concurrency.MessageBox.get!(core.time.Duration, void 
function(bool)*).get(scope core.time.Duration, scope void 
function(bool)*) + 83
7   test                                0x00000001060324bb bool 
std.concurrency.receiveTimeout!(void 
function(bool)*).receiveTimeout(core.time.Duration, void 
function(bool)*) + 59
8   test                                0x000000010602c5c7 void 
test.main().int __foreachbody1416(ref test.Foo) + 71
9   test                                0x00000001060320f0 int 
std.parallelism.ParallelForeach!(test.Foo[]).ParallelForeach.opApply(scope 
int delegate(ref test.Foo)).void doIt() + 256
10  test                                0x00000001060583f4 void 
std.parallelism.run!(void delegate()).run(void delegate()) + 20
11  test                                0x000000010605800c void 
std.parallelism.__T4TaskS213std11parallelism3runTDFZvZ.Task.impl(void*) 
+ 24
12  test                                0x0000000106056da3 void 
std.parallelism.AbstractTask.job() + 15
13  test                                0x0000000106056df9 void 
std.parallelism.TaskPool.doJob(std.parallelism.AbstractTask*) + 33
14  test                                0x0000000106056f20 void 
std.parallelism.TaskPool.workLoop() + 132
15  test                                0x000000010603f915 void 
core.thread.Thread.run() + 49
16  test                                0x000000010603ec5a 
thread_entryPoint + 334
17  libsystem_c.dylib                   0x00007fff9681f742 
_pthread_start + 327
18  libsystem_c.dylib                   0x00007fff9680c181 
thread_start + 13
19  ???                                 0x0000000000000000 0x0 + 0
----------------