id	summary	reporter	owner	description	type	status	milestone	component	version	severity	resolution	keywords	cc
9558	future continuations unit test hangs in get()/pthread_cond_wait() on Mac 10.7/32-bit/x86/darwin-4.2.1	Monty Brandenberg <mcbinc@…>	viboes	"I'm building 32- and 64-bit versions of thread on Mac and validating the result with the unit tests.  Test 'ex_future_then_lib' hangs consistently in pthread_cond_wait() in a 32-bit build, all tests succeed in 64-bit builds.

Platform:  Mac 10.7.5, Xcode 4.3.3, darwin-4.2.1.


Successful build and test (64-bit):

{{{
./bjam toolset=darwin variant=debug --layout=tagged --with-thread  -sNO_BZIP2=1 stage
cd libs/thread/test/
../../../bjam toolset=darwin variant=debug --layout=tagged --with-thread  -sNO_BZIP2=1 -a -q -d2 -d+4

}}}

Hanging build and test (32-bit):

{{{
./bjam toolset=darwin variant=debug address-model=32 architecture=x86 --layout=tagged --with-thread  -sNO_BZIP2=1 stage
cd libs/thread/test/
../../../bjam toolset=darwin variant=debug address-model=32 architecture=x86 --layout=tagged --with-thread  -sNO_BZIP2=1 -a -q -d2 -d+4
}}}

Stacktrace from hung unit test:

{{{
#0  0x9c19c83e in __psynch_cvwait ()
#1  0x93bf3e21 in _pthread_cond_wait ()
#2  0x93ba442c in pthread_cond_wait$UNIX2003 ()
#3  0x00025a0b in boost::condition_variable::wait (this=0x34b16c, m=@0xbffff750) at condition_variable.hpp:73
#4  0x00025bf2 in boost::detail::shared_state_base::wait_internal (this=0x34b120, lk=@0xbffff750, rethrow=true)
    at future.hpp:327
#5  0x00025cf7 in boost::detail::shared_state_base::wait (this=0x34b120, rethrow=true) at future.hpp:346
#6  0x00031b2b in boost::detail::future_async_shared_state_base<int>::wait (this=0x34b120, rethrow=true)
    at future.hpp:845
#7  0x00024c05 in boost::detail::shared_state<int>::get (this=0x34b120) at future.hpp:666
#8  0x000248ca in boost::future<int>::get (this=0xbffff978) at future.hpp:1555
#9  0x000021b3 in main () at future_then.cpp:69

}}}

Extent of output at time of hang (appears not to have run P2):

{{{
Starting program: /Users/monty/3P/3p-boost-update/boost/bin.v2/libs/thread/test/ex_future_then_lib.test/darwin-4.2.1/debug/address-model-32/architecture-x86/threading-multi/ex_future_then_lib 
Reading symbols for shared libraries ++......................... done
0xac7e22c0 - ../example/future_then.cpp[63] <MAIN
0xb0081000 - ../example/future_then.cpp[18] P1
}}}

That's the extent of the bug.  In addition, there's some sloppy return value coding in the example code:

{{{
../example/future_then.cpp: In function ‘int p2s(boost::shared_future<int>)’:
../example/future_then.cpp:59: warning: control reaches end of non-void function
../example/future_then.cpp: In function ‘int p2(boost::future<int>)’:
../example/future_then.cpp:40: warning: control reaches end of non-void function
}}}
"	Bugs	closed	Boost 1.57.0	thread	Boost 1.55.0	Problem	fixed	future continuations