Rene Rivera:
Peter Dimov wrote:
Can someone with access to ARM please run libs/smart_ptr/test/spinlock_test.cpp and/or take a look at boost/detail/spinlock_gcc_arm.hpp? I've verified that it compiles, but can't run it.
What is the expected behavior? I get no output, no CPU usage, and an indefinite running time.
This means a deadlock. The test just locks and unlocks two spinlocks, the expected behavior is to return immediately. You can try spinlock_try_test.cpp which might produce some output. Here's the relevant portion of spinlock_gcc_arm.hpp: bool try_lock() { int r; __asm__ __volatile__( "swp %0, %1, [%2]": "=r"( r ): // outputs "r"( 1 ), "r"( &v_ ): // inputs "memory", "cc" ); return r == 0; } void lock() { for( unsigned k = 0; !try_lock(); ++k ) { boost::detail::yield( k ); } } void unlock() { __asm__ __volatile__( "" ::: "memory" ); *const_cast< int volatile* >( &v_ ) = 0; }