Print or examine semaphore count value in GDB - c++

Question

I am trying to implement a thread pool using ACE Semaphore library. It does not provide any API like sem_getvalue which is in Posix semaphore. I need to debug some flow which is not behaving as expected. Can I examine the semaphore in GDB. I am using Centos as OS.
I initialized two semaphores using the default constructor providing count 0 and 10. I have declared them as static in the class and initialized it in the cpp file as
DP_Semaphore ThreadPool::availableThreads(10);
DP_Semaphore ThreadPool::availableWork(0);
But when I am printing the semaphore in GDB using the print command, I am getting the similar output
(gdb) p this->availableWork
$7 = {
sema = {
semaphore_ = {
sema_ = 0x6fe5a0,
name_ = 0x0
},
removed_ = false
}
}
(gdb) p this->availableThreads
$8 = {
sema = {
semaphore_ = {
sema_ = 0x6fe570,
name_ = 0x0
},
removed_ = false
}
}
Is there a tool which can help me here, or shall I switch to Posix thread and re-write all my code.
EDIT: As requested by #timrau the output of call this->availableWork->dump()
(gdb) p this->availableWork.dump()
[Switching to Thread 0x2aaaae97e940 (LWP 28609)]
The program stopped in another thread while making a function call from GDB.
Evaluation of the expression containing the function
(DP_Semaphore::dump()) will be abandoned.
When the function is done executing, GDB will silently stop.
(gdb) call this->availableWork.dump()
[Switching to Thread 0x2aaaaf37f940 (LWP 28612)]
The program stopped in another thread while making a function call from GDB.
Evaluation of the expression containing the function
(DP_Semaphore::dump()) will be abandoned.
When the function is done executing, GDB will silently stop.
(gdb) info threads
[New Thread 0x2aaaafd80940 (LWP 28613)]
6 Thread 0x2aaaafd80940 (LWP 28613) 0x00002aaaac10a61e in __lll_lock_wait_private ()
from /lib64/libpthread.so.0
* 5 Thread 0x2aaaaf37f940 (LWP 28612) ThreadPool::fetchWork (this=0x78fef0, worker=0x2aaaaf37f038)
at ../../CallManager/src/DP_CallControlTask.cpp:1043
4 Thread 0x2aaaae97e940 (LWP 28609) DP_Semaphore::dump (this=0x6e1460) at ../../Common/src/DP_Semaphore.cpp:21
2 Thread 0x2aaaad57c940 (LWP 28607) 0x00002aaaabe01ff3 in __find_specmb () from /lib64/libc.so.6
1 Thread 0x2aaaacb7b070 (LWP 28604) 0x00002aaaac1027c0 in __nptl_create_event () from /lib64/libpthread.so.0
(gdb)

Answer 1

sema.semaphore_.sema_ in your code looks like a pointer. Try to find it's type in the ACE headers, then convert it to a type and print:
(gdb) p *((sem_t)0x6fe570)
Update: try to convert the address within the structure you posted to sem_t. If you use linux, ACE should be using posix semaphores, so type sem_t must be visible to gdb.