This avoids a pseudo infinite loop where CodeWidget::UpdateCallstack
would lock the CPU in order to read the call stack, causing the CPU to
call Host_UpdateDisasmDialog because it's transitioning from running to
pausing, causing Host::UpdateDisasmDialog to be emitted, causing
CodeWidget::Update to be called, once again causing
CodeWidget::UpdateCallstack to be called, repeating the cycle.
Dolphin didn't go completely unresponsive during this, because
Host_UpdateDisasmDialog schedules the emitting of Host::UpdateDisasmDialog
to happen on another thread without blocking, but it was stopping certain
operations like exiting emulation from working.
This fixes a problem I was having where using frame advance with the
debugger open would frequently cause panic alerts about invalid addresses
due to the CPU thread changing MSR.DR while the host thread was trying
to access memory.
To aid in tracking down all the places where we weren't properly locking
the CPU, I've created a new type (in Core.h) that you have to pass as a
reference or pointer to functions that require running as the CPU thread.
Use: callstack(0x80000000).
!callstack(value) works as a 'does not contain'.
Add strings to expr.h conditionals.
Use quotations: callstack("anim") to check symbols/name.
This affected the memory and registers widgets (and possibly others). I'm pretty sure it regressed in 5f629abd8b89971872b0c2c2cdc8ea0035e8998d.
The SetCodeVisible line is a new fix, but the equivalent already existed in the memory widget.
The call to analyzer.Analyze breaks when it attempts to read an instruction, as it eventually tries to read memory when Memory::m_pRAM is nullptr. Trying to read when execution is not paused in general seems like a bad idea (especially as analyzer.Analyze uses PowerPC::TryReadInstruction which can update icache - this is probably still a problem).
Before, only the symbols box would update. However, if you edit the symbol of a function in the call stack (which seems like something that would happen reasonably often while debugging), the call stack would be out of date until it was updated by clicking on it. Callers and calls were more of an edge case; for them to be out of date, you would need to right-click on an instruction in a function other than the one containing the currently-selected instruction (though it would also affect recursive functions).
