InterruptUnlock()

Release a critical section in an interrupt handler

Synopsis:

#include <sys/neutrino.h>

void InterruptUnlock( intrspin_t* spinlock );

Arguments:

spinlock: The spinlock (a variable shared between the interrupt handler and a thread) used in a call to InterruptLock() to lock the handler.

Library:

libc

Use the -l c option to qcc to link against this library. This library is usually included automatically.

Description:

The InterruptUnlock() function releases a critical section by unlocking the specified spinlock, reenabling interrupts. You can call this function from a thread or from an interrupt handler.

Before calling this function:

The process must have the PROCMGR_AID_IO ability enabled. For more information, see procmgr_ability().
The calling thread must have obtained I/O privileges by calling:
```
ThreadCtl( _NTO_TCTL_IO_LEVEL, (void*)_NTO_IO_LEVEL_1 );
```

If you don't do these things, the thread might SIGSEGV when it calls InterruptUnlock().

Note: This function doesn't support nesting. If a specific thread calls InterruptLock() multiple times with different spinlocks and then calls InterruptUnlock() the same number of times and in reverse order with the locks, the first InterruptUnlock() call reenables interrupts and the critical section is no longer protected.

Classification:

QNX Neutrino

Safety:
Cancellation point	No
Interrupt handler	Yes
Signal handler	Yes
Thread	Yes