Initialize a condition variable
Synopsis:
#include <pthread.h>
pthread_cond_t cond = PTHREAD_COND_INITIALIZER;
int pthread_cond_init( pthread_cond_t *cond,
const pthread_condattr_t *attr );
Arguments:
- cond
- A pointer to the pthread_cond_t object that you want to initialize.
Note:
It's always safe, and typically faster, to assure that cond is 32-bit aligned.
- attr
- NULL, or a pointer to a pthread_condattr_t
object that specifies the attributes that you want to use for the condvar.
For more information, see
pthread_condattr_init().
Library:
libc
Use the -l c option to
qcc
to link against this library.
This library is usually included automatically.
Description:
The pthread_cond_init() function initializes the condition
variable cond with the attributes in the condition variable
attribute object attr. If attr is
NULL, cond is initialized with the default
values for the attributes (see
pthread_condattr_init()).
CAUTION:
You should allocate synchronization objects only in normal memory mappings.
On certain processors, atomic operations such as calls to
pthread_mutex_lock()
will cause a fault if the control structure is allocated in uncached memory.
If the condition variable is statically allocated, you can initialize it
with the default attribute values by assigning to it the macro
PTHREAD_COND_INITIALIZER.
Returns:
- EOK
- Success.
- EBUSY
- The cond argument pointer to a previously initialized
condition variable that hasn't been destroyed.
- EFAULT
- A fault occurred when the kernel tried to access cond or attr.
- EINVAL
- The value specified by cond is invalid.
- ENOMEM
- All kernel synchronization objects are in use, or there wasn't enough memory to initialize the condvar.
Classification:
POSIX 1003.1
| Safety: |
|
|---|
| Cancellation point |
No |
| Interrupt handler |
No |
| Signal handler |
Yes |
| Thread |
Yes |