Name
eventfd_ctx_read — 
     Reads the eventfd counter or wait if it is zero.
 
Synopsis
| ssize_t fsfunceventfd_ctx_read ( | struct eventfd_ctx * ctx, | 
|  | int no_wait, | 
|  | __u64 * cnt ); | 
 
Arguments
- ctx
- 
     [in] Pointer to eventfd context.
     
- no_wait
- 
     [in] Different from zero if the operation should not block.
     
- cnt
- 
     [out] Pointer to the 64-bit counter value.
     
Description
   Returns 0 if successful, or the following error codes:
   
   -EAGAIN      : The operation would have blocked but no_wait was non-zero.
   -ERESTARTSYS : A signal interrupted the wait operation.
   
   If no_wait is zero, the function might sleep until the eventfd internal
   counter becomes greater than zero.