DCE Application Programming Guide

NonStop DCE Application Development
Environment
HP NonStop DCE Application Programming Guide—429551-003
1-6
Unsupported Features
•
NonStop DCE DTS does not provide:
°
The network time protocol (NTP) time provider.
°
Time inaccuracy when retrieving the system time. Both the utc_gettime()
and the utc_getusertime() functions always return the inaccuracy as
infinite.
•
NonStop DCE threads do not support:
°
Preemptive scheduling
The preemptive thread scheduling policies are not supported. Only first-in, first-
out (FIFO) scheduling is supported. Once scheduled, a thread executes until it
blocks.
If any value other than SCHED_FIFO is supplied in the scheduler parameter
of the pthread_setscheduler() or pthread_attr_setsched()
functions, the functions fail. If the threads exception-returning interface is used,
the pthread_unimp_e exception is raised; otherwise, -1 is returned and
errno is set to ENOTSUP.
The default thread scheduling policy is SCHED_FIFO (rather than
SCHED_OTHER or SCHED_FG_NP).
The default thread scheduling priority is the middle of the permitted range for
FIFO scheduling, which is (PRI_FIFO_MIN + PRI_FIFO_MAX)/2.
°
Asynchronous delivery of cancels to a thread
The asynchronous delivery of a cancel indication to a thread is not supported.
If any value other than CANCEL_OFF is supplied in the state parameter of the
pthread_setasynccancel() function, the function fails. If the threads
exception-returning interface is used, the pthread_unimp_e exception is
raised; otherwise, -1 is returned and errno is set to ENOTSUP.
°
Jackets for process-blocking functions
Except for SERVERCLASS_SEND_, SERVERCLASS_DIALOG_BEGIN_,
SERVERCLASS_DIALOG_SEND_, SERVERCLASS_DIALOG_END_, and
SERVERCLASS_DIALOG_ABORT_ jackets and TMF transaction demarcation
jackets, jacket functions are not provided for converting process-blocking
functions to thread-blocking functions. For example, a call to a file or SQL/MP
operation can cause the entire process to block.
•
The dced server API for server management is supported but has not been tested
extensively. In addition, some optional server attributes are not supported.
•
NonStop DCE does not support these security features:
°
The passwd_import and passwd_export commands to integrate the
NonStop operating system and DCE user ID and password management are
not provided.