RCTLBLK_SET_VALUE(3C) Standard C Library Functions RCTLBLK_SET_VALUE(3C)
NAME
rctlblk_set_value, rctlblk_get_firing_time,
rctlblk_get_global_action, rctlblk_get_global_flags,
rctlblk_get_local_action, rctlblk_get_local_flags,
rctlblk_get_privilege, rctlblk_get_recipient_pid, rctlblk_get_value,
rctlblk_get_enforced_value, rctlblk_set_local_action,
rctlblk_set_local_flags, rctlblk_set_privilege,
rctlblk_set_recipient_pid, rctlblk_size - manipulate resource control
blocks
SYNOPSIS
#include <rctl.h>
hrtime_t rctlblk_get_firing_time(
rctlblk_t *rblk);
int rctlblk_get_global_action(
rctlblk_t *rblk);
int rctlblk_get_global_flags(
rctlblk_t *rblk);
int rctlblk_get_local_action(
rctlblk_t *rblk,
int *signalp);
int rctlblk_get_local_flags(
rctlblk_t *rblk);
rctl_priv_t rctlblk_get_privilege(
rctlblk_t *rblk);
id_t rctlblk_get_recipient_pid(
rctlblk_t *rblk);
rctl_qty_t rctlblk_get_value(
rctlblk_t *rblk);
rctl_qty_t rctlblk_get_enforced_value(
rctlblk_t *rblk);
void rctlblk_set_local_action(
rctlblk_t *rblk,
rctl_action_t action,
int signal);
void rctlblk_set_local_flags(
rctlblk_t *rblk,
int flags);
void rctlblk_set_privilege(
rctlblk_t *rblk,
rctl_priv_t privilege);
void rctlblk_set_value(
rctlblk_t *rblk,
rctl_qty_t value);
void rctlblk_set_recipient_pid(
id_tpid);
size_t rctlblk_size(
void);
DESCRIPTION
The resource control block routines allow the establishment or
retrieval of values from a resource control block used to transfer
information using the
getrctl(2) and
setrctl(2) functions. Each of
the routines accesses or sets the resource control block member
corresponding to its name. Certain of these members are read-only
and do not possess set routines.
The firing time of a resource control block is 0 if the resource
control action-value has not been exceeded for its lifetime on the
process. Otherwise the firing time is the value of
gethrtime(3C) at
the moment the action on the resource control value was taken.
The global actions and flags are the action and flags set by
rctladm(8). These values cannot be set with
setrctl(2). Valid
global actions are listed in the table below. Global flags are
generally a published property of the control and are not modifiable.
RCTL_GLOBAL_DENY_ALWAYS The action taken when a control value is
exceeded on this control will always
include denial of the resource.
RCTL_GLOBAL_DENY_NEVER The action taken when a control value is
exceeded on this control will always
exclude denial of the resource; the
resource will always be granted, although
other actions can also be taken.
RCTL_GLOBAL_SIGNAL_NEVER No signal actions are permitted on this
control.
RCTL_GLOBAL_CPU_TIME The valid signals available as local
actions include the
SIGXCPU signal.
RCTL_GLOBAL_FILE_SIZE The valid signals available as local
actions include the
SIGXFSZ signal.
RCTL_GLOBAL_INFINITE This resource control supports the
concept of an unlimited value; generally
true only of accumulation-oriented
resources, such as CPU time.
RCTL_GLOBAL_LOWERABLE Non-privileged callers are able to lower
the value of privileged resource control
values on this control.
RCTL_GLOBAL_NOACTION No global action will be taken when a
resource control value is exceeded on
this control.
RCTL_GLOBAL_NOBASIC No values with the
RCPRIV_BASIC privilege
are permitted on this control.
RCTL_GLOBAL_SYSLOG A standard message will be logged by the
syslog(3C) facility when any resource
control value on a sequence associated
with this control is exceeded.
RCTL_GLOBAL_SYSLOG_NEVER The resource control does not support the
syslog() global action. Exceeding a
resource control value on this control
will not result in a message logged by
the
syslog() facility.
RCTL_GLOBAL_UNOBSERVABLE The resource control (generally on a
task- or project-related control) does
not support observational control values.
An
RCPRIV_BASIC privileged control value
placed by a process on the task or
process will generate an action only if
the value is exceeded by that process.
RCTL_GLOBAL_BYTES This resource control represents a number
of bytes.
RCTL_GLOBAL_SECONDS This resource control represents a
quantity of time in seconds.
RCTL_GLOBAL_COUNT This resource control represents an
integer count.
The local action and flags are those on the current resource control
value represented by this resource control block. Valid actions and
flags are listed in the table below. In the case of
RCTL_LOCAL_SIGNAL, the second argument to
rctlblk_set_local_action() contains the signal to be sent. Similarly, the signal to be sent is
copied into the integer location specified by the second argument to
rctlblk_get_local_action(). A restricted set of signals is made
available for normal use by the resource control facility:
SIGBART,
SIGXRES,
SIGHUP,
SIGSTOP,
SIGTERM, and
SIGKILL. Other signals are
permitted due to global properties of a specific control. Calls to
setrctl() with illegal signals will fail.
RCTL_LOCAL_DENY When this resource control value is
encountered, the request for the resource will
be denied. Set on all values if
RCTL_GLOBAL_DENY_ALWAYS is set for this
control; cleared on all values if
RCTL_GLOBAL_DENY_NEVER is set for this
control.
RCTL_LOCAL_MAXIMAL This resource control value represents a
request for the maximum amount of resource for
this control. If
RCTL_GLOBAL_INFINITE is set
for this resource control,
RCTL_LOCAL_MAXIMAL indicates an unlimited resource control value,
one that will never be exceeded.
RCTL_LOCAL_NOACTION No local action will be taken when this
resource control value is exceeded.
RCTL_LOCAL_SIGNAL The specified signal, sent by
rctlblk_set_local_action(), will be sent to
the process that placed this resource control
value in the value sequence. This behavior is
also true for signal actions on project and
task resource controls. The specified signal
is sent only to the recipient process, not all
processes within the project or task.
The
rctlblk_get_recipient_pid() function returns the value of the
process ID that placed the resource control value for basic rctls.
For privileged or system rctls,
rctlblk_get_recipient_pid() returns
-1.
The
rctlblk_set_recipient_pid() function sets the recipient
pid for a
basic rctl. When
setrctl(2) is called with the flag
RCTL_USE_RECIPIENT_PID, this
pid is used. Otherwise, the PID of the
calling process is used. Only privileged users can set the recipient
PID to one other than the PID of the calling process. Process-scoped
rctls must have a recipient PID that matches the PID of the calling
process.
The
rctlblk_get_privilege() function returns the privilege of the
resource control block. Valid privileges are
RCPRIV_BASIC,
RCPRIV_PRIVILEGED, and
RCPRIV_SYSTEM. System resource controls are
read-only. Privileged resource controls require the
{
PRIV_SYS_RESOURCE} privilege to write, unless the
RCTL_GLOBAL_LOWERABLE global flag is set, in which case unprivileged
applications can lower the value of a privileged control.
The
rctlblk_get_value() and
rctlblk_set_value() functions return or
establish the enforced value associated with the resource control. In
cases where the process, task, or project associated with the control
possesses fewer capabilities than allowable by the current value, the
value returned by
rctlblk_get_enforced_value() will differ from that
returned by
rctlblk_get_value(). This capability difference arises
with processes using an address space model smaller than the maximum
address space model supported by the system.
The
rctlblk_size() function returns the size of a resource control
block for use in memory allocation. The
rctlblk_t * type is an opaque
pointer whose size is not connected with that of the resource control
block itself. Use of
rctlblk_size() is illustrated in the example
below.
RETURN VALUES
The various set routines have no return values. Incorrectly composed
resource control blocks will generate errors when used with
setrctl(2) or
getrctl(2).
ERRORS
No error values are returned. Incorrectly constructed resource
control blocks will be rejected by the system calls.
EXAMPLES
Example 1: Display the contents of a fetched resource control block.
The following example displays the contents of a fetched resource
control block.
#include <rctl.h>
#include <stdio.h>
#include <stdlib.h>
int
main()
{
rctlblk_t *rblk;
int rsignal, raction;
if ((rblk = malloc(rctlblk_size())) == NULL) {
(void) perror("rblk malloc");
exit(1);
}
if (getrctl("process.max-cpu-time", NULL, rblk, RCTL_FIRST) == -1) {
(void) perror("getrctl");
exit(1);
}
raction = rctlblk_get_local_action(rblk, &rsignal),
(void) printf("Resource control for %s\n",
"process.max-cpu-time");
(void) printf("Process ID: %d\n",
(int)rctlblk_get_recipient_pid(rblk));
(void) printf("Privilege: %x\n",
rctlblk_get_privilege(rblk));
(void) printf("Global flags: %x\n",
rctlblk_get_global_flags(rblk));
(void) printf("Global actions: %x\n",
rctlblk_get_global_action(rblk));
(void) printf("Local flags: %x\n",
rctlblk_get_local_flags(rblk));
(void) printf("Local action: %x (%d)\n",
raction, raction == RCTL_LOCAL_SIGNAL ? rsignal : 0);
(void) printf("Value: %llu\n",
rctlblk_get_value(rblk));
(void) printf("\tEnforced value: %llu\n",
rctlblk_get_enforced_value(rblk));
return (0);
}
ATTRIBUTES
See
attributes(7) for descriptions of the following attributes:
+--------------------+-----------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+--------------------+-----------------+
|Interface Stability | Evolving |
+--------------------+-----------------+
|MT-Level | MT-Safe |
+--------------------+-----------------+
SEE ALSO
getrctl(2),
setrctl(2),
gethrtime(3C),
attributes(7),
rctladm(8) August 2, 2016 RCTLBLK_SET_VALUE(3C)