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diff --git a/man-pages-posix-2003/man3p/sched_setparam.3p b/man-pages-posix-2003/man3p/sched_setparam.3p new file mode 100644 index 0000000..33bcbd3 --- /dev/null +++ b/man-pages-posix-2003/man3p/sched_setparam.3p @@ -0,0 +1,183 @@ +.\" Copyright (c) 2001-2003 The Open Group, All Rights Reserved +.TH "SCHED_SETPARAM" 3P 2003 "IEEE/The Open Group" "POSIX Programmer's Manual" +.\" sched_setparam +.SH PROLOG +This manual page is part of the POSIX Programmer's Manual. +The Linux implementation of this interface may differ (consult +the corresponding Linux manual page for details of Linux behavior), +or the interface may not be implemented on Linux. +.SH NAME +sched_setparam \- set scheduling parameters (\fBREALTIME\fP) +.SH SYNOPSIS +.LP +\fB#include <sched.h> +.br +.sp +int sched_setparam(pid_t\fP \fIpid\fP\fB, const struct sched_param +*\fP\fIparam\fP\fB); \fP +\fB +.br +\fP +.SH DESCRIPTION +.LP +The \fIsched_setparam\fP() function shall set the scheduling parameters +of the process specified by \fIpid\fP to the values +specified by the \fBsched_param\fP structure pointed to by \fIparam\fP. +The value of the \fIsched_priority\fP member in the +\fBsched_param\fP structure shall be any integer within the inclusive +priority range for the current scheduling policy of the +process specified by \fIpid\fP. Higher numerical values for the priority +represent higher priorities. If the value of \fIpid\fP +is negative, the behavior of the \fIsched_setparam\fP() function is +unspecified. +.LP +If a process specified by \fIpid\fP exists, and if the calling process +has permission, the scheduling parameters shall be set +for the process whose process ID is equal to \fIpid\fP. +.LP +If \fIpid\fP is zero, the scheduling parameters shall be set for the +calling process. +.LP +The conditions under which one process has permission to change the +scheduling parameters of another process are +implementation-defined. +.LP +Implementations may require the requesting process to have the appropriate +privilege to set its own scheduling parameters or +those of another process. +.LP +The target process, whether it is running or not running, shall be +moved to the tail of the thread list for its priority. +.LP +If the priority of the process specified by the \fIpid\fP argument +is set higher than that of the lowest priority running +process and if the specified process is ready to run, the process +specified by the \fIpid\fP argument shall preempt a lowest +priority running process. Similarly, if the process calling \fIsched_setparam\fP() +sets its own priority lower than that of one or +more other non-empty process lists, then the process that is the head +of the highest priority list shall also preempt the calling +process. Thus, in either case, the originating process might not receive +notification of the completion of the requested priority +change until the higher priority process has executed. +.LP +If +the scheduling policy of the target process is SCHED_SPORADIC, the +value specified by the \fIsched_ss_low_priority\fP member of +the \fIparam\fP argument shall be any integer within the inclusive +priority range for the sporadic server policy. The +\fIsched_ss_repl_period\fP and \fIsched_ss_init_budget\fP members +of the \fIparam\fP argument shall represent the time +parameters to be used by the sporadic server scheduling policy for +the target process. The \fIsched_ss_max_repl\fP member of the +\fIparam\fP argument shall represent the maximum number of replenishments +that are allowed to be pending simultaneously for the +process scheduled under this scheduling policy. +.LP +The specified \fIsched_ss_repl_period\fP shall be greater than or +equal to the specified \fIsched_ss_init_budget\fP for the +function to succeed; if it is not, then the function shall fail. +.LP +The value of \fIsched_ss_max_repl\fP shall be within the inclusive +range [1, {SS_REPL_MAX}] for the function to succeed; if +not, the function shall fail. +.LP +If the scheduling policy of the target process is either SCHED_FIFO +or SCHED_RR, the \fIsched_ss_low_priority\fP, +\fIsched_ss_repl_period\fP, and \fIsched_ss_init_budget\fP members +of the \fIparam\fP argument shall have no effect on the +scheduling behavior. If the scheduling policy of this process is not +SCHED_FIFO, SCHED_RR, or SCHED_SPORADIC, the effects of these +members are implementation-defined; this case includes the SCHED_OTHER +policy. +.LP +If the current scheduling policy for the process specified by \fIpid\fP +is not SCHED_FIFO, SCHED_RR, or +SCHED_SPORADIC, the result is implementation-defined; this +case includes the SCHED_OTHER policy. +.LP +The effect of this function on individual threads is dependent on +the scheduling contention scope of the threads: +.IP " *" 3 +For threads with system scheduling contention scope, these functions +shall have no effect on their scheduling. +.LP +.IP " *" 3 +For threads with process scheduling contention scope, the threads' +scheduling parameters shall not be affected. However, the +scheduling of these threads with respect to threads in other processes +may be dependent on the scheduling parameters of their +process, which are governed using these functions. +.LP +.LP +If an implementation supports a two-level scheduling model in which +library threads are multiplexed on top of several +kernel-scheduled entities, then the underlying kernel-scheduled entities +for the system contention scope threads shall not be +affected by these functions. +.LP +The underlying kernel-scheduled entities for the process contention +scope threads shall have their scheduling parameters changed +to the value specified in \fIparam\fP. Kernel-scheduled entities for +use by process contention scope threads that are created +after this call completes shall inherit their scheduling policy and +associated scheduling parameters from the process. +.LP +This function is not atomic with respect to other threads in the process. +Threads may continue to execute while this function +call is in the process of changing the scheduling policy for the underlying +kernel-scheduled entities used by the process +contention scope threads. +.SH RETURN VALUE +.LP +If successful, the \fIsched_setparam\fP() function shall return zero. +.LP +If the call to \fIsched_setparam\fP() is unsuccessful, the priority +shall remain unchanged, and the function shall return a +value of -1 and set \fIerrno\fP to indicate the error. +.SH ERRORS +.LP +The \fIsched_setparam\fP() function shall fail if: +.TP 7 +.B EINVAL +One or more of the requested scheduling parameters is outside the +range defined for the scheduling policy of the specified +\fIpid\fP. +.TP 7 +.B EPERM +The requesting process does not have permission to set the scheduling +parameters for the specified process, or does not have +the appropriate privilege to invoke \fIsched_setparam\fP(). +.TP 7 +.B ESRCH +No process can be found corresponding to that specified by \fIpid\fP. +.sp +.LP +\fIThe following sections are informative.\fP +.SH EXAMPLES +.LP +None. +.SH APPLICATION USAGE +.LP +None. +.SH RATIONALE +.LP +None. +.SH FUTURE DIRECTIONS +.LP +None. +.SH SEE ALSO +.LP +\fIsched_getparam\fP(), \fIsched_getscheduler\fP(), +\fIsched_setscheduler\fP(), the Base Definitions volume of IEEE\ Std\ 1003.1-2001, +\fI<sched.h>\fP +.SH COPYRIGHT +Portions of this text are reprinted and reproduced in electronic form +from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology +-- Portable Operating System Interface (POSIX), The Open Group Base +Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of +Electrical and Electronics Engineers, Inc and The Open Group. In the +event of any discrepancy between this version and the original IEEE and +The Open Group Standard, the original IEEE and The Open Group Standard +is the referee document. The original Standard can be obtained online at +http://www.opengroup.org/unix/online.html . |