sched_setparam(3c) [opensolaris man page]
sched_setparam(3C) Standard C Library Functions sched_setparam(3C) NAME
sched_setparam - set scheduling parameters SYNOPSIS
#include <sched.h> int sched_setparam(pid_t pid, const struct sched_param *param); DESCRIPTION
The sched_setparam() function sets the scheduling parameters of the process specified by pid to the values specified by the sched_param structure pointed to by param. The value of the sched_priority member in the sched_param structure is any integer within the inclusive pri- ority range for the current scheduling policy of the process specified by pid. Higher numerical values for the priority represent higher priorities. If the value of pid is negative, the behavior of the sched_setparam() function is unspecified. If a process specified by pid exists and if the calling process has permission, the scheduling parameters will be set for the process whose process ID is equal to pid. The real or effective user ID of the calling process must match the real or saved (from exec(2)) user ID of the target process unless the effective user ID of the calling process is 0. See Intro(2). If pid is zero, the scheduling parameters will be set for the calling process. The target process, whether it is running or not running, resumes execution after all other runnable processes of equal or greater priority have been scheduled to run. If the priority of the process specified by the pid 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 pid argument preempts a lowest priority running process. Similarly, if the process calling sched_setparam() 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 also preempts 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. RETURN VALUES
If successful, the sched_setparam() function returns 0. If the call to sched_setparam() is unsuccessful, the priority remains unchanged, and the function returns -1 and sets errno to indicate the error. ERRORS
The sched_setparam() function will fail if: EINVAL One or more of the requested scheduling parameters is outside the range defined for the scheduling policy of the specified pid. 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 sched_setparam(). ESRCH No process can be found corresponding to that specified by pid. ATTRIBUTES
See attributes(5) for descriptions of the following attributes: +-----------------------------+-----------------------------+ |ATTRIBUTE TYPE |ATTRIBUTE VALUE | +-----------------------------+-----------------------------+ |Interface Stability |Committed | +-----------------------------+-----------------------------+ |MT-Level |MT-Safe | +-----------------------------+-----------------------------+ |Standard |See standards(5). | +-----------------------------+-----------------------------+ SEE ALSO
Intro(2), exec(2), librt(3LIB), sched.h(3HEAD), sched_getparam(3C), sched_getscheduler(3C), sched_setscheduler(3C), attributes(5), stan- dards(5) SunOS 5.11 1 Apr 2008 sched_setparam(3C)
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sched_setscheduler(3C) Standard C Library Functions sched_setscheduler(3C) NAME
sched_setscheduler - set scheduling policy and scheduling parameters SYNOPSIS
#include <sched.h> int sched_setscheduler(pid_t pid, int policy, const struct sched_param *param); DESCRIPTION
The sched_setscheduler() function sets the scheduling policy and scheduling parameters of the process specified by pid to policy and the parameters specified in the sched_param structure pointed to by param, respectively. The value of the sched_priority member in the sched_param structure is any integer within the inclusive priority range for the scheduling policy specified by policy. The sched_setsched- uler() function ignores the other members of the sched_param structure. If the value of pid is negative, the behavior of the sched_setscheduler() function is unspecified. The possible values for the policy parameter are defined in the header <sched.h> (see sched.h(3HEAD)): If a process specified by pid exists and if the calling process has permission, the scheduling policy and scheduling parameters are set for the process whose process ID is equal to pid. The real or effective user ID of the calling process must match the real or saved (from exec(2)) user ID of the target process unless the effective user ID of the calling process is 0. See Intro(2). If pid is 0, the scheduling policy and scheduling parameters are set for the calling process. To change the policy of any process to either of the real time policies SCHED_FIFO or SCHED_RR, the calling process must either have the SCHED_FIFO or SCHED_RR policy or have an effective user ID of 0. The sched_setscheduler() function is considered successful if it succeeds in setting the scheduling policy and scheduling parameters of the process specified by pid to the values specified by policy and the structure pointed to by param, respectively. RETURN VALUES
Upon successful completion, the function returns the former scheduling policy of the specified process. If the sched_setscheduler() func- tion fails to complete successfully, the policy and scheduling paramenters remain unchanged, and the function returns -1 and sets errno to indicate the error. ERRORS
The sched_setscheduler() function will fail if: EINVAL The value of policy is invalid, or one or more of the parameters contained in param is outside the valid range for the specified scheduling policy. EPERM The requesting process does not have permission to set either or both of the scheduling parameters or the scheduling policy of the specified process. ESRCH No process can be found corresponding to that specified by pid. ATTRIBUTES
See attributes(5) for descriptions of the following attributes: +-----------------------------+-----------------------------+ | ATTRIBUTE TYPE | ATTRIBUTE VALUE | +-----------------------------+-----------------------------+ |Interface Stability |Committed | +-----------------------------+-----------------------------+ |MT-Level |MT-Safe | +-----------------------------+-----------------------------+ |Standard |See standards(5). | +-----------------------------+-----------------------------+ SEE ALSO
priocntl(1), Intro(2), exec(2), priocntl(2), librt(3LIB), sched.h(3HEAD), sched_get_priority_max(3C), sched_getparam(3C), sched_getsched- uler(3C), sched_setparam(3C), attributes(5), standards(5) SunOS 5.11 1 Apr 2008 sched_setscheduler(3C)