diff options
Diffstat (limited to 'sched.c')
| -rw-r--r-- | sched.c | 239 |
1 files changed, 18 insertions, 221 deletions
@@ -91,11 +91,7 @@ pthread_attr_setschedparam(pthread_attr_t *attr, priority = param->sched_priority; - /* - * Validate priority level. Don't check the - * return values of the function calls because - * we're sure they will succeed. - */ + /* Validate priority level. */ if (priority < sched_get_priority_min(SCHED_OTHER) || priority > sched_get_priority_max(SCHED_OTHER)) { @@ -109,7 +105,7 @@ pthread_attr_setschedparam(pthread_attr_t *attr, int pthread_attr_getschedparam(const pthread_attr_t *attr, - struct sched_param *param) + struct sched_param *param) { if (is_attr(attr) != 0 || param == NULL) { @@ -177,13 +173,9 @@ pthread_setschedparam(pthread_t thread, int policy, return ENOTSUP; } - /* - * Validate priority level. Don't check the - * return values of the function calls because - * we're sure they will succeed. - */ - if (param->sched_priority < sched_get_priority_min(SCHED_OTHER) || - param->sched_priority > sched_get_priority_max(SCHED_OTHER)) + /* Validate priority level. */ + if (param->sched_priority < sched_get_priority_min(policy) || + param->sched_priority > sched_get_priority_max(policy)) { return EINVAL; } @@ -253,14 +245,7 @@ sched_get_priority_max(int policy) { if (policy < SCHED_MIN || policy > SCHED_MAX) { - errno = EINVAL; - return -1; - } - - if (policy != SCHED_OTHER) - { - errno = ENOTSUP; - return -1; + return EINVAL; } #if (THREAD_PRIORITY_LOWEST > THREAD_PRIORITY_NORMAL) @@ -278,14 +263,7 @@ sched_get_priority_min(int policy) { if (policy < SCHED_MIN || policy > SCHED_MAX) { - errno = EINVAL; - return -1; - } - - if (policy != SCHED_OTHER) - { - errno = ENOTSUP; - return -1; + return EINVAL; } #if (THREAD_PRIORITY_LOWEST > THREAD_PRIORITY_NORMAL) @@ -299,175 +277,31 @@ sched_get_priority_min(int policy) int -sched_rr_get_interval(pid_t pid, struct timespec * interval) - /* - * ------------------------------------------------------ - * DOCPUBLIC - * This function updates the timespec structure - * referenced by the interval argument to contain - * the current quantum for the process executing - * under the SCHED_RR policy. If a process, running under - * the round-robin scheduling policy, runs without - * blocking or yielding for more than this amount of - * time, it may be preempted by another runnable - * process (at the same priority). - * - * If the PID argument is zero, the current execution - * time limit for the calling process is returned. - * - * PARAMETERS - * pid Process identifier. - * - * - * DESCRIPTION - * This function updates the timespec structure - * referenced by the interval argument to contain - * the current quantum for the process executing - * under the SCHED_RR policy. If a process, running under - * the round-robin scheduling policy, runs without - * blocking or yielding for more than this amount of - * time, it may be preempted by another runnable - * process (at the same priority). - * - * If the PID argument is zero, the current execution - * time limit for the calling process is returned. - * - * RESULTS - * We don't support SCHED_RR so this routine always fails. - * - * NOTE: Since this is part of POSIX 1003.1b - * (realtime extensions), it is defined as returning - * -1 if an error occurs and sets errno to the actual - * error. - * - * errno: ESRCH Pid doesn't refer to a valid process. - * EPERM The process referenced by pid does - * not allow query access. - * ENOTSUP SCHED_RR is not supported. - * - * ------------------------------------------------------ - */ -{ - /* - * Provide other valid side-effects - * such as EPERM and ESRCH errors. - */ - if (0 != pid) - { - DWORD selfPid = GetCurrentProcessId(); - - if (pid != selfPid) - { - HANDLE h = OpenProcess(PROCESS_QUERY_INFORMATION, FALSE, pid); - - if (NULL == h) - { - errno = (GetLastError() == (0xFF & ERROR_ACCESS_DENIED) - ? EPERM - : ESRCH ); - - return -1; - } - - (void) CloseHandle(h); - } - } - - /* - * We can't return ENOSYS and stay strictly compliant with the - * standard. We don't support round-robin scheduling so - * we return ENOTSUP instead. This is consistent with - * routines which return ENOTSUP if SCHED_RR is given - * as the policy parameter. - */ - errno = ENOTSUP; - return -1; -} - - -int sched_setscheduler(pid_t pid, int policy) - /* - * ------------------------------------------------------ - * DOCPUBLIC - * This function returns 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. - * If the value of pid is negative, the behaviour of the - * sched_setscheduler() function is unspecified. - * - * PARAMETERS - * pid Identifier of the process in which the - * policy will be set. - * policy The new policy value. - * - * - * DESCRIPTION - * This function returns 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. - * If the value of pid is negative, the behaviour of the - * sched_setscheduler() function is unspecified. - * - * RESULTS - * SCHED_OTHER on success this is the only possible - * value that can be returned. - * - * NOTE: Since this is part of POSIX 1003.1b - * (realtime extensions), it is defined as returning - * -1 if an error occurs and sets errno to the actual - * error. - * - * errno: ESRCH 'pid' doesn't refer to an existing - * process. - * EPERM The process referenced by pid does - * not allow set access. - * EINVAL 'policy' is not a valid policy value. - * ENOSYS the policy specified is not supported. - * - * ------------------------------------------------------ - */ { /* * Win32 only has one policy which we call SCHED_OTHER. * However, we try to provide other valid side-effects - * such as EPERM and ESRCH errors. + * such as EPERM and ESRCH errors. Choosing to check + * for a valid policy last allows us to get the most value out + * of this function. */ if (0 != pid) { - DWORD selfPid = GetCurrentProcessId(); + int selfPid = (int) GetCurrentProcessId(); if (pid != selfPid) { - HANDLE h = OpenProcess(PROCESS_SET_INFORMATION, FALSE, pid); + HANDLE h = OpenProcess(PROCESS_SET_INFORMATION, FALSE, (DWORD) pid); if (NULL == h) { - errno = (GetLastError() == (0xFF & ERROR_ACCESS_DENIED) - ? EPERM - : ESRCH ); - + errno = (GetLastError() == (0xFF & ERROR_ACCESS_DENIED)) ? EPERM : ESRCH; return -1; } - - (void) CloseHandle(h); } } - if (policy < SCHED_MIN || policy > SCHED_MAX) - { - errno = EINVAL; - return -1; - } - if (SCHED_OTHER != policy) { errno = ENOSYS; @@ -484,39 +318,6 @@ sched_setscheduler(pid_t pid, int policy) int sched_getscheduler(pid_t pid) - /* - * ------------------------------------------------------ - * DOCPUBLIC - * This function returns the scheduling policy of the - * process specified by pid. If the value of pid is - * negative, the behaviour of the sched_getscheduler() - * function is unspecified. - * - * PARAMETERS - * pid Process identifier. - * - * - * DESCRIPTION - * This function returns the scheduling policy of the - * process specified by pid. If the value of pid is - * negative, the behaviour of the sched_getscheduler() - * function is unspecified. - * - * RESULTS - * SCHED_OTHER on success this is the only possible - * value that can be returned. - * - * NOTE: Since this is part of POSIX 1003.1b - * (realtime extensions), it is defined as returning - * -1 if an error occurs and sets errno to the actual - * error. - * - * errno: ESRCH Pid doesn't refer to a valid process. - * EPERM The process referenced by pid does - * not allow query access. - * - * ------------------------------------------------------ - */ { /* * Win32 only has one policy which we call SCHED_OTHER. @@ -525,22 +326,17 @@ sched_getscheduler(pid_t pid) */ if (0 != pid) { - DWORD selfPid = GetCurrentProcessId(); + int selfPid = (int) GetCurrentProcessId(); if (pid != selfPid) { - HANDLE h = OpenProcess(PROCESS_QUERY_INFORMATION, FALSE, pid); + HANDLE h = OpenProcess(PROCESS_QUERY_INFORMATION, FALSE, (DWORD) pid); if (NULL == h) { - errno = (GetLastError() == (0xFF & ERROR_ACCESS_DENIED) - ? EPERM - : ESRCH ); - + errno = (GetLastError() == (0xFF & ERROR_ACCESS_DENIED)) ? EPERM : ESRCH; return -1; } - - (void) CloseHandle(h); } } @@ -569,7 +365,8 @@ sched_yield(void) * error. * * RESULTS - * 0 always succeeds + * 0 successfully created semaphore, + * ENOSYS sched_yield not supported, * * ------------------------------------------------------ */ |