diff options
Diffstat (limited to 'winsup/cygwin/sched.cc')
| -rw-r--r-- | winsup/cygwin/sched.cc | 44 |
1 files changed, 43 insertions, 1 deletions
diff --git a/winsup/cygwin/sched.cc b/winsup/cygwin/sched.cc index ef12b69b2..f80803e28 100644 --- a/winsup/cygwin/sched.cc +++ b/winsup/cygwin/sched.cc @@ -81,6 +81,18 @@ sched_get_priority_min (int policy) return 15; } +/* Check a scheduler parameter struct for valid settings */ +int +valid_sched_parameters(const struct sched_param *param) +{ + if (param->sched_priority < -14 || param->sched_priority > 15) + { + return 0; + } + return -1; + +} + /* get sched params for process Note, I'm never returning EPERM, @@ -273,7 +285,7 @@ sched_setparam (pid_t pid, const struct sched_param *param) return -1; } - if (param->sched_priority < -14 || param->sched_priority > 15) + if (!valid_sched_parameters(param)) { set_errno (EINVAL); return -1; @@ -384,6 +396,36 @@ sched_setparam (pid_t pid, const struct sched_param *param) return 0; } +/* we map -14 to 15, and 15 to 1 via (16- ((n+16) >> 1)). This lines up with the allowed + * valueswe return elsewhere in the sched* functions. We then map in groups of three to + * allowed thread priority's. The reason for dropping accuracy while still returning + * a wide range of values is to allow more flexible code in the future. + */ +int +sched_set_thread_priority(HANDLE thread, int priority) +{ + int real_pri; + real_pri = 16 - ((priority + 16) >> 1); + if (real_pri <1 || real_pri > 15) + return EINVAL; + + if (real_pri < 4) + real_pri = THREAD_PRIORITY_LOWEST; + else if (real_pri < 7) + real_pri = THREAD_PRIORITY_BELOW_NORMAL; + else if (real_pri < 10) + real_pri = THREAD_PRIORITY_NORMAL; + else if (real_pri < 13) + real_pri = THREAD_PRIORITY_ABOVE_NORMAL; + else + real_pri = THREAD_PRIORITY_HIGHEST; + + if (!SetThreadPriority(thread, real_pri)) + /* invalid handle, no access are the only expected errors. */ + return EPERM; + return 0; +} + /* set the scheduler */ int sched_setscheduler (pid_t pid, int policy, |