PRThreadPriority 编辑

A thread's priority setting.

Syntax

#include <prthread.h>

typedef enum PRThreadPriority
{
   PR_PRIORITY_FIRST   = 0,
   PR_PRIORITY_LOW     = 0,
   PR_PRIORITY_NORMAL  = 1,
   PR_PRIORITY_HIGH    = 2,
   PR_PRIORITY_URGENT  = 3,
   PR_PRIORITY_LAST    = 3
} PRThreadPriority;

Enumerators

PR_PRIORITY_FIRST

Placeholder.

PR_PRIORITY_LOW

The lowest possible priority. This priority is appropriate for threads that are expected to perform intensive computation.

PR_PRIORITY_NORMAL

The most commonly expected priority.

PR_PRIORITY_HIGH

Slightly higher priority than PR_PRIORITY_NORMAL. This priority is for threads performing work of high urgency but short duration.

PR_PRIORITY_URGENT

Highest priority. Only one thread at a time typically has this priority.

PR_PRIORITY_LAST

Placeholder

Description

In general, an NSPR thread of higher priority has a statistically better chance of running relative to threads of lower priority. However, because of the multiple strategies NSPR uses to implement threading on various host platforms, NSPR priorities are not precisely defined. At best they are intended to specify a preference in the amount of CPU time that a higher-priority thread might expect relative to a lower-priority thread. This preference is still subject to resource availability and must not be used in place of proper synchronization.

See Also

Setting Thread Priorities.