2.6 Objects
“Object” is the general term for resources handled by T-Kernel. Besides tasks, objects include memory pools, semaphores, event flags, mailboxes and other synchronization and communication mechanisms, as well as time event handlers (cyclic handlers and alarm handlers).
Attributes can generally be specified when an object is created. Attributes determine detailed differences in object behavior or thE_OBJect initial state. When TA XXXXX is specified for an object, that object is called a “TA XXXXX attributE_OBJect”. If there is no particular attribute to be defined, TA NULL (=0) is specified. Generally there is no interface provided for reading attributes after an object is registered. In an object or handler attribute value, the lower bits indicate system attributes and the upper bits indicate implementation-dependent attributes. This speci.cation does not de.ne the bit position at which the upper and lower distinction is to be made. In principle, however, the system attribute portion is assigned from the least signi.cant bit (LSB) toward the most signi.cant bit (MSB), and implementation-dependent attributes from the MSB toward the LSB. Bits not de.ning any attribute must be cleared to 0.
In some cases an object may contain extended information. Extended information is specified when thE_OBJect is registered. Information passed in parameters when an object starts execution has no e.ect on T-Kernel behavior. Extended information can be read by calling an object status reference system call.
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