Quelle est la valeur du bon dans libdispatch de apple?

Question

Je viens de lire le code source de libdispatch, mais j'ai trouvé qu'il y a un mot, "voucher", juste apparaître tellement de fois, mais je ne sais pas ce que cela signifie réellement. Alors peut-on me dire les vrais moyens de ce mot, merci beaucoup pour votre aide.

Cordialement Axis

Answer 1

Je trouve juste réponse à partir du code source:

/* 
* Mach Voucher - an immutable collection of attribute value handles. 
* 
* The mach voucher is such that it can be passed between processes 
* as a Mach port send right (by convention in the mach_msg_header_t’s 
* msgh_voucher field). 
* 
* You may construct a new mach voucher by passing a construction 
* recipe to host_create_mach_voucher(). The construction recipe supports 
* generic commands for copying, removing, and redeeming attribute value 
* handles from previous vouchers, or running attribute-mananger-specific 
* commands within the recipe. 
* 
* Once the set of attribute value handles is constructed and returned, 
* that set will not change for the life of the voucher (just because the 
* attribute value handle itself doesn't change, the value the handle refers 
* to is free to change at will). 
*/ 

Cordialement

Axis