Re: [boost] Re: Re: Thread-Local Storage (TLS) and templates

From: Gabriel Dos Reis (gdr_at_[hidden])
Date: 2003-02-20 10:53:00

David Abrahams <dave_at_[hidden]> writes:

| Gabriel Dos Reis <gdr_at_[hidden]> writes:
| 
| > David Abrahams <dave_at_[hidden]> writes:
| >
| > | Let me reiterate, just in case somebody missed it: this is a similar
| > | problem to that of using a pointer/reference-to-data-member as a
| > | template paramter.  You can think of each thread-local global variable
| > | as a data member in a big struct, of which there's a single instance
| > | per thread.  The address of this global variable is just as much a
| > | constant as the address of a data member.  There's no problem here,
| > | AFAICT.
| >
| > I see your analogy. 
| >
| > However, my point is that
| >
| >   * a class is closed: that is, by the time you put the closing brace,
| >     the "offset" of the data member is a compile-time constant.
| >
| >   * the number of thread local variables is potentially unbounded,
| >     meaning that, using your analogy, the offset of the corresponding
| >     data-member is not known by the time the compiler finishes
| >     processing a given translation unit.
| 
| OK... is that a problem?

As I'm understanding the issue, yes.  I would love to be proved wrong.

|  The address of a static global is not known
| when the compiler finishes processing a given translation unit either.

Sure the logical address is known.

As opposed to the address of a variable with a TLS.

-- Gaby