- fix showpage1 only decrementing proc counter once limit is reached;
this blocked having more than one loadpages process after NPROC calls,
since the next one has to wait until the last has exited
- allow procs to skip pages currently being loaded by others; this
forced processes to wait for each other at the same page
- bump NPROC from 4 to 8
- (hack) immediately fork a few times after adding all pages at
startup to force loading a batch of pages in parallel
addpage() should not be called with the display locked as it
calls showpage1() which sleeps when there are too many
processes active.
the bug was triggered by plumbing to trigger the addpage().
add new functions pageaddr() that returns a string describing
the page to be loaded. it is in the form of:
/path/to/file!pagename!subpage!....
one can jump to such a page by calling trywalk(name, addr)
where name and addr get concatinated with ! to form a page
address and then the currently loaded pages are walked up
to the nearest page which is then returned. (or nil when
not found). the remaining address will be set in the global
pagewalk variable.
once pages get loaded (asynchronously), pagewalk1() gets
called again on addpage() and continues the walking up to the
last page.
new program flag -j <addr> was added to jump to a page on
startup.
page address (without filename) can also be supplied in
plumb message with the "addr" attribute.
we are not using stdout (fd=1) and it, so dup nullfd over it.
this drops the old window reference when using with -w flag.
the RFNAMEG flag isnt needed because we are calling newwindow()
which forks the namespace for us.
reopen stdin/stdout for the external viewer to the new window.
resizewin() has some extra logic making sure the rect doesnt get too big.
rio would otherwise refuse to create the window and the operation will fail
completely.
