non-zero.
. If the program terminated due to a signal, then the return value is the
- signal number - 128, ie. it is negative and so indicates an unusual
- condition; a diagnostic is printed. This return value can be passed to
- exit(2), which will report the same code to the parent process that a
- POSIX shell's $? would report for a program that died from the signal.
+ signal number + 128, ie. the same value that a POSIX shell's $? would
+ report. A diagnostic is printed.
`start_async`::
There are serious restrictions on what the asynchronous function can do
-because this facility is implemented by a pipe to a forked process on
-UNIX, but by a thread in the same address space on Windows:
+because this facility is implemented by a thread in the same address
+space on most platforms (when pthreads is available), but by a pipe to
+a forked process otherwise:
. It cannot change the program's state (global variables, environment,
etc.) in a way that the caller notices; in other words, .in and .out