The variable is placed in libc.so, and it can be true only in
an outer libc, not libcs loaded via dlmopen or static dlopen.
Since thread creation from inner namespaces does not work,
pthread_create can update __libc_single_threaded directly.
Using __libc_early_init and its initial flag, implementation of this
variable is very straightforward. A future version may reset the flag
during fork (but not in an inner namespace), or after joining all
threads except one.
Reviewed-by: DJ Delorie <dj@redhat.com>
The new format lists the version on each line, as in:
VERSION SYMBOL TYPE [VALUE]
This makes it easier to process the files with line-oriented tools.
The abilist files were converted with this awk script:
/^[^ ]/ { version = $1 }
/^ / { print version, substr($0, 2) }
And sorted under the "C" locale with sort.
