If we have thread local storage, use it instead of posix_getspecific().

Declare and use a variable PL_current_context to store a pointer to the
thread's interpreter struct. Use this to implement implicit context undef
ITHREADS, instead of a call to posix_getspecific().

For normal threaded code, this will eliminate function calls. For threaded
code in shared objects (the typical configuration for Linux distribution
builds) there still needs to be a function call to get the pointer to
thread local variables, but there will only be one per function, not one
per read of the variable.

1 files changed, 3 insertions, 0 deletions

diff --git a/makedef.pl b/makedef.pl
index b5b07a7ece..f13573171e 100644
--- a/makedef.pl
+++ b/makedef.pl
@@ -189,6 +189,9 @@ my %skip;
 # All platforms export boot_DynaLoader unconditionally.
 my %export = ( boot_DynaLoader => 1 );
 
+++$export{PL_current_context}
+    if defined $Config{perl_thread_local} && $define{USE_ITHREADS};
+
 sub try_symbols {
     foreach my $symbol (@_) {
 	++$export{$symbol} unless exists $skip{$symbol};