cpu_switchto(9) [netbsd man page]

CPU_SWITCHTO(9) 					   BSD Kernel Developer's Manual					   CPU_SWITCHTO(9)

NAME

     cpu_switchto -- machine-dependent LWP context switching interface

SYNOPSIS

     #include <sys/cpu.h>

     lwp_t *
     cpu_switchto(lwp_t *oldlwp, lwp_t *newlwp, bool returning);

DESCRIPTION

     The cpu_switchto() function saves the context of the LWP which is currently running on the processor, and restores the context of the LWP
     specified by newlwp.

     Remarks:

	   1.	cpu_switchto() does not switch address spaces.

	   2.	cpu_switchto() sets curlwp(9) to newlwp.  If the architecture does non-interlocked adaptive mutex release, cpu_switchto() does an
		equivalent of membar_producer(3), before and after the modification of curlwp(9).

	   3.	cpu_switchto() should be called at IPL_SCHED.  When the function returns, the caller should lower the priority level as soon as
		possible.

	   4.	cpu_switchto() might be called with spin mutexes held.

     The function takes the following arguments.

	   oldlwp      Specify the LWP from which the switch is going to be made, i.e., the calling LWP.  If it was NULL, the context of the LWP
		       currently running on this processor is not saved.

	   newlwp      Specify the LWP to which to switch.  It must not be NULL.

	   returning   Only meaningful if the architecture implements fast software interrupts.  If true, it indicates that oldlwp is a soft
		       interrupt LWP that is blocking.	It is a good indication that any kind of address space or user activity can be completely
		       ignored.  For example: ras_lookup(9), cache flushes, TLB wirings, adjusting lazy FPU state.  All that is required is to
		       restore the register state and stack, and return to the interrupted LWP.

RETURN VALUES

     The cpu_switchto() function does not return until another LWP calls cpu_switchto().  It returns the oldlwp argument of the cpu_switchto()
     which is called to switch back to our LWP.  It is either a LWP which called cpu_switchto() to switch to us or NULL in case the LWP was exit-
     ing.

SEE ALSO

     membar_producer(3), swapcontext(3), intro(9), mutex(9), spl(9)

BSD
								   June 2, 2011 							       BSD

LWP::Protocol::PSGI(3pm)				User Contributed Perl Documentation				  LWP::Protocol::PSGI(3pm)

NAME

       LWP::Protocol::PSGI - Override LWP's HTTP/HTTPS backend with your own PSGI applciation

SYNOPSIS

	 use LWP::UserAgent;
	 use LWP::Protocol::PSGI;

	 # can be Mojolicious, Catalyst ... any PSGI application
	 my $psgi_app = do {
	     use Dancer;
	     setting apphandler => 'PSGI';
	     get '/search' => sub {
		 return 'googling ' . params->{q};
	     };
	     dance;
	 };

	 LWP::Protocol::PSGI->register($psgi_app);

	 # can hijack any code or module that uses LWP::UserAgent underneath, with no changes
	 my $ua  = LWP::UserAgent->new;
	 my $res = $ua->get("http://www.google.com/search?q=bar");
	 print $res->content; # "googling bar"

DESCRIPTION

       LWP::Protocol::PSGI is a module to hijack any code that uses LWP::UserAgent underneath such that any HTTP or HTTPS requests can be routed
       to your own PSGI application.

       Because it works with any code that uses LWP, you can override various WWW::*, Net::* or WebService::* modules such as WWW::Mechanize,
       without modifying the calling code or its internals.

	 use WWW::Mechanize;
	 use LWP::Protocol::PSGI;

	 LWP::Protocol::PSGI->register($my_psgi_app);

	 my $mech = WWW::Mechanize->new;
	 $mech->get("http://amazon.com/"); # $my_psgi_app runs

METHODS

       register
	     LWP::Protocol::PSGI->register($app);
	     my $guard = LWP::Protocol::PSGI->register($app);

	   Registers an override hook to hijack HTTP requests. If called in a non-void context, returns a Guard object that automatically resets
	   the override when it goes out of context.

	     {
		 my $guard = LWP::Protocol::PSGI->register($app);
		 # hijack the code using LWP with $app
	     }

	     # now LWP uses the original HTTP implementations

       unregister
	     LWP::Protocol::PSGI->unregister;

	   Resets all the overrides for LWP. If you use the guard interface described above, it will be automatically called for you.

AUTHOR

       Tatsuhiko Miyagawa <miyagawa@bulknews.net>

COPYRIGHT

       Copyright 2011- Tatsuhiko Miyagawa

LICENSE

       This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

SEE ALSO

       Plack::Client LWP::UserAgent

perl v5.12.3							    2011-05-12						  LWP::Protocol::PSGI(3pm)