Co-routines moved to a separate module with sysdep implementation (ae2be13a) · Commits · 戴 / Bird

lib/coroutine.h

0 → 100644

+22 −0

Original line number	Diff line number	Diff line
		/*
		* BIRD Coroutines
		*
		* (c) 2017 Martin Mares <mj@ucw.cz>
		*
		* Can be freely distributed and used under the terms of the GNU GPL.
		*/

		#ifndef _BIRD_COROUTINE_H_
		#define _BIRD_COROUTINE_H_

		// The structure is completely opaque, implemented by sysdep
		typedef struct coroutine coroutine;

		coroutine coro_new(struct pool pool, void (entry_point)(void arg), void *arg);
		void coro_suspend(void);
		void coro_resume(coroutine *c);

		struct birdsock;
		int coro_sk_read(struct birdsock *s);

		#endif

nest/cli.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -66,8 +66,8 @@
		#include "nest/bird.h"
		#include "nest/cli.h"
		#include "conf/conf.h"
		#include "lib/coroutine.h"
		#include "lib/string.h"
		#include "sysdep/unix/unix.h" // FIXME

		pool *cli_pool;

sysdep/unix/Makefile

+1 −1

Original line number	Diff line number	Diff line
		src := io.c krt.c log.c main.c random.c
		src := io.c krt.c log.c main.c random.c coroutine.c
		obj := $(src-o-files)
		$(all-daemon)
		$(cf-local)

sysdep/unix/coroutine.c

0 → 100644

+135 −0

Original line number	Diff line number	Diff line
		/*
		* BIRD Coroutines
		*
		* (c) 2017 Martin Mares <mj@ucw.cz>
		*
		* Can be freely distributed and used under the terms of the GNU GPL.
		*/

		#ifndef _GNU_SOURCE
		#define _GNU_SOURCE
		#endif

		#include <stdlib.h>
		#include <ucontext.h>

		#include "nest/bird.h"
		#include "lib/coroutine.h"
		#include "lib/resource.h"
		#include "lib/socket.h"
		#include "sysdep/unix/unix.h"

		struct coroutine {
		resource r;
		ucontext_t ctx;
		void *stack;
		void (entry_point)(void arg);
		void *arg;
		};

		static ucontext_t *main_context;
		static coroutine *coro_current; // NULL for main context

		#define CORO_STACK_SIZE 65536

		static void
		coro_free(resource *r)
		{
		coroutine c = (coroutine ) r;
		xfree(c->stack);
		}

		static void
		coro_dump(resource *r UNUSED)
		{
		debug("\n");
		}

		static size_t
		coro_memsize(resource *r)
		{
		coroutine c = (coroutine ) r;
		return sizeof(c) + CORO_STACK_SIZE + 2ALLOC_OVERHEAD;
		}

		static struct resclass coro_class = {
		.name = "Coroutine",
		.size = sizeof(struct coroutine),
		.free = coro_free,
		.dump = coro_dump,
		.memsize = coro_memsize,
		};

		static void
		coro_do_start(void)
		{
		ASSERT(coro_current);
		coro_current->entry_point(coro_current->arg);
		bug("Coroutine returned unexpectedly");
		}

		struct coroutine *
		coro_new(pool p, void (entry_point)(void ), void arg)
		{
		if (!main_context)
		{
		main_context = xmalloc(sizeof(*main_context));
		if (getcontext(main_context) < 0)
		bug("getcontext() failed");
		}

		coroutine *c = ralloc(p, &coro_class);
		c->entry_point = entry_point;
		c->arg = arg;
		if (getcontext(&c->ctx) < 0)
		bug("getcontext() failed");
		c->stack = xmalloc(CORO_STACK_SIZE);
		c->ctx.uc_stack.ss_sp = c->stack;
		c->ctx.uc_stack.ss_size = CORO_STACK_SIZE;

		makecontext(&c->ctx, coro_do_start, 0);

		return c;
		}

		void
		coro_suspend(void)
		{
		ASSERT(coro_current);
		ASSERT(main_context);
		coroutine *c = coro_current;
		coro_current = NULL;
		swapcontext(&c->ctx, main_context);
		ASSERT(coro_current == c);
		}

		void
		coro_resume(coroutine *c)
		{
		ASSERT(!coro_current);
		coro_current = c;
		swapcontext(main_context, &c->ctx);
		ASSERT(!coro_current);
		}

		/* Coroutine-based I/O */

		static int
		coro_sk_rx_hook(sock *sk, uint size UNUSED)
		{
		ASSERT(sk->rx_coroutine);
		ASSERT(!coro_current);
		coro_resume(sk->rx_coroutine);
		return 0;
		}

		int
		coro_sk_read(sock *s)
		{
		ASSERT(coro_current);
		s->rx_coroutine = coro_current;
		s->rx_hook = coro_sk_rx_hook;
		coro_suspend();
		s->rx_hook = NULL;
		return s->rpos - s->rbuf;
		}

sysdep/unix/io.c

+0 −110

Original line number	Diff line number	Diff line
		@@ -2377,113 +2377,3 @@ test_old_bird(char *path)
		die("I found another BIRD running.");
		close(fd);
		}

		/* EXPERIMENTAL: Support for coroutines */

		#include <ucontext.h>

		struct coroutine {
		resource r;
		ucontext_t ctx;
		void *stack;
		void (entry_point)(void arg);
		void *arg;
		};

		static ucontext_t *main_context;
		static coroutine *coro_current; // NULL for main context

		static void
		coro_free(resource *r)
		{
		coroutine c = (coroutine ) r;
		xfree(c->stack);
		}

		static void
		coro_dump(resource *r UNUSED)
		{
		debug("\n");
		}

		static struct resclass coro_class = {
		.name = "Coroutine",
		.size = sizeof(struct coroutine),
		.free = coro_free,
		.dump = coro_dump,
		// FIXME: Implement memsize
		};

		static void
		coro_do_start(void)
		{
		ASSERT(coro_current);
		coro_current->entry_point(coro_current->arg);
		bug("Coroutine returned unexpectedly");
		}

		struct coroutine *
		coro_new(pool p, void (entry_point)(void ), void arg)
		{
		if (!main_context)
		{
		main_context = xmalloc(sizeof(*main_context));
		if (getcontext(main_context) < 0)
		bug("getcontext() failed");
		}

		coroutine *c = ralloc(p, &coro_class);
		c->entry_point = entry_point;
		c->arg = arg;
		if (getcontext(&c->ctx) < 0)
		bug("getcontext() failed");
		c->stack = xmalloc(65536);
		c->ctx.uc_stack.ss_sp = c->stack;
		c->ctx.uc_stack.ss_size = 65536;

		makecontext(&c->ctx, coro_do_start, 0);

		return c;
		}

		// Return to main context
		void
		coro_suspend(void)
		{
		ASSERT(coro_current);
		ASSERT(main_context);
		coroutine *c = coro_current;
		coro_current = NULL;
		swapcontext(&c->ctx, main_context);
		ASSERT(coro_current == c);
		}

		// Resume context
		void
		coro_resume(coroutine *c)
		{
		ASSERT(!coro_current);
		coro_current = c;
		swapcontext(main_context, &c->ctx);
		ASSERT(!coro_current);
		}

		static int
		coro_sk_rx_hook(sock *sk, uint size UNUSED)
		{
		ASSERT(sk->rx_coroutine);
		ASSERT(!coro_current);
		coro_resume(sk->rx_coroutine);
		return 0;
		}

		int
		coro_sk_read(sock *s)
		{
		ASSERT(coro_current);
		s->rx_coroutine = coro_current;
		s->rx_hook = coro_sk_rx_hook;
		coro_suspend();
		s->rx_hook = NULL;
		return s->rpos - s->rbuf;
		}

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