From 525fa2c1f0e955455bed3fdb397aceb1e6e69a57 Mon Sep 17 00:00:00 2001 From: Martin Mares Date: Mon, 5 Jun 2000 12:19:12 +0000 Subject: [PATCH] Documented sockets, events and timers. --- lib/Doc | 2 +- lib/event.c | 54 +++++++++++++++++ lib/resource.sgml | 10 +--- nest/Doc | 1 + sysdep/unix/io.c | 143 ++++++++++++++++++++++++++++++++++++++++++++-- 5 files changed, 196 insertions(+), 14 deletions(-) diff --git a/lib/Doc b/lib/Doc index 6367cd72..6be6250d 100644 --- a/lib/Doc +++ b/lib/Doc @@ -6,5 +6,5 @@ D resource.sgml S resource.c S mempool.c S slab.c -S socket.h S event.c +S ../sysdep/unix/io.c diff --git a/lib/event.c b/lib/event.c index 1f418d20..788aab42 100644 --- a/lib/event.c +++ b/lib/event.c @@ -6,6 +6,21 @@ * Can be freely distributed and used under the terms of the GNU GPL. */ +/** + * DOC: Events + * + * Events are there to keep track of deferred execution. + * Since BIRD is single-threaded, it requires long lasting tasks to be split to smaller + * parts, so that no module can monopolize the CPU. To split such a task, just create + * an &event resource, point it to the function you want to have called and call ev_schedule() + * to ask the core to run the event when nothing more important will require attention. + * + * You can also define your own event lists (the &event_list structure), enqueue your + * events in them and explicitly ask to run them. + * + * The actual implementation is system dependent. + */ + #include "nest/bird.h" #include "lib/event.h" @@ -39,6 +54,13 @@ static struct resclass ev_class = { ev_dump }; +/** + * ev_new - create a new event + * @p: resource pool + * + * This function creates a new event resource. To use it, + * you need to fill the structure fields and call ev_schedule(). + */ event * ev_new(pool *p) { @@ -50,6 +72,16 @@ ev_new(pool *p) return e; } +/** + * ev_run - run an event + * @e: an event + * + * This function explicitly runs the event @e (calls its hook + * function) and removes it from an event list if it's linked to any. + * + * From the hook function, you can call ev_enqueue() or ev_schedule() + * to re-add the event. + */ inline void ev_run(event *e) { @@ -57,6 +89,14 @@ ev_run(event *e) e->hook(e->data); } +/** + * ev_enqueue - enqueue an event + * @l: an event list + * @e: an event + * + * ev_enqueue() stores the event @e to the specified event + * list @l which can be run by calling ev_run_list(). + */ inline void ev_enqueue(event_list *l, event *e) { @@ -64,12 +104,26 @@ ev_enqueue(event_list *l, event *e) add_tail(l, &e->n); } +/** + * ev_schedule - schedule an event + * @e: an event + * + * This function schedules an event by enqueueing it to a system-wide + * event list which is run by the platform dependent code whenever + * appropriate. + */ void ev_schedule(event *e) { ev_enqueue(&global_event_list, e); } +/** + * ev_run_list - run an event list + * @l: an event list + * + * This function calls ev_run() for all events enqueued in the list @l. + */ int ev_run_list(event_list *l) { diff --git a/lib/resource.sgml b/lib/resource.sgml index 4123dd68..df02bbfc 100644 --- a/lib/resource.sgml +++ b/lib/resource.sgml @@ -36,15 +36,7 @@ type. diff --git a/nest/Doc b/nest/Doc index 8cb73102..38af0feb 100644 --- a/nest/Doc +++ b/nest/Doc @@ -9,3 +9,4 @@ S iface.c S neighbor.c S cli.c S locks.c +# rt-dev.c documented in Protocols chapter diff --git a/sysdep/unix/io.c b/sysdep/unix/io.c index ca233113..3ba6ce69 100644 --- a/sysdep/unix/io.c +++ b/sysdep/unix/io.c @@ -73,8 +73,23 @@ tracked_fopen(pool *p, char *name, char *mode) return f; } -/* - * Timers +/** + * DOC: Timers + * + * Timers are resources which represent a wish of a module to call + * a function at the specified time. The platform dependent code + * doesn't guarantee the exact timing, only that a timer function + * won't be called before the requested time. + * + * In BIRD, real time is represented by values of the &bird_clock_t type + * which are integral numbers corresponding to a number of seconds since + * a fixed (but platform dependent) epoch. The current time can be read + * from a variable @now with reasonable accuracy. + * + * Each timer is described by a &timer structure containing a pointer + * to the handler function (@hook), data private to this function (@data), + * time the function should be called at (@expires, 0 for inactive timers), + * for the other fields see |timer.h|. */ #define NEAR_TIMER_LIMIT 4 @@ -115,6 +130,14 @@ static struct resclass tm_class = { tm_dump }; +/** + * tm_new - create a timer + * @p: pool + * + * This function creates a new timer resource and returns + * a pointer to it. To use the timer, you need to fill in + * the structure fields and call tm_start() to start timing. + */ timer * tm_new(pool *p) { @@ -136,6 +159,23 @@ tm_insert_near(timer *t) insert_node(&t->n, n->prev); } +/** + * tm_start - start a timer + * @t: timer + * @after: number of seconds the timer should be run after + * + * This function schedules the hook function of the timer to + * be called after @after seconds. If the timer has been already + * started, it's @expire time is replaced by the new value. + * + * You can have set the @randomize field of @t, the timeout + * will be increased by a random number of seconds chosen + * uniformly from range 0 .. @randomize. + * + * You can call tm_start() from the handler function of the timer + * to request another run of the timer. Also, you can set the @recurrent + * field to have the timer re-added automatically with the same timeout. + */ void tm_start(timer *t, unsigned after) { @@ -159,6 +199,13 @@ tm_start(timer *t, unsigned after) } } +/** + * tm_stop - stop a timer + * @t: timer + * + * This function stops a timer. If the timer is already stopped, + * nothing happens. + */ void tm_stop(timer *t) { @@ -250,6 +297,13 @@ tm_shot(void) } } +/** + * tm_parse_date - parse a date + * @x: date string + * + * tm_parse_date() takes a textual representation of a date (dd-mm-yyyy) + * and converts it to the corresponding value of type &bird_clock_t. + */ bird_clock_t tm_parse_date(char *x) { @@ -268,6 +322,14 @@ tm_parse_date(char *x) return t; } +/** + * tm_format_date - convert date to textual representation + * @x: destination buffer of size %TM_DATE_BUFFER_SIZE + * @t: time + * + * This function formats the given time value @t to a textual + * date representation (dd-mm-yyyy). + */ void tm_format_date(char *x, bird_clock_t t) { @@ -277,6 +339,14 @@ tm_format_date(char *x, bird_clock_t t) bsprintf(x, "%02d-%02d-%04d", tm->tm_mday, tm->tm_mon+1, tm->tm_year+1900); } +/** + * tm_format_datetime - convert date and time to textual representation + * @x: destination buffer of size %TM_DATETIME_BUFFER_SIZE + * @t: time + * + * This function formats the given time value @t to a textual + * date/time representation (dd-mm-yyyy hh:mm:ss). + */ void tm_format_datetime(char *x, bird_clock_t t) { @@ -287,6 +357,14 @@ tm_format_datetime(char *x, bird_clock_t t) strcpy(x, ""); } +/** + * tm_format_reltime - convert date and time to relative textual representation + * @x: destination buffer of size %TM_RELTIME_BUFFER_SIZE + * @t: time + * + * This function formats the given time value @t to a short + * textual representation relative to the current time. + */ void tm_format_reltime(char *x, bird_clock_t t) { @@ -303,8 +381,17 @@ tm_format_reltime(char *x, bird_clock_t t) bsprintf(x, "%d", tm->tm_year+1900); } -/* - * Sockets +/** + * DOC: Sockets + * + * Socket resources represent network connections. Their data structure (&socket) + * contains a lot of fields defining the exact type of the socket, the local and + * remote addresses and ports, pointers to socket buffers and finally pointers to + * hook functions to be called when new data have arrived to the receive buffer + * (@rx_hook), when the contents of the transmit buffer have been transmitted + * (@tx_hook) and when an error or connection close occurs (@err_hook). + * + * You should not use rfree() from inside a socket hook, please use sk_close() instead. */ #ifndef SOL_IP @@ -350,6 +437,14 @@ static struct resclass sk_class = { sk_dump }; +/** + * sk_new - create a socket + * @p: pool + * + * This function creates a new socket resource. If you want to use it, + * you need to fill in all the required fields of the structure and + * call sk_open() to do the actual opening of the socket. + */ sock * sk_new(pool *p) { @@ -502,6 +597,16 @@ sk_passive_connected(sock *s, struct sockaddr *sa, int al, int type) return 0; } +/** + * sk_open - open a socket + * @s: socket + * + * This function takes a socket resource created by sk_new() and + * initialized by the user and binds a corresponding network connection + * to it. + * + * Result: 0 for success, -1 for an error. + */ int sk_open(sock *s) { @@ -683,6 +788,14 @@ bad: return -1; } +/** + * sk_close - close a socket + * @s: a socket + * + * If sk_close() has been called from outside of any socket hook, + * it translates to a rfree(), else it just marks the socket for + * deletion as soon as the socket hook returns. + */ void sk_close(sock *s) { @@ -746,6 +859,18 @@ sk_maybe_write(sock *s) } } +/** + * sk_send - send data to a socket + * @s: socket + * @len: number of bytes to send + * + * This function sends @len bytes of data prepared in the + * transmit buffer of the socket @s to the network connection. + * If the packet can be sent immediately, it does so and returns + * 1, else it queues the packet for later processing, returns 0 + * and calls the @tx_hook of the socket when the tranmission + * takes place. + */ int sk_send(sock *s, unsigned len) { @@ -756,6 +881,16 @@ sk_send(sock *s, unsigned len) return sk_maybe_write(s); } +/** + * sk_send_to - send data to a specific destination + * @s: socket + * @len: number of bytes to send + * @addr: IP address to send the packet to + * @port: port to send the packet to + * + * This is a sk_send() replacement for connectionless packet sockets + * which allows destination of the packet to be chosen dynamically. + */ int sk_send_to(sock *s, unsigned len, ip_addr addr, unsigned port) {