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- /* * Copyright (c) 2017, The Tor Project, Inc. */
- /* See LICENSE for licensing information */
- /**
- * \file scheduler.h
- * \brief Header file for scheduler*.c
- **/
- #ifndef TOR_SCHEDULER_H
- #define TOR_SCHEDULER_H
- #include "or.h"
- #include "channel.h"
- #include "testsupport.h"
- /** Scheduler type, we build an ordered list with those values from the
- * parsed strings in Schedulers. The reason to do such a thing is so we can
- * quickly and without parsing strings select the scheduler at anytime. */
- typedef enum {
- SCHEDULER_NONE = -1,
- SCHEDULER_VANILLA = 1,
- SCHEDULER_KIST = 2,
- SCHEDULER_KIST_LITE = 3,
- } scheduler_types_t;
- /**
- * A scheduler implementation is a collection of function pointers. If you
- * would like to add a new scheduler called foo, create scheduler_foo.c,
- * implement at least the mandatory ones, and implement get_foo_scheduler()
- * that returns a complete scheduler_t for your foo scheduler. See
- * scheduler_kist.c for an example.
- *
- * These function pointers SHOULD NOT be used anywhere outside of the
- * scheduling source files. The rest of Tor should communicate with the
- * scheduling system through the functions near the bottom of this file, and
- * those functions will call into the current scheduler implementation as
- * necessary.
- *
- * If your scheduler doesn't need to implement something (for example: it
- * doesn't create any state for itself, thus it has nothing to free when Tor
- * is shutting down), then set that function pointer to NULL.
- */
- typedef struct scheduler_s {
- /* Scheduler type. This is used for logging when the scheduler is switched
- * during runtime. */
- scheduler_types_t type;
- /* (Optional) To be called when we want to prepare a scheduler for use.
- * Perhaps Tor just started and we are the lucky chosen scheduler, or
- * perhaps Tor is switching to this scheduler. No matter the case, this is
- * where we would prepare any state and initialize parameters. You might
- * think of this as the opposite of free_all(). */
- void (*init)(void);
- /* (Optional) To be called when we want to tell the scheduler to delete all
- * of its state (if any). Perhaps Tor is shutting down or perhaps we are
- * switching schedulers. */
- void (*free_all)(void);
- /* (Mandatory) Libevent controls the main event loop in Tor, and this is
- * where we register with libevent the next execution of run_sched_ev [which
- * ultimately calls run()]. */
- void (*schedule)(void);
- /* (Mandatory) This is the heart of a scheduler! This is where the
- * excitement happens! Here libevent has given us the chance to execute, and
- * we should do whatever we need to do in order to move some cells from
- * their circuit queues to output buffers in an intelligent manner. We
- * should do this quickly. When we are done, we'll try to schedule() ourself
- * if more work needs to be done to setup the next scheduling run. */
- void (*run)(void);
- /*
- * External event not related to the scheduler but that can influence it.
- */
- /* (Optional) To be called whenever Tor finds out about a new consensus.
- * First the scheduling system as a whole will react to the new consensus
- * and change the scheduler if needed. After that, the current scheduler
- * (which might be new) will call this so it has the chance to react to the
- * new consensus too. If there's a consensus parameter that your scheduler
- * wants to keep an eye on, this is where you should check for it. */
- void (*on_new_consensus)(const networkstatus_t *old_c,
- const networkstatus_t *new_c);
- /* (Optional) To be called when a channel is being freed. Sometimes channels
- * go away (for example: the relay on the other end is shutting down). If
- * the scheduler keeps any channel-specific state and has memory to free
- * when channels go away, implement this and free it here. */
- void (*on_channel_free)(const channel_t *);
- /* (Optional) To be called whenever Tor is reloading configuration options.
- * For example: SIGHUP was issued and Tor is rereading its torrc. A
- * scheduler should use this as an opportunity to parse and cache torrc
- * options so that it doesn't have to call get_options() all the time. */
- void (*on_new_options)(void);
- } scheduler_t;
- /*****************************************************************************
- * Globally visible scheduler variables/values
- *
- * These are variables/constants that all of Tor should be able to see.
- *****************************************************************************/
- /* Default interval that KIST runs (in ms). */
- #define KIST_SCHED_RUN_INTERVAL_DEFAULT 10
- /* Minimum interval that KIST runs. This value disables KIST. */
- #define KIST_SCHED_RUN_INTERVAL_MIN 0
- /* Maximum interval that KIST runs (in ms). */
- #define KIST_SCHED_RUN_INTERVAL_MAX 100
- /*****************************************************************************
- * Globally visible scheduler functions
- *
- * These functions are how the rest of Tor communicates with the scheduling
- * system.
- *****************************************************************************/
- void scheduler_init(void);
- void scheduler_free_all(void);
- void scheduler_conf_changed(void);
- void scheduler_notify_networkstatus_changed(const networkstatus_t *old_c,
- const networkstatus_t *new_c);
- MOCK_DECL(void, scheduler_release_channel, (channel_t *chan));
- /*
- * Ways for a channel to interact with the scheduling system. A channel only
- * really knows (i) whether or not it has cells it wants to send, and
- * (ii) whether or not it would like to write.
- */
- void scheduler_channel_wants_writes(channel_t *chan);
- MOCK_DECL(void, scheduler_channel_doesnt_want_writes, (channel_t *chan));
- MOCK_DECL(void, scheduler_channel_has_waiting_cells, (channel_t *chan));
- /*****************************************************************************
- * Private scheduler functions
- *
- * These functions are only visible to the scheduling system, the current
- * scheduler implementation, and tests.
- *****************************************************************************/
- #ifdef SCHEDULER_PRIVATE_
- /*********************************
- * Defined in scheduler.c
- *********************************/
- /* Triggers a BUG() and extra information with chan if available. */
- #define SCHED_BUG(cond, chan) \
- (PREDICT_UNLIKELY(cond) ? \
- ((BUG(cond)) ? (scheduler_bug_occurred(chan), 1) : 0) : 0)
- void scheduler_bug_occurred(const channel_t *chan);
- smartlist_t *get_channels_pending(void);
- MOCK_DECL(int, scheduler_compare_channels,
- (const void *c1_v, const void *c2_v));
- void scheduler_ev_active(int flags);
- void scheduler_ev_add(const struct timeval *next_run);
- #ifdef TOR_UNIT_TESTS
- extern smartlist_t *channels_pending;
- extern struct event *run_sched_ev;
- extern const scheduler_t *the_scheduler;
- void scheduler_touch_channel(channel_t *chan);
- #endif /* defined(TOR_UNIT_TESTS) */
- /*********************************
- * Defined in scheduler_kist.c
- *********************************/
- #ifdef SCHEDULER_KIST_PRIVATE
- /* Socket table entry which holds information of a channel's socket and kernel
- * TCP information. Only used by KIST. */
- typedef struct socket_table_ent_s {
- HT_ENTRY(socket_table_ent_s) node;
- const channel_t *chan;
- /* Amount written this scheduling run */
- uint64_t written;
- /* Amount that can be written this scheduling run */
- uint64_t limit;
- /* TCP info from the kernel */
- uint32_t cwnd;
- uint32_t unacked;
- uint32_t mss;
- uint32_t notsent;
- } socket_table_ent_t;
- typedef HT_HEAD(outbuf_table_s, outbuf_table_ent_s) outbuf_table_t;
- MOCK_DECL(int, channel_should_write_to_kernel,
- (outbuf_table_t *table, channel_t *chan));
- MOCK_DECL(void, channel_write_to_kernel, (channel_t *chan));
- MOCK_DECL(void, update_socket_info_impl, (socket_table_ent_t *ent));
- int scheduler_can_use_kist(void);
- void scheduler_kist_set_full_mode(void);
- void scheduler_kist_set_lite_mode(void);
- scheduler_t *get_kist_scheduler(void);
- int kist_scheduler_run_interval(const networkstatus_t *ns);
- #ifdef TOR_UNIT_TESTS
- extern int32_t sched_run_interval;
- #endif /* TOR_UNIT_TESTS */
- #endif /* defined(SCHEDULER_KIST_PRIVATE) */
- /*********************************
- * Defined in scheduler_vanilla.c
- *********************************/
- scheduler_t *get_vanilla_scheduler(void);
- #endif /* defined(SCHEDULER_PRIVATE_) */
- #endif /* !defined(TOR_SCHEDULER_H) */
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