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Diffstat (limited to 'src/app/main/subsysmgr.c')
| -rw-r--r-- | src/app/main/subsysmgr.c | 252 |
1 files changed, 252 insertions, 0 deletions
diff --git a/src/app/main/subsysmgr.c b/src/app/main/subsysmgr.c new file mode 100644 index 0000000000..5aa4fd76c9 --- /dev/null +++ b/src/app/main/subsysmgr.c @@ -0,0 +1,252 @@ +/* Copyright (c) 2003-2004, Roger Dingledine + * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. + * Copyright (c) 2007-2019, The Tor Project, Inc. */ +/* See LICENSE for licensing information */ + +#include "orconfig.h" +#include "app/main/subsysmgr.h" + +#include "lib/dispatch/dispatch_naming.h" +#include "lib/dispatch/msgtypes.h" +#include "lib/err/torerr.h" +#include "lib/log/log.h" +#include "lib/malloc/malloc.h" +#include "lib/pubsub/pubsub_build.h" +#include "lib/pubsub/pubsub_connect.h" + +#include <stdio.h> +#include <stdlib.h> +#include <string.h> + +/** + * True iff we have checked tor_subsystems for consistency. + **/ +static bool subsystem_array_validated = false; + +/** + * True if a given subsystem is initialized. Expand this array if there + * are more than this number of subsystems. (We'd rather not + * dynamically allocate in this module.) + **/ +static bool sys_initialized[128]; + +/** + * Exit with a raw assertion if the subsystems list is inconsistent; + * initialize the subsystem_initialized array. + **/ +static void +check_and_setup(void) +{ + if (subsystem_array_validated) + return; + + raw_assert(ARRAY_LENGTH(sys_initialized) >= n_tor_subsystems); + memset(sys_initialized, 0, sizeof(sys_initialized)); + + int last_level = MIN_SUBSYS_LEVEL; + + for (unsigned i = 0; i < n_tor_subsystems; ++i) { + const subsys_fns_t *sys = tor_subsystems[i]; + if (sys->level < MIN_SUBSYS_LEVEL || sys->level > MAX_SUBSYS_LEVEL) { + fprintf(stderr, "BUG: Subsystem %s (at %u) has an invalid level %d. " + "It is supposed to be between %d and %d (inclusive).\n", + sys->name, i, sys->level, MIN_SUBSYS_LEVEL, MAX_SUBSYS_LEVEL); + raw_assert_unreached_msg("There is a bug in subsystem_list.c"); + } + if (sys->level < last_level) { + fprintf(stderr, "BUG: Subsystem %s (at #%u) is in the wrong position. " + "Its level is %d; but the previous subsystem's level was %d.\n", + sys->name, i, sys->level, last_level); + raw_assert_unreached_msg("There is a bug in subsystem_list.c"); + } + last_level = sys->level; + } + + subsystem_array_validated = true; +} + +/** + * Initialize all the subsystems; exit on failure. + **/ +int +subsystems_init(void) +{ + return subsystems_init_upto(MAX_SUBSYS_LEVEL); +} + +/** + * Initialize all the subsystems whose level is less than or equal to + * <b>target_level</b>; exit on failure. + **/ +int +subsystems_init_upto(int target_level) +{ + check_and_setup(); + + for (unsigned i = 0; i < n_tor_subsystems; ++i) { + const subsys_fns_t *sys = tor_subsystems[i]; + if (!sys->supported) + continue; + if (sys->level > target_level) + break; + if (sys_initialized[i]) + continue; + int r = 0; + if (sys->initialize) { + // Note that the logging subsystem is designed so that it does no harm + // to log a message in an uninitialized state. These messages will be + // discarded for now, however. + log_debug(LD_GENERAL, "Initializing %s", sys->name); + r = sys->initialize(); + } + if (r < 0) { + fprintf(stderr, "BUG: subsystem %s (at %u) initialization failed.\n", + sys->name, i); + raw_assert_unreached_msg("A subsystem couldn't be initialized."); + } + sys_initialized[i] = true; + } + + return 0; +} + +/** + * Add publish/subscribe relationships to <b>builder</b> for all + * initialized subsystems of level no more than <b>target_level</b>. + **/ +int +subsystems_add_pubsub_upto(pubsub_builder_t *builder, + int target_level) +{ + for (unsigned i = 0; i < n_tor_subsystems; ++i) { + const subsys_fns_t *sys = tor_subsystems[i]; + if (!sys->supported) + continue; + if (sys->level > target_level) + break; + if (! sys_initialized[i]) + continue; + int r = 0; + if (sys->add_pubsub) { + subsys_id_t sysid = get_subsys_id(sys->name); + raw_assert(sysid != ERROR_ID); + pubsub_connector_t *connector; + connector = pubsub_connector_for_subsystem(builder, sysid); + r = sys->add_pubsub(connector); + pubsub_connector_free(connector); + } + if (r < 0) { + fprintf(stderr, "BUG: subsystem %s (at %u) could not connect to " + "publish/subscribe system.", sys->name, sys->level); + raw_assert_unreached_msg("A subsystem couldn't be connected."); + } + } + + return 0; +} + +/** + * Add publish/subscribe relationships to <b>builder</b> for all + * initialized subsystems. + **/ +int +subsystems_add_pubsub(pubsub_builder_t *builder) +{ + return subsystems_add_pubsub_upto(builder, MAX_SUBSYS_LEVEL); +} + +/** + * Shut down all the subsystems. + **/ +void +subsystems_shutdown(void) +{ + subsystems_shutdown_downto(MIN_SUBSYS_LEVEL - 1); +} + +/** + * Shut down all the subsystems whose level is above <b>target_level</b>. + **/ +void +subsystems_shutdown_downto(int target_level) +{ + check_and_setup(); + + for (int i = (int)n_tor_subsystems - 1; i >= 0; --i) { + const subsys_fns_t *sys = tor_subsystems[i]; + if (!sys->supported) + continue; + if (sys->level <= target_level) + break; + if (! sys_initialized[i]) + continue; + if (sys->shutdown) { + log_debug(LD_GENERAL, "Shutting down %s", sys->name); + sys->shutdown(); + } + sys_initialized[i] = false; + } +} + +/** + * Run pre-fork code on all subsystems that declare any + **/ +void +subsystems_prefork(void) +{ + check_and_setup(); + + for (int i = (int)n_tor_subsystems - 1; i >= 0; --i) { + const subsys_fns_t *sys = tor_subsystems[i]; + if (!sys->supported) + continue; + if (! sys_initialized[i]) + continue; + if (sys->prefork) { + log_debug(LD_GENERAL, "Pre-fork: %s", sys->name); + sys->prefork(); + } + } +} + +/** + * Run post-fork code on all subsystems that declare any + **/ +void +subsystems_postfork(void) +{ + check_and_setup(); + + for (unsigned i = 0; i < n_tor_subsystems; ++i) { + const subsys_fns_t *sys = tor_subsystems[i]; + if (!sys->supported) + continue; + if (! sys_initialized[i]) + continue; + if (sys->postfork) { + log_debug(LD_GENERAL, "Post-fork: %s", sys->name); + sys->postfork(); + } + } +} + +/** + * Run thread-cleanup code on all subsystems that declare any + **/ +void +subsystems_thread_cleanup(void) +{ + check_and_setup(); + + for (int i = (int)n_tor_subsystems - 1; i >= 0; --i) { + const subsys_fns_t *sys = tor_subsystems[i]; + if (!sys->supported) + continue; + if (! sys_initialized[i]) + continue; + if (sys->thread_cleanup) { + log_debug(LD_GENERAL, "Thread cleanup: %s", sys->name); + sys->thread_cleanup(); + } + } +} |