diff options
| -rw-r--r-- | Makefile | 8 | ||||
| -rw-r--r-- | src/libmdsserver/linked-list.h | 2 | ||||
| -rw-r--r-- | src/mds-base.c | 22 | ||||
| -rw-r--r-- | src/mds-base.h | 41 | ||||
| -rw-r--r-- | src/mds-server/globals.c | 6 | ||||
| -rw-r--r-- | src/mds-server/globals.h | 29 | ||||
| -rw-r--r-- | src/mds-server/mds-server.c | 201 | ||||
| -rw-r--r-- | src/mds-server/mds-server.h | 5 | ||||
| -rw-r--r-- | src/mds-server/reexec.c | 243 | ||||
| -rw-r--r-- | src/mds-server/reexec.h | 54 | ||||
| -rw-r--r-- | src/mds-server/sending.c | 6 | ||||
| -rw-r--r-- | src/mds-server/signals.c | 65 | ||||
| -rw-r--r-- | src/mds-server/signals.h | 31 | ||||
| -rw-r--r-- | src/mds-server/slavery.c | 18 | ||||
| -rw-r--r-- | src/mds-server/slavery.h | 12 |
15 files changed, 275 insertions, 468 deletions
@@ -76,17 +76,17 @@ LIBOBJ = linked-list hash-table fd-table mds-message util # Build rules. .PHONY: all -all: bin/mds bin/mds-server bin/libmdsserver.so obj/mds-base.o +all: obj/mds-base.o bin/mds bin/mds-server bin/libmdsserver.so MDS_SERVER_OBJ_ = mds-server interception_condition client multicast \ queued_interception globals signals interceptors \ sending slavery reexec receiving -MDS_SERVER_OBJ = $(foreach O,$(MDS_SERVER_OBJ_),mds-server/$(O)) +MDS_SERVER_OBJ = obj/mds-base.o $(foreach O,$(MDS_SERVER_OBJ_),obj/mds-server/$(O).o) -bin/mds-server: $(foreach O,$(MDS_SERVER_OBJ),obj/$(O).o) bin/libmdsserver.so +bin/mds-server: $(MDS_SERVER_OBJ) bin/libmdsserver.so mkdir -p $(shell dirname $@) - $(CC) $(C_FLAGS) -o $@ $(LDS) $(foreach O,$(MDS_SERVER_OBJ),obj/$(O).o) + $(CC) $(C_FLAGS) -o $@ $(LDS) $(MDS_SERVER_OBJ) ifeq ($(DEBUG),y) mv $@ $@.real cp test.d/mds-server $@ diff --git a/src/libmdsserver/linked-list.h b/src/libmdsserver/linked-list.h index 30808fc..5b1a44d 100644 --- a/src/libmdsserver/linked-list.h +++ b/src/libmdsserver/linked-list.h @@ -273,7 +273,7 @@ int linked_list_unmarshal(linked_list_t* restrict this, char* restrict data); * @param node:ssize_t The variable to store the node in at each iteration */ #define foreach_linked_list_node(list, node) \ - for (node = list.edge; (node = list.next[node]) != list.edge;) + for (node = list.edge; node = list.next[node], node != list.edge;) #endif diff --git a/src/mds-base.c b/src/mds-base.c index 1de8c68..65e5d88 100644 --- a/src/mds-base.c +++ b/src/mds-base.c @@ -58,11 +58,14 @@ int socket_fd = -1; */ static int parse_cmdline(void) { + int i; + #if (LIBEXEC_ARGC_EXTRA_LIMIT < 2) # error LIBEXEC_ARGC_EXTRA_LIMIT is too small, need at least 2. #endif - int i; + + /* Parse command line arguments. */ for (i = 1; i < argc; i++) { char* arg = argv[i]; @@ -85,6 +88,12 @@ static int parse_cmdline(void) is_respawn = 1; eprint("re-exec performed."); } + + /* Check that manditory arguments have been specified. */ + exit_if (is_respawn < 0, + eprintf("missing state argument, require either %s or %s.", + "--initial-spawn", "--respawn");); + return 0; } @@ -199,17 +208,18 @@ static int base_marshal(int reexec_fd) /* Store the state. */ buf_set_next(state_buf_, int, socket_fd); - marshal_server(state_buf_); + fail_if (marshal_server(state_buf_)); /* Send the marshalled data into the file. */ fail_if (full_write(reexec_fd, state_buf, state_n) < 0); - free(state_buf); + free(state_buf); return 0; pfail: perror(*argv); + free(state_buf); return 1; } @@ -285,6 +295,9 @@ int main(int argc_, char** argv_) trap_signals(); + /* Initialise the server. */ + try (preinitialise_server()); + if (is_reexec == 0) { if (server_characteristics.require_display) @@ -300,6 +313,9 @@ int main(int argc_, char** argv_) try (base_unmarshal()); } + /* Initialise the server. */ + try (postinitialise_server()); + /* Run the server. */ try (master_loop()); diff --git a/src/mds-base.h b/src/mds-base.h index 28d7432..e92e73e 100644 --- a/src/mds-base.h +++ b/src/mds-base.h @@ -138,6 +138,16 @@ extern void received_terminate(int signo); /** * This function should be implemented by the actual server implementation * + * This function will be invoked before `initialise_server` (if not re-exec:ing) + * or before `unmarshal_server` (if re-exec:ing) + * + * @return Non-zero on error + */ +extern int preinitialise_server(void); + +/** + * This function should be implemented by the actual server implementation + * * This function should initialise the server, * and it not invoked after a re-exec. * @@ -148,12 +158,24 @@ extern int initialise_server(void); /** * This function should be implemented by the actual server implementation * - * Unmarshal server implementation specific data and update the servers state accordingly + * This function will be invoked asgter `initialise_server` (if not re-exec:ing) + * or after `unmarshal_server` (if re-exec:ing) * - * @param state_buf The marshalled data that as not been read already - * @return Non-zero on error + * @return Non-zero on error */ -extern int unmarshal_server(char* state_buf); +extern int postinitialise_server(void); + +/** + * This function should be implemented by the actual server implementation + * + * Calculate the number of bytes that will be stored by `marshal_server` + * + * On failure the program should `abort()` or exit by other means. + * However it should not be possible for this function to fail. + * + * @return The number of bytes that will be stored by `marshal_server` + */ +extern size_t marshal_server_size(void) __attribute__((pure)); /** * This function should be implemented by the actual server implementation @@ -168,14 +190,12 @@ extern int marshal_server(char* state_buf); /** * This function should be implemented by the actual server implementation * - * Calculate the number of bytes that will be stored by `marshal_server` - * - * On failure the program should `abort()` or exit by other means. - * However it should not be possible for this function to fail. + * Unmarshal server implementation specific data and update the servers state accordingly * - * @return The number of bytes that will be stored by `marshal_server` + * @param state_buf The marshalled data that as not been read already + * @return Non-zero on error */ -extern size_t marshal_server_size(void); +extern int unmarshal_server(char* state_buf); /** * This function should be implemented by the actual server implementation @@ -187,7 +207,6 @@ extern size_t marshal_server_size(void); */ extern int reexec_failure_recover(void); - /** * This function should be implemented by the actual server implementation * diff --git a/src/mds-server/globals.c b/src/mds-server/globals.c index 0d2c6b6..0f0aa9f 100644 --- a/src/mds-server/globals.c +++ b/src/mds-server/globals.c @@ -18,17 +18,11 @@ #include "globals.h" -int argc; -char** argv; - volatile sig_atomic_t running = 1; -volatile sig_atomic_t reexecing = 0; -volatile sig_atomic_t terminating = 0; size_t running_slaves = 0; pthread_mutex_t slave_mutex; pthread_cond_t slave_cond; -pthread_t master_thread; fd_table_t client_map; linked_list_t client_list; uint64_t next_client_id = 1; diff --git a/src/mds-server/globals.h b/src/mds-server/globals.h index 1016ae7..e9465f0 100644 --- a/src/mds-server/globals.h +++ b/src/mds-server/globals.h @@ -18,6 +18,8 @@ #ifndef MDS_MDS_SERVER_GLOBALS_H #define MDS_MDS_SERVER_GLOBALS_H +#include "../mds-base.h" /* Include here so other do not need to. */ + #include <libmdsserver/linked-list.h> #include <libmdsserver/hash-table.h> @@ -34,32 +36,10 @@ /** - * Number of elements in `argv` - */ -extern int argc; - -/** - * Command line arguments - */ -extern char** argv; - - -/** * The program run state, 1 when running, 0 when shutting down */ extern volatile sig_atomic_t running; -/** - * Non-zero when the program is about to re-exec. - * Most at all times be at least as true as `terminating`. - */ -extern volatile sig_atomic_t reexecing; - -/** - * Non-zero when the program is about to terminate - */ -extern volatile sig_atomic_t terminating; - /** * The number of running slaves @@ -77,11 +57,6 @@ extern pthread_mutex_t slave_mutex; extern pthread_cond_t slave_cond; /** - * The thread that runs the master loop - */ -extern pthread_t master_thread; - -/** * Map from client socket file descriptor to all information (client_t) */ extern fd_table_t client_map; diff --git a/src/mds-server/mds-server.c b/src/mds-server/mds-server.c index 3179ee7..b1008cd 100644 --- a/src/mds-server/mds-server.c +++ b/src/mds-server/mds-server.c @@ -22,11 +22,9 @@ #include "client.h" #include "queued_interception.h" #include "multicast.h" -#include "signals.h" #include "interceptors.h" #include "sending.h" #include "slavery.h" -#include "reexec.h" #include "receiving.h" #include <libmdsserver/config.h> @@ -47,19 +45,41 @@ #include <inttypes.h> +/** + * This variable should declared by the actual server implementation. + * It must be configured before `main` is invoked. + * + * This tells the server-base how to behave + */ +server_characteristics_t server_characteristics = + { + .require_privileges = 0, + .require_display = 0 /* We will service one ourself. */ + }; + + + +#define __free(I) \ + if (I > 0) pthread_mutex_destroy(&slave_mutex); \ + if (I > 1) pthread_cond_destroy(&slave_cond); \ + if (I > 2) pthread_mutex_destroy(&modify_mutex); \ + if (I > 3) pthread_cond_destroy(&modify_cond); \ + if (I >= 4) hash_table_destroy(&modify_map, NULL, NULL); \ + if (I >= 5) fd_table_destroy(&client_map, NULL, NULL); \ + if (I >= 6) linked_list_destroy(&client_list) + +#define error_if(I, CONDITION) \ + if (CONDITION) { perror(*argv); __free(I); return 1; } + /** - * Entry point of the server + * This function will be invoked before `initialise_server` (if not re-exec:ing) + * or before `unmarshal_server` (if re-exec:ing) * - * @param argc_ Number of elements in `argv_` - * @param argv_ Command line arguments - * @return Non-zero on error + * @return Non-zero on error */ -int main(int argc_, char** argv_) +int preinitialise_server(void) { - int is_respawn = -1; - int socket_fd = -1; - int reexec = 0; int unparsed_args_ptr = 1; char* unparsed_args[ARGC_LIMIT + LIBEXEC_ARGC_EXTRA_LIMIT + 1]; int i; @@ -69,58 +89,27 @@ int main(int argc_, char** argv_) #endif - argc = argc_; - argv = argv_; - - - /* Drop privileges like it's hot. */ - fail_if (drop_privileges()); - - /* Sanity check the number of command line arguments. */ - exit_if (argc > ARGC_LIMIT + LIBEXEC_ARGC_EXTRA_LIMIT, - eprint("that number of arguments is ridiculous, I will not allow it.");); - - /* Parse command line arguments. */ for (i = 1; i < argc; i++) { char* arg = argv[i]; - int v; - if ((v = strequals(arg, "--initial-spawn")) || /* Initial spawn? */ - strequals(arg, "--respawn")) /* Respawning after crash? */ - { - exit_if (is_respawn == v, - eprintf("conflicting arguments %s and %s cannot be combined.", - "--initial-spawn", "--respawn");); - is_respawn = !v; - } - else if (startswith(arg, "--socket-fd=")) /* Socket file descriptor. */ + if (startswith(arg, "--socket-fd=")) /* Socket file descriptor. */ { exit_if (socket_fd != -1, eprintf("duplicate declaration of %s.", "--socket-fd");); exit_if (strict_atoi(arg += strlen("--socket-fd="), &socket_fd, 0, INT_MAX) < 0, eprintf("invalid value for %s: %s.", "--socket-fd", arg);); } - else if (strequals(arg, "--re-exec")) /* Re-exec state-marshal. */ - reexec = 1; else if (startswith(arg, "--alarm=")) /* Schedule an alarm signal for forced abort. */ alarm((unsigned)min(atoi(arg + strlen("--alarm=")), 60)); /* At most 1 minute. */ else - /* Not recognised, it is probably for another server. */ - unparsed_args[unparsed_args_ptr++] = arg; + if (!strequals(arg, "--initial-spawn") && !strequals(arg, "--respawn")) + /* Not recognised, it is probably for another server. */ + unparsed_args[unparsed_args_ptr++] = arg; } unparsed_args[unparsed_args_ptr] = NULL; - if (reexec) - { - is_respawn = 1; - eprint("re-exec performed."); - } - /* Check that manditory arguments have been specified. */ - exit_if (is_respawn < 0, - eprintf("missing state argument, require either %s or %s.", - "--initial-spawn", "--respawn");); exit_if (socket_fd < 0, eprint("missing socket file descriptor argument.");); @@ -142,85 +131,91 @@ int main(int argc_, char** argv_) } } -#define __free(I) \ - if (I >= 0) fd_table_destroy(&client_map, NULL, NULL); \ - if (I >= 1) linked_list_destroy(&client_list); \ - if (I >= 2) pthread_mutex_destroy(&slave_mutex); \ - if (I >= 3) pthread_cond_destroy(&slave_cond); \ - if (I >= 4) pthread_mutex_destroy(&modify_mutex); \ - if (I >= 5) pthread_cond_destroy(&modify_cond); \ - if (I >= 6) hash_table_destroy(&modify_map, NULL, NULL) - -#define error_if(I, CONDITION) if (CONDITION) { perror(*argv); __free(I); return 1; } - - /* Create list and table of clients. */ - if (reexec == 0) - { - error_if (0, fd_table_create(&client_map)); - error_if (1, linked_list_create(&client_list, 32)); - } - - /* Store the current thread so it can be killed from elsewhere. */ - master_thread = pthread_self(); - - /* Set up traps for especially handled signals. */ - error_if (1, trap_signals() < 0); /* Create mutex and condition for slave counter. */ - error_if (1, (errno = pthread_mutex_init(&slave_mutex, NULL))); - error_if (2, (errno = pthread_cond_init(&slave_cond, NULL))); + error_if (0, (errno = pthread_mutex_init(&slave_mutex, NULL))); + error_if (1, (errno = pthread_cond_init(&slave_cond, NULL))); /* Create mutex, condition and map for message modification. */ - error_if (3, (errno = pthread_mutex_init(&modify_mutex, NULL))); - error_if (4, (errno = pthread_cond_init(&modify_cond, NULL))); - error_if (5, hash_table_create(&modify_map)); + error_if (2, (errno = pthread_mutex_init(&modify_mutex, NULL))); + error_if (3, (errno = pthread_cond_init(&modify_cond, NULL))); + error_if (4, hash_table_create(&modify_map)); -#undef error_if + return 0; - /* Unmarshal the state of the server. */ - if (reexec) - complete_reexec(socket_fd); + pfail: + perror(*argv); + return 1; +} + + +/** + * This function should initialise the server, + * and it not invoked after a re-exec. + * + * @return Non-zero on error + */ +int initialise_server(void) +{ + /* Create list and table of clients. */ + error_if (5, fd_table_create(&client_map)); + error_if (6, linked_list_create(&client_list, 32)); + return 0; +} + + +/** + * This function will be invoked asgter `initialise_server` (if not re-exec:ing) + * or after `unmarshal_server` (if re-exec:ing) + * + * @return Non-zero on error + */ +int __attribute__((const)) postinitialise_server(void) +{ + /* We do not need to initialise anything else. */ + return 0; +} + + +/** + * Perform the server's mission + * + * @return Non-zero on error + */ +int master_loop(void) +{ /* Accepting incoming connections. */ while (running && (terminating == 0)) - if (accept_connection(socket_fd) == 1) + if (accept_connection() == 1) break; - if (reexecing) - goto reexec; - /* Join with all slaves threads. */ with_mutex (slave_mutex, while (running_slaves > 0) pthread_cond_wait(&slave_cond, &slave_mutex);); - /* Release resources. */ - __free(9999); + if (reexecing == 0) + { + /* Release resources. */ + __free(9999); + } return 0; - -#undef __free - - - reexec: - perform_reexec(reexec); - /* Returning non-zero is important, otherwise the server cannot - be respawn if the re-exec fails. */ - - pfail: - perror(*argv); - return 1; } +#undef error_if +#undef __free + + /** * Accept an incoming and start a slave thread for it * - * @param socket_fd The file descriptor of the server socket - * @return Zero normally, 1 if terminating + * @return Zero normally, 1 if terminating */ -int accept_connection(int socket_fd) +int accept_connection(void) { pthread_t slave_thread; int client_fd; @@ -255,8 +250,8 @@ int accept_connection(int socket_fd) */ void* slave_loop(void* data) { - int socket_fd = (int)(intptr_t)data; - size_t information_address = fd_table_get(&client_map, (size_t)socket_fd); + int slave_fd = (int)(intptr_t)data; + size_t information_address = fd_table_get(&client_map, (size_t)slave_fd); client_t* information = (client_t*)(void*)information_address; char* msgbuf = NULL; char buf[] = "To: all"; @@ -267,7 +262,7 @@ void* slave_loop(void* data) if (information == NULL) /* Did not re-exec. */ { /* Initialise the client. */ - fail_if ((information = initialise_client(socket_fd)) == NULL); + fail_if ((information = initialise_client(slave_fd)) == NULL); /* Register client to receive broadcasts. */ add_intercept_condition(information, buf, 0, 0, 0); @@ -324,7 +319,7 @@ void* slave_loop(void* data) fail: /* This done on success as well. */ /* Close socket and free resources. */ - close(socket_fd); + close(slave_fd); free(msgbuf); if (information != NULL) { @@ -335,7 +330,7 @@ void* slave_loop(void* data) /* Unmap client and decrease the slave count. */ with_mutex (slave_mutex, - fd_table_remove(&client_map, socket_fd); + fd_table_remove(&client_map, slave_fd); running_slaves--; pthread_cond_signal(&slave_cond);); return NULL; diff --git a/src/mds-server/mds-server.h b/src/mds-server/mds-server.h index 19f3044..3bce7ed 100644 --- a/src/mds-server/mds-server.h +++ b/src/mds-server/mds-server.h @@ -27,10 +27,9 @@ /** * Accept an incoming and start a slave thread for it * - * @param socket_fd The file descriptor of the server socket - * @return Zero normally, 1 if terminating + * @return Zero normally, 1 if terminating */ -int accept_connection(int socket_fd); +int accept_connection(void); /** * Master function for slave threads diff --git a/src/mds-server/reexec.c b/src/mds-server/reexec.c index 2b41112..6667a73 100644 --- a/src/mds-server/reexec.c +++ b/src/mds-server/reexec.c @@ -15,7 +15,6 @@ * You should have received a copy of the GNU General Public License * along with this program. If not, see <http://www.gnu.org/licenses/>. */ -#include "reexec.h" #include "globals.h" #include "client.h" @@ -41,51 +40,74 @@ #include <string.h> + /** - * Marshal the server's state into a file + * Calculate the number of bytes that will be stored by `marshal_server` + * + * On failure the program should `abort()` or exit by other means. + * However it should not be possible for this function to fail. * - * @param fd The file descriptor - * @return Negative on error + * @return The number of bytes that will be stored by `marshal_server` */ -int marshal_server(int fd) +size_t marshal_server_size(void) { size_t list_size = linked_list_marshal_size(&client_list); size_t map_size = fd_table_marshal_size(&client_map); size_t list_elements = 0; size_t state_n = 0; - char* state_buf = NULL; - char* state_buf_; ssize_t node; - /* Calculate the grand size of all client information. */ - for (node = client_list.edge;; list_elements++) + foreach_linked_list_node (client_list, node) { - if ((node = client_list.next[node]) == client_list.edge) - break; state_n += client_marshal_size((client_t*)(void*)(client_list.values[node])); + list_elements++; } /* Add the size of the rest of the program's state. */ state_n += sizeof(int) + sizeof(sig_atomic_t) + 2 * sizeof(uint64_t) + 2 * sizeof(size_t); state_n += list_elements * sizeof(size_t) + list_size + map_size; - /* Allocate a buffer for all data. */ - state_buf = state_buf_ = malloc(state_n); - fail_if (state_buf == NULL); + return state_n; +} + + +/** + * Marshal server implementation specific data into a buffer + * + * @param state_buf The buffer for the marshalled data + * @return Non-zero on error + */ +int marshal_server(char* state_buf) +{ + size_t list_size = linked_list_marshal_size(&client_list); + size_t list_elements = 0; + ssize_t node; + + + /* Release resources. */ + pthread_mutex_destroy(&slave_mutex); + pthread_cond_destroy(&slave_cond); + pthread_mutex_destroy(&modify_mutex); + pthread_cond_destroy(&modify_cond); + hash_table_destroy(&modify_map, NULL, NULL); + + /* Count the number of clients that online. */ + foreach_linked_list_node (client_list, node) + list_elements++; /* Tell the new version of the program what version of the program it is marshalling. */ - buf_set_next(state_buf_, int, MDS_SERVER_VARS_VERSION); + buf_set_next(state_buf, int, MDS_SERVER_VARS_VERSION); /* Marshal the miscellaneous state data. */ - buf_set_next(state_buf_, sig_atomic_t, running); - buf_set_next(state_buf_, uint64_t, next_client_id); - buf_set_next(state_buf_, uint64_t, next_modify_id); + buf_set_next(state_buf, sig_atomic_t, running); + buf_set_next(state_buf, uint64_t, next_client_id); + buf_set_next(state_buf, uint64_t, next_modify_id); /* Tell the program how large the marshalled client list is and how any clients are marshalled. */ - buf_set_next(state_buf_, size_t, list_size); - buf_set_next(state_buf_, size_t, list_elements); + buf_set_next(state_buf, size_t, list_size); + buf_set_next(state_buf, size_t, list_elements); /* Marshal the clients. */ foreach_linked_list_node (client_list, node) @@ -96,27 +118,28 @@ int marshal_server(int fd) client_t* value = (client_t*)(void*)value_address; /* Marshal the address, it is used the the client list and the client map, that will be marshalled. */ - buf_set_next(state_buf_, size_t, value_address); + buf_set_next(state_buf, size_t, value_address); /* Marshal the client informationation. */ - state_buf_ += client_marshal(value, state_buf_) / sizeof(char); + state_buf += client_marshal(value, state_buf) / sizeof(char); } /* Marshal the client list. */ - linked_list_marshal(&client_list, state_buf_); - state_buf_ += list_size / sizeof(char); + linked_list_marshal(&client_list, state_buf); + state_buf += list_size / sizeof(char); /* Marshal the client map. */ - fd_table_marshal(&client_map, state_buf_); + fd_table_marshal(&client_map, state_buf); - /* Send the marshalled data into the file. */ - fail_if (full_write(fd, state_buf, state_n) < 0); - free(state_buf); - return 0; + /* Release resources. */ + foreach_linked_list_node (client_list, node) + { + client_t* client = (client_t*)(void*)(client_list.values[node]); + client_destroy(client); + } + fd_table_destroy(&client_map, NULL, NULL); + linked_list_destroy(&client_list); - pfail: - perror(*argv); - free(state_buf); - return -1; + return 0; } @@ -136,17 +159,16 @@ static size_t unmarshal_remapper(size_t old) return hash_table_get(&unmarshal_remap_map, old); } + /** - * Unmarshal the server's state from a file + * Unmarshal server implementation specific data and update the servers state accordingly * - * @param fd The file descriptor - * @return Negative on error + * @param state_buf The marshalled data that as not been read already + * @return Non-zero on error */ -int unmarshal_server(int fd) +int unmarshal_server(char* state_buf) { int with_error = 0; - char* state_buf; - char* state_buf_; size_t list_size; size_t list_elements; size_t i; @@ -154,35 +176,27 @@ int unmarshal_server(int fd) pthread_t slave_thread; - /* Read the file. */ - if ((state_buf = state_buf_ = full_read(fd)) == NULL) - { - perror(*argv); - return -1; - } - /* Create memory address remapping table. */ if (hash_table_create(&unmarshal_remap_map)) { perror(*argv); - free(state_buf); hash_table_destroy(&unmarshal_remap_map, NULL, NULL); return -1; } /* Get the marshal protocal version. Not needed, there is only the one version right now. */ - /* buf_get(state_buf_, int, 0, MDS_SERVER_VARS_VERSION); */ - buf_next(state_buf_, int, 1); + /* buf_get(state_buf, int, 0, MDS_SERVER_VARS_VERSION); */ + buf_next(state_buf, int, 1); /* Unmarshal the miscellaneous state data. */ - buf_get_next(state_buf_, sig_atomic_t, running); - buf_get_next(state_buf_, uint64_t, next_client_id); - buf_get_next(state_buf_, uint64_t, next_modify_id); + buf_get_next(state_buf, sig_atomic_t, running); + buf_get_next(state_buf, uint64_t, next_client_id); + buf_get_next(state_buf, uint64_t, next_modify_id); /* Get the marshalled size of the client list and how any clients that are marshalled. */ - buf_get_next(state_buf_, size_t, list_size); - buf_get_next(state_buf_, size_t, list_elements); + buf_get_next(state_buf, size_t, list_size); + buf_get_next(state_buf, size_t, list_elements); /* Unmarshal the clients. */ for (i = 0; i < list_elements; i++) @@ -196,9 +210,9 @@ int unmarshal_server(int fd) goto clients_fail; /* Unmarshal the address, it is used the the client list and the client map, that are also marshalled. */ - buf_get_next(state_buf_, size_t, value_address); + buf_get_next(state_buf, size_t, value_address); /* Unmarshal the client information. */ - n = client_unmarshal(value, state_buf_); + n = client_unmarshal(value, state_buf); if (n == 0) goto clients_fail; @@ -208,7 +222,7 @@ int unmarshal_server(int fd) goto clients_fail; /* Delayed seeking. */ - state_buf_ += n / sizeof(char); + state_buf += n / sizeof(char); /* On error, seek past all clients. */ @@ -218,29 +232,26 @@ int unmarshal_server(int fd) with_error = 1; if (value != NULL) { - buf_prev(state_buf_, size_t, 1); + buf_prev(state_buf, size_t, 1); free(value); } for (; i < list_elements; i++) /* There is not need to close the sockets, it is done by the caller because there are conditions where we cannot get here anyway. */ - state_buf_ += client_unmarshal_skip(state_buf_) / sizeof(char); + state_buf += client_unmarshal_skip(state_buf) / sizeof(char); break; } /* Unmarshal the client list. */ - if (linked_list_unmarshal(&client_list, state_buf_)) + if (linked_list_unmarshal(&client_list, state_buf)) goto critical_fail; - state_buf_ += list_size / sizeof(char); + state_buf += list_size / sizeof(char); /* Unmarshal the client map. */ - if (fd_table_unmarshal(&client_map, state_buf_, unmarshal_remapper)) + if (fd_table_unmarshal(&client_map, state_buf, unmarshal_remapper)) goto critical_fail; - /* Release the raw data. */ - free(state_buf); - /* Remove non-found elements from the fd table. */ #define __bit(I, _OP_) client_map.used[I / 64] _OP_ ((uint64_t)1 << (I % 64)) if (with_error) @@ -262,116 +273,38 @@ int unmarshal_server(int fd) { /* Start the clients. (Errors do not need to be reported.) */ client_t* client = (client_t*)(void*)new_address; - int socket_fd = client->socket_fd; + int slave_fd = client->socket_fd; /* Increase number of running slaves. */ with_mutex (slave_mutex, running_slaves++;); /* Start slave thread. */ - create_slave(&slave_thread, socket_fd); + create_slave(&slave_thread, slave_fd); } } /* Release the remapping table's resources. */ hash_table_destroy(&unmarshal_remap_map, NULL, NULL); - return -with_error; - - critical_fail: - perror(*argv); - abort(); -} - - -/** - * Marshal and re-execute the server - * - * @param reexec Whether the server was previously re-executed - */ -void perform_reexec(int reexec) -{ - pid_t pid = getpid(); - int reexec_fd; - char shm_path[NAME_MAX + 1]; - ssize_t node; - - /* Join with all slaves threads. */ - with_mutex (slave_mutex, - while (running_slaves > 0) - pthread_cond_wait(&slave_cond, &slave_mutex);); + return with_error; - /* Release resources. */ - pthread_mutex_destroy(&slave_mutex); - pthread_cond_destroy(&slave_cond); - pthread_mutex_destroy(&modify_mutex); - pthread_cond_destroy(&modify_cond); - hash_table_destroy(&modify_map, NULL, NULL); - /* Marshal the state of the server. */ - xsnprintf(shm_path, SHM_PATH_PATTERN, (unsigned long int)pid); - reexec_fd = shm_open(shm_path, O_RDWR | O_CREAT | O_EXCL, S_IRWXU); - if (reexec_fd < 0) - { - perror(*argv); - return; - } - fail_if (marshal_server(reexec_fd) < 0); - close(reexec_fd); - reexec_fd = -1; - - /* Release resources. */ - foreach_linked_list_node (client_list, node) - { - client_t* client = (client_t*)(void*)(client_list.values[node]); - client_destroy(client); - } - fd_table_destroy(&client_map, NULL, NULL); - linked_list_destroy(&client_list); - - /* Re-exec the server. */ - reexec_server(argc, argv, reexec); - - pfail: + critical_fail: perror(*argv); - if (reexec_fd >= 0) - close(reexec_fd); - shm_unlink(shm_path); + abort(); } /** - * Attempt to reload the server after a re-execution + * Attempt to recover from an re-exec failure that has been + * detected after the server successfully updated it execution image * - * @param socket_fd The file descriptor of the server socket + * @return Non-zero on error */ -void complete_reexec(int socket_fd) +int reexec_failure_recover(void) { - pid_t pid = getpid(); - int reexec_fd, r; - char shm_path[NAME_MAX + 1]; - - /* Acquire access to marshalled data. */ - xsnprintf(shm_path, SHM_PATH_PATTERN, (unsigned long int)pid); - reexec_fd = shm_open(shm_path, O_RDONLY, S_IRWXU); - fail_if (reexec_fd < 0); /* Critical. */ - - /* Unmarshal state. */ - r = unmarshal_server(reexec_fd); - - /* Close and unlink marshalled data. */ - close(reexec_fd); - shm_unlink(shm_path); - - /* Recover after failure. */ - if (r < 0) - { - /* Close all files (hopefully sockets) we do not know what they are. */ - close_files((fd > 2) && (fd != socket_fd) && (fd_table_contains_key(&client_map, fd) == 0)); - } - - return; - pfail: - perror(*argv); - abort(); + /* Close all files (hopefully sockets) we do not know what they are. */ + close_files((fd > 2) && (fd != socket_fd) && (fd_table_contains_key(&client_map, fd) == 0)); + return 0; } diff --git a/src/mds-server/reexec.h b/src/mds-server/reexec.h deleted file mode 100644 index 266fdfd..0000000 --- a/src/mds-server/reexec.h +++ /dev/null @@ -1,54 +0,0 @@ -/** - * mds — A micro-display server - * Copyright © 2014 Mattias Andrée (maandree@member.fsf.org) - * - * This program is free software: you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation, either version 3 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program. If not, see <http://www.gnu.org/licenses/>. - */ -#ifndef MDS_MDS_SERVER_REEXEC_H -#define MDS_MDS_SERVER_REEXEC_H - - -/** - * Marshal the server's state into a file - * - * @param fd The file descriptor - * @return Negative on error - */ -int marshal_server(int fd); - -/** - * Unmarshal the server's state from a file - * - * @param fd The file descriptor - * @return Negative on error - */ -int unmarshal_server(int fd); - -/** - * Marshal and re-execute the server - * - * @param reexec Whether the server was previously re-executed - */ -void perform_reexec(int reexec); - -/** - * Attempt to reload the server after a re-execution - * - * @param socket_fd The file descriptor of the server socket - */ -void complete_reexec(int socket_fd); - - -#endif - diff --git a/src/mds-server/sending.c b/src/mds-server/sending.c index 8c40cc4..ec29a81 100644 --- a/src/mds-server/sending.c +++ b/src/mds-server/sending.c @@ -38,13 +38,13 @@ /** * Get the client by its socket's file descriptor in a synchronised manner * - * @param socket_fd The file descriptor of the client's socket + * @param client_fd The file descriptor of the client's socket * @return The client */ -static client_t* client_by_socket(int socket_fd) +static client_t* client_by_socket(int client_fd) { size_t address; - with_mutex (slave_mutex, address = fd_table_get(&client_map, socket_fd);); + with_mutex (slave_mutex, address = fd_table_get(&client_map, client_fd);); return (client_t*)(void*)address; } diff --git a/src/mds-server/signals.c b/src/mds-server/signals.c index b16b28a..325fa35 100644 --- a/src/mds-server/signals.c +++ b/src/mds-server/signals.c @@ -15,20 +15,16 @@ * You should have received a copy of the GNU General Public License * along with this program. If not, see <http://www.gnu.org/licenses/>. */ -#include "signals.h" #include "globals.h" #include "client.h" #include <libmdsserver/linked-list.h> #include <libmdsserver/macros.h> -#include <libmdsserver/util.h> #include <stdio.h> -#include <errno.h> -#include <stdlib.h> #include <pthread.h> -#include <signal.h> +#include <errno.h> /** @@ -58,12 +54,14 @@ static void signal_all(int signo) /** - * Called with the signal SIGUSR1 is caught. - * This function should cue a re-exec of the program. + * This function is called when a signal that + * signals the server to re-exec has been received * - * @param signo The caught signal + * When this function is invoked, it should set `reexecing` to a non-zero value + * + * @param signo The signal that has been received */ -static void sigusr1_trap(int signo) +void received_reexec(int signo) { if (reexecing == 0) { @@ -75,57 +73,20 @@ static void sigusr1_trap(int signo) /** - * Called with the signal SIGTERM is caught. - * This function should cue a termination of the program. + * This function is called when a signal that + * signals the server to re-exec has been received * - * @param signo The caught signal - */ -static void sigterm_trap(int signo) -{ - if (terminating == 0) - { - terminating = 1; - eprint("terminate signal received."); - signal_all(signo); - } -} - - -/** - * Called with the signal SIGINT is caught. - * This function should cue a termination of the program. + * When this function is invoked, it should set `terminating` to a non-zero value * - * @param signo The caught signal + * @param signo The signal that has been received */ -static void sigint_trap(int signo) +void received_terminate(int signo) { if (terminating == 0) { terminating = 1; - eprint("terminal interrupt signal received."); + eprint("terminate signal received."); signal_all(signo); } } - -/** - * Set up signal traps for all especially handled signals - * - * @return Zero on success, -1 on error - */ -int trap_signals(void) -{ - /* Make the server update without all slaves dying on SIGUSR1. */ - fail_if (xsigaction(SIGUSR1, sigusr1_trap) < 0); - - /* Implement clean exit on SIGTERM. */ - fail_if (xsigaction(SIGTERM, sigterm_trap) < 0); - - /* Implement clean exit on SIGINT. */ - fail_if (xsigaction(SIGINT, sigint_trap) < 0); - - return 0; - pfail: - return -1; -} - diff --git a/src/mds-server/signals.h b/src/mds-server/signals.h deleted file mode 100644 index b4a49ed..0000000 --- a/src/mds-server/signals.h +++ /dev/null @@ -1,31 +0,0 @@ -/** - * mds — A micro-display server - * Copyright © 2014 Mattias Andrée (maandree@member.fsf.org) - * - * This program is free software: you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation, either version 3 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program. If not, see <http://www.gnu.org/licenses/>. - */ -#ifndef MDS_MDS_SERVER_SIGNALS_H -#define MDS_MDS_SERVER_SIGNALS_H - - -/** - * Set up signal traps for all especially handled signals - * - * @return Zero on success, -1 on error - */ -int trap_signals(void); - - -#endif - diff --git a/src/mds-server/slavery.c b/src/mds-server/slavery.c index 627bde0..4b92154 100644 --- a/src/mds-server/slavery.c +++ b/src/mds-server/slavery.c @@ -71,13 +71,13 @@ int fetch_message(client_t* client) /** * Create, start and detache a slave thread * - * @param thread The address at where to store the thread - * @param socket_fd The file descriptor of the slave's socket - * @return Zero on success, -1 on error, error message will have been printed + * @param thread The address at where to store the thread + * @param slave_fd The file descriptor of the slave's socket + * @return Zero on success, -1 on error, error message will have been printed */ -int create_slave(pthread_t* thread_slot, int socket_fd) +int create_slave(pthread_t* thread_slot, int slave_fd) { - if ((errno = pthread_create(thread_slot, NULL, slave_loop, (void*)(intptr_t)socket_fd))) + if ((errno = pthread_create(thread_slot, NULL, slave_loop, (void*)(intptr_t)slave_fd))) { perror(*argv); with_mutex (slave_mutex, running_slaves--;); @@ -95,10 +95,10 @@ int create_slave(pthread_t* thread_slot, int socket_fd) /** * Initialise a client, except for threading * - * @param socket_fd The file descriptor of the client's socket + * @param client_fd The file descriptor of the client's socket * @return The client information, NULL on error */ -client_t* initialise_client(int socket_fd) +client_t* initialise_client(int client_fd) { ssize_t entry = LINKED_LIST_UNUSED; int locked = 0; @@ -117,14 +117,14 @@ client_t* initialise_client(int socket_fd) fail_if (entry == LINKED_LIST_UNUSED); /* Add client to table. */ - tmp = fd_table_put(&client_map, socket_fd, (size_t)(void*)information); + tmp = fd_table_put(&client_map, client_fd, (size_t)(void*)information); fail_if ((tmp == 0) && errno); pthread_mutex_unlock(&slave_mutex); locked = 0; /* Fill information table. */ information->list_entry = entry; - information->socket_fd = socket_fd; + information->socket_fd = client_fd; information->open = 1; fail_if (mds_message_initialise(&(information->message))); diff --git a/src/mds-server/slavery.h b/src/mds-server/slavery.h index 0b94e7d..92144fd 100644 --- a/src/mds-server/slavery.h +++ b/src/mds-server/slavery.h @@ -35,19 +35,19 @@ int fetch_message(client_t* client); /** * Create, start and detache a slave thread * - * @param thread The address at where to store the thread - * @param socket_fd The file descriptor of the slave's socket - * @return Zero on success, -1 on error, error message will have been printed + * @param thread The address at where to store the thread + * @param slave_fd The file descriptor of the slave's socket + * @return Zero on success, -1 on error, error message will have been printed */ -int create_slave(pthread_t* thread_slot, int socket_fd); +int create_slave(pthread_t* thread_slot, int slave_fd); /** * Initialise a client, except for threading * - * @param socket_fd The file descriptor of the client's socket + * @param client_fd The file descriptor of the client's socket * @return The client information, NULL on error */ -client_t* initialise_client(int socket_fd); +client_t* initialise_client(int client_fd); #endif |