diff options
| -rw-r--r-- | src/mds-server.c | 61 |
1 files changed, 54 insertions, 7 deletions
diff --git a/src/mds-server.c b/src/mds-server.c index 34d5419..7a50e7f 100644 --- a/src/mds-server.c +++ b/src/mds-server.c @@ -36,6 +36,9 @@ +#define MDS_SERVER_VARS_VERSION 0 + + /** * Number of elements in `argv` */ @@ -54,6 +57,11 @@ static char** argv; static volatile sig_atomic_t running = 1; /** + * Non-zero when the program is about to re-exec + */ +static volatile sig_atomic_t reexecing = 0; + +/** * The number of running slaves */ static int running_slaves = 0; @@ -80,9 +88,6 @@ static linked_list_t client_list; -/* TODO make the server update without all slaves dying on SIGUSR1 */ - - /** * Entry point of the server * @@ -124,6 +129,7 @@ int main(int argc_, char** argv_) } + /* TODO: support re-exec */ /* Parse command line arguments. */ for (i = 1; i < argc; i++) { @@ -227,8 +233,11 @@ int main(int argc_, char** argv_) pthread_cond_init(&slave_cond, NULL); + /* TODO make the server update without all slaves dying on SIGUSR1 */ + + /* Accepting incoming connections. */ - while (running) + while (running && (reexecing == 0)) { /* Accept connection. */ int client_fd = accept(socket_fd, NULL, NULL); @@ -240,6 +249,8 @@ int main(int argc_, char** argv_) { case EINTR: /* Interrupted. */ + if (reexecing) + goto reexec; break; case ECONNABORTED: @@ -271,6 +282,8 @@ int main(int argc_, char** argv_) pthread_mutex_unlock(&slave_mutex); } } + if (reexecing) + goto reexec; /* Wait for all slaves to close. */ @@ -285,6 +298,21 @@ int main(int argc_, char** argv_) linked_list_destroy(&client_list); return 0; + + + reexec: + /* Join with all slaves threads. */ + pthread_mutex_lock(&slave_mutex); + while (running_slaves > 0) + pthread_cond_wait(&slave_cond, &slave_mutex); + pthread_mutex_unlock(&slave_mutex); + + /* TODO: marshal and exec */ + + /* Returning non-zero is important, otherwise the server cannot + be respawn if the re-exec fails. */ + perror(*argv); + return 1; } @@ -342,7 +370,7 @@ void* slave_loop(void* data) /* Fetch messages from the slave. */ - for (;;) + while (reexecing == 0) { r = mds_message_read(&(information->message), socket_fd); if (r == 0) @@ -363,11 +391,14 @@ void* slave_loop(void* data) { /* TODO */ } - break; /* Connection closed. */ + /* Connection closed. */ + break; } else if (errno == EINTR) { - /* TODO */ + /* Stop the thread if we are re-exec:ing the server. */ + if (reexecing) + goto reexec; } else { @@ -375,6 +406,9 @@ void* slave_loop(void* data) goto fail; } } + /* Stop the thread if we are re-exec:ing the server. */ + if (reexecing) + goto reexec; fail: @@ -396,6 +430,19 @@ void* slave_loop(void* data) pthread_mutex_unlock(&slave_mutex); return NULL; + + + reexec: + /* Tell the master thread that the slave has closed, + this is done because re-exec causes a race-condition + between the acception of a slave and the execution + of the the slave thread. */ + pthread_mutex_lock(&slave_mutex); + running_slaves--; + pthread_cond_signal(&slave_cond); + pthread_mutex_unlock(&slave_mutex); + + return NULL; } |