diff options
Diffstat (limited to 'xpp/astribank_is_starting.c')
| -rw-r--r-- | xpp/astribank_is_starting.c | 190 |
1 files changed, 190 insertions, 0 deletions
diff --git a/xpp/astribank_is_starting.c b/xpp/astribank_is_starting.c new file mode 100644 index 0000000..578ea9b --- /dev/null +++ b/xpp/astribank_is_starting.c @@ -0,0 +1,190 @@ +#define _GNU_SOURCE /* 2.3 and later will define this from autoconfig.h */ +#include <sys/types.h> +#include <sys/ipc.h> +#include <sys/sem.h> +#include <errno.h> +#include <getopt.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <time.h> + +static char *progname; +static const key_t key_astribanks = 0xAB11A0; +static int debug; +static int verbose; +static int timeout_seconds = 60; + + +static void usage(void) +{ + fprintf(stderr, "Usage: %s [-d] [-t <seconds>] [-a|-r|-w]\n", progname); + exit(1); +} + +static int absem_get(int createit) +{ + int flags = (createit) ? IPC_CREAT | 0644 : 0; + int absem; + + if((absem = semget(key_astribanks, 1, flags)) < 0) + absem = -errno; + return absem; +} + +static int absem_touch(void) +{ + int absem; + + if((absem = absem_get(1)) < 0) { + perror(__FUNCTION__); + return absem; + } + if(semctl(absem, 0, SETVAL, 0) < 0) { + perror("SETVAL"); + return -errno; + } + if(debug) + fprintf(stderr, "%s: touched absem\n", progname); + if(verbose) + printf("Astribanks initialization is starting\n"); + return 0; +} + +static int absem_remove(void) +{ + int absem; + + if((absem = absem_get(0)) < 0) { + if(absem == -ENOENT) { + if(debug) + fprintf(stderr, "%s: absem already removed\n", progname); + return 0; + } + perror(__FUNCTION__); + return absem; + } + if(semctl(absem, 0, IPC_RMID, 0) < 0) { + perror("RMID"); + return -errno; + } + if(debug) + fprintf(stderr, "%s: removed absem\n", progname); + if(verbose) + printf("Astribanks initialization is done\n"); + return 0; +} + +static int absem_wait(void) +{ + int absem; + struct sembuf sops; + long now; + long start_wait; + struct timespec timeout; + + if((absem = absem_get(0)) < 0) { + perror(__FUNCTION__); + return absem; + } + sops.sem_num = 0; + sops.sem_op = -1; + sops.sem_flg = 0; + start_wait = time(NULL); + timeout.tv_sec = timeout_seconds; + timeout.tv_nsec = 0; + if(semtimedop(absem, &sops, 1, &timeout) < 0) { + switch(errno) { + case EIDRM: /* Removed -- OK */ + break; + case EAGAIN: /* Timeout -- Report */ + fprintf(stderr, "Astribanks waiting timed out\n"); + return -errno; + default: /* Unexpected errors */ + perror("semop"); + return -errno; + } + /* fall-thgough */ + } + now = time(NULL); + if(debug) + fprintf(stderr, "%s: waited on absem %ld seconds\n", progname, now - start_wait); + if(verbose) + printf("Finished after %ld seconds\n", now - start_wait); + return 0; +} + +static int absem_detected(void) +{ + int absem; + + if((absem = absem_get(0)) < 0) { + if(debug) + fprintf(stderr, "%s: absem does not exist\n", progname); + return absem; + } + if(debug) + fprintf(stderr, "%s: absem exists\n", progname); + if(verbose) + printf("Astribanks are initializing...\n"); + return 0; +} + +int main(int argc, char *argv[]) +{ + const char options[] = "dvarwt:h"; + int val; + + progname = argv[0]; + while (1) { + int c; + int t; + + c = getopt (argc, argv, options); + if (c == -1) + break; + + switch (c) { + case 'd': + debug++; + break; + case 'v': + verbose++; + break; + case 't': + t = atoi(optarg); + if(t <= 0) { + fprintf(stderr, + "%s: -t expect a positive number of seconds: '%s'\n", + progname, optarg); + usage(); + } + timeout_seconds = t; + break; + case 'a': + if((val = absem_touch()) < 0) { + fprintf(stderr, "%s: Add failed: %d\n", progname, val); + return 1; + } + return 0; + case 'r': + if((val = absem_remove()) < 0) { + fprintf(stderr, "%s: Remove failed: %d\n", progname, val); + return 1; + } + return 0; + case 'w': + if((val = absem_wait()) < 0) { + fprintf(stderr, "%s: Wait failed: %d\n", progname, val); + return 1; + } + return 0; + case 'h': + default: + fprintf(stderr, "Unknown option '%c'\n", c); + usage(); + } + } + val = absem_detected(); + return (val == 0) ? 0 : 1; +} |