Edit File: ex_lock.c
/*- * See the file LICENSE for redistribution information. * * Copyright (c) 1997,2008 Oracle. All rights reserved. * * $Id: ex_lock.c,v 12.6 2008/01/08 20:58:23 bostic Exp $ */ #include <sys/types.h> #include <stdlib.h> #include <string.h> #ifdef _WIN32 extern int getopt(int, char * const *, const char *); #else #include <unistd.h> #endif #include <db.h> int db_init __P((const char *, u_int32_t, int)); int main __P((int, char *[])); int usage __P((void)); DB_ENV *dbenv; const char *progname = "ex_lock"; /* Program name. */ int main(argc, argv) int argc; char *argv[]; { extern char *optarg; extern int optind; DBT lock_dbt; DB_LOCK lock; DB_LOCK *locks; db_lockmode_t lock_type; long held; size_t len; u_int32_t locker, maxlocks; int ch, do_unlink, did_get, i, lockid, lockcount, ret; const char *home; char opbuf[16], objbuf[1024], lockbuf[16]; home = "TESTDIR"; maxlocks = 0; do_unlink = 0; while ((ch = getopt(argc, argv, "h:m:u")) != EOF) switch (ch) { case 'h': home = optarg; break; case 'm': if ((i = atoi(optarg)) <= 0) return (usage()); maxlocks = (u_int32_t)i; /* XXX: possible overflow. */ break; case 'u': do_unlink = 1; break; case '?': default: return (usage()); } argc -= optind; argv += optind; if (argc != 0) return (usage()); /* Initialize the database environment. */ if ((ret = db_init(home, maxlocks, do_unlink)) != 0) return (ret); locks = 0; lockcount = 0; /* * Accept lock requests. */ if ((ret = dbenv->lock_id(dbenv, &locker)) != 0) { dbenv->err(dbenv, ret, "unable to get locker id"); (void)dbenv->close(dbenv, 0); return (EXIT_FAILURE); } lockid = -1; memset(&lock_dbt, 0, sizeof(lock_dbt)); for (held = 0, did_get = 0;;) { printf("Operation get/release [get]> "); fflush(stdout); if (fgets(opbuf, sizeof(opbuf), stdin) == NULL) break; if ((len = strlen(opbuf)) <= 1 || strcmp(opbuf, "get\n") == 0) { /* Acquire a lock. */ printf("input object (text string) to lock> "); fflush(stdout); if (fgets(objbuf, sizeof(objbuf), stdin) == NULL) break; if ((len = strlen(objbuf)) <= 1) continue; do { printf("lock type read/write [read]> "); fflush(stdout); if (fgets(lockbuf, sizeof(lockbuf), stdin) == NULL) break; len = strlen(lockbuf); } while (len > 1 && strcmp(lockbuf, "read\n") != 0 && strcmp(lockbuf, "write\n") != 0); if (len == 1 || strcmp(lockbuf, "read\n") == 0) lock_type = DB_LOCK_READ; else lock_type = DB_LOCK_WRITE; lock_dbt.data = objbuf; lock_dbt.size = (u_int32_t)strlen(objbuf); ret = dbenv->lock_get(dbenv, locker, DB_LOCK_NOWAIT, &lock_dbt, lock_type, &lock); if (ret == 0) { did_get = 1; lockid = lockcount++; if (locks == NULL) locks = (DB_LOCK *)malloc(sizeof(DB_LOCK)); else locks = (DB_LOCK *)realloc(locks, lockcount * sizeof(DB_LOCK)); locks[lockid] = lock; } } else { /* Release a lock. */ do { printf("input lock to release> "); fflush(stdout); if (fgets(objbuf, sizeof(objbuf), stdin) == NULL) break; } while ((len = strlen(objbuf)) <= 1); lockid = strtol(objbuf, NULL, 16); if (lockid < 0 || lockid >= lockcount) { printf("Lock #%d out of range\n", lockid); continue; } lock = locks[lockid]; ret = dbenv->lock_put(dbenv, &lock); did_get = 0; } switch (ret) { case 0: printf("Lock #%d %s\n", lockid, did_get ? "granted" : "released"); held += did_get ? 1 : -1; break; case DB_LOCK_NOTGRANTED: dbenv->err(dbenv, ret, NULL); break; case DB_LOCK_DEADLOCK: dbenv->err(dbenv, ret, "lock_%s", did_get ? "get" : "put"); break; default: dbenv->err(dbenv, ret, "lock_%s", did_get ? "get" : "put"); (void)dbenv->close(dbenv, 0); return (EXIT_FAILURE); } } printf("\nClosing lock region %ld locks held\n", held); if (locks != NULL) free(locks); if ((ret = dbenv->close(dbenv, 0)) != 0) { fprintf(stderr, "%s: dbenv->close: %s\n", progname, db_strerror(ret)); return (EXIT_FAILURE); } return (EXIT_SUCCESS); } /* * db_init -- * Initialize the environment. */ int db_init(home, maxlocks, do_unlink) const char *home; u_int32_t maxlocks; int do_unlink; { int ret; if ((ret = db_env_create(&dbenv, 0)) != 0) { fprintf(stderr, "%s: db_env_create: %s\n", progname, db_strerror(ret)); return (EXIT_FAILURE); } if (do_unlink) { if ((ret = dbenv->remove(dbenv, home, DB_FORCE)) != 0) { fprintf(stderr, "%s: dbenv->remove: %s\n", progname, db_strerror(ret)); return (EXIT_FAILURE); } if ((ret = db_env_create(&dbenv, 0)) != 0) { fprintf(stderr, "%s: db_env_create: %s\n", progname, db_strerror(ret)); return (EXIT_FAILURE); } } dbenv->set_errfile(dbenv, stderr); dbenv->set_errpfx(dbenv, progname); if (maxlocks != 0) dbenv->set_lk_max_locks(dbenv, maxlocks); if ((ret = dbenv->open(dbenv, home, DB_CREATE | DB_INIT_LOCK, 0)) != 0) { dbenv->err(dbenv, ret, NULL); (void)dbenv->close(dbenv, 0); return (EXIT_FAILURE); } return (0); } int usage() { (void)fprintf(stderr, "usage: %s [-u] [-h home] [-m maxlocks]\n", progname); return (EXIT_FAILURE); }
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