-/* $Id: flock.c,v 1.4.2.3 2006-08-14 10:39:24 adam Exp $
- Copyright (C) 1995-2005
+/* $Id: flock.c,v 1.4.2.4 2006-10-23 11:37:11 adam Exp $
+ Copyright (C) 1995-2006
Index Data ApS
This file is part of the Zebra server.
#include <unistd.h>
#endif
+#include <zebra-lock.h>
#include <zebra-flock.h>
#include <yaz/xmalloc.h>
#include <yaz/log.h>
+/** have this module (mutex) been initialized? */
+static int initialized = 0;
+
+/** whether fcntl locks are shared for all threads in a process (POSIX) */
+static int posix_locks = 1;
+
+/** mutex for lock_list below */
+Zebra_mutex lock_list_mutex;
+
+/** our list of file locked files */
+static struct zebra_lock_info *lock_list = 0;
+
+/** the internal handle, with a pointer to each lock file info */
+struct zebra_lock_handle {
+#ifndef WIN32
+ /** so we can call zebra_lock_rdwr_wunlock or zebra_lock_lock_runlock */
+ int write_flag;
+#endif
+ struct zebra_lock_info *p;
+};
+
struct zebra_lock_info {
+ /** file descriptor */
int fd;
+ /** full path (xmalloc'ed) */
char *fname;
+ /** reference counter: number of zebra_lock_handles pointing to us */
+ int ref_count;
+#ifndef WIN32
+ /** number of file write locks/read locks */
+ int no_file_write_lock;
+ int no_file_read_lock;
+ Zebra_lock_rdwr rdwr_lock;
+ Zebra_mutex file_mutex;
+#endif
+ /** next in lock list */
+ struct zebra_lock_info *next;
};
-static int log_level = 0 /* YLOG_LOG|YLOG_FLUSH */;
+static int log_level = 0;
-char *zebra_mk_fname (const char *dir, const char *name)
+char *zebra_mk_fname(const char *dir, const char *name)
{
int dlen = dir ? strlen(dir) : 0;
- char *fname = xmalloc (dlen + strlen(name) + 3);
-
+ char *fname = xmalloc(dlen + strlen(name) + 3);
+
#ifdef WIN32
if (dlen)
{
int last_one = dir[dlen-1];
-
- if (!strchr ("/\\:", last_one))
- sprintf (fname, "%s\\%s", dir, name);
+
+ if (!strchr("/\\:", last_one))
+ sprintf(fname, "%s\\%s", dir, name);
else
- sprintf (fname, "%s%s", dir, name);
+ sprintf(fname, "%s%s", dir, name);
}
else
- sprintf (fname, "%s", name);
+ sprintf(fname, "%s", name);
#else
if (dlen)
{
int last_one = dir[dlen-1];
- if (!strchr ("/", last_one))
- sprintf (fname, "%s/%s", dir, name);
+ if (!strchr("/", last_one))
+ sprintf(fname, "%s/%s", dir, name);
else
- sprintf (fname, "%s%s", dir, name);
+ sprintf(fname, "%s%s", dir, name);
}
else
- sprintf (fname, "%s", name);
+ sprintf(fname, "%s", name);
#endif
return fname;
}
-ZebraLockHandle zebra_lock_create (const char *dir, const char *name)
+ZebraLockHandle zebra_lock_create(const char *dir, const char *name)
{
char *fname = zebra_mk_fname(dir, name);
- ZebraLockHandle h = (ZebraLockHandle) xmalloc (sizeof(*h));
+ struct zebra_lock_info *p = 0;
+ ZebraLockHandle h = 0;
+
+ assert(initialized);
- h->fd = -1;
+ zebra_mutex_lock(&lock_list_mutex);
+ /* see if we have the same filename in a global list of "lock files" */
+#ifndef WIN32
+ if (posix_locks)
+ {
+ for (p = lock_list; p ; p = p->next)
+ if (!strcmp(p->fname, fname))
+ break;
+ }
+#endif
+ if (!p)
+ { /* didn't match (or we didn't want it to match! */
+ p = (struct zebra_lock_info *) xmalloc(sizeof(*p));
+
+ p->ref_count = 0;
#ifdef WIN32
- h->fd = open (name, O_BINARY|O_RDONLY);
- if (h->fd == -1)
- h->fd = open (fname, (O_BINARY|O_CREAT|O_RDWR), 0666);
+ p->fd = open(name, O_BINARY|O_RDONLY);
+ if (p->fd == -1)
+ p->fd = open(fname, (O_BINARY|O_CREAT|O_RDWR), 0666);
#else
- h->fd= open (fname, (O_BINARY|O_CREAT|O_RDWR), 0666);
+ p->fd = open(fname, (O_BINARY|O_CREAT|O_RDWR), 0666);
+#endif
+ if (p->fd == -1)
+ {
+ xfree(p);
+ logf(LOG_WARN | LOG_ERRNO,
+ "zebra_lock_create fail fname=%s", fname);
+ p = 0;
+ }
+ else
+ {
+ p->fname = fname;
+ fname = 0; /* fname buffer now owned by p->fname */
+#ifndef WIN32
+ if (posix_locks)
+ zebra_lock_rdwr_init(&p->rdwr_lock);
+
+ zebra_mutex_init(&p->file_mutex);
+ p->no_file_write_lock = 0;
+ p->no_file_read_lock = 0;
#endif
- if (h->fd == -1)
+ p->next = lock_list;
+ lock_list = p;
+ }
+ }
+ if (p)
{
- xfree (h);
- h = 0;
+ /* we have lock info so we can make a handle pointing to that */
+ p->ref_count++;
+ h = (ZebraLockHandle) xmalloc(sizeof(*h));
+ h->p = p;
+#ifndef WIN32
+ h->write_flag = 0;
+#endif
+ logf(log_level, "zebra_lock_create fd=%d p=%p fname=%s",
+ h->p->fd, h, p->fname);
}
- h->fname = fname;
- yaz_log(log_level, "zebra_lock_create fd=%d p=%p fname=%s", h->fd, h, h->fname);
+ zebra_mutex_unlock(&lock_list_mutex);
+ xfree(fname); /* free it - if it's still there */
+
return h;
}
-void zebra_lock_destroy (ZebraLockHandle h)
+void zebra_lock_destroy(ZebraLockHandle h)
{
if (!h)
return;
- yaz_log(log_level, "zebra_lock_destroy fd=%d p=%p fname=%s", h->fd, h, h->fname);
- if (h->fd != -1)
- close (h->fd);
- xfree (h->fname);
- xfree (h);
+ logf(log_level, "zebra_lock_destroy fd=%d p=%p fname=%s",
+ h->p->fd, h, h->p->fname);
+ zebra_mutex_lock(&lock_list_mutex);
+ logf(log_level, "zebra_lock_destroy fd=%d p=%p fname=%s refcount=%d",
+ h->p->fd, h, h->p->fname, h->p->ref_count);
+ assert(h->p->ref_count > 0);
+ --(h->p->ref_count);
+ if (h->p->ref_count == 0)
+ {
+ /* must remove shared info from lock_list */
+ struct zebra_lock_info **hp = &lock_list;
+ while (*hp)
+ {
+ if (*hp == h->p)
+ {
+ *hp = h->p->next;
+ break;
+ }
+ else
+ hp = &(*hp)->next;
+ }
+
+ logf(log_level, "zebra_lock_destroy fd=%d p=%p fname=%s remove",
+ h->p->fd, h, h->p->fname);
+
+#ifndef WIN32
+ if (posix_locks)
+ zebra_lock_rdwr_destroy(&h->p->rdwr_lock);
+ zebra_mutex_destroy(&h->p->file_mutex);
+#endif
+ if (h->p->fd != -1)
+ close(h->p->fd);
+ xfree(h->p->fname);
+ xfree(h->p);
+ }
+ xfree(h);
+ zebra_mutex_unlock(&lock_list_mutex);
}
#ifndef WIN32
-static int unixLock (int fd, int type, int cmd)
+static int unixLock(int fd, int type, int cmd)
{
struct flock area;
+ int r;
area.l_type = type;
area.l_whence = SEEK_SET;
area.l_len = area.l_start = 0L;
- return fcntl (fd, cmd, &area);
+
+ logf(log_level, "fcntl begin type=%d fd=%d", type, fd);
+ r = fcntl(fd, cmd, &area);
+ if (r == -1)
+ logf(LOG_WARN|LOG_ERRNO, "fcntl FAIL type=%d fd=%d", type, fd);
+ else
+ logf(log_level, "fcntl type=%d OK fd=%d", type, fd);
+
+ return r;
}
#endif
-int zebra_lock_w (ZebraLockHandle h)
+int zebra_lock_w(ZebraLockHandle h)
{
int r;
- yaz_log(log_level, "zebra_lock_w fd=%d p=%p fname=%s", h->fd, h, h->fname);
+ int do_lock = 0;
+ logf(log_level, "zebra_lock_w fd=%d p=%p fname=%s begin",
+ h->p->fd, h, h->p->fname);
+
#ifdef WIN32
- while ((r = _locking (h->fd, _LK_LOCK, 1)))
+ while ((r = _locking(h->p->fd, _LK_LOCK, 1)))
;
#else
- r = unixLock (h->fd, F_WRLCK, F_SETLKW);
+ if (posix_locks)
+ zebra_lock_rdwr_wlock(&h->p->rdwr_lock);
+
+ zebra_mutex_lock(&h->p->file_mutex);
+ if (h->p->no_file_write_lock == 0)
+ do_lock = 1;
+ h->p->no_file_write_lock++;
+ if (do_lock)
+ {
+ /* if there is already a read lock.. upgrade to write lock */
+ r = unixLock(h->p->fd, F_WRLCK, F_SETLKW);
+ }
+ else
+ {
+ assert(posix_locks);
+ }
+ zebra_mutex_unlock(&h->p->file_mutex);
+
+ h->write_flag = 1;
#endif
- yaz_log(log_level, "zebra_lock_w fd=%d p=%p fname=%s OK", h->fd, h, h->fname);
+ logf(log_level, "zebra_lock_w fd=%d p=%p fname=%s end",
+ h->p->fd, h, h->p->fname);
+
return r;
}
-int zebra_lock_r (ZebraLockHandle h)
+int zebra_lock_r(ZebraLockHandle h)
{
int r;
- yaz_log(log_level, "zebra_lock_r fd=%d p=%p fname=%s", h->fd, h, h->fname);
+ int do_lock = 0;
+
+ logf(log_level, "zebra_lock_r fd=%d p=%p fname=%s begin",
+ h->p->fd, h, h->p->fname);
#ifdef WIN32
- while ((r = _locking (h->fd, _LK_LOCK, 1)))
+ while ((r = _locking(h->p->fd, _LK_LOCK, 1)))
;
#else
- r = unixLock (h->fd, F_RDLCK, F_SETLKW);
+ if (posix_locks)
+ zebra_lock_rdwr_rlock(&h->p->rdwr_lock);
+
+ zebra_mutex_lock(&h->p->file_mutex);
+ if (h->p->no_file_read_lock == 0 && h->p->no_file_write_lock == 0)
+ do_lock = 1;
+ h->p->no_file_read_lock++;
+ if (do_lock)
+ {
+ /* only read lock if no write locks already */
+ r = unixLock(h->p->fd, F_RDLCK, F_SETLKW);
+ }
+ else
+ {
+ assert(posix_locks);
+ }
+ zebra_mutex_unlock(&h->p->file_mutex);
+
+ h->write_flag = 0;
#endif
- yaz_log(log_level, "zebra_lock_r fd=%d p=%p fname=%s OK", h->fd, h, h->fname);
+ logf(log_level, "zebra_lock_r fd=%d p=%p fname=%s end",
+ h->p->fd, h, h->p->fname);
return r;
}
-int zebra_unlock (ZebraLockHandle h)
+int zebra_unlock(ZebraLockHandle h)
{
- yaz_log(log_level, "zebra_unlock fd=%d p=%p fname=%s", h->fd, h, h->fname);
+ int r = 0;
+ logf(log_level, "zebra_unlock fd=%d p=%p fname=%s begin",
+ h->p->fd, h, h->p->fname);
#ifdef WIN32
- return _locking (h->fd, _LK_UNLCK, 1);
+ r = _locking(h->p->fd, _LK_UNLCK, 1);
#else
- return unixLock (h->fd, F_UNLCK, F_SETLKW);
+ zebra_mutex_lock(&h->p->file_mutex);
+ if (h->write_flag)
+ {
+ if (h->p->no_file_write_lock > 0)
+ h->p->no_file_write_lock--;
+ }
+ else
+ {
+ if (h->p->no_file_read_lock > 0)
+ h->p->no_file_read_lock--;
+ }
+ if (h->p->no_file_read_lock == 0 && h->p->no_file_write_lock == 0)
+ r = unixLock(h->p->fd, F_UNLCK, F_SETLKW);
+ else
+ {
+ r = 0;
+ assert(posix_locks);
+ }
+
+ zebra_mutex_unlock(&h->p->file_mutex);
+
+ if (posix_locks)
+ {
+ if (h->write_flag)
+ zebra_lock_rdwr_wunlock(&h->p->rdwr_lock);
+ else
+ zebra_lock_rdwr_runlock(&h->p->rdwr_lock);
+ }
#endif
+ logf(log_level, "zebra_unlock fd=%d p=%p fname=%s end",
+ h->p->fd, h, h->p->fname);
+ return r;
}
+/** \brief see if the fcntl locking is not POSIX
+ *
+ * The default posix_locks=1 is assumed.. This function sets posix_locks
+ * to zero if linuxthreads is in use.
+ */
+static int check_for_linuxthreads()
+{
+#if __linux
+#ifdef _CS_GNU_LIBPTHREAD_VERSION
+ char conf_buf[512];
+ size_t r = confstr(_CS_GNU_LIBPTHREAD_VERSION, conf_buf, sizeof(conf_buf));
+ if (r == 0)
+ {
+ logf(LOG_WARN|LOG_ERRNO, "confstr failed");
+ return -1;
+ }
+ if (strncmp(conf_buf, "linuxthreads", 12) == 0)
+ posix_locks = 0; /* Using linuxthreads.. */
+#else
+ posix_locks = 0; /* Old GLIBC on Linux. Assume linuxthreads */
+#endif
+#endif
+ return 0;
+}
+
+void zebra_flock_init()
+{
+ if (!initialized)
+ {
+ initialized = 1;
+ log_level = yaz_log_module_level("flock");
+ logf(log_level, "zebra_flock_init");
+ check_for_linuxthreads();
+ zebra_mutex_init(&lock_list_mutex);
+ logf(log_level, "posix_locks: %d", posix_locks);
+ }
+}
+
+/*
+ * Local variables:
+ * c-basic-offset: 4
+ * indent-tabs-mode: nil
+ * End:
+ * vim: shiftwidth=4 tabstop=8 expandtab
+ */
+
--- /dev/null
+/* $Id: tstflock.c,v 1.16.2.1 2006-10-23 11:37:11 adam Exp $
+ Copyright (C) 1995-2006
+ Index Data ApS
+
+This file is part of the Zebra server.
+
+Zebra 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 2, or (at your option) any later
+version.
+
+Zebra 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, write to the Free Software
+Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+
+*/
+
+#include <assert.h>
+#include <stdlib.h>
+#include <yaz/test.h>
+#include <yaz/log.h>
+#if HAVE_SYS_TIME_H
+#include <sys/time.h>
+#endif
+#include <time.h>
+
+#if HAVE_SYS_STAT_H
+#include <sys/stat.h>
+#endif
+#if HAVE_SYS_TYPES_H
+#include <sys/types.h>
+#endif
+#if HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+#if HAVE_SYS_WAIT_H
+#include <sys/wait.h>
+#endif
+
+#include <fcntl.h>
+
+#ifdef WIN32
+#include <io.h>
+#endif
+
+#if YAZ_POSIX_THREADS
+#include <pthread.h>
+#endif
+#ifdef WIN32
+#include <windows.h>
+#include <process.h>
+#endif
+
+#include <zebra-flock.h>
+#include <string.h>
+
+static char seq[1000];
+static char *seqp = 0;
+
+#define NUM_THREADS 100
+
+#if YAZ_POSIX_THREADS
+pthread_cond_t sleep_cond = PTHREAD_COND_INITIALIZER;
+pthread_mutex_t sleep_mutex = PTHREAD_MUTEX_INITIALIZER;
+#endif
+
+int test_fd = 0;
+
+static void small_sleep()
+{
+#ifdef WIN32
+ Sleep(2);
+#else
+#if YAZ_POSIX_THREADS
+ struct timespec abstime;
+ struct timeval now;
+
+ gettimeofday(&now, 0);
+ abstime.tv_sec = now.tv_sec;
+ abstime.tv_nsec = 1000000 + now.tv_usec * 1000;
+ if (abstime.tv_nsec > 1000000000) /* 1s = 1e9 ns */
+ {
+ abstime.tv_nsec -= 1000000000;
+ abstime.tv_sec++;
+ }
+ pthread_mutex_lock(&sleep_mutex);
+ pthread_cond_timedwait(&sleep_cond, &sleep_mutex, &abstime);
+ pthread_mutex_unlock(&sleep_mutex);
+#endif
+#endif
+}
+
+void *run_func(void *arg)
+{
+ int i;
+ int *pdata = (int*) arg;
+ int use_write_lock = *pdata;
+ ZebraLockHandle lh = zebra_lock_create(0, "my.LCK");
+ for (i = 0; i<2; i++)
+ {
+ int write_lock = use_write_lock;
+
+ if (use_write_lock == 2) /* random lock */
+ write_lock = (rand() & 3) == 3 ? 1 : 0;
+
+ if (write_lock)
+ {
+ zebra_lock_w(lh);
+
+ write(test_fd, "L", 1);
+ *seqp++ = 'L';
+ small_sleep();
+ *seqp++ = 'U';
+ write(test_fd, "U", 1);
+
+ zebra_unlock(lh);
+ }
+ else
+ {
+ zebra_lock_r(lh);
+
+ write(test_fd, "l", 1);
+ *seqp++ = 'l';
+ small_sleep();
+ *seqp++ = 'u';
+ write(test_fd, "u", 1);
+
+ zebra_unlock(lh);
+ }
+ }
+ zebra_lock_destroy(lh);
+ *pdata = 123;
+ return 0;
+}
+
+#ifdef WIN32
+DWORD WINAPI ThreadProc(void *p)
+{
+ run_func(p);
+ return 0;
+}
+#endif
+
+static void tst_thread(int num, int write_flag)
+{
+#ifdef WIN32
+ HANDLE handles[NUM_THREADS];
+ DWORD dwThreadId[NUM_THREADS];
+#endif
+#if YAZ_POSIX_THREADS
+ pthread_t child_thread[NUM_THREADS];
+#endif
+ int i, id[NUM_THREADS];
+
+ seqp = seq;
+ assert (num <= NUM_THREADS);
+ for (i = 0; i < num; i++)
+ {
+ id[i] = write_flag;
+#if YAZ_POSIX_THREADS
+ pthread_create(&child_thread[i], 0 /* attr */, run_func, &id[i]);
+#endif
+#ifdef WIN32
+ if (1)
+ {
+ void *pData = &id[i];
+ handles[i] = CreateThread(
+ NULL, /* default security attributes */
+ 0, /* use default stack size */
+ ThreadProc, /* thread function */
+ pData, /* argument to thread function */
+ 0, /* use default creation flags */
+ &dwThreadId[i]); /* returns the thread identifier */
+ }
+
+#endif
+ }
+#if YAZ_POSIX_THREADS
+ for (i = 0; i<num; i++)
+ pthread_join(child_thread[i], 0);
+#endif
+#ifdef WIN32
+ WaitForMultipleObjects(num, handles, TRUE, INFINITE);
+#endif
+ for (i = 0; i < num; i++)
+ YAZ_CHECK(id[i] == 123);
+ *seqp++ = '\0';
+ logf(LOG_LOG, "tst_thread(%d,%d) returns seq=%s",
+ num, write_flag, seq);
+}
+
+static void tst()
+{
+ tst_thread(4, 1); /* write locks */
+ if (1)
+ {
+ int i = 0;
+ while (seq[i])
+ {
+ YAZ_CHECK_EQ(seq[i], 'L');
+ YAZ_CHECK_EQ(seq[i+1], 'U');
+ i = i + 2;
+ }
+ }
+
+ tst_thread(6, 0); /* read locks */
+
+ tst_thread(20, 2); /* random locks */
+}
+
+void fork_tst()
+{
+#if HAVE_SYS_WAIT_H
+ pid_t pid[2];
+ int i;
+
+ for (i = 0; i<2; i++)
+ {
+ pid[i] = fork();
+ if (!pid[i])
+ {
+ tst();
+ exit(0);
+ }
+ }
+ for (i = 0; i<2; i++)
+ {
+ int status;
+ waitpid(pid[i], &status, 0);
+ YAZ_CHECK(status == 0);
+ }
+#else
+ tst();
+#endif
+}
+
+int main(int argc, char **argv)
+{
+ char logname[220];
+ YAZ_CHECK_INIT(argc, argv);
+
+ sprintf(logname, "%.200s.log", argv[0]);
+ yaz_log_init_file(logname);
+
+ /* ensure the flock system logs in our test */
+ yaz_log_init_level(yaz_log_mask_str("flock"));
+
+ zebra_flock_init();
+
+ test_fd = open("tstflock.out", (O_BINARY|O_CREAT|O_RDWR), 0666);
+ YAZ_CHECK(test_fd != -1);
+ if (test_fd != -1)
+ {
+ fork_tst();
+ }
+ YAZ_CHECK_TERM;
+}
+
+
+/*
+ * Local variables:
+ * c-basic-offset: 4
+ * indent-tabs-mode: nil
+ * End:
+ * vim: shiftwidth=4 tabstop=8 expandtab
+ */
+
projects / idzebra-moved-to-github.git / commitdiff