add missing space to recent servport.c translated string.

[~andy/fetchmail] / lock.c

diff --git a/lock.c b/lock.c
index e69de29bb2d1d6434b8b29ae775ad8c2e48c5391..b8dbc50308a52ffd75d8807aa4405a3a8c3a7da5 100644 (file)
--- a/lock.c
+++ b/lock.c
@@ -0,0 +1,145 @@
+/*
+ * lock.c -- cross-platform concurrency locking for fetchmail
+ *
+ * For license terms, see the file COPYING in this directory.
+ */
+#include "config.h"
+
+#include <stdio.h>
+#ifdef HAVE_STRING_H
+#include <string.h> /* strcat() */
+#endif
+#if defined(STDC_HEADERS)
+#include <stdlib.h>
+#endif
+#if defined(HAVE_UNISTD_H)
+#include <unistd.h>
+#endif
+#include <errno.h>
+#include <fcntl.h>
+#include <signal.h>
+
+#include "fetchmail.h"
+#include "i18n.h"
+
+static char *lockfile;         /* name of lockfile */
+static int lock_acquired;      /* have we acquired a lock */
+
+void lock_setup(void)
+/* set up the global lockfile name */
+{
+    /* set up to do lock protocol */
+#define        FETCHMAIL_PIDFILE       "fetchmail.pid"
+    if (getuid() == ROOT_UID) {
+       lockfile = (char *)xmalloc(
+               sizeof(PID_DIR) + sizeof(FETCHMAIL_PIDFILE) + 1);
+       strcpy(lockfile, PID_DIR);
+       strcat(lockfile, "/");
+       strcat(lockfile, FETCHMAIL_PIDFILE);
+    } else {
+       lockfile = (char *)xmalloc(strlen(fmhome)+sizeof(FETCHMAIL_PIDFILE)+2);
+       strcpy(lockfile, fmhome);
+       strcat(lockfile, "/");
+        if (fmhome == home)
+          strcat(lockfile, ".");
+       strcat(lockfile, FETCHMAIL_PIDFILE);
+    }
+#undef FETCHMAIL_PIDFILE
+}
+
+#ifdef HAVE_ON_EXIT
+static void unlockit(int n, void *p)
+#else
+static void unlockit(void)
+#endif
+/* must-do actions for exit (but we can't count on being able to do malloc) */
+{
+    if (lockfile && lock_acquired)
+       unlink(lockfile);
+}
+
+void lock_dispose(void)
+/* arrange for a lock to be removed on process exit */
+{
+#ifdef HAVE_ATEXIT
+    atexit(unlockit);
+#endif
+#ifdef HAVE_ON_EXIT
+    on_exit(unlockit, (char *)NULL);
+#endif
+}
+
+int lock_state(void)
+{
+    int                pid, st;
+    FILE       *lockfp;
+    int                bkgd = FALSE;
+
+    if ((lockfp = fopen(lockfile, "r")) != NULL)
+    {
+       int args = fscanf(lockfp, "%d %d", &pid, &st);
+       bkgd = (args == 2);
+
+       if (ferror(lockfp))
+           fprintf(stderr, GT_("fetchmail: error reading lockfile \"%s\": %s\n"),
+                   lockfile, strerror(errno));
+
+       if (args == 0 || kill(pid, 0) == -1) {
+           fprintf(stderr,GT_("fetchmail: removing stale lockfile\n"));
+           pid = 0;
+           if (unlink(lockfile))
+               perror(lockfile);
+       }
+       fclose(lockfp); /* not checking should be safe, file mode was "r" */
+    } else {
+       pid = 0;
+       if (errno != ENOENT)
+           fprintf(stderr, GT_("fetchmail: error opening lockfile \"%s\": %s\n"),
+                   lockfile, strerror(errno));
+    }
+
+    return(bkgd ? -pid : pid);
+}
+
+void lock_assert(void)
+/* assert that we already posess a lock */
+{
+    lock_acquired = TRUE;
+}
+
+void lock_or_die(void)
+/* get a lock on a given host or exit */
+{
+    int fd;
+    char       tmpbuf[50];
+
+    if (!lock_acquired) {
+       int e = 0;
+
+       if ((fd = open(lockfile, O_WRONLY|O_CREAT|O_EXCL, 0666)) != -1) {
+           snprintf(tmpbuf, sizeof(tmpbuf), "%ld\n", (long)getpid());
+           if (write(fd, tmpbuf, strlen(tmpbuf)) < strlen(tmpbuf)) e = 1;
+           if (run.poll_interval)
+           {
+               snprintf(tmpbuf, sizeof(tmpbuf), "%d\n", run.poll_interval);
+               if (write(fd, tmpbuf, strlen(tmpbuf)) < strlen(tmpbuf)) e = 1;
+           }
+           if (fsync(fd)) e = 1;
+           if (close(fd)) e = 1;
+       }
+       if (e == 0) {
+           lock_acquired = TRUE;
+       } else {
+           perror(lockfile);
+           fprintf(stderr, GT_("fetchmail: lock creation failed.\n"));
+           exit(PS_EXCLUDE);
+       }
+    }
+}
+
+void fm_lock_release(void)
+/* release a lock on a given host */
+{
+    unlink(lockfile);
+}
+/* lock.c ends here */