1 files changed, 108 insertions, 0 deletions
diff --git a/src/rcclock.c b/src/rcclock.c
new file mode 100644
index 0000000..b8f0e8f
--- /dev/null
+++ b/src/rcclock.c
@@ -0,0 +1,108 @@
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <time.h>
+#include <errno.h>
+
+#include "../config.h"
+
+#ifdef HAVE_SYS_FILE_H
+# include <sys/file.h>
+#endif /* HAVE_SYS_FILE_H */
+
+#ifdef HAVE_UNISTD_H
+# include <unistd.h>
+#endif /* HAVE_UNISTD_H */
+
+#ifdef HAVE_SYS_TYPES_H
+# include <sys/types.h>
+#endif /* HAVE_SYS_TYPES_H */
+#ifdef HAVE_SYS_STAT_H
+# include <sys/stat.h>
+#endif /* HAVE_SYS_STAT_H */
+
+#include "rcchome.h"
+#include "rcclock.h"
+
+static int lockfd = -1;
+
+int rccLock() {
+# ifdef HAVE_SYS_FILE_H
+    int err, i;
+    int size;
+    char *stmp;
+    struct timespec wait = { 0, 10000000 };
+    
+    if (lockfd>=0) return -1;    
+    
+    size = strlen(rcc_home_dir) + 32;
+    stmp = (char*)malloc(size*sizeof(char));
+    if (!stmp) return -1;
+
+    sprintf(stmp,"%s/.rcc/", rcc_home_dir);
+    mkdir(stmp, 00755);
+    
+    sprintf(stmp,"%s/.rcc/locks/", rcc_home_dir);
+    mkdir(stmp, 00700);
+
+    sprintf(stmp,"%s/.rcc/locks/rcc.lock", rcc_home_dir);
+
+    lockfd = open(stmp, O_RDWR|O_CREAT, 0644);
+    if (lockfd >= 0) {
+	for (err = -1, i = 0; i < (LIBRCC_LOCK_WAIT/10); i++) {
+	    err = flock(lockfd, LOCK_EX|LOCK_NB);
+	    if ((err)&&(errno == EWOULDBLOCK)) nanosleep(&wait, NULL);
+	    else break;
+	}
+
+	if (err) {
+	    close(lockfd);
+
+		// Removing invalid lock
+	    if (i == (LIBRCC_LOCK_WAIT/10)) {
+		remove(stmp);
+
+		lockfd = open(stmp, O_RDWR|O_CREAT, 0644);
+		if (lockfd >= 0) {
+		    for (err = -1, i = 0; i < (LIBRCC_LOCK_WAIT/10); i++) {
+			err = flock(lockfd, LOCK_EX|LOCK_NB);
+			if ((err)&&(errno == EWOULDBLOCK)) nanosleep(&wait, NULL);
+			else break;
+		    }
+		    
+		    if (err) close(lockfd);
+		    else return 0;
+		} 
+	    }
+	    
+	    lockfd = -1;
+	    return -1;
+	} 
+
+	return 0;
+    }
+    
+    return -1;
+# else  /* HAVE_SYS_FILE_H */
+    return 0;
+# endif /* HAVE_SYS_FILE_H */
+}
+
+void rccUnLock() {
+#ifdef HAVE_SYS_FILE_H
+    int size;
+    char *stmp;
+
+    if (lockfd<0) return;
+    
+    size = strlen(rcc_home_dir) + 32;
+    stmp = (char*)malloc(size*sizeof(char));
+    if (!stmp) return;
+
+    sprintf(stmp,"%s/.rcc/locks/rcc.lock", rcc_home_dir);
+
+    flock(lockfd, LOCK_UN);
+    close(lockfd);
+    lockfd = -1;
+#endif /* HAVE_SYS_FILE_H */
+}