[PATCH] Unlock refs files on error exit

From

Daniel Barkalow <barkalow@iabervon.org>

Date

Jul 4, 2005, 20:08 UTC

Message-ID

<Pine.LNX.4.21.0507041557310.30848-100000@iabervon.org>

Signed-off-by: Daniel Barkalow <barkalow@iabervon.org>

Index: refs.c
===================================================================
--- 3d3e671c0ac57ea66434768c2b3432352b7c20ae/refs.c  (mode:100644 sha1:447080edde385a470a815944c2f002c1e51699a5)
+++ 62a74516551505e5fd2b5c2fd14486f3ac8a400e/refs.c  (mode:100644 sha1:6e75e82665f5c8e3e155579228c5104c16318239)
@@ -2,6 +2,14 @@
 #include "cache.h"
 
 #include <errno.h>
+#include <signal.h>
+
+#define MAX_LOCKS 10
+
+static int setup = 0;
+
+static int num_locks = 0;
+static char *locknames[MAX_LOCKS];
 
 static int read_ref(const char *path, unsigned char *sha1)
 {
@@ -88,6 +96,22 @@
 	return ret;
 }
 
+static void remove_lock_files(void)
+{
+	int i;
+	if (getpid() != setup)
+		return;
+	for (i = 0; i < num_locks; i++) {
+		unlink(locknames[i]);
+	}
+	num_locks = 0;
+}
+
+static void remove_lock_files_on_signal(int signo) 
+{
+	remove_lock_files();
+}
+
 static int read_ref_file(const char *filename, unsigned char *sha1) {
 	int fd = open(filename, O_RDONLY);
 	char hex[41];
@@ -120,9 +144,12 @@
 static int lock_ref_file(const char *filename, const char *lock_filename,
 			 const unsigned char *old_sha1)
 {
-	int fd = open(lock_filename, O_WRONLY | O_CREAT | O_EXCL, 0666);
+	int fd;
 	unsigned char current_sha1[20];
 	int retval;
+	if (num_locks >= MAX_LOCKS)
+		return error("Too many locks in refs.c");
+	fd = open(lock_filename, O_WRONLY | O_CREAT | O_EXCL, 0666);
 	if (fd < 0) {
 		return error("Couldn't open lock file for %s: %s",
 			     filename, strerror(errno));
@@ -151,6 +178,12 @@
 				     sha1_to_hex(current_sha1), filename);
 		}
 	}
+	if (!setup) {
+		signal(SIGINT, remove_lock_files_on_signal);
+		atexit(remove_lock_files);
+		setup = getpid();
+	}
+	locknames[num_locks++] = strdup(lock_filename);
 	return fd;
 }
 
@@ -175,6 +208,7 @@
 {
 	char *hex = sha1_to_hex(sha1);
 	char term = '\n';
+	int i;
 	if (write(fd, hex, 40) < 40 ||
 	    write(fd, &term, 1) < 1) {
 		error("Couldn't write %s\n", filename);
@@ -182,7 +216,14 @@
 		return -1;
 	}
 	close(fd);
-	rename(lock_filename, filename);
+	if (rename(lock_filename, filename))
+		return error("Couldn't update %s", filename);
+	for (i = 0; i < num_locks; i++) {
+		if (!strcmp(lock_filename, locknames[i])) {
+			locknames[i] = locknames[--num_locks];
+			break;
+		}
+	}
 	return 0;
 }