diff options
Diffstat (limited to 'camel/camel-lock-client.c')
-rw-r--r-- | camel/camel-lock-client.c | 329 |
1 files changed, 0 insertions, 329 deletions
diff --git a/camel/camel-lock-client.c b/camel/camel-lock-client.c deleted file mode 100644 index a2dc1e591a..0000000000 --- a/camel/camel-lock-client.c +++ /dev/null @@ -1,329 +0,0 @@ -/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- - * - * Copyright (C) 2001 Ximian Inc. - * - * Authors: Michael Zucchi <notzed@ximian.com> - * - * This program 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 of the - * License, or (at your option) any later version. - * - * This program 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 - * USA - */ - -#ifdef HAVE_CONFIG_H -#include <config.h> -#endif - -#include <stdio.h> -#include <stdlib.h> - -#include <errno.h> -#include <string.h> - -#include <sys/types.h> -#include <sys/stat.h> -#include <sys/wait.h> - -#include <unistd.h> -#include <fcntl.h> - -#ifdef ENABLE_THREADS -#include <pthread.h> -#endif - -#include "camel-exception.h" -#include "camel-lock-helper.h" -#include "camel-lock-client.h" - -#define d(x) - -/* dunno where this fucking thing is got from */ -/* see also camel-lock.c */ -#define _(x) (x) - -#ifdef ENABLE_THREADS -static pthread_mutex_t lock_lock = PTHREAD_MUTEX_INITIALIZER; -#define LOCK() pthread_mutex_lock(&lock_lock) -#define UNLOCK() pthread_mutex_unlock(&lock_lock) -#else -#define LOCK() -#define UNLOCK() -#endif - -static int lock_sequence; -static int lock_helper_pid = -1; -static int lock_stdin_pipe[2], lock_stdout_pipe[2]; - -static int read_n(int fd, void *buffer, int inlen) -{ - char *p = buffer; - int len, left = inlen; - - do { - len = read(fd, p, left); - if (len == -1) { - if (errno != EINTR) - return -1; - } else { - left -= len; - p += len; - } - } while (left > 0 && len != 0); - - return inlen - left; -} - -static int write_n(int fd, void *buffer, int inlen) -{ - char *p = buffer; - int len, left = inlen; - - do { - len = write(fd, p, left); - if (len == -1) { - if (errno != EINTR) - return -1; - } else { - left -= len; - p += len; - } - } while (left > 0); - - return inlen; -} - -static int camel_lock_helper_init(CamelException *ex) -{ - if (pipe(lock_stdin_pipe) == -1 - || pipe(lock_stdout_pipe) == -1) { - camel_exception_setv(ex, CAMEL_EXCEPTION_SYSTEM, - _("Cannot build locking helper pipe: %s"), - strerror(errno)); - return -1; - } - - lock_helper_pid = fork(); - switch(lock_helper_pid) { - case -1: - close(lock_stdin_pipe[0]); - close(lock_stdin_pipe[1]); - close(lock_stdout_pipe[0]); - close(lock_stdout_pipe[1]); - camel_exception_setv(ex, CAMEL_EXCEPTION_SYSTEM, - _("Cannot fork locking helper: %s"), - strerror(errno)); - return -1; - case 0: - close(STDIN_FILENO); - dup(lock_stdin_pipe[0]); - close(STDOUT_FILENO); - dup(lock_stdout_pipe[1]); - close(lock_stdin_pipe[0]); - close(lock_stdin_pipe[1]); - close(lock_stdout_pipe[0]); - close(lock_stdout_pipe[1]); - execl(CAMEL_SBINDIR "/camel-lock-helper", "camel-lock-helper", NULL); - d(fprintf(stderr, "shit, couldn't exec lock helper!\n")); - /* it'll pick this up when it tries to use us */ - exit(255); - default: - close(lock_stdin_pipe[0]); - close(lock_stdout_pipe[1]); - - /* so the child knows when we vanish */ - fcntl(lock_stdin_pipe[1], F_SETFD, FD_CLOEXEC); - fcntl(lock_stdout_pipe[0], F_SETFD, FD_CLOEXEC); - } - - return 0; -} - -int camel_lock_helper_lock(const char *path, CamelException *ex) -{ - struct _CamelLockHelperMsg *msg; - int len = strlen(path); - int res = -1; - int retry = 3; - - LOCK(); - - if (lock_helper_pid == -1) { - if (camel_lock_helper_init(ex) == -1) { - UNLOCK(); - return -1; - } - } - - msg = alloca(len + sizeof(*msg)); -again: - msg->magic = CAMEL_LOCK_HELPER_MAGIC; - msg->seq = lock_sequence; - msg->id = CAMEL_LOCK_HELPER_LOCK; - msg->data = len; - memcpy(msg+1, path, len); - - write_n(lock_stdin_pipe[1], msg, len+sizeof(*msg)); - - do { - /* should also have a timeout here? cancellation? */ - len = read_n(lock_stdout_pipe[0], msg, sizeof(*msg)); - if (len == 0) { - /* child quit, do we try ressurect it? */ - res = CAMEL_LOCK_HELPER_STATUS_PROTOCOL; - /* if the child exited, this should get it, waidpid returns 0 if the child hasn't */ - if (waitpid(lock_helper_pid, NULL, WNOHANG) > 0) { - lock_helper_pid = -1; - close(lock_stdout_pipe[0]); - close(lock_stdin_pipe[1]); - lock_stdout_pipe[0] = -1; - lock_stdin_pipe[1] = -1; - } - goto fail; - } - - if (msg->magic != CAMEL_LOCK_HELPER_RETURN_MAGIC - || msg->seq > lock_sequence) { - res = CAMEL_LOCK_HELPER_STATUS_PROTOCOL; - d(printf("lock child protocol error\n")); - camel_exception_setv(ex, CAMEL_EXCEPTION_SYSTEM, - _("Could not lock '%s': protocol error with lock-helper"), path); - goto fail; - } - } while (msg->seq < lock_sequence); - - if (msg->seq == lock_sequence) { - switch(msg->id) { - case CAMEL_LOCK_HELPER_STATUS_OK: - d(printf("lock child locked ok, id is %d\n", msg->data)); - res = msg->data; - break; - default: - camel_exception_setv(ex, CAMEL_EXCEPTION_SYSTEM, - _("Could not lock '%s'"), path); - d(printf("locking failed ! status = %d\n", msg->id)); - break; - } - } else if (retry > 0) { - d(printf("sequence failure, lost message? retry?\n")); - retry--; - goto again; - } else { - camel_exception_setv(ex, CAMEL_EXCEPTION_SYSTEM, - _("Could not lock '%s': protocol error with lock-helper"), path); - } - -fail: - lock_sequence++; - - UNLOCK(); - - return res; -} - -int camel_lock_helper_unlock(int lockid) -{ - struct _CamelLockHelperMsg *msg; - int res = -1; - int retry = 3; - int len; - - d(printf("unlocking lock id %d\n", lockid)); - - LOCK(); - - /* impossible to unlock if we haven't locked yet */ - if (lock_helper_pid == -1) { - UNLOCK(); - return -1; - } - - msg = alloca(sizeof(*msg)); -again: - msg->magic = CAMEL_LOCK_HELPER_MAGIC; - msg->seq = lock_sequence; - msg->id = CAMEL_LOCK_HELPER_UNLOCK; - msg->data = lockid; - - write_n(lock_stdin_pipe[1], msg, sizeof(*msg)); - - do { - /* should also have a timeout here? cancellation? */ - len = read_n(lock_stdout_pipe[0], msg, sizeof(*msg)); - if (len == 0) { - /* child quit, do we try ressurect it? */ - res = CAMEL_LOCK_HELPER_STATUS_PROTOCOL; - if (waitpid(lock_helper_pid, NULL, WNOHANG) > 0) { - lock_helper_pid = -1; - close(lock_stdout_pipe[0]); - close(lock_stdin_pipe[1]); - lock_stdout_pipe[0] = -1; - lock_stdin_pipe[1] = -1; - } - goto fail; - } - - if (msg->magic != CAMEL_LOCK_HELPER_RETURN_MAGIC - || msg->seq > lock_sequence) { - goto fail; - } - } while (msg->seq < lock_sequence); - - if (msg->seq == lock_sequence) { - switch(msg->id) { - case CAMEL_LOCK_HELPER_STATUS_OK: - d(printf("lock child unlocked ok\n")); - res = 0; - break; - default: - d(printf("locking failed ! \n")); - break; - } - } else if (retry > 0) { - d(printf("sequence failure, lost message? retry?\n")); - lock_sequence++; - retry--; - goto again; - } - -fail: - lock_sequence++; - - UNLOCK(); - - return res; -} - -#if 0 -int main(int argc, char **argv) -{ - int id1, id2; - - d(printf("locking started\n")); - camel_lock_helper_init(); - - id1 = camel_lock_helper_lock("1 path 1"); - if (id1 != -1) { - d(printf("lock ok, unlock\n")); - camel_lock_helper_unlock(id1); - } - - id1 = camel_lock_helper_lock("2 path 1"); - id2 = camel_lock_helper_lock("2 path 2"); - camel_lock_helper_unlock(id2); - camel_lock_helper_unlock(id1); - - id1 = camel_lock_helper_lock("3 path 1"); - id2 = camel_lock_helper_lock("3 path 2"); - camel_lock_helper_unlock(id1); -} -#endif |