pollfds mutex protection

diff --git a/libusb/io.c b/libusb/io.c
index 4b37175..8ea9a4b 100644 (file)
--- a/libusb/io.c
+++ b/libusb/io.c
@@ -42,6 +42,7 @@ static pthread_mutex_t flying_transfers_lock = PTHREAD_MUTEX_INITIALIZER;
 
 /* list of poll fd's */
 static struct list_head pollfds;
+static pthread_mutex_t pollfds_lock = PTHREAD_MUTEX_INITIALIZER;
 
 /* user callbacks for pollfd changes */
 static libusb_pollfd_added_cb fd_added_cb = NULL;
@@ -944,6 +945,7 @@ static int handle_events(struct timeval *tv)
 
        FD_ZERO(&readfds);
        FD_ZERO(&writefds);
+       pthread_mutex_lock(&pollfds_lock);
        list_for_each_entry(ipollfd, &pollfds, list) {
                struct libusb_pollfd *pollfd = &ipollfd->pollfd;
                int fd = pollfd->fd;
@@ -958,6 +960,7 @@ static int handle_events(struct timeval *tv)
                if (fd > maxfd)
                        maxfd = fd;
        }
+       pthread_mutex_unlock(&pollfds_lock);
 
        if (have_readfds)
                _readfds = &readfds;
@@ -1134,7 +1137,9 @@ int usbi_add_pollfd(int fd, short events)
        usbi_dbg("add fd %d events %d", fd, events);
        ipollfd->pollfd.fd = fd;
        ipollfd->pollfd.events = events;
+       pthread_mutex_lock(&pollfds_lock);
        list_add(&ipollfd->list, &pollfds);
+       pthread_mutex_unlock(&pollfds_lock);
 
        if (fd_added_cb)
                fd_added_cb(fd, events);
@@ -1147,6 +1152,7 @@ void usbi_remove_pollfd(int fd)
        int found = 0;
 
        usbi_dbg("remove fd %d", fd);
+       pthread_mutex_lock(&pollfds_lock);
        list_for_each_entry(ipollfd, &pollfds, list)
                if (ipollfd->pollfd.fd == fd) {
                        found = 1;
@@ -1155,10 +1161,12 @@ void usbi_remove_pollfd(int fd)
 
        if (!found) {
                usbi_err("couldn't find fd %d to remove", fd);
+               pthread_mutex_unlock(&pollfds_lock);
                return;
        }
 
        list_del(&ipollfd->list);
+       pthread_mutex_unlock(&pollfds_lock);
        free(ipollfd);
        if (fd_removed_cb)
                fd_removed_cb(fd);
@@ -1176,22 +1184,25 @@ void usbi_remove_pollfd(int fd)
  */
 API_EXPORTED const struct libusb_pollfd **libusb_get_pollfds(void)
 {
-       struct libusb_pollfd **ret;
+       struct libusb_pollfd **ret = NULL;
        struct usbi_pollfd *ipollfd;
        size_t i = 0;
        size_t cnt = 0;
 
+       pthread_mutex_lock(&pollfds_lock);
        list_for_each_entry(ipollfd, &pollfds, list)
                cnt++;
 
        ret = calloc(cnt + 1, sizeof(struct libusb_pollfd *));
        if (!ret)
-               return NULL;
+               goto out;
 
        list_for_each_entry(ipollfd, &pollfds, list)
                ret[i++] = (struct libusb_pollfd *) ipollfd;
        ret[cnt] = NULL;
 
+out:
+       pthread_mutex_unlock(&pollfds_lock);
        return (const struct libusb_pollfd **) ret;
 }