On 08/28/2012 11:14 PM, Peter Hutterer wrote:
uinput can be too slow, leaving us with GuessDeviceNode() failing and an
empty device string. Use inotify to tell us when a /dev/input/event device
appeared and then continue. However, even when inotify tells us the device
is there, the EVIOCGNAME may still fail on the device, so we need to keep
the backup GuessDeviceNode() in place.
This leaves us with a race condition - if a different device pops up while
we're waiting, then we may still not get the device name. Chance of that
happening is tiny.
Signed-off-by: Peter Hutterer <[email protected]>
---
src/device.cpp | 59 +++++++++++++++++++++++++++++++++++++-
test/.gitignore | 1 +
test/Makefile.am | 10 +++++--
test/PIXART-USB-OPTICAL-MOUSE.desc | 41 ++++++++++++++++++++++++++
test/device-test.cpp | 33 +++++++++++++++++++++
5 files changed, 141 insertions(+), 3 deletions(-)
create mode 100644 test/PIXART-USB-OPTICAL-MOUSE.desc
create mode 100644 test/device-test.cpp
diff --git a/src/device.cpp b/src/device.cpp
index 232d3ae..ea98d17 100644
--- a/src/device.cpp
+++ b/src/device.cpp
@@ -31,6 +31,8 @@
#include <linux/input.h>
#include <fcntl.h>
#include <dirent.h>
+#include <sys/inotify.h>
+#include <poll.h>
#include <stdexcept>
@@ -110,6 +112,48 @@ void xorg::testing::evemu::Device::GuessDeviceNode(time_t
ctime) {
free(event_devices);
}
+static std::string wait_for_inotify(int fd)
+{
+ std::string devnode;
+ bool found = false;
+ struct pollfd pfd;
+
+ pfd.fd = fd;
+ pfd.events = POLLIN;
+
+ char buf[1024];
+ size_t bufidx = 0;
+
+ while (!found && poll(&pfd, 1, 2000) > 0) {
+ ssize_t r;
+
+ r = read(fd, buf + bufidx, sizeof(buf) - bufidx);
+ if (r == -1 && errno != EAGAIN) {
+ std::cerr << "inotify read failed with: " << std::string(strerror(errno))
<< std::endl;
+ break;
+ }
+
+ bufidx += r;
+
+ struct inotify_event *e = reinterpret_cast<struct inotify_event*>(buf);
+
+ while (bufidx > sizeof(*e) && bufidx >= sizeof(*e) + e->len) {
+ if (strncmp(e->name, "event", 5) == 0) {
+ devnode = DEV_INPUT_DIR + std::string(e->name);
+ found = true;
+ break;
+ }
+
+ /* this packet didn't contain what we're looking for */
+ int len = sizeof(*e) + e->len;
+ memmove(buf, buf + len, bufidx - len);
+ bufidx -= len;
+ }
+ }
+
+ return devnode;
+}
+
xorg::testing::evemu::Device::Device(const std::string& path)
: d_(new Private) {
static const char UINPUT_NODE[] = "/dev/uinput";
@@ -132,6 +176,14 @@ xorg::testing::evemu::Device::Device(const std::string&
path)
fclose(fp);
+ int ifd = inotify_init1(IN_NONBLOCK);
+ if (ifd == -1 || inotify_add_watch(ifd, DEV_INPUT_DIR, IN_CREATE) == -1) {
+ std::cerr << "Failed to create inotify watch" << std::endl;
+ if (ifd != -1)
+ close(ifd);
+ ifd = -1;
+ }
+
d_->fd = open(UINPUT_NODE, O_WRONLY);
if (d_->fd < 0) {
evemu_delete(d_->device);
@@ -145,7 +197,12 @@ xorg::testing::evemu::Device::Device(const std::string&
path)
throw std::runtime_error("Failed to create evemu device");
}
- GuessDeviceNode(d_->ctime);
+ if (ifd != -1) {
+ std::string devnode = wait_for_inotify(ifd);
+ if (event_is_device(devnode, evemu_get_name(d_->device), d_->ctime))
+ d_->device_node = devnode;
+ close(ifd);
We could instead loop around here waiting until the correct device is
seen, potentially with a timeout? I'm guessing you've already thought of
that, so I'm interested to hear your thoughts.
+ } /* else guess node when we'll need it */
}
void xorg::testing::evemu::Device::Play(const std::string& path) const {
diff --git a/test/.gitignore b/test/.gitignore
index f1d10c3..51494ab 100644
--- a/test/.gitignore
+++ b/test/.gitignore
@@ -1,2 +1,3 @@
process-test
xserver-test
+device-test
diff --git a/test/Makefile.am b/test/Makefile.am
index ed6416a..4f847b3 100644
--- a/test/Makefile.am
+++ b/test/Makefile.am
@@ -25,10 +25,12 @@
# SOFTWARE.
#
-noinst_PROGRAMS = process-test xserver-test
+noinst_PROGRAMS = process-test xserver-test device-test
+noinst_DATA = PIXART-USB-OPTICAL-MOUSE.desc
AM_CPPFLAGS = $(GTEST_CPPFLAGS)
-AM_CXXFLAGS = $(BASE_CXXFLAGS)
+AM_CXXFLAGS = $(BASE_CXXFLAGS) \
+ -DTEST_ROOT_DIR=\"$(abs_top_srcdir)/test/\"
tests_libraries = \
libgtest.a \
@@ -45,6 +47,10 @@ xserver_test_SOURCES = xserver-test.cpp
xserver_test_CPPFLAGS = $(AM_CPPFLAGS) -I$(top_srcdir)/include
xserver_test_LDADD = $(tests_libraries)
+device_test_SOURCES = device-test.cpp
+device_test_CPPFLAGS = $(AM_CPPFLAGS) -I$(top_srcdir)/include
+device_test_LDADD = $(tests_libraries)
+
check_LIBRARIES = libgtest.a libxorg-gtest.a
# build googletest as static lib
diff --git a/test/PIXART-USB-OPTICAL-MOUSE.desc
b/test/PIXART-USB-OPTICAL-MOUSE.desc
new file mode 100644
index 0000000..787c837
--- /dev/null
+++ b/test/PIXART-USB-OPTICAL-MOUSE.desc
@@ -0,0 +1,41 @@
+# standard USB mouse
+# Input driver version is 1.0.1
+# Input device ID: bus 0x3 vendor 0x93a product 0x2510 version 0x110
+# Input device name: "PIXART USB OPTICAL MOUSE"
+# Supported events:
+# Event type 0 (EV_SYN)
+# Event type 1 (EV_KEY)
+# Event code 272 (BTN_LEFT)
+# Event code 273 (BTN_RIGHT)
+# Event code 274 (BTN_MIDDLE)
+# Event type 2 (EV_REL)
+# Event code 0 (REL_X)
+# Event code 1 (REL_Y)
+# Event code 8 (REL_WHEEL)
+# Event type 4 (EV_MSC)
+# Event code 4 (MSC_SCAN)
+#
+N: PIXART USB OPTICAL MOUSE
+I: 0003 093a 2510 0110
+P: 00 00 00 00 00 00 00 00
+B: 00 17 00 00 00 00 00 00 00
+B: 01 00 00 00 00 00 00 00 00
+B: 01 00 00 00 00 00 00 00 00
+B: 01 00 00 00 00 00 00 00 00
+B: 01 00 00 00 00 00 00 00 00
+B: 01 00 00 07 00 00 00 00 00
+B: 01 00 00 00 00 00 00 00 00
+B: 01 00 00 00 00 00 00 00 00
+B: 01 00 00 00 00 00 00 00 00
+B: 01 00 00 00 00 00 00 00 00
+B: 01 00 00 00 00 00 00 00 00
+B: 01 00 00 00 00 00 00 00 00
+B: 01 00 00 00 00 00 00 00 00
+B: 02 03 01 00 00 00 00 00 00
+B: 03 00 00 00 00 00 00 00 00
+B: 04 10 00 00 00 00 00 00 00
+B: 05 00 00 00 00 00 00 00 00
+B: 11 00 00 00 00 00 00 00 00
+B: 12 00 00 00 00 00 00 00 00
+B: 15 00 00 00 00 00 00 00 00
+B: 15 00 00 00 00 00 00 00 00
diff --git a/test/device-test.cpp b/test/device-test.cpp
new file mode 100644
index 0000000..56ec676
--- /dev/null
+++ b/test/device-test.cpp
@@ -0,0 +1,33 @@
+#include <gtest/gtest.h>
+#include <xorg/gtest/xorg-gtest.h>
+
+#ifdef HAVE_EVEMU
+
+using namespace xorg::testing;
+
+TEST(DEVICE, DeviceNode)
+{
+ SCOPED_TRACE("TESTCASE: Device node is /dev/input/eventX");
+
+ xorg::testing::evemu::Device d(TEST_ROOT_DIR
"PIXART-USB-OPTICAL-MOUSE.desc");
+
+ ASSERT_EQ(d.GetDeviceNode().compare(0, 16, "/dev/input/event"), 0);
+}
+
+TEST(Device, InotifyWait)
+{
+ SCOPED_TRACE("TESTCASE: device node can never be empty.\n"
+ "This test may show false positives");
+
+ xorg::testing::evemu::Device d(TEST_ROOT_DIR
"PIXART-USB-OPTICAL-MOUSE.desc");
+
+ ASSERT_FALSE(d.GetDeviceNode().empty());
+}
+
+#endif
+
+int main(int argc, char *argv[]) {
+ testing::InitGoogleTest(&argc, argv);
+ return RUN_ALL_TESTS();
+}
+
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