[PATCH libevdev 3/3] Add per-device log handlers
Peter Hutterer
peter.hutterer at who-t.net
Sun May 18 21:01:51 PDT 2014
The global log handler isn't a good choice for a low-level library. In the
caser of the X server, both evdev and synaptics are now using the libevdev but
are loaded from the same server process. Thus, there's only one log handler,
but evdev and synaptics don't talk to each other (a bit childish, I know).
Add a per-device log handler that overrides the global log handler, and fall
back to the global log handler if no device log handler is set. The log
macros take care of that automatically, especially as we can't do per-device
log handlers for the uinput code.
This also makes libevdev_new_from_fd() a bit less useful since we can't set
the log handler beforehand.
Signed-off-by: Peter Hutterer <peter.hutterer at who-t.net>
---
Not really happy with this, but I'm yet to find a better solution. Comments
appreciated.
libevdev/libevdev-int.h | 31 +++++++--------
libevdev/libevdev-uinput.c | 6 +--
libevdev/libevdev.c | 85 +++++++++++++++++++++++++++++++----------
libevdev/libevdev.h | 95 +++++++++++++++++++++++++++++++++++++++++++---
libevdev/libevdev.sym | 8 ++++
test/test-libevdev-init.c | 74 ++++++++++++++++++++++++++++++++++++
6 files changed, 255 insertions(+), 44 deletions(-)
diff --git a/libevdev/libevdev-int.h b/libevdev/libevdev-int.h
index f587e76..5b6d7de 100644
--- a/libevdev/libevdev-int.h
+++ b/libevdev/libevdev-int.h
@@ -106,31 +106,32 @@ struct libevdev {
unsigned long *tracking_id_changes;
size_t tracking_id_changes_sz; /* in bytes */
} mt_sync;
-};
-struct logdata {
- enum libevdev_log_priority priority; /** minimum logging priority */
- libevdev_log_func_t handler; /** handler function */
- void *userdata; /** user-defined data pointer */
+ struct {
+ enum libevdev_log_priority priority; /** minimum logging priority */
+ libevdev_device_log_func_t handler; /** handler function */
+ void *userdata; /** user-defined data pointer */
+ } log;
};
-extern struct logdata log_data;
-#define log_msg_cond(priority, ...) \
+#define log_msg_cond(dev, priority, ...) \
do { \
- if (libevdev_get_log_priority() >= priority) \
- log_msg(priority, log_data.userdata, __FILE__, __LINE__, __func__, __VA_ARGS__); \
+ if (log_priority(dev) >= priority) \
+ log_msg(dev, priority, __FILE__, __LINE__, __func__, __VA_ARGS__); \
} while(0)
-#define log_error(...) log_msg_cond(LIBEVDEV_LOG_ERROR, __VA_ARGS__)
-#define log_info(...) log_msg_cond(LIBEVDEV_LOG_INFO, __VA_ARGS__)
-#define log_dbg(...) log_msg_cond(LIBEVDEV_LOG_DEBUG, __VA_ARGS__)
-#define log_bug(...) log_msg_cond(LIBEVDEV_LOG_ERROR, "BUG: "__VA_ARGS__)
+#define log_error(dev, ...) log_msg_cond(dev, LIBEVDEV_LOG_ERROR, __VA_ARGS__)
+#define log_info(dev, ...) log_msg_cond(dev, LIBEVDEV_LOG_INFO, __VA_ARGS__)
+#define log_dbg(dev, ...) log_msg_cond(dev, LIBEVDEV_LOG_DEBUG, __VA_ARGS__)
+#define log_bug(dev, ...) log_msg_cond(dev, LIBEVDEV_LOG_ERROR, "BUG: "__VA_ARGS__)
extern void
-log_msg(enum libevdev_log_priority priority,
- void *data,
+log_msg(const struct libevdev *dev,
+ enum libevdev_log_priority priority,
const char *file, int line, const char *func,
const char *format, ...) LIBEVDEV_ATTRIBUTE_PRINTF(6, 7);
+extern enum libevdev_log_priority
+log_priority(const struct libevdev *dev);
/**
* @return a pointer to the next element in the queue, or NULL if the queue
diff --git a/libevdev/libevdev-uinput.c b/libevdev/libevdev-uinput.c
index f176a00..e0ae31e 100644
--- a/libevdev/libevdev-uinput.c
+++ b/libevdev/libevdev-uinput.c
@@ -236,7 +236,7 @@ fetch_syspath_and_devnode(struct libevdev_uinput *uinput_dev)
if (strcmp(buf, uinput_dev->name) == 0) {
if (uinput_dev->syspath) {
/* FIXME: could descend into bit comparison here */
- log_info("multiple identical devices found. syspath is unreliable\n");
+ log_info(NULL, "multiple identical devices found. syspath is unreliable\n");
break;
} else {
strcpy(buf, SYS_INPUT_DIR);
@@ -274,7 +274,7 @@ libevdev_uinput_create_from_device(const struct libevdev *dev, int fd, struct li
new_device->fd_is_managed = 1;
} else if (fd < 0) {
- log_bug("Invalid fd %d\n", fd);
+ log_bug(NULL, "Invalid fd %d\n", fd);
errno = EBADF;
goto error;
}
@@ -317,7 +317,7 @@ libevdev_uinput_create_from_device(const struct libevdev *dev, int fd, struct li
new_device->fd = fd;
if (fetch_syspath_and_devnode(new_device) == -1) {
- log_error("unable to fetch syspath or device node.\n");
+ log_error(NULL, "unable to fetch syspath or device node.\n");
errno = ENODEV;
goto error;
}
diff --git a/libevdev/libevdev.c b/libevdev/libevdev.c
index a316831..1e472a5 100644
--- a/libevdev/libevdev.c
+++ b/libevdev/libevdev.c
@@ -36,6 +36,12 @@
#define MAXEVENTS 64
+struct logdata {
+ enum libevdev_log_priority priority; /** minimum logging priority */
+ libevdev_log_func_t handler; /** handler function */
+ void *userdata; /** user-defined data pointer */
+};
+
enum event_filter_status {
EVENT_FILTER_NONE, /**< Event untouched by filters */
EVENT_FILTER_MODIFIED, /**< Event was modified */
@@ -48,11 +54,11 @@ static inline int*
slot_value(const struct libevdev *dev, int slot, int axis)
{
if (unlikely(slot > dev->num_slots)) {
- log_bug("Slot %d exceeds number of slots (%d)\n", slot, dev->num_slots);
+ log_bug(dev, "Slot %d exceeds number of slots (%d)\n", slot, dev->num_slots);
slot = 0;
}
if (unlikely(axis < ABS_MT_MIN || axis > ABS_MT_MAX)) {
- log_bug("MT axis %d is outside the valid range [%d,%d]\n",
+ log_bug(dev, "MT axis %d is outside the valid range [%d,%d]\n",
axis, ABS_MT_MIN, ABS_MT_MAX);
axis = ABS_MT_MIN;
}
@@ -136,24 +142,34 @@ struct logdata log_data = {
};
void
-log_msg(enum libevdev_log_priority priority,
- void *data,
+log_msg(const struct libevdev *dev,
+ enum libevdev_log_priority priority,
const char *file, int line, const char *func,
const char *format, ...)
{
va_list args;
- if (!log_data.handler || priority > log_data.priority)
+ if (dev && dev->log.handler) {
+ if (priority > dev->log.priority)
+ return;
+ } else if (!log_data.handler || priority > log_data.priority)
return;
+
va_start(args, format);
- log_data.handler(priority, data, file, line, func, format, args);
+ if (dev && dev->log.handler)
+ dev->log.handler(dev, priority, dev->log.userdata, file, line, func, format, args);
+ else
+ log_data.handler(priority, log_data.userdata, file, line, func, format, args);
va_end(args);
}
static void
libevdev_reset(struct libevdev *dev)
{
+ enum libevdev_log_priority pri = dev->log.priority;
+ libevdev_device_log_func_t handler = dev->log.handler;
+
free(dev->name);
free(dev->phys);
free(dev->uniq);
@@ -168,6 +184,8 @@ libevdev_reset(struct libevdev *dev)
dev->current_slot = -1;
dev->grabbed = LIBEVDEV_UNGRAB;
dev->sync_state = SYNC_NONE;
+ dev->log.priority = pri;
+ dev->log.handler = handler;
libevdev_enable_event_type(dev, EV_SYN);
}
@@ -235,11 +253,36 @@ libevdev_get_log_priority(void)
return log_data.priority;
}
+LIBEVDEV_EXPORT void
+libevdev_set_device_log_function(struct libevdev *dev,
+ libevdev_device_log_func_t logfunc,
+ enum libevdev_log_priority priority,
+ void *data)
+{
+ if (!dev) {
+ log_bug(NULL, "device must not be NULL\n");
+ return;
+ }
+
+ dev->log.priority = priority;
+ dev->log.handler = logfunc;
+ dev->log.userdata = data;
+}
+
+enum libevdev_log_priority
+log_priority(const struct libevdev *dev)
+{
+ if (dev && dev->log.handler)
+ return dev->log.priority;
+ else
+ return libevdev_get_log_priority();
+}
+
LIBEVDEV_EXPORT int
libevdev_change_fd(struct libevdev *dev, int fd)
{
if (!dev->initialized) {
- log_bug("device not initialized. call libevdev_set_fd() first\n");
+ log_bug(dev, "device not initialized. call libevdev_set_fd() first\n");
return -1;
}
dev->fd = fd;
@@ -254,7 +297,7 @@ libevdev_set_fd(struct libevdev* dev, int fd)
char buf[256];
if (dev->initialized) {
- log_bug("device already initialized.\n");
+ log_bug(dev, "device already initialized.\n");
return -EBADF;
} else if (fd < 0)
return -EBADF;
@@ -743,7 +786,7 @@ drain_events(struct libevdev *dev)
return;
if (rc < 0) {
- log_error("Failed to drain events before sync.\n");
+ log_error(dev, "Failed to drain events before sync.\n");
return;
}
@@ -758,7 +801,7 @@ drain_events(struct libevdev *dev)
we can drain them.
*/
if (iterations >= max_iterations)
- log_info("Unable to drain events, buffer size mismatch.\n");
+ log_info(dev, "Unable to drain events, buffer size mismatch.\n");
}
static int
@@ -913,7 +956,7 @@ sanitize_event(const struct libevdev *dev,
if (unlikely(dev->num_slots > -1 &&
libevdev_event_is_code(ev, EV_ABS, ABS_MT_SLOT) &&
(ev->value < 0 || ev->value >= dev->num_slots))) {
- log_bug("Device \"%s\" received an invalid slot index %d."
+ log_bug(dev, "Device \"%s\" received an invalid slot index %d."
"Capping to announced max slot number %d.\n",
dev->name, ev->value, dev->num_slots - 1);
ev->value = dev->num_slots - 1;
@@ -930,7 +973,7 @@ sanitize_event(const struct libevdev *dev,
*slot_value(dev, dev->current_slot, ABS_MT_TRACKING_ID) == -1) ||
(ev->value != -1 &&
*slot_value(dev, dev->current_slot, ABS_MT_TRACKING_ID) != -1)))) {
- log_bug("Device \"%s\" received a double tracking ID %d in slot %d.\n",
+ log_bug(dev, "Device \"%s\" received a double tracking ID %d in slot %d.\n",
dev->name, ev->value, dev->current_slot);
return EVENT_FILTER_DISCARD;
}
@@ -945,13 +988,13 @@ libevdev_next_event(struct libevdev *dev, unsigned int flags, struct input_event
enum event_filter_status filter_status;
if (!dev->initialized) {
- log_bug("device not initialized. call libevdev_set_fd() first\n");
+ log_bug(dev, "device not initialized. call libevdev_set_fd() first\n");
return -EBADF;
} else if (dev->fd < 0)
return -EBADF;
if (!(flags & (LIBEVDEV_READ_FLAG_NORMAL|LIBEVDEV_READ_FLAG_SYNC|LIBEVDEV_READ_FLAG_FORCE_SYNC))) {
- log_bug("invalid flags %#x\n.\n", flags);
+ log_bug(dev, "invalid flags %#x\n.\n", flags);
return -EINVAL;
}
@@ -1029,7 +1072,7 @@ libevdev_next_event(struct libevdev *dev, unsigned int flags, struct input_event
if (queue_peek(dev, 0, &next) == 0 &&
next.type == EV_SYN && next.code == SYN_DROPPED)
- log_info("SYN_DROPPED received after finished "
+ log_info(dev, "SYN_DROPPED received after finished "
"sync - you're not keeping up\n");
}
}
@@ -1045,7 +1088,7 @@ libevdev_has_event_pending(struct libevdev *dev)
int rc;
if (!dev->initialized) {
- log_bug("device not initialized. call libevdev_set_fd() first\n");
+ log_bug(dev, "device not initialized. call libevdev_set_fd() first\n");
return -EBADF;
} else if (dev->fd < 0)
return -EBADF;
@@ -1451,7 +1494,7 @@ libevdev_kernel_set_abs_info(struct libevdev *dev, unsigned int code, const stru
int rc;
if (!dev->initialized) {
- log_bug("device not initialized. call libevdev_set_fd() first\n");
+ log_bug(dev, "device not initialized. call libevdev_set_fd() first\n");
return -EBADF;
} else if (dev->fd < 0)
return -EBADF;
@@ -1474,13 +1517,13 @@ libevdev_grab(struct libevdev *dev, enum libevdev_grab_mode grab)
int rc = 0;
if (!dev->initialized) {
- log_bug("device not initialized. call libevdev_set_fd() first\n");
+ log_bug(dev, "device not initialized. call libevdev_set_fd() first\n");
return -EBADF;
} else if (dev->fd < 0)
return -EBADF;
if (grab != LIBEVDEV_GRAB && grab != LIBEVDEV_UNGRAB) {
- log_bug("invalid grab parameter %#x\n", grab);
+ log_bug(dev, "invalid grab parameter %#x\n", grab);
return -EINVAL;
}
@@ -1585,7 +1628,7 @@ libevdev_kernel_set_led_values(struct libevdev *dev, ...)
size_t nleds = 0;
if (!dev->initialized) {
- log_bug("device not initialized. call libevdev_set_fd() first\n");
+ log_bug(dev, "device not initialized. call libevdev_set_fd() first\n");
return -EBADF;
} else if (dev->fd < 0)
return -EBADF;
@@ -1641,7 +1684,7 @@ LIBEVDEV_EXPORT int
libevdev_set_clock_id(struct libevdev *dev, int clockid)
{
if (!dev->initialized) {
- log_bug("device not initialized. call libevdev_set_fd() first\n");
+ log_bug(dev, "device not initialized. call libevdev_set_fd() first\n");
return -EBADF;
} else if (dev->fd < 0)
return -EBADF;
diff --git a/libevdev/libevdev.h b/libevdev/libevdev.h
index 2c46102..884303f 100644
--- a/libevdev/libevdev.h
+++ b/libevdev/libevdev.h
@@ -619,6 +619,29 @@ extern "C" {
*/
/**
+ * @defgroup logging Logging library logging facilities
+ *
+ * libevdev provides two methods of logging library-internal messages. The
+ * old method is to provide a global log handler in
+ * libevdev_set_log_function(). The new method is to provide a per-context
+ * log handler in libevdev_set_device_log_function(). Developers are encouraged
+ * to use the per-context logging facilities over the global log handler as
+ * it provides access to the libevdev instance that caused a message, and is
+ * more flexible when libevdev is used from within a shared library.
+ *
+ * If a caller sets both the global log handler and a per-context log
+ * handler, each device with a per-context log handler will only invoke that
+ * log handler.
+ *
+ * @note To set a context-specific log handler, a context is needed.
+ * Thus developers are discouraged from using libevdev_new_from_fd() as
+ * important messages from the device initialization process may get lost.
+ *
+ * @note A context-specific handler cannot be used for libevdev's uinput
+ * devices. @ref uinput must use the global log handler.
+ */
+
+/**
* @defgroup bits Querying device capabilities
*
* Abstraction functions to handle device capabilities, specificially
@@ -768,7 +791,7 @@ int libevdev_new_from_fd(int fd, struct libevdev **dev);
void libevdev_free(struct libevdev *dev);
/**
- * @ingroup init
+ * @ingroup logging
*/
enum libevdev_log_priority {
LIBEVDEV_LOG_ERROR = 10, /**< critical errors and application bugs */
@@ -777,7 +800,7 @@ enum libevdev_log_priority {
};
/**
- * @ingroup init
+ * @ingroup logging
*
* Logging function called by library-internal logging.
* This function is expected to treat its input like printf would.
@@ -800,21 +823,27 @@ typedef void (*libevdev_log_func_t)(enum libevdev_log_priority priority,
LIBEVDEV_ATTRIBUTE_PRINTF(6, 0);
/**
- * @ingroup init
+ * @ingroup logging
*
* Set a printf-style logging handler for library-internal logging. The default
* logging function is to stdout.
*
+ * @note The global log handler is only called if no context-specific log
+ * handler has been set with libevdev_set_device_log_function().
+ *
* @param logfunc The logging function for this device. If NULL, the current
* logging function is unset and no logging is performed.
* @param data User-specific data passed to the log handler.
*
* @note This function may be called before libevdev_set_fd().
+ *
+ * @deprecated Use per-context logging instead, see
+ * libevdev_set_device_log_function().
*/
void libevdev_set_log_function(libevdev_log_func_t logfunc, void *data);
/**
- * @ingroup init
+ * @ingroup logging
*
* Define the minimum level to be printed to the log handler.
* Messages higher than this level are printed, others are discarded. This
@@ -822,20 +851,76 @@ void libevdev_set_log_function(libevdev_log_func_t logfunc, void *data);
*
* @param priority Minimum priority to be printed to the log.
*
+ * @deprecated Use per-context logging instead, see
+ * libevdev_set_device_log_function().
*/
void libevdev_set_log_priority(enum libevdev_log_priority priority);
/**
- * @ingroup init
+ * @ingroup logging
*
* Return the current log priority level. Messages higher than this level
* are printed, others are discarded. This is a global setting.
*
* @return the current log level
+ *
+ * @deprecated Use per-context logging instead, see
+ * libevdev_set_device_log_function().
*/
enum libevdev_log_priority libevdev_get_log_priority(void);
/**
+ * @ingroup logging
+ *
+ * Logging function called by library-internal logging for a specific
+ * libevdev context. This function is expected to treat its input like
+ * printf would.
+ *
+ * @param dev The evdev device
+ * @param priority Log priority of this message
+ * @param data User-supplied data pointer (see libevdev_set_log_function())
+ * @param file libevdev source code file generating this message
+ * @param line libevdev source code line generating this message
+ * @param func libevdev source code function generating this message
+ * @param format printf-style format string
+ * @param args List of arguments
+ *
+ * @see libevdev_set_log_function
+ */
+typedef void (*libevdev_device_log_func_t)(const struct libevdev *dev,
+ enum libevdev_log_priority priority,
+ void *data,
+ const char *file, int line,
+ const char *func,
+ const char *format, va_list args)
+ LIBEVDEV_ATTRIBUTE_PRINTF(7, 0);
+
+/**
+ * @ingroup logging
+ *
+ * Set a printf-style logging handler for library-internal logging for this
+ * device context. The default logging function is NULL, i.e. the global log
+ * handler is invoked. If a context-specific log handler is set, the global
+ * log handler is not invoked for this device.
+ *
+ * @note This log function applies for this device context only, even if
+ * another context exists for the same fd.
+ *
+ * @param dev The evdev device
+ * @param logfunc The logging function for this device. If NULL, the current
+ * logging function is unset and logging falls back to the global log
+ * handler, if any.
+ * @param priority Minimum priority to be printed to the log.
+ * @param data User-specific data passed to the log handler.
+ *
+ * @note This function may be called before libevdev_set_fd().
+ */
+void libevdev_set_device_log_function(struct libevdev *dev,
+ libevdev_device_log_func_t logfunc,
+ enum libevdev_log_priority priority,
+ void *data);
+
+/**
* @ingroup init
*/
enum libevdev_grab_mode {
diff --git a/libevdev/libevdev.sym b/libevdev/libevdev.sym
index ef4f06b..228e555 100644
--- a/libevdev/libevdev.sym
+++ b/libevdev/libevdev.sym
@@ -102,3 +102,11 @@ global:
local:
*;
};
+
+LIBEVDEV_1_3 {
+global:
+ libevdev_set_device_log_function;
+
+local:
+ *;
+} LIBEVDEV_1;
diff --git a/test/test-libevdev-init.c b/test/test-libevdev-init.c
index 61fea4b..d45a319 100644
--- a/test/test-libevdev-init.c
+++ b/test/test-libevdev-init.c
@@ -271,6 +271,79 @@ START_TEST(test_log_data)
}
END_TEST
+struct libevdev *devlogdata;
+static int dev_log_fn_called = 0;
+static void devlogfunc(const struct libevdev *dev,
+ enum libevdev_log_priority priority,
+ void *data,
+ const char *file, int line, const char *func,
+ const char *f, va_list args)
+{
+ ck_assert(dev == data);
+ dev_log_fn_called++;
+}
+
+START_TEST(test_device_log_init)
+{
+ struct libevdev *dev = NULL;
+ enum libevdev_log_priority old;
+
+ old = libevdev_get_log_priority();
+ libevdev_set_log_priority(LIBEVDEV_LOG_DEBUG);
+ libevdev_set_log_function(logfunc, logdata);
+
+ /* error for NULL device */
+ libevdev_set_device_log_function(NULL, NULL,
+ LIBEVDEV_LOG_ERROR, NULL);
+ ck_assert_int_eq(log_fn_called, 1);
+
+ /* error for NULL device */
+ libevdev_set_device_log_function(NULL, devlogfunc,
+ LIBEVDEV_LOG_ERROR, NULL);
+ ck_assert_int_eq(log_fn_called, 2);
+
+ log_fn_called = 0;
+
+ dev = libevdev_new();
+ ck_assert(dev != NULL);
+
+ libevdev_set_device_log_function(dev, NULL,
+ LIBEVDEV_LOG_ERROR, NULL);
+
+ /* libevdev_next_event(dev, LIBEVDEV_READ_FLAG_NORMAL, NULL) should
+ trigger a log message. */
+
+ /* expect global handler triggered */
+ libevdev_next_event(dev, LIBEVDEV_READ_FLAG_NORMAL, NULL);
+ ck_assert_int_eq(log_fn_called, 1);
+ ck_assert_int_eq(dev_log_fn_called, 0);
+
+ /* expect device handler triggered */
+ libevdev_set_device_log_function(dev, devlogfunc,
+ LIBEVDEV_LOG_ERROR, dev);
+ libevdev_next_event(dev, LIBEVDEV_READ_FLAG_NORMAL, NULL);
+ ck_assert_int_eq(log_fn_called, 1);
+ ck_assert_int_eq(dev_log_fn_called, 1);
+
+ /* device handler set, but priority filters. don't expect any log
+ handler to be called.
+ we don't have any log msgs > ERROR at the moment, so test it by
+ setting an invalid priority. */
+ libevdev_set_device_log_function(dev, devlogfunc,
+ LIBEVDEV_LOG_ERROR - 1, dev);
+ libevdev_next_event(dev, LIBEVDEV_READ_FLAG_NORMAL, NULL);
+ ck_assert_int_eq(log_fn_called, 1);
+ ck_assert_int_eq(dev_log_fn_called, 1);
+
+ libevdev_free(dev);
+
+ log_fn_called = 0;
+ libevdev_set_log_priority(old);
+ libevdev_set_log_function(test_logfunc_abort_on_error, NULL);
+
+}
+END_TEST
+
START_TEST(test_device_init)
{
struct uinput_device* uidev;
@@ -477,6 +550,7 @@ libevdev_init_test(void)
tcase_add_test(tc, test_log_set_get_priority);
tcase_add_test(tc, test_log_default_priority);
tcase_add_test(tc, test_log_data);
+ tcase_add_test(tc, test_device_log_init);
suite_add_tcase(s, tc);
tc = tcase_create("device fd init");
--
1.9.0
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