From 856740a94ea585734beccf84086034d6418a1803 Mon Sep 17 00:00:00 2001
From: Luca Longinotti <l@longi.li>
Date: Fri, 19 Aug 2016 11:39:46 +0200
Subject: [PATCH] C11 Threads: add non-standard function to get the current
 thread name. DVS128/DAVIS: set better thread names for the data acquisition
 thread, as well as the libusb internal threads.

---
 src/c11threads_posix.h | 20 ++++++++++++++++++++
 src/davis_common.c     | 20 +++++++++++++++++++-
 src/davis_common.h     |  1 +
 src/dvs128.c           | 21 +++++++++++++++++++--
 src/dvs128.h           |  1 +
 5 files changed, 60 insertions(+), 3 deletions(-)

diff --git a/src/c11threads_posix.h b/src/c11threads_posix.h
index 99f24b61..6efb2ca2 100644
--- a/src/c11threads_posix.h
+++ b/src/c11threads_posix.h
@@ -362,6 +362,26 @@ static inline int thrd_set_name(const char *name) {
 #endif
 }
 
+static inline int thrd_get_name(char *name, size_t maxNameLength) {
+#if defined(OS_LINUX)
+	(void)(maxNameLength); // UNUSED FOR LINUX.
+
+	if (prctl(PR_GET_NAME, name) != 0) {
+		return (thrd_error);
+	}
+
+	return (thrd_success);
+#elif defined(OS_MACOSX)
+	if (pthread_getname_np(pthread_self(), name, maxNameLength) != 0) {
+		return (thrd_error);
+	}
+
+	return (thrd_success);
+#else
+	return (thrd_error);
+#endif
+}
+
 // NON STANDARD!
 static inline int thrd_set_priority(int priority) {
 #if defined(OS_LINUX)
diff --git a/src/davis_common.c b/src/davis_common.c
index 71638296..54f5dcb7 100644
--- a/src/davis_common.c
+++ b/src/davis_common.c
@@ -186,10 +186,25 @@ bool davisCommonOpen(davisHandle handle, uint16_t VID, uint16_t PID, uint8_t DID
 
 	atomic_thread_fence(memory_order_release);
 
+	// Set device thread name. Maximum length of 15 chars due to Linux limitations.
+	snprintf(state->deviceThreadName, 15 + 1, "%s ID-%" PRIu16, deviceName, deviceID);
+	state->deviceThreadName[15] = '\0';
+
 	// Search for device and open it.
 	// Initialize libusb using a separate context for each device.
 	// This is to correctly support one thread per device.
-	if ((errno = libusb_init(&state->deviceContext)) != LIBUSB_SUCCESS) {
+	// libusb may create its own threads at this stage, so we temporarly set
+	// a different thread name.
+	char originalThreadName[15 + 1]; // +1 for terminating NUL character.
+	thrd_get_name(originalThreadName, 15);
+	originalThreadName[15] = '\0';
+
+	thrd_set_name(state->deviceThreadName);
+	errno = libusb_init(&state->deviceContext);
+
+	thrd_set_name(originalThreadName);
+
+	if (errno != LIBUSB_SUCCESS) {
 		caerLog(CAER_LOG_CRITICAL, __func__, "Failed to initialize libusb context. Error: %d.", errno);
 		return (false);
 	}
@@ -3829,6 +3844,9 @@ static int davisDataAcquisitionThread(void *inPtr) {
 
 	caerLog(CAER_LOG_DEBUG, handle->info.deviceString, "Initializing data acquisition thread ...");
 
+	// Set thread name.
+	thrd_set_name(state->deviceThreadName);
+
 	// Reset configuration update, so as to not re-do work afterwards.
 	atomic_store(&state->dataAcquisitionThreadConfigUpdate, 0);
 
diff --git a/src/davis_common.h b/src/davis_common.h
index be9d673a..cf07615b 100644
--- a/src/davis_common.h
+++ b/src/davis_common.h
@@ -58,6 +58,7 @@ struct davis_state {
 	void (*dataShutdownNotify)(void *ptr);
 	void *dataShutdownUserPtr;
 	// USB Device State
+	char deviceThreadName[15 + 1]; // +1 for terminating NUL character.
 	libusb_context *deviceContext;
 	libusb_device_handle *deviceHandle;
 	// USB Transfer Settings
diff --git a/src/dvs128.c b/src/dvs128.c
index 7967fcb3..e659677a 100644
--- a/src/dvs128.c
+++ b/src/dvs128.c
@@ -85,12 +85,26 @@ caerDeviceHandle dvs128Open(uint16_t deviceID, uint8_t busNumberRestrict, uint8_
 
 	atomic_thread_fence(memory_order_release);
 
+	// Set device thread name. Maximum length of 15 chars due to Linux limitations.
+	snprintf(state->deviceThreadName, 15 + 1, "%s ID-%" PRIu16, DVS_DEVICE_NAME, deviceID);
+	state->deviceThreadName[15] = '\0';
+
 	// Search for device and open it.
 	// Initialize libusb using a separate context for each device.
 	// This is to correctly support one thread per device.
-	if ((errno = libusb_init(&state->deviceContext)) != LIBUSB_SUCCESS) {
-		free(handle);
+	// libusb may create its own threads at this stage, so we temporarly set
+	// a different thread name.
+	char originalThreadName[15 + 1]; // +1 for terminating NUL character.
+	thrd_get_name(originalThreadName, 15);
+	originalThreadName[15] = '\0';
+
+	thrd_set_name(state->deviceThreadName);
+	errno = libusb_init(&state->deviceContext);
 
+	thrd_set_name(originalThreadName);
+
+	if (errno != LIBUSB_SUCCESS) {
+		free(handle);
 		caerLog(CAER_LOG_CRITICAL, __func__, "Failed to initialize libusb context. Error: %d.", errno);
 		return (NULL);
 	}
@@ -1239,6 +1253,9 @@ static int dvs128DataAcquisitionThread(void *inPtr) {
 
 	caerLog(CAER_LOG_DEBUG, handle->info.deviceString, "Initializing data acquisition thread ...");
 
+	// Set thread name.
+	thrd_set_name(state->deviceThreadName);
+
 	// Reset configuration update, so as to not re-do work afterwards.
 	atomic_store(&state->dataAcquisitionThreadConfigUpdate, 0);
 
diff --git a/src/dvs128.h b/src/dvs128.h
index 4c69ac34..ef645923 100644
--- a/src/dvs128.h
+++ b/src/dvs128.h
@@ -52,6 +52,7 @@ struct dvs128_state {
 	void (*dataShutdownNotify)(void *ptr);
 	void *dataShutdownUserPtr;
 	// USB Device State
+	char deviceThreadName[15 + 1]; // +1 for terminating NUL character.
 	libusb_context *deviceContext;
 	libusb_device_handle *deviceHandle;
 	// USB Transfer Settings