From 06987c624481201495334fa114e90a2ff26331c1 Mon Sep 17 00:00:00 2001
From: Lorenz Meier <lm@inf.ethz.ch>
Date: Mon, 2 Nov 2015 11:05:09 +0100
Subject: [PATCH] Lock vdev devmap

---
 src/drivers/device/vdev.cpp | 33 +++++++++++++++++++++++++++++++++
 1 file changed, 33 insertions(+)

diff --git a/src/drivers/device/vdev.cpp b/src/drivers/device/vdev.cpp
index 60761ed511..4aa58447f3 100644
--- a/src/drivers/device/vdev.cpp
+++ b/src/drivers/device/vdev.cpp
@@ -67,6 +67,7 @@ private:
 
 #define PX4_MAX_DEV 500
 static px4_dev_t *devmap[PX4_MAX_DEV];
+pthread_mutex_t devmutex = PTHREAD_MUTEX_INITIALIZER;
 
 /*
  * The standard NuttX operation dispatch table can't call C++ member functions
@@ -142,8 +143,12 @@ VDev::register_driver(const char *name, void *data)
 
 	// Make sure the device does not already exist
 	// FIXME - convert this to a map for efficiency
+
+	pthread_mutex_lock(&devmutex);
+
 	for (int i = 0; i < PX4_MAX_DEV; ++i) {
 		if (devmap[i] && (strcmp(devmap[i]->name, name) == 0)) {
+			pthread_mutex_unlock(&devmutex);
 			return -EEXIST;
 		}
 	}
@@ -157,6 +162,8 @@ VDev::register_driver(const char *name, void *data)
 		}
 	}
 
+	pthread_mutex_unlock(&devmutex);
+
 	if (ret != PX4_OK) {
 		PX4_ERR("No free devmap entries - increase PX4_MAX_DEV");
 	}
@@ -174,6 +181,8 @@ VDev::unregister_driver(const char *name)
 		return -EINVAL;
 	}
 
+	pthread_mutex_lock(&devmutex);
+
 	for (int i = 0; i < PX4_MAX_DEV; ++i) {
 		if (devmap[i] && (strcmp(name, devmap[i]->name) == 0)) {
 			delete devmap[i];
@@ -184,6 +193,8 @@ VDev::unregister_driver(const char *name)
 		}
 	}
 
+	pthread_mutex_unlock(&devmutex);
+
 	return ret;
 }
 
@@ -194,15 +205,20 @@ VDev::unregister_class_devname(const char *class_devname, unsigned class_instanc
 	char name[32];
 	snprintf(name, sizeof(name), "%s%u", class_devname, class_instance);
 
+	pthread_mutex_lock(&devmutex);
+
 	for (int i = 0; i < PX4_MAX_DEV; ++i) {
 		if (devmap[i] && strcmp(devmap[i]->name, name) == 0) {
 			delete devmap[i];
 			PX4_DEBUG("Unregistered class DEV %s", name);
 			devmap[i] = NULL;
+			pthread_mutex_unlock(&devmutex);
 			return PX4_OK;
 		}
 	}
 
+	pthread_mutex_unlock(&devmutex);
+
 	return -EINVAL;
 }
 
@@ -497,15 +513,20 @@ VDev *VDev::getDev(const char *path)
 	PX4_DEBUG("VDev::getDev");
 	int i = 0;
 
+	pthread_mutex_lock(&devmutex);
+
 	for (; i < PX4_MAX_DEV; ++i) {
 		//if (devmap[i]) {
 		//	printf("%s %s\n", devmap[i]->name, path);
 		//}
 		if (devmap[i] && (strcmp(devmap[i]->name, path) == 0)) {
+			pthread_mutex_unlock(&devmutex);
 			return (VDev *)(devmap[i]->cdev);
 		}
 	}
 
+	pthread_mutex_unlock(&devmutex);
+
 	return NULL;
 }
 
@@ -514,11 +535,15 @@ void VDev::showDevices()
 	int i = 0;
 	PX4_INFO("Devices:");
 
+	pthread_mutex_lock(&devmutex);
+
 	for (; i < PX4_MAX_DEV; ++i) {
 		if (devmap[i] && strncmp(devmap[i]->name, "/dev/", 5) == 0) {
 			PX4_INFO("   %s", devmap[i]->name);
 		}
 	}
+
+	pthread_mutex_unlock(&devmutex);
 }
 
 void VDev::showTopics()
@@ -526,11 +551,15 @@ void VDev::showTopics()
 	int i = 0;
 	PX4_INFO("Devices:");
 
+	pthread_mutex_lock(&devmutex);
+
 	for (; i < PX4_MAX_DEV; ++i) {
 		if (devmap[i] && strncmp(devmap[i]->name, "/obj/", 5) == 0) {
 			PX4_INFO("   %s", devmap[i]->name);
 		}
 	}
+
+	pthread_mutex_unlock(&devmutex);
 }
 
 void VDev::showFiles()
@@ -538,12 +567,16 @@ void VDev::showFiles()
 	int i = 0;
 	PX4_INFO("Files:");
 
+	pthread_mutex_lock(&devmutex);
+
 	for (; i < PX4_MAX_DEV; ++i) {
 		if (devmap[i] && strncmp(devmap[i]->name, "/obj/", 5) != 0 &&
 		    strncmp(devmap[i]->name, "/dev/", 5) != 0) {
 			PX4_INFO("   %s", devmap[i]->name);
 		}
 	}
+
+	pthread_mutex_unlock(&devmutex);
 }
 
 const char *VDev::topicList(unsigned int *next)