uhd: Replace Boost mutexes and locks with standard options

This is a very mechanical task that could almost have been done with
sed. Boost versions of mutexes and locks were removed, and replaced with
std:: versions. The replacement tables are as follows:

== Mutexes ==
- boost::mutex -> std::mutex
- boost::recursive_mutex -> std::recursive_mutex

Mutexes behave identically between Boost and std:: and have the same
API.

== Locks ==
C++11 has only two types of lock that we use/need in UHD:
- std::lock_guard: Identical to boost::lock_guard
- std::unique_lock: Identical to boost::unique_lock

Boost also has boost::mutex::scoped_lock, which is a typedef for
boost::unique_lock<>. However, we often have used scoped_lock where we
meant to use lock_guard<>. The name is a bit misleading, "scoped lock"
sounding a bit like an RAII mechanism. Therefore, some previous
boost::mutex::scoped_lock are now std::lock_guard<>.

std::unique_lock is required when doing more than RAII locking (i.e.,
unlocking, relocking, usage with condition variables, etc.).

== Condition Variables ==
Condition variables were out of the scope of this lock/mutex change, but
in UHD, we inconsistently use boost::condition vs.
boost::condition_variable. The former is a templated version of the
latter, and thus works fine with std::mutex'es. Therefore, some
boost::condition_variable where changed to boost::condition.

All locks and mutexes use `#include <mutex>`. The corresponding Boost
includes were removed. In some cases, this exposed issues with implicit
Boost includes elsewhere. The missing explicit includes were added.

1 files changed, 9 insertions, 10 deletions

diff --git a/host/lib/property_tree.cpp b/host/lib/property_tree.cpp
index 53268efd3..14d3ae8c4 100644
--- a/host/lib/property_tree.cpp
+++ b/host/lib/property_tree.cpp
@@ -8,9 +8,8 @@
 
 #include <uhd/property_tree.hpp>
 #include <uhd/types/dict.hpp>
-#include <boost/thread/mutex.hpp>
-#include <iostream>
 #include <memory>
+#include <mutex>
 
 using namespace uhd;
 
@@ -79,7 +78,7 @@ public:
     sptr subtree(const fs_path& path_) const override
     {
         const fs_path path = _root / path_;
-        boost::mutex::scoped_lock lock(_guts->mutex);
+        std::lock_guard<std::mutex> lock(_guts->mutex);
 
         property_tree_impl* subtree = new property_tree_impl(path);
         subtree->_guts              = this->_guts; // copy the guts sptr
@@ -89,7 +88,7 @@ public:
     void remove(const fs_path& path_) override
     {
         const fs_path path = _root / path_;
-        boost::mutex::scoped_lock lock(_guts->mutex);
+        std::lock_guard<std::mutex> lock(_guts->mutex);
 
         node_type* parent = NULL;
         node_type* node   = &_guts->root;
@@ -107,7 +106,7 @@ public:
     bool exists(const fs_path& path_) const override
     {
         const fs_path path = _root / path_;
-        boost::mutex::scoped_lock lock(_guts->mutex);
+        std::lock_guard<std::mutex> lock(_guts->mutex);
 
         node_type* node = &_guts->root;
         for (const std::string& name : path_tokenizer(path)) {
@@ -121,7 +120,7 @@ public:
     std::vector<std::string> list(const fs_path& path_) const override
     {
         const fs_path path = _root / path_;
-        boost::mutex::scoped_lock lock(_guts->mutex);
+        std::lock_guard<std::mutex> lock(_guts->mutex);
 
         node_type* node = &_guts->root;
         for (const std::string& name : path_tokenizer(path)) {
@@ -136,7 +135,7 @@ public:
     std::shared_ptr<void> _pop(const fs_path& path_) override
     {
         const fs_path path = _root / path_;
-        boost::mutex::scoped_lock lock(_guts->mutex);
+        std::lock_guard<std::mutex> lock(_guts->mutex);
 
         node_type* parent = NULL;
         node_type* node   = &_guts->root;
@@ -159,7 +158,7 @@ public:
     void _create(const fs_path& path_, const std::shared_ptr<void>& prop) override
     {
         const fs_path path = _root / path_;
-        boost::mutex::scoped_lock lock(_guts->mutex);
+        std::lock_guard<std::mutex> lock(_guts->mutex);
 
         node_type* node = &_guts->root;
         for (const std::string& name : path_tokenizer(path)) {
@@ -176,7 +175,7 @@ public:
     std::shared_ptr<void>& _access(const fs_path& path_) const override
     {
         const fs_path path = _root / path_;
-        boost::mutex::scoped_lock lock(_guts->mutex);
+        std::lock_guard<std::mutex> lock(_guts->mutex);
 
         node_type* node = &_guts->root;
         for (const std::string& name : path_tokenizer(path)) {
@@ -205,7 +204,7 @@ private:
     struct tree_guts_type
     {
         node_type root;
-        boost::mutex mutex;
+        std::mutex mutex;
     };
 
     // members, the tree and root prefix