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.

2 files changed, 8 insertions, 8 deletions

diff --git a/host/lib/usrp/cores/i2c_core_200.cpp b/host/lib/usrp/cores/i2c_core_200.cpp
index 93e3fedf8..fd9332638 100644
--- a/host/lib/usrp/cores/i2c_core_200.cpp
+++ b/host/lib/usrp/cores/i2c_core_200.cpp
@@ -8,8 +8,8 @@
 #include <uhd/exception.hpp>
 #include <uhd/utils/log.hpp>
 #include <uhdlib/usrp/cores/i2c_core_200.hpp>
-#include <boost/thread/mutex.hpp>
 #include <chrono>
+#include <mutex>
 #include <thread>
 
 #define REG_I2C_WR_PRESCALER_LO (1 << 3) | 0
@@ -137,13 +137,13 @@ private:
 
     void poke(const size_t what, const uint8_t cmd)
     {
-        boost::mutex::scoped_lock lock(_mutex);
+        std::lock_guard<std::mutex> lock(_mutex);
         _iface->poke32(_base, (what << 8) | cmd);
     }
 
     uint8_t peek(const size_t what)
     {
-        boost::mutex::scoped_lock lock(_mutex);
+        std::lock_guard<std::mutex> lock(_mutex);
         _iface->poke32(_base, what << 8);
         return uint8_t(_iface->peek32(_readback));
     }
@@ -151,7 +151,7 @@ private:
     wb_iface::sptr _iface;
     const size_t _base;
     const size_t _readback;
-    boost::mutex _mutex;
+    std::mutex _mutex;
 };
 
 i2c_core_200::sptr i2c_core_200::make(
diff --git a/host/lib/usrp/cores/user_settings_core_3000.cpp b/host/lib/usrp/cores/user_settings_core_3000.cpp
index 9e04175c2..7293f9070 100644
--- a/host/lib/usrp/cores/user_settings_core_3000.cpp
+++ b/host/lib/usrp/cores/user_settings_core_3000.cpp
@@ -7,7 +7,7 @@
 
 #include <uhd/exception.hpp>
 #include <uhdlib/usrp/cores/user_settings_core_3000.hpp>
-#include <boost/thread/thread.hpp>
+#include <mutex>
 
 using namespace uhd;
 
@@ -38,7 +38,7 @@ public:
         if (offset % sizeof(uint64_t) != 0)
             throw uhd::value_error("peek64: Incorrect address alignment");
 
-        boost::unique_lock<boost::mutex> lock(_mutex);
+        std::unique_lock<std::mutex> lock(_mutex);
         _iface->poke32(
             REG_USER_RB_ADDR, offset >> 3); // Translate byte offset to 64-bit offset
         return _iface->peek64(_rb_reg_addr);
@@ -49,7 +49,7 @@ public:
         if (offset % sizeof(uint32_t) != 0)
             throw uhd::value_error("poke32: Incorrect address alignment");
 
-        boost::unique_lock<boost::mutex> lock(_mutex);
+        std::unique_lock<std::mutex> lock(_mutex);
         _iface->poke32(
             REG_USER_SR_ADDR, offset >> 2); // Translate byte offset to 64-bit offset
         _iface->poke32(REG_USER_SR_DATA, value);
@@ -72,7 +72,7 @@ private:
     wb_iface::sptr _iface;
     const wb_addr_type _sr_base_addr;
     const wb_addr_type _rb_reg_addr;
-    boost::mutex _mutex;
+    std::mutex _mutex;
 };
 
 wb_iface::sptr user_settings_core_3000::make(