Abstract out mutex type. Make threads optional.

10 files changed, 83 insertions, 21 deletions

diff --git a/src/lib/utils/calendar.cpp b/src/lib/utils/calendar.cpp
index 2ed90486a..4f6c835d1 100644
--- a/src/lib/utils/calendar.cpp
+++ b/src/lib/utils/calendar.cpp
@@ -11,7 +11,7 @@
 #include <ctime>
 #include <sstream>
 #include <iomanip>
-#include <mutex>
+#include <botan/mutex.h>
 #include <stdlib.h>
 
 #if defined(BOTAN_HAS_BOOST_DATETIME)
@@ -72,7 +72,7 @@ std::time_t boost_timegm(std::tm *tm)
 
 #pragma message "Caution! A fallback version of timegm() is used which is not thread-safe"
 
-std::mutex ENV_TZ;
+mutex_type ENV_TZ;
 
 std::time_t fallback_timegm(std::tm *tm)
    {
diff --git a/src/lib/utils/http_util/http_util.cpp b/src/lib/utils/http_util/http_util.cpp
index 1286e4026..5624f2e4f 100644
--- a/src/lib/utils/http_util/http_util.cpp
+++ b/src/lib/utils/http_util/http_util.cpp
@@ -226,11 +226,6 @@ Response POST_sync(const std::string& url,
    return http_sync("POST", url, content_type, body, allowable_redirects);
    }
 
-std::future<Response> GET_async(const std::string& url, size_t allowable_redirects)
-   {
-   return std::async(std::launch::async, GET_sync, url, allowable_redirects);
-   }
-
 }
 
 }
diff --git a/src/lib/utils/http_util/http_util.h b/src/lib/utils/http_util/http_util.h
index 6688285c6..918dfc269 100644
--- a/src/lib/utils/http_util/http_util.h
+++ b/src/lib/utils/http_util/http_util.h
@@ -10,7 +10,6 @@
 
 #include <botan/types.h>
 #include <botan/exceptn.h>
-#include <future>
 #include <vector>
 #include <map>
 #include <chrono>
@@ -88,9 +87,6 @@ BOTAN_DLL Response POST_sync(const std::string& url,
                              const std::vector<byte>& body,
                              size_t allowable_redirects = 1);
 
-std::future<Response> BOTAN_DLL GET_async(const std::string& url,
-                                                    size_t allowable_redirects = 1);
-
 BOTAN_DLL std::string url_encode(const std::string& url);
 
 }
diff --git a/src/lib/utils/info.txt b/src/lib/utils/info.txt
index 511e6b0e8..189b2da1f 100644
--- a/src/lib/utils/info.txt
+++ b/src/lib/utils/info.txt
@@ -14,6 +14,7 @@ exceptn.h
 loadstor.h
 mem_ops.h
 mul128.h
+mutex.h
 parsing.h
 rotate.h
 types.h
diff --git a/src/lib/utils/locking_allocator/locking_allocator.cpp b/src/lib/utils/locking_allocator/locking_allocator.cpp
index c6181d4c0..770464d92 100644
--- a/src/lib/utils/locking_allocator/locking_allocator.cpp
+++ b/src/lib/utils/locking_allocator/locking_allocator.cpp
@@ -11,7 +11,7 @@
 #include <algorithm>
 #include <cstdlib>
 #include <string>
-#include <mutex>
+#include <botan/mutex.h>
 
 namespace Botan {
 
@@ -58,7 +58,7 @@ void* mlock_allocator::allocate(size_t num_elems, size_t elem_size)
    if(n < BOTAN_MLOCK_ALLOCATOR_MIN_ALLOCATION || n > BOTAN_MLOCK_ALLOCATOR_MAX_ALLOCATION)
       return nullptr;
 
-   std::lock_guard<std::mutex> lock(m_mutex);
+   lock_guard_type<mutex_type> lock(m_mutex);
 
    auto best_fit = m_freelist.end();
 
@@ -146,7 +146,7 @@ bool mlock_allocator::deallocate(void* p, size_t num_elems, size_t elem_size)
    if(!ptr_in_pool(m_pool, m_poolsize, p, n))
       return false;
 
-   std::lock_guard<std::mutex> lock(m_mutex);
+   lock_guard_type<mutex_type> lock(m_mutex);
 
    const size_t start = static_cast<byte*>(p) - m_pool;
 
diff --git a/src/lib/utils/locking_allocator/locking_allocator.h b/src/lib/utils/locking_allocator/locking_allocator.h
index db75bc02a..5c19852c0 100644
--- a/src/lib/utils/locking_allocator/locking_allocator.h
+++ b/src/lib/utils/locking_allocator/locking_allocator.h
@@ -10,7 +10,7 @@
 
 #include <botan/types.h>
 #include <vector>
-#include <mutex>
+#include <botan/mutex.h>
 
 namespace Botan {
 
@@ -32,7 +32,7 @@ class BOTAN_DLL mlock_allocator
 
       ~mlock_allocator();
 
-      std::mutex m_mutex;
+      mutex_type m_mutex;
       std::vector<std::pair<size_t, size_t>> m_freelist;
       byte* m_pool = nullptr;
       size_t m_poolsize = 0;
diff --git a/src/lib/utils/mutex.h b/src/lib/utils/mutex.h
new file mode 100644
index 000000000..0daea3148
--- /dev/null
+++ b/src/lib/utils/mutex.h
@@ -0,0 +1,61 @@
+/*
+* (C) 2016 Jack Lloyd
+*
+* Botan is released under the Simplified BSD License (see license.txt)
+*/
+
+#ifndef BOTAN_UTIL_MUTEX_H__
+#define BOTAN_UTIL_MUTEX_H__
+
+#include <botan/build.h>
+#include <botan/types.h>
+
+#if defined(BOTAN_TARGET_OS_HAS_THREADS)
+
+#include <mutex>
+
+namespace Botan {
+
+template<typename T> using lock_guard_type = std::lock_guard<T>;
+typedef std::mutex mutex_type;
+
+}
+
+#elif defined(BOTAN_TARGET_OS_TYPE_IS_UNIKERNEL)
+
+// No threads
+
+namespace Botan {
+
+template<typename Mutex>
+class lock_guard
+   {
+   public:
+      explicit lock_guard(Mutex& m) : m_mutex(m)
+         { m_mutex.lock(); }
+
+      ~lock_guard() { m_mutex.unlock(); }
+
+      lock_guard(const lock_guard& other) = delete;
+      lock_guard& operator=(const lock_guard& other) = delete;
+   private:
+      Mutex& m_mutex;
+   };
+
+class noop_mutex
+   {
+   public:
+      void lock() {}
+      void unlock() {}
+   };
+
+typedef noop_mutex mutex_type;
+template<typename T> using lock_guard_type = lock_guard<T>;
+
+}
+
+#else
+  #error "Threads unexpectedly disabled in non unikernel build"
+#endif
+
+#endif
diff --git a/src/lib/utils/os_utils.cpp b/src/lib/utils/os_utils.cpp
index 56ec59cc0..4020a4be3 100644
--- a/src/lib/utils/os_utils.cpp
+++ b/src/lib/utils/os_utils.cpp
@@ -34,7 +34,7 @@ uint32_t get_process_id()
 #elif defined(BOTAN_TARGET_OS_IS_WINDOWS) || defined(BOTAN_TARGET_OS_IS_MINGW)
    return ::GetCurrentProcessId();
 #elif defined(BOTAN_TARGET_OS_TYPE_IS_UNIKERNEL)
-   return 0;
+   return 0; // truly no meaningful value
 #else
    #error "Missing get_process_id"
 #endif
diff --git a/src/lib/utils/semaphore.cpp b/src/lib/utils/semaphore.cpp
index f30c43661..62c31d3e3 100644
--- a/src/lib/utils/semaphore.cpp
+++ b/src/lib/utils/semaphore.cpp
@@ -7,6 +7,8 @@
 
 #include <botan/internal/semaphore.h>
 
+#if defined(BOTAN_TARGET_OS_HAS_THREADS)
+
 // Based on code by Pierre Gaston (http://p9as.blogspot.com/2012/06/c11-semaphores.html)
 
 namespace Botan {
@@ -15,7 +17,7 @@ void Semaphore::release(size_t n)
    {
    for(size_t i = 0; i != n; ++i)
       {
-      std::lock_guard<std::mutex> lock(m_mutex);
+      lock_guard_type<mutex_type> lock(m_mutex);
 
       ++m_value;
 
@@ -29,7 +31,7 @@ void Semaphore::release(size_t n)
 
 void Semaphore::acquire()
    {
-   std::unique_lock<std::mutex> lock(m_mutex);
+   std::unique_lock<mutex_type> lock(m_mutex);
    --m_value;
    if(m_value < 0)
       {
@@ -39,3 +41,5 @@ void Semaphore::acquire()
    }
 
 }
+
+#endif
diff --git a/src/lib/utils/semaphore.h b/src/lib/utils/semaphore.h
index 994a15f21..87e6b84fe 100644
--- a/src/lib/utils/semaphore.h
+++ b/src/lib/utils/semaphore.h
@@ -8,11 +8,15 @@
 #ifndef BOTAN_SEMAPHORE_H__
 #define BOTAN_SEMAPHORE_H__
 
-#include <mutex>
+#include <botan/mutex.h>
+
+#if defined(BOTAN_TARGET_OS_HAS_THREADS)
 #include <condition_variable>
+#endif
 
 namespace Botan {
 
+#if defined(BOTAN_TARGET_OS_HAS_THREADS)
 class Semaphore
    {
    public:
@@ -25,9 +29,10 @@ class Semaphore
    private:
       int m_value;
       int m_wakeups;
-      std::mutex m_mutex;
+      mutex_type m_mutex;
       std::condition_variable m_cond;
    };
+#endif
 
 }