Win32 semaphore implementation (instead of pthreads)

source/utils/CarlaSemUtils.hpp

@@ -21,15 +21,19 @@
 #include "CarlaUtils.hpp"
 
 #include <ctime>
-#include <sys/time.h>
-#include <sys/types.h>
-#include <semaphore.h>
 
-#if defined(CARLA_OS_MAC)
-# include <fcntl.h>
+#ifdef CARLA_OS_WIN
+struct sem_t { HANDLE handle; };
+#else
+# include <sys/time.h>
+# include <sys/types.h>
+# include <semaphore.h>
+# ifdef CARLA_OS_MAC
+#  include <fcntl.h>
 extern "C" {
-# include "osx_sem_timedwait.c"
+#  include "osx_sem_timedwait.c"
 };
+# endif
 #endif
 
 /*
@@ -38,7 +42,19 @@ extern "C" {
 static inline
 sem_t* carla_sem_create() noexcept
 {
-#if defined(CARLA_OS_MAC)
+#if defined(CARLA_OS_WIN)
+    sem_t* const sem = (sem_t*)std::malloc(sizeof(sem_t));
+    CARLA_SAFE_ASSERT_RETURN(sem != nullptr, nullptr);
+
+    SECURITY_ATTRIBUTES sa;
+    carla_zeroStruct(sa);
+    sa.nLength        = sizeof(SECURITY_ATTRIBUTES);
+    sa.bInheritHandle = TRUE;
+
+    sem->handle = ::CreateSemaphore(&sa, 0, 1, nullptr);
+
+    return sem;
+#elif defined(CARLA_OS_MAC)
     static ulong sCounter = 0;
     ++sCounter;
 
@@ -77,7 +93,10 @@ void carla_sem_destroy(sem_t* const sem) noexcept
 {
     CARLA_SAFE_ASSERT_RETURN(sem != nullptr,);
 
-#if defined(CARLA_OS_MAC)
+#if defined(CARLA_OS_WIN)
+      ::CloseHandle(sem->handle);
+      std::free(sem);
+#elif defined(CARLA_OS_MAC)
     ::sem_close(sem);
 #else
     // we can't call "sem_destroy(sem)" directly because it will free memory which we allocated during carla_sem_create()
@@ -87,12 +106,12 @@ void carla_sem_destroy(sem_t* const sem) noexcept
     sem_t sem2;
     std::memcpy(&sem2, sem, sizeof(sem_t));
 
+    // destroy semaphore
+    ::sem_destroy(&sem2);
+
     // free memory allocated in carla_sem_create()
     // FIXME
     //std::free(sem);
-
-    // destroy semaphore
-    ::sem_destroy(&sem2);
 #endif
 }
 
@@ -104,7 +123,11 @@ bool carla_sem_post(sem_t* const sem) noexcept
 {
     CARLA_SAFE_ASSERT_RETURN(sem != nullptr, false);
 
+#ifdef CARLA_OS_WIN
+    return (::ReleaseSemaphore(sem->handle, 1, nullptr) != FALSE);
+#else
     return (::sem_post(sem) == 0);
+#endif
 }
 
 /*
@@ -116,20 +139,36 @@ bool carla_sem_timedwait(sem_t* const sem, const uint secs) noexcept
     CARLA_SAFE_ASSERT_RETURN(sem != nullptr, false);
     CARLA_SAFE_ASSERT_RETURN(secs > 0, false);
 
+#if defined(CARLA_OS_WIN)
+    const DWORD result = ::WaitForSingleObject(sem->handle, secs*1000);
+
+    switch (result)
+    {
+    case WAIT_OBJECT_0:
+        return true;
+    case WAIT_TIMEOUT:
+        errno = ETIMEDOUT;
+        return false;
+    default:
+        errno = EINTR;
+        return false;
+    }
+#else
     timespec timeout;
-#ifdef CARLA_OS_LINUX
+# ifdef CARLA_OS_LINUX
     ::clock_gettime(CLOCK_REALTIME, &timeout);
-#else
+# else
     timeval now;
     ::gettimeofday(&now, nullptr);
     timeout.tv_sec  = now.tv_sec;
     timeout.tv_nsec = now.tv_usec * 1000;
-#endif
+# endif
     timeout.tv_sec += static_cast<time_t>(secs);
 
     try {
         return (::sem_timedwait(sem, &timeout) == 0);
     } CARLA_SAFE_EXCEPTION_RETURN("sem_timedwait", false);
+#endif
 }
 
 // -----------------------------------------------------------------------