# devkitPPC does not provide POSIX semaphores, which OpenAL Soft needs.
# However, devkitPPC provides an alternative semaphore implementation in an external library, libogc.
# This patch makes OpenAL Soft use libogc semaphores if POSIX semaphores is not found.

diff --git a/CMakeLists.txt b/CMakeLists.txt
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -134,6 +134,12 @@ if("${CMAKE_C_PLATFORM_ID}" STREQUAL "QNX")
     set(INC_PATHS ${INC_PATHS} /usr/include)
     set(LINKER_FLAGS ${LINKER_FLAGS} -L/usr/lib)
 endif()
+CHECK_INCLUDE_FILE("semaphore.h" HAVE_SEMAPHORE_H)
+if(NOT HAVE_SEMAPHORE_H)
+    message("semaphore.h not found; using libogc semaphores instead")
+    set(INC_PATHS ${INC_PATHS} "$ENV{DEVKITPRO}/libogc/include")
+    set(INC_PATHS ${INC_PATHS} "$ENV{DEVKITPRO}/libogc/include/ogc")
+endif()
 
 # When the library is built for static linking, apps should define
 # AL_LIBTYPE_STATIC when including the AL headers.
diff --git a/common/threads.cpp b/common/threads.cpp
--- a/common/threads.cpp
+++ b/common/threads.cpp
@@ -83,8 +83,6 @@ void semaphore::post()
 void semaphore::wait() noexcept
 { WaitForSingleObject(static_cast<HANDLE>(mSem), INFINITE); }
 
-bool semaphore::try_wait() noexcept
-{ return WaitForSingleObject(static_cast<HANDLE>(mSem), 0) == WAIT_OBJECT_0; }
 
 } // namespace al
 
@@ -134,8 +132,6 @@ void semaphore::post()
 void semaphore::wait() noexcept
 { dispatch_semaphore_wait(mSem, DISPATCH_TIME_FOREVER); }
 
-bool semaphore::try_wait() noexcept
-{ return dispatch_semaphore_wait(mSem, DISPATCH_TIME_NOW) == 0; }
 
 } // namespace al
 
@@ -147,27 +143,41 @@ namespace al {
 
 semaphore::semaphore(unsigned int initial)
 {
+#ifdef LWP_SEM_NULL
+    if(LWP_SemInit(&mSem, initial, 0xffffffff) != 0)
+#else
     if(sem_init(&mSem, 0, initial) != 0)
+#endif
         throw std::system_error(std::make_error_code(std::errc::resource_unavailable_try_again));
 }
 
 semaphore::~semaphore()
+#ifdef LWP_SEM_NULL
+{ LWP_SemDestroy(mSem); }
+#else
 { sem_destroy(&mSem); }
+#endif
 
 void semaphore::post()
 {
+#ifdef LWP_SEM_NULL
+    if(LWP_SemPost(mSem) != 0)
+#else
     if(sem_post(&mSem) != 0)
+#endif
         throw std::system_error(std::make_error_code(std::errc::value_too_large));
 }
 
 void semaphore::wait() noexcept
 {
+#ifdef LWP_SEM_NULL
+    LWP_SemWait(mSem);
+#else
     while(sem_wait(&mSem) == -1 && errno == EINTR) {
     }
+#endif
 }
 
-bool semaphore::try_wait() noexcept
-{ return sem_trywait(&mSem) == 0; }
 
 } // namespace al
 
diff --git a/common/threads.h b/common/threads.h
--- a/common/threads.h
+++ b/common/threads.h
@@ -40,7 +40,6 @@ public:
 
     void post();
     void wait() noexcept;
-    bool try_wait() noexcept;
 };
 
 } // namespace al