Simplify semaphore

Signed-off-by: falkTX <falktx@falktx.com>

Author: falkTX

plugins/common/Semaphore.hpp

@@ -1,17 +1,7 @@
 /*
  * DISTRHO Plugin Framework (DPF)
- * Copyright (C) 2012-2022 Filipe Coelho <falktx@falktx.com>
- *
- * Permission to use, copy, modify, and/or distribute this software for any purpose with
- * or without fee is hereby granted, provided that the above copyright notice and this
- * permission notice appear in all copies.
- *
- * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD
- * TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN
- * NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
- * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER
- * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
- * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ * Copyright (C) 2012-2023 Filipe Coelho <falktx@falktx.com>
+ * SPDX-License-Identifier: ISC
  */
 
 #ifndef DISTRHO_SEMAPHORE_HPP_INCLUDED
@@ -28,20 +18,14 @@
 # endif
 # include <winsock2.h>
 # include <windows.h>
-#elif defined(__MOD_DEVICES__)
-# include <linux/futex.h>
-# include <sys/time.h>
-# include <errno.h>
-# include <syscall.h>
-# include <unistd.h>
 #else
 # include <semaphore.h>
 # include <sys/time.h>
 #endif
 
 START_NAMESPACE_DISTRHO
 
-// -----------------------------------------------------------------------
+// --------------------------------------------------------------------------------------------------------------------
 
 class Semaphore
 {
@@ -56,8 +40,6 @@ class Semaphore
        #elif defined(DISTRHO_OS_WINDOWS)
         handle = ::CreateSemaphoreA(nullptr, initialValue, std::max(initialValue, 1), nullptr);
         DISTRHO_SAFE_ASSERT_RETURN(handle != INVALID_HANDLE_VALUE,);
-       #elif defined(__MOD_DEVICES__)
-        value = initialValue;
        #else
         ::sem_init(&sem, 0, initialValue);
        #endif
@@ -69,8 +51,6 @@ class Semaphore
         ::semaphore_destroy(mach_task_self(), sem);
        #elif defined(DISTRHO_OS_WINDOWS)
         ::CloseHandle(handle);
-       #elif defined(__MOD_DEVICES__)
-        // nothing here
        #else
         ::sem_destroy(&sem);
        #endif
@@ -82,10 +62,6 @@ class Semaphore
         ::semaphore_signal(sem);
        #elif defined(DISTRHO_OS_WINDOWS)
         ::ReleaseSemaphore(handle, 1, nullptr);
-       #elif defined(__MOD_DEVICES__)
-        // if already unlocked, do not wake futex
-        if (::__sync_bool_compare_and_swap(&value, 0, 1))
-            ::syscall(__NR_futex, &value, FUTEX_WAKE_PRIVATE, 1, nullptr, nullptr, 0);
        #else
         ::sem_post(&sem);
        #endif
@@ -97,18 +73,6 @@ class Semaphore
         return ::semaphore_wait(sem) == KERN_SUCCESS;
        #elif defined(DISTRHO_OS_WINDOWS)
         return ::WaitForSingleObject(handle, INFINITE) == WAIT_OBJECT_0;
-       #elif defined(__MOD_DEVICES__)
-        for (;;)
-        {
-            if (::__sync_bool_compare_and_swap(&value, 1, 0))
-                return true;
-
-            if (::syscall(__NR_futex, &value, FUTEX_WAIT_PRIVATE, 0, nullptr, nullptr, 0) != 0)
-            {
-                if (errno != EAGAIN && errno != EINTR)
-                    return false;
-            }
-        }
        #else
         return ::sem_wait(&sem) == 0;
        #endif
@@ -121,39 +85,25 @@ class Semaphore
         return ::semaphore_timedwait(sem, time) == KERN_SUCCESS;
        #elif defined(DISTRHO_OS_WINDOWS)
         return ::WaitForSingleObject(handle, numSecs * 1000) == WAIT_OBJECT_0;
-       #elif defined(__MOD_DEVICES__)
-        const struct timespec timeout = { static_cast<time_t>(numSecs), 0 };
-        for (;;)
-        {
-            if (::__sync_bool_compare_and_swap(&value, 1, 0))
-                return true;
-
-            if (::syscall(__NR_futex, &value, FUTEX_WAIT_PRIVATE, 0, &timeout, nullptr, 0) != 0)
-            {
-                if (errno != EAGAIN && errno != EINTR)
-                    return false;
-            }
-        }
        #else
         struct timespec timeout;
         ::clock_gettime(CLOCK_REALTIME, &timeout);
         timeout.tv_sec += numSecs;
         return ::sem_timedwait(&sem, &timeout) == 0;
        #endif
     }
+
 private:
    #if defined(DISTRHO_OS_MAC)
     ::semaphore_t sem;
    #elif defined(DISTRHO_OS_WINDOWS)
     ::HANDLE handle;
-   #elif defined(__MOD_DEVICES__)
-    int value;
    #else
     ::sem_t sem;
    #endif
 };
 
-// -----------------------------------------------------------------------
+// --------------------------------------------------------------------------------------------------------------------
 
 END_NAMESPACE_DISTRHO