From dba634132e8c03a612b5ba3fc6e6948b2c275f4e Mon Sep 17 00:00:00 2001
From: Jean-Baptiste Boric <jblbeurope@gmail.com>
Date: Mon, 26 Dec 2016 21:45:27 +0100
Subject: [PATCH] mthread: add pthread spinlock emulation

---
 minix/include/minix/mthread.h         | 10 ++++
 minix/lib/libmthread/pthread_compat.c | 66 +++++++++++++++++++++++++++
 2 files changed, 76 insertions(+)

diff --git a/minix/include/minix/mthread.h b/minix/include/minix/mthread.h
index bb4ba56d6..9a159830b 100644
--- a/minix/include/minix/mthread.h
+++ b/minix/include/minix/mthread.h
@@ -154,6 +154,7 @@ typedef mthread_mutexattr_t pthread_mutexattr_t;
 typedef mthread_attr_t pthread_attr_t;
 typedef mthread_event_t pthread_event_t;
 typedef mthread_rwlock_t pthread_rwlock_t;
+typedef mthread_mutex_t pthread_spinlock_t; /* emulate spinlocks with mutexes */
 
 /* LSC: No equivalent, so void* for now. */
 typedef void *pthread_rwlockattr_t;
@@ -161,6 +162,8 @@ typedef void *pthread_rwlockattr_t;
 #define PTHREAD_ONCE_INIT 0
 #define PTHREAD_MUTEX_INITIALIZER ((pthread_mutex_t) -1)
 #define PTHREAD_COND_INITIALIZER ((pthread_cond_t) -1)
+#define PTHREAD_PROCESS_PRIVATE 0
+#define PTHREAD_PROCESS_SHARED 1
 
 __BEGIN_DECLS
 /* allocate.c */
@@ -222,6 +225,13 @@ int pthread_rwlock_rdlock(pthread_rwlock_t *rwlock);
 int pthread_rwlock_wrlock(pthread_rwlock_t *rwlock);
 int pthread_rwlock_unlock(pthread_rwlock_t *rwlock);
 
+/* pthread_compat.c */
+int pthread_spin_destroy(pthread_spinlock_t *lock);
+int pthread_spin_init(pthread_spinlock_t *lock, int UNUSED(pshared));
+int pthread_spin_lock(pthread_spinlock_t *lock);
+int pthread_spin_trylock(pthread_spinlock_t *lock);
+int pthread_spin_unlock(pthread_spinlock_t *lock);
+
 /* schedule.c */
 int pthread_yield(void);
 int sched_yield(void);
diff --git a/minix/lib/libmthread/pthread_compat.c b/minix/lib/libmthread/pthread_compat.c
index 1a4b92e74..20b0a8f4f 100644
--- a/minix/lib/libmthread/pthread_compat.c
+++ b/minix/lib/libmthread/pthread_compat.c
@@ -139,6 +139,72 @@ int pthread_rwlock_init(pthread_rwlock_t *rwlock, pthread_rwlockattr_t *UNUSED(a
 	return mthread_rwlock_init(rwlock);
 }
 
+/*===========================================================================*
+ *				pthread_spin_destroy			     *
+ *===========================================================================*/
+int pthread_spin_destroy(pthread_spinlock_t *lock)
+{
+	pthread_mutex_t *mutex = (pthread_mutex_t*)lock;
+
+	if (PTHREAD_MUTEX_INITIALIZER == *mutex) {
+		mthread_mutex_init(mutex, NULL);
+	}
+
+	return mthread_mutex_destroy(mutex);
+}
+
+/*===========================================================================*
+ *				pthread_spin_init			     *
+ *===========================================================================*/
+int pthread_spin_init(pthread_spinlock_t *lock, int UNUSED(pshared))
+{
+	pthread_mutex_t *mutex = (pthread_mutex_t*)lock;
+
+	return mthread_mutex_init(mutex, NULL);
+}
+
+/*===========================================================================*
+ *				pthread_spin_lock			     *
+ *===========================================================================*/
+int pthread_spin_lock(pthread_spinlock_t *lock)
+{
+	pthread_mutex_t *mutex = (pthread_mutex_t*)lock;
+
+	if (PTHREAD_MUTEX_INITIALIZER == *mutex) {
+		mthread_mutex_init(mutex, NULL);
+	}
+
+	return mthread_mutex_lock(mutex);
+}
+
+/*===========================================================================*
+ *				pthread_spin_trylock			     *
+ *===========================================================================*/
+int pthread_spin_trylock(pthread_spinlock_t *lock)
+{
+	pthread_mutex_t *mutex = (pthread_mutex_t*)lock;
+
+	if (PTHREAD_MUTEX_INITIALIZER == *mutex) {
+		mthread_mutex_init(mutex, NULL);
+	}
+
+	return mthread_mutex_trylock(mutex);
+}
+
+/*===========================================================================*
+ *				pthread_spin_unlock			     *
+ *===========================================================================*/
+int pthread_spin_unlock(pthread_spinlock_t *lock)
+{
+	pthread_mutex_t *mutex = (pthread_mutex_t*)lock;
+
+	if (PTHREAD_MUTEX_INITIALIZER == *mutex) {
+		mthread_mutex_init(mutex, NULL);
+	}
+
+	return mthread_mutex_unlock(mutex);
+}
+
 #if !defined(__weak_alias)
 #error __weak_alias is required to compile the pthread compat library
 #endif