From 7da708ea69432adcd00270622415d5d6ebf61f62 Mon Sep 17 00:00:00 2001
From: Hans-Kristian Arntzen <post@arntzen-software.no>
Date: Mon, 24 Jan 2022 15:17:57 +0100
Subject: [PATCH] vkd3d: Add an RW lock wrapper.

For longer-lived locks where spinlock is bad form. To be used for
pipeline library.

Signed-off-by: Hans-Kristian Arntzen <post@arntzen-software.no>
---
 include/private/vkd3d_threads.h | 78 +++++++++++++++++++++++++++++++++
 1 file changed, 78 insertions(+)

diff --git a/include/private/vkd3d_threads.h b/include/private/vkd3d_threads.h
index a252a64b..623fcd0e 100644
--- a/include/private/vkd3d_threads.h
+++ b/include/private/vkd3d_threads.h
@@ -114,6 +114,48 @@ static inline int pthread_mutex_destroy(pthread_mutex_t *lock)
     return 0;
 }
 
+/* SRWLocks distinguish between write and read unlocks, but pthread interface does not,
+ * so make a trivial wrapper type instead to avoid any possible API conflicts. */
+typedef struct rwlock
+{
+    SRWLOCK rwlock;
+} rwlock_t;
+
+static inline int rwlock_init(rwlock_t *lock)
+{
+    InitializeSRWLock(&lock->rwlock);
+    return 0;
+}
+
+static inline int rwlock_lock_write(rwlock_t *lock)
+{
+    AcquireSRWLockExclusive(&lock->rwlock);
+    return 0;
+}
+
+static inline int rwlock_lock_read(rwlock_t *lock)
+{
+    AcquireSRWLockShared(&lock->rwlock);
+    return 0;
+}
+
+static inline int rwlock_unlock_write(rwlock_t *lock)
+{
+    ReleaseSRWLockExclusive(&lock->rwlock);
+    return 0;
+}
+
+static inline int rwlock_unlock_read(rwlock_t *lock)
+{
+    ReleaseSRWLockShared(&lock->rwlock);
+    return 0;
+}
+
+static inline int rwlock_destroy(rwlock_t *lock)
+{
+    return 0;
+}
+
 static inline int pthread_cond_init(pthread_cond_t *cond, void *attr)
 {
     (void)attr;
@@ -172,6 +214,42 @@ static inline void vkd3d_set_thread_name(const char *name)
 {
     pthread_setname_np(pthread_self(), name);
 }
+
+typedef struct rwlock
+{
+    pthread_rwlock_t rwlock;
+} rwlock_t;
+
+static inline int rwlock_init(rwlock_t *lock)
+{
+    return pthread_rwlock_init(&lock->rwlock, NULL);
+}
+
+static inline int rwlock_lock_write(rwlock_t *lock)
+{
+    return pthread_rwlock_wrlock(&lock->rwlock);
+}
+
+static inline int rwlock_lock_read(rwlock_t *lock)
+{
+    return pthread_rwlock_rdlock(&lock->rwlock);
+}
+
+static inline int rwlock_unlock_write(rwlock_t *lock)
+{
+    return pthread_rwlock_unlock(&lock->rwlock);
+}
+
+static inline int rwlock_unlock_read(rwlock_t *lock)
+{
+    return pthread_rwlock_unlock(&lock->rwlock);
+}
+
+static inline int rwlock_destroy(rwlock_t *lock)
+{
+    return pthread_rwlock_destroy(&lock->rwlock);
+}
+
 #define PTHREAD_ONCE_CALLBACK
 #endif