From bfe4892be124c6e7504fa6dc6f7419bb3a174001 Mon Sep 17 00:00:00 2001
From: BunnyFl <166477956+BunnyFl@users.noreply.github.com>
Date: Mon, 2 Nov 2026 02:05:03 +0100
Subject: [PATCH] fix(agc,libkernel): prime the host shared mutexes left
 unprimed on Windows

winpthreads initializes a statically initialized rwlock on its first lock
and fails a concurrent first lock with EINVAL, which std::shared_mutex
ignores, so that lock does not exclude (docs/dev/debt/shader.md). Lock
depthGuardMutex, PipelineCacheSynchronization's mutex and the event flag
registry mutex once when created, through a PrimedSharedMutex shared from
a libc header.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
---
 .../libSceAgcDriver/Graphics/include/Context.hpp   |  3 ++-
 .../libSceAgcDriver/Graphics/src/DepthSurface.cpp  |  3 ++-
 .../Graphics/src/MultisampleTarget.cpp             |  9 +--------
 core/libs/prx/libc/include/PrimedSharedMutex.hpp   | 14 ++++++++++++++
 .../libs/prx/libkernel/EventFlag/src/EventFlag.cpp |  3 ++-
 5 files changed, 21 insertions(+), 11 deletions(-)
 create mode 100644 core/libs/prx/libc/include/PrimedSharedMutex.hpp

diff --git a/core/libs/prx/libSceAgcDriver/Graphics/include/Context.hpp b/core/libs/prx/libSceAgcDriver/Graphics/include/Context.hpp
index 985840aef9..855d3c7873 100644
--- a/core/libs/prx/libSceAgcDriver/Graphics/include/Context.hpp
+++ b/core/libs/prx/libSceAgcDriver/Graphics/include/Context.hpp
@@ -6,6 +6,7 @@
 #endif
 #include <mutex>
 #include <vulkan/vulkan.h>
+#include "prx/libc/include/PrimedSharedMutex.hpp"
 #include <array>
 #include <atomic>
 #include <cstdint>
@@ -46,7 +47,7 @@ public:
     SnapshotLock TryLockForSnapshot() const { return SnapshotLock(mutex, std::try_to_lock); }
 
 private:
-    mutable std::shared_mutex mutex;
+    mutable PrimedSharedMutex mutex;
 };
 
 inline void Require(bool condition, const std::string& reason) {
diff --git a/core/libs/prx/libSceAgcDriver/Graphics/src/DepthSurface.cpp b/core/libs/prx/libSceAgcDriver/Graphics/src/DepthSurface.cpp
index 77566d0d96..ac80e3921c 100644
--- a/core/libs/prx/libSceAgcDriver/Graphics/src/DepthSurface.cpp
+++ b/core/libs/prx/libSceAgcDriver/Graphics/src/DepthSurface.cpp
@@ -2,6 +2,7 @@
 #include "prx/libSceAgcDriver/Graphics/include/DepthSurface.hpp"
 #include "prx/libSceAgcDriver/Execution/include/GuestMemory.hpp"
 #include "prx/libc/include/GuestAllocations.hpp"
+#include "prx/libc/include/PrimedSharedMutex.hpp"
 #include "prx/libSceAgcDriver/Graphics/include/BufferPool.hpp"
 #include "prx/libSceAgcDriver/Graphics/include/Recorder.hpp"
 #include "prx/libSceAgcDriver/Graphics/include/GuestBufferMemory.hpp"
@@ -82,7 +83,7 @@ struct DepthGuard {
 };
 
 std::shared_mutex& depthGuardMutex() {
-    static std::shared_mutex mutex;
+    static PrimedSharedMutex mutex;
     return mutex;
 }
 
diff --git a/core/libs/prx/libSceAgcDriver/Graphics/src/MultisampleTarget.cpp b/core/libs/prx/libSceAgcDriver/Graphics/src/MultisampleTarget.cpp
index c0ac9798e8..e6fc8bc491 100644
--- a/core/libs/prx/libSceAgcDriver/Graphics/src/MultisampleTarget.cpp
+++ b/core/libs/prx/libSceAgcDriver/Graphics/src/MultisampleTarget.cpp
@@ -16,6 +16,7 @@
 #include "IntermediateRepresentation/IrMetadata/BufferFormat.hpp"
 #include "prx/libSceAgcDriver/Execution/include/GuestMemory.hpp"
 #include "prx/libc/include/GuestAllocations.hpp"
+#include "prx/libc/include/PrimedSharedMutex.hpp"
 #include <algorithm>
 #include <array>
 #include <atomic>
@@ -774,14 +775,6 @@ struct GuardedRange {
     bool fmask = false;
 };
 
-class PrimedSharedMutex : public std::shared_mutex {
-public:
-    PrimedSharedMutex() {
-        lock();
-        unlock();
-    }
-};
-
 std::shared_mutex& guardedMutex() {
     static PrimedSharedMutex mutex;
     return mutex;
diff --git a/core/libs/prx/libc/include/PrimedSharedMutex.hpp b/core/libs/prx/libc/include/PrimedSharedMutex.hpp
new file mode 100644
index 0000000000..7f6a9d8e7f
--- /dev/null
+++ b/core/libs/prx/libc/include/PrimedSharedMutex.hpp
@@ -0,0 +1,14 @@
+#ifndef CORE_LIBS_PRX_LIBC_INCLUDE_PRIMEDSHAREDMUTEX_HPP
+#define CORE_LIBS_PRX_LIBC_INCLUDE_PRIMEDSHAREDMUTEX_HPP
+
+#include <shared_mutex>
+
+class PrimedSharedMutex : public std::shared_mutex {
+public:
+    PrimedSharedMutex() {
+        lock();
+        unlock();
+    }
+};
+
+#endif
diff --git a/core/libs/prx/libkernel/EventFlag/src/EventFlag.cpp b/core/libs/prx/libkernel/EventFlag/src/EventFlag.cpp
index 65ae972430..4351a30052 100644
--- a/core/libs/prx/libkernel/EventFlag/src/EventFlag.cpp
+++ b/core/libs/prx/libkernel/EventFlag/src/EventFlag.cpp
@@ -4,6 +4,7 @@
 #include <atomic>
 #include "SceTypes.hpp"
 #include "prx/libc/include/General.hpp"
+#include "prx/libc/include/PrimedSharedMutex.hpp"
 #include "prx/libkernel/Time/include/Time.hpp"
 #include "prx/libkernel/Time/include/TimedWait.hpp"
 #include <chrono>
@@ -97,7 +98,7 @@ struct EventFlagHandle {
     bool opened = false;
 };
 
-std::shared_mutex eventFlagRegistryMutex;
+PrimedSharedMutex eventFlagRegistryMutex;
 std::unordered_map<KernelEventFlag, std::shared_ptr<EventFlagHandle>> eventFlagRegistry;
 
 std::shared_ptr<EventFlagHandle> ResolveEventFlag(KernelEventFlag handle) {