feat(agc): store pending storage-image results at each flip with APS5_STORE_AT_FLIP

core/libs/prx/libSceAgcDriver/Execution/src/VulkanDevice.cpp

@@ -2079,6 +2079,8 @@ FrameDumps& Dumps() {
 }
 
 bool VulkanDevice::PresentDisplayBuffer(const DisplayBuffer& buffer) {
+    static const bool storeAtFlip = Graphics::StorageTexture::StoreAtFlipRequested(std::getenv("APS5_STORE_AT_FLIP"));
+    if (storeAtFlip) Graphics::StorageTexture::FlushAllPending("flip");
     if (buffer.tilingMode == 1) {
         const auto pixels = ReadDisplayBuffer(buffer);
         return present(buffer.width, buffer.height, true, pixels);

core/libs/prx/libSceAgcDriver/Graphics/include/Texture.hpp

@@ -152,6 +152,7 @@ class StorageTexture : public std::enable_shared_from_this<StorageTexture> {
     // overlapping pending image, as before).
     static bool FlushPending(std::uint64_t address, std::size_t bytes, const StorageTexture* except = nullptr, const char* reason = "memory access", PublishScope scope = PublishScope::Whole, bool* published = nullptr);
     static void FlushAllPending(const char* reason);
+    static bool StoreAtFlipRequested(const char* value);
     // See PendingSerial: a change of a surface's source outside the registry (a unit shadow
     // retile) moves it too.
     static void BumpPendingSerial();

core/libs/prx/libSceAgcDriver/Graphics/src/Texture.cpp

@@ -2520,6 +2520,12 @@ void StorageTexture::FlushAllPending(const char* reason) {
     static_cast<void>(FlushPending(0, std::numeric_limits<std::size_t>::max(), nullptr, reason));
 }
 
+bool StorageTexture::StoreAtFlipRequested(const char* value) {
+    if (value == nullptr) return false;
+    if (std::strcmp(value, "1") == 0) return true;
+    throw std::runtime_error(std::string("APS5_STORE_AT_FLIP=") + value + ": expected 1");
+}
+
 std::shared_ptr<StorageTexture> StorageTexture::FindPending(std::uint64_t address, std::uint64_t bytes) {
     auto& pending = Pending();
     std::lock_guard lock(pending.mutex);

core/libs/prx/libSceAgcDriver/tests/Graphics.cpp

@@ -3461,6 +3461,13 @@ void highestDrawIndexTests() {
     expectFailure([&] { HighestDrawIndex(bytesOf(narrow), 1, false); }, "unsupported index size");
 }
 
+void storeAtFlipTests() {
+    using AgcDriver::Graphics::StorageTexture;
+    Require(!StorageTexture::StoreAtFlipRequested(nullptr), "an unset APS5_STORE_AT_FLIP stored at each flip");
+    Require(StorageTexture::StoreAtFlipRequested("1"), "APS5_STORE_AT_FLIP=1 did not store at each flip");
+    for (const char* value : {"0", "", "true", "11"}) expectFailure([&] { StorageTexture::StoreAtFlipRequested(value); }, "expected 1");
+}
+
 void vertexCopyTests() {
     using AgcDriver::Graphics::PlanVertexCopies;
     using AgcDriver::Graphics::VertexFetch;
@@ -3586,6 +3593,7 @@ int main() {
         validationTests();
         vertexCopyTests();
         highestDrawIndexTests();
+        storeAtFlipTests();
         pixelParameterSlotTests();
         rectListTests();
         floatControlsModeTests();

docs/dev/TechnicalDebt.md

@@ -271,6 +271,7 @@ Throughout the project, every function at every stage either **does exactly what
   - a system call that writes into a protected page fails with `EFAULT` instead of faulting. `GuestArena::HostWrite` lifts the protection for the calls it brackets (the file reads); a host call that writes guest memory without it (sockets, `clock_gettime` and the like into a watched page) fails;
   - code that changes the protection of watched pages, or maps over them, has to call `GuestWriteWatchProtectionChanged`, and code that asks the kernel for a page's protection has to ask `GuestWriteWatchProtection` first, since a watched page is read-only between a collection and the next write. Nothing calls either yet: the macOS memory paths are not in the tree;
   - the handler is installed when libc loads and passes other faults to the handler installed before it. A handler installed later has to do the same.
+- [Pending storage-image results](../../core/libs/prx/libSceAgcDriver/Graphics/src/Texture.cpp) (libSceAgcDriver) are stored when something reads their memory, not when the GPU work that wrote them completes. A title that waits for that work, frees the image and reuses its memory can have the new data overwritten by the late store (#1970). `APS5_STORE_AT_FLIP=1` stores every pending result at each flip; storing them at the title's GPU waits (labels, fences) is unimplemented.
 - Windows host-pointer imports of the guest mapping itself are compared instead of write-watched: a driver can mark imported pages dirty after the synchronous import window. Shared memory imported through a separate writable alias retains protection-based tracking on the guest views; driver access to the import alias does not disarm those views. [GuestMemory](../../core/libs/prx/libSceAgcDriver/Execution/src/GuestMemory.cpp) excludes every overlapping 64 KiB tracker block while its backing is retained. A full block replaced by fresh private backing regains tracking and gets a new generation; protection changes, partial replacements and shared remappings do not restore it. This preserves CPU edits through byte comparisons but disables snapshot reuse and unit shadows for excluded blocks; restoring tracking on import retirement without replacing the backing and measuring the comparison cost remain unimplemented.
 - [shm_open](../../core/libs/prx/libkernel/File/src/SharedMemory.cpp) (libkernel) creates only anonymous objects (`SHM_ANON`), each backed by a host anonymous file: a `memfd` on Linux, a delete-on-close temporary file on Windows. The flag checks follow FreeBSD 11's `kern_shm_open`; the mode is ignored. Named objects throw. The descriptor cannot be mapped yet: `mmap` accepts only private anonymous mappings and fails a descriptor mapping with `EOPNOTSUPP`, so the known caller (the bundled Mesa in PPSA59322, which truncates the object and maps it `MAP_SHARED`) gets that failure
 - [sceNetSendmsg and sceNetRecvmsg](../../core/libs/prx/libSceNet/Export.cpp) (libSceNet) copy the scatter/gather list through one host buffer and accept only the flags `sceNetSend`/`sceNetRecv` accept. Sending control data throws; a receive never returns control data (`msg_controllen` 0), since no socket option that queues it is supported

docs/user/USAGE.md

@@ -108,6 +108,10 @@ Games that open the console's system font sets (`sceFontOpenFontSet`) need font
 
 The game runs on the first Vulkan 1.1 device with graphics and compute queues and swapchain presentation, preferring a discrete GPU over an integrated one. Set `ANYPS5_GPU` to a part of a device name, compared without regard to case, to run on another device; the names are printed at start-up in the `Physical device candidate` lines. When no usable device contains the text, the start fails and the error lists the device names.
 
+### Storing GPU results at each flip
+
+GPU results in storage images and render targets stay on the GPU until something reads their memory. A title that frees such an image after waiting for its GPU work and reuses the memory can have its new data overwritten when the results are stored later ([TechnicalDebt](../dev/TechnicalDebt.md)). `APS5_STORE_AT_FLIP=1` stores every pending result when a display buffer is flipped, at the cost of one write-back per pending image and frame. Any other value stops the title at its first flip.
+
 ## Exit codes
 
 `0`: conversion succeeded. `1`: invalid arguments. `2`: conversion failed; the error is printed to stderr. With `--autorun`, successful conversion returns the launched application's exit code.