Add support for a shared memory mapping on Kernel & User Memory

src/core/psxemulator.h

@@ -189,7 +189,7 @@ class Emulator {
     Settings<SettingMcd1, SettingMcd2, SettingBios, SettingPpfDir, SettingPsxExe,
              SettingXa, SettingSpuIrq, SettingBnWMdec, SettingScaler, SettingAutoVideo, SettingVideo, SettingFastBoot,
              SettingDebugSettings, SettingRCntFix, SettingIsoPath, SettingLocale, SettingMcd1Inserted,
-             SettingMcd2Inserted, SettingDynarec, Setting8MB, SettingGUITheme, SettingDither, SettingCachedDithering,
+             SettingMcd2Inserted, SettingDynarec, Setting8MB,SettingGUITheme, SettingDither, SettingCachedDithering,
              SettingGLErrorReporting, SettingGLErrorReportingSeverity, SettingFullCaching, SettingHardwareRenderer,
              SettingShownAutoUpdateConfig, SettingAutoUpdate, SettingMSAA, SettingLinearFiltering, SettingKioskMode,
              SettingMcd1Pocketstation, SettingMcd2Pocketstation, SettingBiosBrowsePath, SettingEXP1Filepath,

src/core/psxmem.cc

@@ -89,7 +89,11 @@ int PCSX::Memory::init() {
     m_readLUT = (uint8_t **)calloc(0x10000, sizeof(void *));
     m_writeLUT = (uint8_t **)calloc(0x10000, sizeof(void *));
 
-    m_wram = (uint8_t *)calloc(0x00800000, 1);
+    // Init all memory as named mappings
+    bool success = m_wramShared.init("wram", 0x00800000, true);
+    if (success) g_system->message(_("SharedMem failed to share memory for wram, falling back to memory alloc\n"));
+    m_wram = m_wramShared.getPtr();
+
     m_exp1 = (uint8_t *)calloc(0x00800000, 1);
     m_hard = (uint8_t *)calloc(0x00010000, 1);
     m_bios = (uint8_t *)calloc(0x00080000, 1);
@@ -239,7 +243,6 @@ The distributed OpenBIOS.bin file can be an appropriate BIOS replacement.
 }
 
 void PCSX::Memory::shutdown() {
-    free(m_wram);
     free(m_exp1);
     free(m_hard);
     free(m_bios);

src/core/psxmem.h

@@ -23,6 +23,7 @@
 #include <vector>
 
 #include "core/psxemulator.h"
+#include "support/sharedmem.h"
 
 #if defined(__BIGENDIAN__)
 
@@ -186,8 +187,12 @@ class Memory {
     int m_writeok = 1;
     uint32_t m_biosCRC = 0;
 
+    // Shared memory wrappers, pointers below point to these where appropriate
+    SharedMem m_wramShared;
+
     // hopefully this should become private eventually, with only certain classes having direct access.
   public:
+
     uint8_t *m_wram = nullptr;  // Kernel & User Memory (8 Meg)
     uint8_t *m_exp1 = nullptr;  // Expansion Region 1 (ROM/RAM) / Parallel Port (512K)
     uint8_t *m_bios = nullptr;  // BIOS ROM (512K)

src/gui/widgets/memory_observer.cc

@@ -37,7 +37,8 @@ PCSX::Widgets::MemoryObserver::MemoryObserver(bool& show) : m_show(show), m_list
         for (const auto& addressValuePair : m_addressValuePairs) {
             if (addressValuePair.frozen) {
                 const auto dataSize = getStrideFromValueType(m_scanValueType);
-                memcpy(g_emulator->m_mem->m_wram + addressValuePair.address - 0x80000000, &addressValuePair.frozenValue,
+                memcpy(g_emulator->m_mem->m_wram + addressValuePair.address - 0x80000000,
+                       &addressValuePair.frozenValue,
                        dataSize);
             }
         }

src/support/sharedmem-unix.cc

@@ -0,0 +1,95 @@
+/*
+
+MIT License
+
+Copyright (c) 2022 PCSX-Redux authors
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+
+*/
+
+#if !defined(_WIN32) && !defined(_WIN64)
+
+#include "support/sharedmem.h"
+
+#include <assert.h>
+#include <fcntl.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <sys/mman.h>
+#include <sys/stat.h>
+
+bool PCSX::SharedMem::init(const char* id, size_t size, bool initToZero) {
+    assert(m_mem == nullptr);
+    bool doRawAlloc = true;
+    m_size = size;
+    // Try to create a shared memory mapping, if an ID is provided
+    if (id != nullptr) {
+        // Build the full name to share as
+        m_sharedName = getSharedName(id, static_cast<uint32_t>(getpid()));
+        // Try to create a shared memory mapping, if a name is provided
+        m_fd = shm_open(m_sharedName.c_str(), O_RDWR | O_CREAT, S_IRUSR | S_IWUSR);
+        if (m_fd >= 0) {
+            // fd is ready, reserve the memory we need
+            int result = ftruncate(m_fd, static_cast<off_t>(size));
+            if (result < 0) {
+                shm_unlink(m_sharedName.c_str());
+                close(m_fd);
+                m_fd = -1;
+            } else {
+                // ftruncate completed, now map the memory at 0 offset
+                void* basePointer = mmap(nullptr, size, PROT_READ | PROT_WRITE, MAP_SHARED, m_fd, 0);
+                // Validate success and assign the view to m_mem
+                if (basePointer != MAP_FAILED) {
+                    doRawAlloc = false;
+                    m_mem = static_cast<uint8_t*>(basePointer);
+                    // Initialise memory to zero, if requested
+                    if (initToZero) {
+                        memset(m_mem, 0, size);
+                    }
+                } else {
+                    shm_unlink(m_sharedName.c_str());
+                    close(m_fd);
+                    m_fd = -1;
+                }
+            }
+        }
+    }
+    // Alloc memory directly if we opted out or had problems creating the memory map
+    if (doRawAlloc) {
+        // calloc will automatically init memory to zero
+        m_mem = (uint8_t*)calloc(size, 1);
+    }
+
+    // Return false if we had to fall back to a raw alloc
+    return !(doRawAlloc && id != nullptr);
+}
+
+PCSX::SharedMem::~SharedMem() {
+    if (m_fd == -1) {
+        free(m_mem);
+    } else {
+        munmap(m_mem, m_size);
+        shm_unlink(m_sharedName.c_str());
+        close(m_fd);
+    }
+}
+
+#endif

src/support/sharedmem-windows.cc

@@ -0,0 +1,83 @@
+/*
+
+MIT License
+
+Copyright (c) 2022 PCSX-Redux authors
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+
+*/
+#if defined(_WIN32) || defined(_WIN64)
+
+#include "support/sharedmem.h"
+#include "support/windowswrapper.h"
+
+#include <assert.h>
+
+bool PCSX::SharedMem::init(const char* id, size_t size, bool initToZero) {
+    assert(m_mem == nullptr);
+    bool doRawAlloc = true;
+    m_size = size;
+    // Try to create a shared memory mapping, if an id is provided
+    if (id != nullptr) {
+        // Build the full name to share as
+        std::string fullname = getSharedName(id, static_cast<uint32_t>(GetCurrentProcessId()));
+        // Create the memory mapping handle
+        m_fileHandle = CreateFileMappingA(INVALID_HANDLE_VALUE, nullptr, PAGE_READWRITE,
+            static_cast<uint32_t>(size >> 32), static_cast<uint32_t>(size), fullname.c_str());
+        if (m_fileHandle != INVALID_HANDLE_VALUE) {
+            // Create a view of the memory mapping at 0 offset
+            void* basePointer = MapViewOfFileEx(m_fileHandle, FILE_MAP_READ | FILE_MAP_WRITE, 0, 0, size, nullptr);
+            // Validate success and assign the view to m_mem
+            if (basePointer != nullptr) {
+                doRawAlloc = false;
+                m_mem = static_cast<uint8_t *>(basePointer);
+                // Initialise memory to zero, if requested
+                if (initToZero) {
+                    memset(m_mem, 0, size);
+                }
+            } else {
+                CloseHandle(m_fileHandle);
+                m_fileHandle = nullptr;
+            }
+        } else {
+            m_fileHandle = nullptr;
+        }
+    }
+    // Alloc memory directly if we opted out or had problems creating the memory map
+    if (doRawAlloc) {
+        // calloc will automatically init memory to zero
+        m_mem = (uint8_t *)calloc(size, 1);
+    }
+    // Return false if we had to fall back to a raw alloc
+    return !(doRawAlloc && id != nullptr);
+}
+
+PCSX::SharedMem::~SharedMem() {
+    if (m_fileHandle != nullptr) {
+        UnmapViewOfFile(m_mem);
+        m_mem = nullptr;
+        CloseHandle(m_fileHandle);
+        m_fileHandle = nullptr;
+    } else {
+        free(m_mem);
+    }
+}
+
+#endif

src/support/sharedmem.cc

@@ -0,0 +1,33 @@
+/*
+
+MIT License
+
+Copyright (c) 2022 PCSX-Redux authors
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+
+*/
+
+#include "support/sharedmem.h"
+#include "fmt/format.h"
+
+std::string PCSX::SharedMem::getSharedName(const char* id, uint32_t pid) {
+    // Example name: pcsx-redux-wram-37045
+    return fmt::format("pcsx-redux-{}-{}", id, pid);
+}

src/support/sharedmem.h

@@ -0,0 +1,63 @@
+/*
+
+MIT License
+
+Copyright (c) 2022 PCSX-Redux authors
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+
+*/
+
+#pragma once
+
+#include <stdint.h>
+#include <string>
+
+namespace PCSX {
+
+class SharedMem {
+  public:
+    SharedMem() {}
+    ~SharedMem();
+
+    /**
+     * Returns true if:
+     *  - the memory was sucessfully shared with the given ID, or
+     *  - no ID was given and a raw alloc was performed
+     * Returns false if:
+     *  - the memory failed to successfully share and defaulted to a raw alloc
+     */
+    bool init(const char* id, size_t size, bool initToZero);
+
+    uint8_t* getPtr() { return m_mem; }
+    size_t getSize() { return m_size; }
+
+  private:
+    std::string getSharedName(const char* id, uint32_t pid);
+
+  private:
+    uint8_t* m_mem = nullptr;
+    size_t m_size = 0;
+
+    void* m_fileHandle = nullptr;
+    std::string m_sharedName;
+    int m_fd = -1;
+};
+
+}  // namespace PCSX

vsprojects/support/support.vcxproj

@@ -301,6 +301,7 @@
     <ClInclude Include="..\..\src\support\strings-helpers.h" />
     <ClInclude Include="..\..\src\support\protobuf.h" />
     <ClInclude Include="..\..\src\support\settings.h" />
+    <ClInclude Include="..\..\src\support\sharedmem.h" />
     <ClInclude Include="..\..\src\support\sjis_conv.h" />
     <ClInclude Include="..\..\src\support\slice.h" />
     <ClInclude Include="..\..\src\support\ssize_t.h" />
@@ -337,6 +338,9 @@
     <ClCompile Include="..\..\src\support\file.cc" />
     <ClCompile Include="..\..\src\support\md5.cc" />
     <ClCompile Include="..\..\src\support\mem4g.cc" />
+    <ClCompile Include="..\..\src\support\sharedmem-unix.cc" />
+    <ClCompile Include="..\..\src\support\sharedmem-windows.cc" />
+    <ClCompile Include="..\..\src\support\sharedmem.cc" />
     <ClCompile Include="..\..\src\support\sjis_conv.cc" />
     <ClCompile Include="..\..\src\support\uvfile.cc" />
     <ClCompile Include="..\..\src\support\version-linux.cc" />

vsprojects/support/support.vcxproj.filters

@@ -165,6 +165,9 @@
     <ClInclude Include="..\..\src\support\mem4g.h">
       <Filter>Header Files</Filter>
     </ClInclude>
+    <ClInclude Include="..\..\src\support\sharedmem.h">
+      <Filter>Header Files</Filter>
+    </ClInclude>
   </ItemGroup>
   <ItemGroup>
     <ClCompile Include="..\..\src\support\file.cc">
@@ -209,6 +212,15 @@
     <ClCompile Include="..\..\src\support\mem4g.cc">
       <Filter>Source Files</Filter>
     </ClCompile>
+    <ClCompile Include="..\..\src\support\sharedmem-windows.cc">
+      <Filter>Source Files</Filter>
+    </ClCompile>
+    <ClCompile Include="..\..\src\support\sharedmem-unix.cc">
+      <Filter>Source Files</Filter>
+    </ClCompile>
+    <ClCompile Include="..\..\src\support\sharedmem.cc">
+      <Filter>Source Files</Filter>
+    </ClCompile>
   </ItemGroup>
   <ItemGroup>
     <None Include="packages.config" />