Add internal service guard helper, needed for proper thread safe service init/exit

nx/source/services/nv.c

@@ -1,34 +1,26 @@
 #define NX_SERVICE_ASSUME_NON_DOMAIN
 #include <string.h>
-#include "types.h"
-#include "result.h"
-#include "arm/atomics.h"
+#include "service_guard.h"
 #include "kernel/tmem.h"
-#include "sf/service.h"
 #include "services/applet.h"
-#include "nvidia/ioctl.h"
 #include "services/nv.h"
-#include "services/sm.h"
+#include "nvidia/ioctl.h"
 
 __attribute__((weak)) u32 __nx_nv_transfermem_size = 0x800000;
 
 static Service g_nvSrv;
 static Service g_nvSrvClone;
-static u64 g_refCnt;
 
 static size_t g_nvIpcBufferSize = 0;
 static TransferMemory g_nvTransfermem;
 
-static Result _nvInitialize(Handle proc, Handle sharedmem, u32 transfermem_size);
+static Result _nvCmdInitialize(Handle proc, Handle sharedmem, u32 transfermem_size);
 static Result _nvSetClientPID(u64 AppletResourceUserId);
 
-Result nvInitialize(void)
+NX_GENERATE_SERVICE_GUARD(nv);
+
+Result _nvInitialize(void)
 {
-    atomicIncrement64(&g_refCnt);
-
-    if (serviceIsActive(&g_nvSrv))
-        return 0;
-
     Result rc = 0;
     u64 AppletResourceUserId = 0;
 
@@ -58,7 +50,7 @@ Result nvInitialize(void)
             rc = tmemCreate(&g_nvTransfermem, __nx_nv_transfermem_size, Perm_None);
 
         if (R_SUCCEEDED(rc))
-            rc = _nvInitialize(CUR_PROCESS_HANDLE, g_nvTransfermem.handle, __nx_nv_transfermem_size);
+            rc = _nvCmdInitialize(CUR_PROCESS_HANDLE, g_nvTransfermem.handle, __nx_nv_transfermem_size);
 
         // Clone the session handle - the cloned session is used to execute certain commands in parallel
         if (R_SUCCEEDED(rc))
@@ -80,16 +72,14 @@ Result nvInitialize(void)
     return rc;
 }
 
-void nvExit(void)
+void _nvCleanup(void)
 {
-    if (atomicDecrement64(&g_refCnt) == 0) {
-        serviceClose(&g_nvSrvClone);
-        serviceClose(&g_nvSrv);
-        tmemClose(&g_nvTransfermem);
-    }
+    serviceClose(&g_nvSrvClone);
+    serviceClose(&g_nvSrv);
+    tmemClose(&g_nvTransfermem);
 }
 
-static Result _nvInitialize(Handle proc, Handle sharedmem, u32 transfermem_size)
+static Result _nvCmdInitialize(Handle proc, Handle sharedmem, u32 transfermem_size)
 {
     return serviceDispatchIn(&g_nvSrv, 3, transfermem_size,
         .in_num_handles = 2,

nx/source/services/service_guard.h

@@ -0,0 +1,58 @@
+#pragma once
+#include "types.h"
+#include "result.h"
+#include "kernel/mutex.h"
+#include "sf/service.h"
+#include "services/sm.h"
+
+typedef struct ServiceGuard
+{
+    Mutex mutex;
+    u32 refCount;
+} ServiceGuard;
+
+NX_INLINE bool serviceGuardBeginInit(ServiceGuard* g)
+{
+    mutexLock(&g->mutex);
+    return (g->refCount++) == 0;
+}
+
+NX_INLINE Result serviceGuardEndInit(ServiceGuard* g, Result rc, void (*cleanupFunc)(void))
+{
+    if (R_FAILED(rc))
+    {
+        cleanupFunc();
+        --g->refCount;
+    }
+    mutexUnlock(&g->mutex);
+    return rc;
+}
+
+NX_INLINE void serviceGuardExit(ServiceGuard* g, void (*cleanupFunc)(void))
+{
+    mutexLock(&g->mutex);
+    if (g->refCount && (--g->refCount) == 0)
+        cleanupFunc();
+    mutexUnlock(&g->mutex);
+}
+
+#define NX_GENERATE_SERVICE_GUARD_PARAMS(name, _paramdecl, _parampass) \
+\
+static ServiceGuard g_##name##Guard; \
+NX_INLINE Result _##name##Initialize _paramdecl; \
+static void _##name##Cleanup(void); \
+\
+Result name##Initialize _paramdecl \
+{ \
+    Result rc = 0; \
+    if (serviceGuardBeginInit(&g_##name##Guard)) \
+        rc = _##name##Initialize _parampass; \
+    return serviceGuardEndInit(&g_##name##Guard, rc, _##name##Cleanup); \
+} \
+\
+void name##Exit(void) \
+{ \
+    serviceGuardExit(&g_##name##Guard, _##name##Cleanup); \
+}
+
+#define NX_GENERATE_SERVICE_GUARD(name) NX_GENERATE_SERVICE_GUARD_PARAMS(name, (void), ())

nx/source/services/sm.c

@@ -1,14 +1,9 @@
 // Copyright 2017 plutoo
 #define NX_SERVICE_ASSUME_NON_DOMAIN
-#include "types.h"
-#include "result.h"
-#include "arm/atomics.h"
-#include "sf/service.h"
+#include "service_guard.h"
 #include "services/fatal.h"
-#include "services/sm.h"
 
 static Service g_smSrv;
-static u64 g_refCnt;
 
 #define MAX_OVERRIDES 32
 
@@ -45,14 +40,10 @@ Handle smGetServiceOverride(u64 name)
     return INVALID_HANDLE;
 }
 
+NX_GENERATE_SERVICE_GUARD(sm);
 
-Result smInitialize(void)
+Result _smInitialize(void)
 {
-    atomicIncrement64(&g_refCnt);
-
-    if (smHasInitialized())
-        return 0;
-
     Handle sm_handle;
     Result rc = svcConnectToNamedPort(&sm_handle, "sm:");
     while (R_VALUE(rc) == KERNELRESULT(NotFound)) {
@@ -73,18 +64,12 @@ Result smInitialize(void)
         rc = serviceDispatchIn(&g_smSrv, 0, in, .in_send_pid = true);
     }
 
-    if (R_FAILED(rc))
-        smExit();
-
     return rc;
 }
 
-void smExit(void)
+void _smCleanup(void)
 {
-    if (atomicDecrement64(&g_refCnt) == 0)
-    {
-        serviceClose(&g_smSrv);
-    }
+    serviceClose(&g_smSrv);
 }
 
 Service *smGetServiceSession(void)