Implement per-thread non-blocking behavior for srvGetServiceHandle...

implement srvWaitForPortRegistered and srvIsPortRegistered as well.

libctru/include/3ds/srv.h

@@ -10,6 +10,14 @@ Result srvInit(void);
 /// Exits the service API.
 void srvExit(void);
 
+/**
+ * @brief Makes srvGetServiceHandle non-blocking for the current thread (or blocking, the default), in case of unavailable (full) requested services.
+ * @param blocking Whether srvGetServiceHandle should be non-blocking.
+ *                 srvGetServiceHandle will always block if the service hasn't been registered yet,
+ *                 use srvIsServiceRegistered to check whether that is the case or not.
+ */
+void srvSetBlockingPolicy(bool nonBlocking);
+
 /**
  * @brief Gets the current service API session handle.
  * @return The current service API session handle.
@@ -20,6 +28,9 @@ Handle *srvGetSessionHandle(void);
  * @brief Retrieves a service handle, retrieving from the environment handle list if possible.
  * @param out Pointer to write the handle to.
  * @param name Name of the service.
+ * @return 0 if no error occured,
+ *         0xD8E06406 if the caller has no right to access the service,
+ *         0xD0401834 if the requested service port is full and srvGetServiceHandle is non-blocking (see @ref srvSetBlockingPolicy).
  */
 Result srvGetServiceHandle(Handle* out, const char* name);
 
@@ -50,6 +61,9 @@ Result srvUnregisterService(const char* name);
  * @brief Retrieves a service handle.
  * @param out Pointer to output the handle to.
  * @param name Name of the service.
+ * * @return 0 if no error occured,
+ *           0xD8E06406 if the caller has no right to access the service,
+ *           0xD0401834 if the requested service port is full and srvGetServiceHandle is non-blocking (see @ref srvSetBlockingPolicy).
  */
 Result srvGetServiceHandleDirect(Handle* out, const char* name);
 
@@ -73,6 +87,12 @@ Result srvUnregisterPort(const char* name);
  */
 Result srvGetPort(Handle* out, const char* name);
 
+/**
+ * @brief Waits for a port to be registered.
+ * @param name Name of the port to wait for registration.
+ */
+Result srvWaitForPortRegistered(const char* name);
+
 /**
  * @brief Subscribes to a notification.
  * @param notificationId ID of the notification.
@@ -112,3 +132,10 @@ Result srvPublishAndGetSubscriber(u32* processIdCountOut, u32* processIdsOut, u3
  * @param name Name of the service to check.
  */
 Result srvIsServiceRegistered(bool* registeredOut, const char* name);
+
+/**
+ * @brief Checks whether a port is registered.
+ * @param registeredOut Pointer to output the registration status to.
+ * @param name Name of the port to check.
+ */
+Result srvIsPortRegistered(bool* registeredOut, const char* name);

libctru/source/internal.h

@@ -26,6 +26,9 @@ typedef struct
 	// FS session override
 	u32    fs_magic;
 	Handle fs_session;
+
+	// Whether srvGetServiceHandle is non-blocking in case of full service ports.
+	bool srv_blocking_policy;
 } ThreadVars;
 
 static inline ThreadVars* getThreadVars(void)

libctru/source/srv.c

@@ -14,9 +14,17 @@
 #include <3ds/os.h>
 #include <3ds/services/srvpm.h>
 
+#include "internal.h"
+
 static Handle srvHandle;
 static int srvRefCount;
 
+static bool srvGetBlockingPolicy(void)
+{
+	ThreadVars *tv = getThreadVars();
+	return tv->magic == THREADVARS_MAGIC && tv->srv_blocking_policy;
+}
+
 Result srvInit(void)
 {
 	Result rc = 0;
@@ -43,6 +51,12 @@ void srvExit(void)
 	srvHandle = 0;
 }
 
+void srvSetBlockingPolicy(bool nonBlocking)
+{
+	ThreadVars *tv = getThreadVars();
+	tv->srv_blocking_policy = nonBlocking;
+}
+
 Handle *srvGetSessionHandle(void)
 {
 	return &srvHandle;
@@ -128,7 +142,7 @@ Result srvGetServiceHandleDirect(Handle* out, const char* name)
 	cmdbuf[0] = IPC_MakeHeader(0x5,4,0); // 0x50100
 	strncpy((char*) &cmdbuf[1], name,8);
 	cmdbuf[3] = strnlen(name, 8);
-	cmdbuf[4] = 0x0;
+	cmdbuf[4] = (u32)srvGetBlockingPolicy(); // per-thread setting, default is blocking
 
 	if(R_FAILED(rc = svcSendSyncRequest(srvHandle)))return rc;
 
@@ -184,6 +198,20 @@ Result srvGetPort(Handle* out, const char* name)
 	return cmdbuf[1];
 }
 
+Result srvWaitForPortRegistered(const char* name)
+{
+	Result rc = 0;
+	u32* cmdbuf = getThreadCommandBuffer();
+
+	cmdbuf[0] = IPC_MakeHeader(0x8,4,0); // 0x80100
+	strncpy((char*) &cmdbuf[1], name,8);
+	cmdbuf[3] = strnlen(name, 8);
+	cmdbuf[4] = 0x1;
+
+	if(R_FAILED(rc = svcSendSyncRequest(srvHandle)))return rc;
+	return cmdbuf[1];
+}
+
 Result srvSubscribe(u32 notificationId)
 {
 	Result rc = 0;
@@ -269,3 +297,21 @@ Result srvIsServiceRegistered(bool* registeredOut, const char* name)
 
 	return cmdbuf[1];
 }
+
+Result srvIsPortRegistered(bool* registeredOut, const char* name)
+{
+	Handle port;
+	Result rc = srvGetPort(&port, name);
+
+	if(rc == 0xD8801BFA)
+	{
+		if(registeredOut) *registeredOut = false;
+		return 0;
+	}
+	else if(R_SUCCEEDED(rc))
+	{
+		if(registeredOut) *registeredOut = true;
+		svcCloseHandle(port);
+	}
+	return rc;
+}

libctru/source/system/syscalls.c

@@ -51,6 +51,7 @@ void __system_initSyscalls(void)
 	tv->reent = _impure_ptr;
 	tv->thread_ptr = NULL;
 	tv->tls_tp = __tls_start-8; // ARM ELF TLS ABI mandates an 8-byte header
+	tv->srv_blocking_policy = false;
 
 	u32 tls_size = __tdata_lma_end - __tdata_lma;
 	if (tls_size)

libctru/source/thread.c

@@ -33,6 +33,7 @@ static void _thread_begin(void* arg)
 	tv->reent = &t->reent;
 	tv->thread_ptr = t;
 	tv->tls_tp = (u8*)t->stacktop-8; // ARM ELF TLS ABI mandates an 8-byte header
+	tv->srv_blocking_policy = false;
 	t->ep(t->arg);
 	threadExit(0);
 }