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linux: Fix 'explicit_reply' semantics

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By storing the reply socket descriptor inside the 'Ipc_ostream::_dst'
capability instead as part of the connection state object, we can
use the 'explicit_reply' mechanism as usual. Right now, we store
both the tid and socket handle in 'Native_capability::Dst'. In the
final version, the 'tid' member will be gone.
This commit is contained in:
Norman Feske
2012-07-18 14:48:37 +02:00
parent 1c3b9a6f68
commit 508d2050a6
3 changed files with 50 additions and 70 deletions
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50
base-linux/include/base/native_types.h
View File

@ -94,14 +94,17 @@ namespace Genode {
inline bool operator != (Native_thread_id t1, Native_thread_id t2) { inline bool operator != (Native_thread_id t1, Native_thread_id t2) {
return (t1.tid != t2.tid) || (t1.pid != t2.pid); } return (t1.tid != t2.tid) || (t1.pid != t2.pid); }
struct Cap_dst_policy { struct Cap_dst_policy
{
struct Dst struct Dst
{ {
long tid; /* XXX to be removed once the transition to SCM rights long tid; /* XXX to be removed once the transition to SCM rights
is completed */ is completed */
int socket; int socket;
/**
* Default constructor creates invalid destination
*/
Dst() : tid(0), socket(-1) { } Dst() : tid(0), socket(-1) { }
Dst(long tid, int socket) : tid(tid), socket(socket) { } Dst(long tid, int socket) : tid(tid), socket(socket) { }
@ -119,45 +122,10 @@ namespace Genode {
typedef Native_capability_tpl<Cap_dst_policy> Native_capability; typedef Native_capability_tpl<Cap_dst_policy> Native_capability;
class Native_connection_state /**
{ * The connection state is the socket handle of the RPC entrypoint
public: */
typedef int Native_connection_state;
struct Reply_socket_error { };
private:
int _socket; /* server-entrypoint socket */
int _reply_socket; /* reply socket */
public:
Native_connection_state() : _socket(-1), _reply_socket(-1) { }
void socket(int socket) { _socket = socket; }
int socket() const { return _socket; }
/*
* FIXME Check for unsupported usage pattern: Reply sockets should
* only be set once and read once.
*/
void reply_socket(int socket)
{
if (_reply_socket != -1) throw Reply_socket_error();
_reply_socket = socket;
}
int reply_socket()
{
if (_reply_socket == -1) throw Reply_socket_error();
int s = _reply_socket;
_reply_socket = -1;
return s;
}
};
struct Native_config struct Native_config
{ {

42
base-linux/src/base/ipc/ipc.cc
View File

@ -108,8 +108,8 @@ Ipc_istream::~Ipc_istream() { }
void Ipc_client::_prepare_next_call() void Ipc_client::_prepare_next_call()
{ {
/* prepare next request in buffer */ /* prepare next request in buffer */
long local_name = Ipc_ostream::_dst.local_name(); long const local_name = Ipc_ostream::_dst.local_name();
long tid = Native_capability::dst().tid; long const tid = Native_capability::dst().tid;
_write_offset = 0; _write_offset = 0;
_write_to_buf(local_name); _write_to_buf(local_name);
@ -151,9 +151,10 @@ void Ipc_server::_prepare_next_reply_wait()
/* read client thread id from request buffer */ /* read client thread id from request buffer */
long tid = 0; long tid = 0;
if (_reply_needed) { if (_reply_needed) {
/* XXX to be removed */
long tid;
if (_reply_needed)
_read_from_buf(tid); _read_from_buf(tid);
Ipc_ostream::_dst = Native_capability(Dst(tid, -1), 0); /* only _tid member is used */
}
/* prepare next reply */ /* prepare next reply */
_write_offset = 0; _write_offset = 0;
@ -167,21 +168,34 @@ void Ipc_server::_prepare_next_reply_wait()
void Ipc_server::_wait() void Ipc_server::_wait()
{ {
/* wait for new server request */
try {
lx_wait(_rcv_cs, _rcv_msg->buf, _rcv_msg->size());
} catch (Blocking_canceled) { }
/* now we have a request to reply, determine reply destination */
_reply_needed = true; _reply_needed = true;
_prepare_next_reply_wait();
try {
int const reply_socket = lx_wait(_rcv_cs, _rcv_msg->buf, _rcv_msg->size());
/*
* Remember reply capability
*
* The 'local_name' of a capability is meaningful for addressing server
* objects only. Because a reply capabilities does not address a server
* object, the 'local_name' is meaningless.
*/
enum { DUMMY_LOCAL_NAME = -1 };
typedef Native_capability::Dst Dst;
enum { DUMMY_TID = -1 };
Dst dst(DUMMY_TID, reply_socket);
Ipc_ostream::_dst = Native_capability(dst, DUMMY_LOCAL_NAME);
_prepare_next_reply_wait();
} catch (Blocking_canceled) { }
} }
void Ipc_server::_reply() void Ipc_server::_reply()
{ {
try { try {
lx_reply(_rcv_cs, _snd_msg->buf, _write_offset); lx_reply(Ipc_ostream::_dst.dst().socket, _snd_msg->buf, _write_offset);
} catch (Ipc_error) { } } catch (Ipc_error) { }
_prepare_next_reply_wait(); _prepare_next_reply_wait();
@ -192,7 +206,7 @@ void Ipc_server::_reply_wait()
{ {
/* when first called, there was no request yet */ /* when first called, there was no request yet */
if (_reply_needed) if (_reply_needed)
lx_reply(_rcv_cs, _snd_msg->buf, _write_offset); lx_reply(Ipc_ostream::_dst.dst().socket, _snd_msg->buf, _write_offset);
_wait(); _wait();
} }
@ -202,7 +216,7 @@ Ipc_server::Ipc_server(Msgbuf_base *snd_msg, Msgbuf_base *rcv_msg)
: Ipc_istream(rcv_msg), : Ipc_istream(rcv_msg),
Ipc_ostream(Native_capability(), snd_msg), _reply_needed(false) Ipc_ostream(Native_capability(), snd_msg), _reply_needed(false)
{ {
_rcv_cs.socket(lx_server_socket(Thread_base::myself())); _rcv_cs = lx_server_socket(Thread_base::myself());
_prepare_next_reply_wait(); _prepare_next_reply_wait();
} }

28
base-linux/src/platform/linux_socket.h
View File

@ -199,7 +199,7 @@ static void lx_call(long thread_id,
ret = lx_sendmsg(reply_channel[LOCAL_SOCKET], send_msg.msg(), 0); ret = lx_sendmsg(reply_channel[LOCAL_SOCKET], send_msg.msg(), 0);
if (ret < 0) { if (ret < 0) {
PRAW("lx_sendmsg failed with %d in call()", ret); PRAW("lx_sendmsg failed with %d in lx_call()", ret);
throw Genode::Ipc_error(); throw Genode::Ipc_error();
} }
@ -209,7 +209,7 @@ static void lx_call(long thread_id,
ret = lx_recvmsg(reply_channel[LOCAL_SOCKET], recv_msg.msg(), 0); ret = lx_recvmsg(reply_channel[LOCAL_SOCKET], recv_msg.msg(), 0);
if (ret < 0) { if (ret < 0) {
PRAW("lx_recvmsg failed with %d in call()", ret); PRAW("lx_recvmsg failed with %d in lx_call()", ret);
throw Genode::Ipc_error(); throw Genode::Ipc_error();
} }
@ -221,8 +221,10 @@ static void lx_call(long thread_id,
/** /**
* Utility: Wait for request from client * Utility: Wait for request from client
*
* \return socket descriptor of reply capability
*/ */
static void lx_wait(Genode::Native_connection_state &cs, static int lx_wait(Genode::Native_connection_state &cs,
void *buf, Genode::size_t buf_len) void *buf, Genode::size_t buf_len)
{ {
int ret; int ret;
@ -232,37 +234,33 @@ static void lx_wait(Genode::Native_connection_state &cs,
msg.prepare_reply_socket_slot(); msg.prepare_reply_socket_slot();
msg.buffer(buf, buf_len); msg.buffer(buf, buf_len);
ret = lx_recvmsg(cs.socket(), msg.msg(), 0); ret = lx_recvmsg(cs, msg.msg(), 0);
if (ret < 0) { if (ret < 0) {
PRAW("lx_recvmsg failed with %d in wait()", ret); PRAW("lx_recvmsg failed with %d in lx_wait()", ret);
throw Genode::Ipc_error(); throw Genode::Ipc_error();
} }
/* remember socket descriptor for reply */ return msg.reply_socket();
cs.reply_socket(msg.reply_socket());
} }
/** /**
* Utility: Send reply to client * Utility: Send reply to client
*/ */
static void lx_reply(Genode::Native_connection_state &cs, static void lx_reply(int reply_socket,
void *buf, Genode::size_t buf_len) void *buf, Genode::size_t buf_len)
{ {
int ret; int ret;
int sd = cs.reply_socket();
Message msg; Message msg;
msg.buffer(buf, buf_len); msg.buffer(buf, buf_len);
ret = lx_sendmsg(sd, msg.msg(), 0); ret = lx_sendmsg(reply_socket, msg.msg(), 0);
if (ret < 0) { if (ret < 0)
PRAW("lx_sendmsg failed with %d in reply()", ret); PRAW("lx_sendmsg failed with %d in lx_reply()", ret);
throw Genode::Ipc_error();
}
lx_close(sd); lx_close(reply_socket);
} }
#endif /* _PLATFORM__LINUX_SOCKET_H_ */ #endif /* _PLATFORM__LINUX_SOCKET_H_ */