You may want to explore using messaging (RTOS) to the single thread that is
handling UDP.
From: lwip-users <lwip-users-bounces+greenwoodg=leidos....@nongnu.org> On
Behalf Of zulu4711
Sent: Monday, October 1, 2018 12:55 AM
To: lwip-users@nongnu.org
Subject: EXTERNAL: [lwip-users] UDP and Raw API, lwip running with RTOS
I have lwip up and running in an embbeded system using a RTOS (Keil RTX kernel)
and this seems to work alright. I'm testing with sockets and netconn UDP, all
ok (over PPP). I'm also beginning to look at the raw API (this will fit the
project best in the end), and this works also. Now, I know that the raw API is
only to be called from one single thread. However, I need to be able to call
send etc from several threads. I was wondering if the following code is ok for
that, before using the raw API I call LOCK_TCPIP_CORE()/UNLOCK_TCPIP_CORE(). I
followed the netconn API and it seems this is the way the locking is done there
? Am I right in this, and is this a "allowed" way of doing what I want ? Or,
are there a better approach to this ?
//---------------------------------------------------------------------------------------
// Callback function for received data
//---------------------------------------------------------------------------------------
static void rxUDP(void *arg, struct udp_pcb *upcb, struct pbuf *p, struct
ip_addr *addr, u16_t port) { char str[128]; // if packet is valid if (p !=
NULL) { // WARNING: p can be a chain of buffers (in this example we pretend it
is just a single buffer :)! if (p->len < sizeof(str)) { memcpy(str, p->payload,
p->len); str[p->len]=0; messageDebug(DBG_WAR, __MODULE__, __LINE__, "UDP Packet
Received! Payload: [%s], port=%i", str, port); } pbuf_free(p); } }
//---------------------------------------------------------------------------------------
// Thread that sends UDP message every 1000 to 2000 mSec
//---------------------------------------------------------------------------------------
void thRawUDP(void) { extern struct netif ppp_netif; err_t error; ip_addr_t
ip_remote; struct udp_pcb *pUDPPCB; struct pbuf *pBuf; char data[] = "Hello
world"; setNameRTXMON(__FUNCTION__); // wait for netif to come up (a little
dirty) messageDebug(DBG_WAR, __MODULE__, __LINE__, "Waiting for PPP Netif to
come up.."); while (netif_is_link_up(&ppp_netif)==0) OS_WAIT(1000);
messageDebug(DBG_WAR, __MODULE__, __LINE__, "PPP Netif is up"); // Convert from
ASCII "xxx.xxx.xxx.xxx" to IP ipaddr_aton(SERVER_IP_ADDR, &ip_remote); // Lock
the stack.. LOCK_TCPIP_CORE(); pUDPPCB = udp_new(); // Bind to any local port
error = udp_bind(pUDPPCB, IP_ADDR_ANY, 0); messageDebug(DBG_WAR, __MODULE__,
__LINE__, "udp_bind=%i", error); error = udp_connect(pUDPPCB, &ip_remote,
SERVER_PORT_NUM); messageDebug(DBG_WAR, __MODULE__, __LINE__, "udp_connect=%i",
error); udp_recv(pUDPPCB, rxUDP, NULL); UNLOCK_TCPIP_CORE(); while (1) { //
Allocate pbuf (might end up being a chain of buffers!) pBuf =
pbuf_alloc(PBUF_TRANSPORT, sizeof(data), PBUF_POOL); if (!pBuf) {
messageDebug(DBG_ERR, __MODULE__, __LINE__, "error allocating buffer");
OS_WAIT(1000); continue; } // The pBuf we get can be a chain of buffers int
bytesLeft = sizeof(data); // Number of bytes we still need to move to buffer(s)
struct pbuf *packetTempBuffer; // used to traverse the (possible) list of
buffers int chunk; // NUmber of bytes we copy to the current buffer int index =
0; // Index into the source buffer packetTempBuffer = pBuf; while ( (bytesLeft)
&& (packetTempBuffer != NULL) ) { chunk = bytesLeft; if ( chunk >
packetTempBuffer->len ) { chunk = packetTempBuffer->len; } // copy one part
memcpy(packetTempBuffer->payload, &data[index], chunk); // next buffer in chain
(if any) packetTempBuffer = packetTempBuffer->next; bytesLeft -= chunk; index
+= chunk; }; //memcpy(pBuf->payload, data, sizeof(data)); // WARNING: No
gurantee that pbuf is not multiple buffers in order to hold the data!
messageDebug(DBG_WAR, __MODULE__, __LINE__,"Sending"); // Lock stack
LOCK_TCPIP_CORE(); udp_send(pUDPPCB, pBuf); UNLOCK_TCPIP_CORE();
pbuf_free(pBuf); OS_WAIT(1000+(rand()%1000)); } }
________________________________
Sent from the lwip-users mailing list
archive<http://lwip.100.n7.nabble.com/lwip-users-f3.html> at Nabble.com.
_______________________________________________
lwip-users mailing list
lwip-users@nongnu.org
https://lists.nongnu.org/mailman/listinfo/lwip-users
