moving free_pbuf_chain to an external file in order to be shared from udp and tcp

Author: andreagilardoni

libraries/lwIpWrapper/src/lwipClient.cpp

@@ -5,6 +5,7 @@ extern "C" {
 #include "Arduino.h"
 
 #include "lwipClient.h"
+#include "lwippbuf.h"
 #include "CNetIf.h"
 #include "utils.h"
 // FIXME understand hos to syncronize the interrupt thread and "userspace"
@@ -310,8 +311,10 @@ int lwipClient::read(uint8_t* buffer, size_t size) {
     arduino::lock();
     uint16_t copied = pbuf_copy_partial(this->tcp_info->pbuf_head, buffer, size, this->tcp_info->pbuf_offset);
 
-    this->free_pbuf_chain(copied);
-    // __enable_irq();
+    this->tcp_info->pbuf_head = free_pbuf_chain(this->tcp_info->pbuf_head, copied, &this->tcp_info->pbuf_offset);
+
+    // acknowledge the received data
+    tcp_recved(this->tcp_info->pcb, copied);
     arduino::unlock();
 
     return copied;
@@ -433,50 +436,11 @@ size_t lwipClient::read_until_token(
 
     uint16_t copied = pbuf_copy_partial(this->tcp_info->pbuf_head, (uint8_t*)buffer, buf_copy_len, this->tcp_info->pbuf_offset);
 
-    this->free_pbuf_chain(copied);
-    arduino::unlock();
-
-    return copied;
-}
-
-void lwipClient::free_pbuf_chain(uint16_t copied) {
-    arduino::lock();
-    /*
-     * free pbufs that have been copied, if copied == 0 we have an error
-     * free the buffer chain starting from the head up to the last entire pbuf ingested
-     * taking into account the previously not entirely consumed pbuf
-     */
-    uint32_t tobefreed = 0;
-    copied += this->tcp_info->pbuf_offset;
-
-    // in order to clean up the chain we need to find the pbuf in the last pbuf in the chain
-    // that got completely consumed by the application, dechain it from it successor and delete the chain before it
-
-    struct pbuf *head = this->tcp_info->pbuf_head, *last=head, *prev=nullptr; // FIXME little optimization prev can be substituted by last->next
-
-    while(last!=nullptr && last->len + tobefreed <= copied) {
-        tobefreed += last->len;
-        prev = last;
-        last = last->next;
-    }
-
-    // dechain if we are not at the end of the chain (last == nullptr)
-    // and if we haven't copied entirely the first pbuf (prev == nullptr) (head == last)
-    // if we reached the end of the chain set the this pbuf pointer to nullptr
-    if(prev != nullptr) {
-        prev->next = nullptr;
-        this->tcp_info->pbuf_head = last;
-    }
-
-    // the chain that is referenced by head is detached by the one referenced by this->tcp_info->pbuf_head
-    // free the chain if we haven't copied entirely the first pbuf (prev == nullptr)
-    if(this->tcp_info->pbuf_head != head) {
-        uint8_t refs = pbuf_free(head);
-    }
-
-    this->tcp_info->pbuf_offset = copied - tobefreed; // This offset should be referenced to the first pbuf in queue
+    this->tcp_info->pbuf_head = free_pbuf_chain(this->tcp_info->pbuf_head, copied, &this->tcp_info->pbuf_offset);
 
     // acknowledge the received data
     tcp_recved(this->tcp_info->pcb, copied);
     arduino::unlock();
+
+    return copied;
 }

libraries/lwIpWrapper/src/lwipClient.h

@@ -104,7 +104,6 @@ class lwipClient : public arduino::Client {
     ip_addr_t _ip;
 
     err_t connected_callback(struct tcp_pcb* tpcb, err_t err);
-    void free_pbuf_chain(uint16_t copied);
     err_t recv_callback(struct tcp_pcb* tpcb, struct pbuf* p, err_t err);
 
     friend err_t _lwip_tcp_recv_callback(void* arg, struct tcp_pcb* tpcb, struct pbuf* p, err_t err);

libraries/lwIpWrapper/src/lwippbuf.cpp

@@ -0,0 +1,44 @@
+#include "lwippbuf.h"
+#include "utils.h"
+
+struct pbuf* free_pbuf_chain(struct pbuf* p, uint16_t copied, uint16_t *offset) {
+    arduino::lock();
+    /*
+     * free pbufs that have been copied, if copied == 0 we have an error
+     * free the buffer chain starting from the head up to the last entire pbuf ingested
+     * taking into account the previously not entirely consumed pbuf
+     */
+    uint32_t tobefreed = 0;
+    copied += *offset;
+
+    // in order to clean up the chain we need to find the pbuf in the last pbuf in the chain
+    // that got completely consumed by the application, dechain it from it successor and delete the chain before it
+
+    struct pbuf *head = p, *last=head, *prev=nullptr; // FIXME little optimization prev can be substituted by last->next
+
+    while(last!=nullptr && last->len + tobefreed <= copied) {
+        tobefreed += last->len;
+        prev = last;
+        last = last->next;
+    }
+
+    // dechain if we are not at the end of the chain (last == nullptr)
+    // and if we haven't copied entirely the first pbuf (prev == nullptr) (head == last)
+    // if we reached the end of the chain set the this pbuf pointer to nullptr
+    if(prev != nullptr) {
+        prev->next = nullptr;
+        p = last;
+    }
+
+    // the chain that is referenced by head is detached by the one referenced by p
+    // free the chain if we haven't copied entirely the first pbuf (prev == nullptr)
+    if(p != head) {
+        uint8_t refs = pbuf_free(head);
+    }
+
+    *offset = copied - tobefreed; // This offset should be referenced to the first pbuf in queue
+
+    arduino::unlock();
+
+    return p;
+}

libraries/lwIpWrapper/src/lwippbuf.h

@@ -0,0 +1,12 @@
+#pragma once
+#include <lwip/include/lwip/pbuf.h>
+
+/**
+ * This function aim to free a pbuf chain that has been partially consumed.
+ * @param p the head of the pbuf chain
+ * @param copied the size that had been consumed in the last operation
+ * @param offset the size that had been consumed in the previous operations,
+ *               this value will be updated with the ffset of the new head
+ * @return the new pbuf head
+ */
+struct pbuf* free_pbuf_chain(struct pbuf* p, uint16_t copied, uint16_t *offset);