From 2ccb23e06a7e9b35463f55fd9c31f44c04eb48f3 Mon Sep 17 00:00:00 2001
From: Radkesvat <134321679+radkesvat@users.noreply.github.com>
Date: Tue, 4 Jun 2024 19:40:16 +0000
Subject: [PATCH] [WIP] 80% pipe line

---
 ww/pipe_line.c | 95 +++++++++++++++++++++++++++++++++++++-------------
 ww/pipe_line.h |  4 +--
 2 files changed, 72 insertions(+), 27 deletions(-)

diff --git a/ww/pipe_line.c b/ww/pipe_line.c
index 95dd2d0a..aadd5b48 100644
--- a/ww/pipe_line.c
+++ b/ww/pipe_line.c
@@ -1,9 +1,13 @@
 #include "pipe_line.h"
+#include "buffer_pool.h"
 #include "hmutex.h"
 #include "hplatform.h"
+#include "loggers/network_logger.h"
+#include "shiftbuffer.h"
 #include "tunnel.h"
 #include <stdatomic.h>
 #include <stdint.h>
+#include <string.h>
 
 struct msg_event
 {
@@ -14,10 +18,34 @@ struct msg_event
 
 typedef void (*MsgTargetFunction)(pipe_line_t *pl, void *arg);
 
+static void lock(pipe_line_t *pl)
+{
+    int old_refc = atomic_fetch_add_explicit(&pl->refc, 1, memory_order_relaxed);
+    if (old_refc == 0)
+    {
+        LOGF("PipeLine: thread-safety done incorrectly lock()");
+        exit(1);
+    }
+    (void) old_refc;
+}
+static void unlock(pipe_line_t *pl)
+{
+    int old_refc = atomic_fetch_add_explicit(&pl->refc, -1, memory_order_relaxed);
+    if (old_refc == 1)
+    {
+        if (! atomic_load_explicit(&(pl->closed), memory_order_relaxed))
+        {
+            LOGF("PipeLine: thread-safety done incorrectly unlock()");
+            exit(1);
+        }
+        free(pl);
+    }
+}
 static void onMsgReceived(hevent_t *ev)
 {
     struct msg_event *msg_ev = hevent_userdata(ev);
     (*(MsgTargetFunction *) (&(msg_ev->function)))(msg_ev->pl, msg_ev->arg);
+    unlock(msg_ev->pl);
     free(msg_ev);
 }
 
@@ -28,7 +56,7 @@ static void sendMessage(pipe_line_t *pl, MsgTargetFunction fn, void *arg, uint8_
         fn(pl, arg);
         return;
     }
-
+    lock(pl);
     struct msg_event *evdata = malloc(sizeof(struct msg_event));
     *evdata                  = (struct msg_event){.pl = pl, .function = *(void **) (&fn), .arg = arg};
 
@@ -39,17 +67,30 @@ static void sendMessage(pipe_line_t *pl, MsgTargetFunction fn, void *arg, uint8_
     hevent_set_userdata(&ev, evdata);
     hloop_post_event(loops[tid_to], &ev);
 }
+void writeBufferToRightSide(pipe_line_t *pl, void *arg)
+{
+    shift_buffer_t *buf = arg;
+    if (pl->right_line == NULL)
+    {
+        reuseBuffer(buffer_pools[pl->right_tid], buf);
+        return;
+    }
+    context_t *ctx = newContext(pl->left_line);
+    ctx->payload = buf;
+    pl->local_up_stream(pl->self, ctx);
+}
 
 void finishLeftSide(pipe_line_t *pl, void *arg)
 {
     (void) arg;
+
     if (pl->left_line == NULL)
     {
         return;
     }
     context_t *fctx = newFinContext(pl->left_line);
-    // doneLineDownSide(pl->left_line);
-    // destroyLine(pl->left_line);
+    doneLineUpSide(pl->left_line);
+    destroyLine(pl->left_line);
     pl->left_line = NULL;
     pl->local_down_stream(pl->self, fctx);
 }
@@ -62,8 +103,8 @@ void finishRightSide(pipe_line_t *pl, void *arg)
         return;
     }
     context_t *fctx = newFinContext(pl->right_line);
-    // doneLineUpSide(pl->right_line);
-    // destroyLine(pl->right_line);
+    doneLineDownSide(pl->right_line);
+    destroyLine(pl->right_line);
     pl->right_line = NULL;
     pl->local_up_stream(pl->self, fctx);
 }
@@ -137,7 +178,6 @@ bool writePipeLineLTR(pipe_line_t *pl, context_t *c)
     // other flags are not supposed to come to pipe line
     assert(c->fin || c->payload != NULL);
 
-    atomic_compare_exchange_strong_explicit
     if (atomic_load_explicit(&pl->closed, memory_order_relaxed))
     {
         return false;
@@ -145,32 +185,37 @@ bool writePipeLineLTR(pipe_line_t *pl, context_t *c)
 
     if (c->fin)
     {
-        atomic_store_explicit(&pl->closed, true, memory_order_relaxed);
+        assert(pl->left_line);
+        doneLineUpSide(pl->left_line);
         destroyLine(pl->left_line);
         pl->left_line = NULL;
-        destroyLine(line_t *l)
-    }
-    else 
-    {
-        assert(c->payload != NULL);
 
+        bool expected = false;
+
+        if (atomic_compare_exchange_strong_explicit(&(pl->closed), &expected, true, memory_order_relaxed,
+                                                    memory_order_relaxed))
+        {
+            // we managed to close the channel
+            destroyContext(c);
+            sendMessage(pl, finishRightSide, NULL, pl->left_tid, pl->right_tid);
+            unlock(pl);
+            return true;
+        }
+        // other line managed to close first and also queued us the fin packet
+        return false;
     }
 
-    if (pl->direct_mode)
-    {
-        // c = switchLine(c, pl->right_line);
-
-        pl->self->up->upStream(pl->self->up, c);
-
-        return true;
-    }
+    assert(c->payload != NULL);
+    sendMessage(pl, writeBufferToRightSide, c->payload, pl->left_tid, pl->right_tid);
+    c->payload = NULL;
+    destroyContext(c);
 
     return true;
 }
 
-bool writePipeLineRTL(pipe_line_t *p, context_t *c)
-{
-}
+// bool writePipeLineRTL(pipe_line_t *p, context_t *c)
+// {
+// }
 
-pipe_line_t *newPipeLine(uint8_t tid_left, uint8_t tid_right);
-void         freePipeLine(pipe_line_t *p);
+// pipe_line_t *newPipeLine(uint8_t tid_left, uint8_t tid_right);
+// void         freePipeLine(pipe_line_t *p);
diff --git a/ww/pipe_line.h b/ww/pipe_line.h
index 305ff135..d31e8f90 100644
--- a/ww/pipe_line.h
+++ b/ww/pipe_line.h
@@ -2,6 +2,7 @@
 
 #include "tunnel.h"
 #include "ww.h"
+#include <stdatomic.h>
 
 /*
 
@@ -15,8 +16,8 @@
 
 struct pipe_line_s
 {
-    bool           direct_mode;
     atomic_bool    closed;
+    atomic_int    refc;
 
     // thread local:
     tunnel_t *self;
@@ -34,5 +35,4 @@ typedef struct pipe_line_s pipe_line_t;
 
 bool         writePipeLineLTR(pipe_line_t *p, context_t *c);
 bool         writePipeLineRTL(pipe_line_t *p, context_t *c);
-void         freePipeLine(pipe_line_t *p);
 pipe_line_t *newPipeLine(uint8_t tid_left, tunnel_t *self, uint8_t tid_right);