Update networking layer w/ CURL and emscripten impl

External/curl-8.17.0/docs/libcurl/opts/CURLMOPT_SOCKETDATA.md

@@ -0,0 +1,81 @@
+---
+c: Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
+SPDX-License-Identifier: curl
+Title: CURLMOPT_SOCKETDATA
+Section: 3
+Source: libcurl
+See-also:
+  - CURLMOPT_SOCKETFUNCTION (3)
+  - CURLMOPT_TIMERFUNCTION (3)
+  - curl_multi_socket_action (3)
+Protocol:
+  - All
+Added-in: 7.15.4
+---
+
+# NAME
+
+CURLMOPT_SOCKETDATA - custom pointer passed to the socket callback
+
+# SYNOPSIS
+
+~~~c
+#include <curl/curl.h>
+
+CURLMcode curl_multi_setopt(CURLM *handle, CURLMOPT_SOCKETDATA, void *pointer);
+~~~
+
+# DESCRIPTION
+
+A data *pointer* to pass to the socket callback set with the
+CURLMOPT_SOCKETFUNCTION(3) option.
+
+This pointer is not touched by libcurl but is only passed in as the socket
+callback's **clientp** argument.
+
+# DEFAULT
+
+NULL
+
+# %PROTOCOLS%
+
+# EXAMPLE
+
+~~~c
+struct priv {
+  void *ours;
+};
+
+static int sock_cb(CURL *e, curl_socket_t s, int what, void *cbp, void *sockp)
+{
+  struct priv *p = sockp;
+  printf("my ptr: %p\n", p->ours);
+
+  if(what == CURL_POLL_REMOVE) {
+    /* remove the socket from our collection */
+  }
+  if(what & CURL_POLL_IN) {
+    /* wait for read on this socket */
+  }
+  if(what & CURL_POLL_OUT) {
+    /* wait for write on this socket */
+  }
+
+  return 0;
+}
+
+int main(void)
+{
+  struct priv setup;
+  CURLM *multi = curl_multi_init();
+  /* ... use socket callback and custom pointer */
+  curl_multi_setopt(multi, CURLMOPT_SOCKETFUNCTION, sock_cb);
+  curl_multi_setopt(multi, CURLMOPT_SOCKETDATA, &setup);
+}
+~~~
+
+# %AVAILABILITY%
+
+# RETURN VALUE
+
+Returns CURLM_OK.