Update networking layer w/ CURL and emscripten impl

2025-11-08 01:50:36 +11:00
parent a17925904d
commit f6874dc55a
4105 changed files with 694617 additions and 179 deletions
@@ -0,0 +1,111 @@
+---
+c: Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
+SPDX-License-Identifier: curl
+Title: CURLMOPT_TIMERFUNCTION
+Section: 3
+Source: libcurl
+See-also:
+  - CURLMOPT_SOCKETFUNCTION (3)
+  - CURLMOPT_TIMERDATA (3)
+Protocol:
+  - All
+Added-in: 7.16.0
+---
+
+# NAME
+
+CURLMOPT_TIMERFUNCTION - callback to receive timeout values
+
+# SYNOPSIS
+
+~~~c
+#include <curl/curl.h>
+
+int timer_callback(CURLM *multi,    /* multi handle */
+                   long timeout_ms, /* timeout in number of ms */
+                   void *clientp);  /* private callback pointer */
+
+CURLMcode curl_multi_setopt(CURLM *handle, CURLMOPT_TIMERFUNCTION, timer_callback);
+~~~
+
+# DESCRIPTION
+
+Pass a pointer to your callback function, which should match the prototype
+shown above.
+
+Certain features, such as timeouts and retries, require you to call libcurl
+even when there is no activity on the file descriptors.
+
+Your callback function **timer_callback** should install a single
+non-repeating timer with an expire time of **timeout_ms** milliseconds. When
+that timer fires, call either curl_multi_socket_action(3) or
+curl_multi_perform(3), depending on which interface you use.
+
+If this callback is called when a timer is already running, this new expire
+time *replaces* the former timeout. The application should then effectively
+cancel the old timeout and set a new timeout using this new expire time.
+
+A **timeout_ms** value of -1 passed to this callback means you should delete
+the timer. All other values are valid expire times in number of milliseconds -
+including zero milliseconds.
+
+The **timer_callback** is called when the timeout expire time is changed.
+
+The **clientp** pointer is set with CURLMOPT_TIMERDATA(3).
+
+The timer callback should return 0 on success, and -1 on error. If this
+callback returns error, **all** transfers currently in progress in this multi
+handle are aborted and made to fail.
+
+This callback can be used instead of, or in addition to,
+curl_multi_timeout(3).
+
+**WARNING:** do not call libcurl directly from within the callback itself when
+the **timeout_ms** value is zero, since it risks triggering an unpleasant
+recursive behavior that immediately calls another call to the callback with a
+zero timeout...
+
+# DEFAULT
+
+NULL
+
+# %PROTOCOLS%
+
+# EXAMPLE
+
+~~~c
+struct priv {
+  void *custom;
+};
+
+static int timerfunc(CURLM *multi, long timeout_ms, void *clientp)
+{
+  struct priv *mydata = clientp;
+  printf("our ptr: %p\n", mydata->custom);
+
+  if(timeout_ms >= 0) {
+    /* this is the new single timeout to wait for, including zero */
+  }
+  else {
+    /* delete the timeout, nothing to wait for now */
+  }
+  return 0;
+}
+
+int main(void)
+{
+  struct priv mydata;
+  CURLM *multi = curl_multi_init();
+  curl_multi_setopt(multi, CURLMOPT_TIMERFUNCTION, timerfunc);
+  curl_multi_setopt(multi, CURLMOPT_TIMERDATA, &mydata);
+}
+~~~
+
+# %AVAILABILITY%
+
+# RETURN VALUE
+
+curl_multi_setopt(3) returns a CURLMcode indicating success or error.
+
+CURLM_OK (0) means everything was OK, non-zero means an error occurred, see
+libcurl-errors(3).