[SOLVED] after adding CURLOPT_TIMEOUT_MS curl doesn't send anything

after adding CURLOPT_TIMEOUT_MS curl doesn't send anything

I have a while loop, and inside that loop I send a PUT request into google firebase REST api. It works very well, but if I want to fasten things up (the while loop waits for the curl response every round of the loop which is very slow sometimes, over 200ms), I'm trying to add the CURLOPT_TIMEOUT_MS and set it to a low 1 millisecond.

TLDR; after adding line

curl_easy_setopt(curl, CURLOPT_TIMEOUT_MS, 1L);

My curl does not send anything to the server anymore. Or does the server somehow force the client to receive the returning value from the request?

Solution

You tell curl to fail the operation if it isn't completed within 1 millisecond. Not many requests are completed that quickly, especially not if you're using DNS or just use connections over the Internet.

So yes, most transfers will then just return CURLE_OPERATION_TIMEDOUT (28) with no content.