From: Daniel Stenberg <daniel@haxx.se>
Date: Sun, 12 Mar 2023 22:55:09 +0000 (+0100)
Subject: multi: make multi_perform ignore/unignore signals less often
X-Git-Tag: curl-8_0_0~28
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=bc90308328afb8;p=thirdparty%2Fcurl.git

multi: make multi_perform ignore/unignore signals less often

For improved performance

Reported-by: Jerome St-Louis
Ref: #10743
Closes #10750
---

diff --git a/lib/multi.c b/lib/multi.c
index 3bf72ce655..6e272cb665 100644
--- a/lib/multi.c
+++ b/lib/multi.c
@@ -2706,18 +2706,25 @@ CURLMcode curl_multi_perform(struct Curl_multi *multi, int *running_handles)
     return CURLM_RECURSIVE_API_CALL;
 
   data = multi->easyp;
-  while(data) {
+  if(data) {
     CURLMcode result;
+    bool nosig = data->set.no_signal;
     SIGPIPE_VARIABLE(pipe_st);
-
     sigpipe_ignore(data, &pipe_st);
-    result = multi_runsingle(multi, &now, data);
+    /* Do the loop and only alter the signal ignore state if the next handle
+       has a different NO_SIGNAL state than the previous */
+    do {
+      if(data->set.no_signal != nosig) {
+        sigpipe_restore(&pipe_st);
+        sigpipe_ignore(data, &pipe_st);
+        nosig = data->set.no_signal;
+      }
+      result = multi_runsingle(multi, &now, data);
+      if(result)
+        returncode = result;
+      data = data->next; /* operate on next handle */
+    } while(data);
     sigpipe_restore(&pipe_st);
-
-    if(result)
-      returncode = result;
-
-    data = data->next; /* operate on next handle */
   }
 
   /*
diff --git a/lib/sigpipe.h b/lib/sigpipe.h
index 14ab25b67c..48761ad0fd 100644
--- a/lib/sigpipe.h
+++ b/lib/sigpipe.h
@@ -50,7 +50,6 @@ static void sigpipe_ignore(struct Curl_easy *data,
   if(!data->set.no_signal) {
     struct sigaction action;
     /* first, extract the existing situation */
-    memset(&ig->old_pipe_act, 0, sizeof(struct sigaction));
     sigaction(SIGPIPE, NULL, &ig->old_pipe_act);
     action = ig->old_pipe_act;
     /* ignore this signal */