use accept4 for tcp_accept when available (twitter#171)

swlynch99 · Jul 26, 2018 · e710712 · e710712
1 parent 21ba10e
commit e710712
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Showing 4 changed files with 14 additions and 0 deletions.
diff --git a/CMakeLists.txt b/CMakeLists.txt
@@ -96,6 +96,7 @@ check_symbol_exists(sys_signame signal.h HAVE_SIGNAME)
 
 include(CheckFunctionExists)
 check_function_exists(backtrace HAVE_BACKTRACE)
+check_function_exists(accept4 HAVE_ACCEPT4)
 
 include(TestBigEndian)
 test_big_endian(HAVE_BIG_ENDIAN)

diff --git a/config.h.in b/config.h.in
@@ -12,6 +12,8 @@
 
 #cmakedefine HAVE_BACKTRACE
 
+#cmakedefine HAVE_ACCEPT4
+
 #cmakedefine HAVE_BIG_ENDIAN
 
 #cmakedefine HAVE_LOGGING

diff --git a/include/cc_define.h b/include/cc_define.h
@@ -54,6 +54,10 @@ extern "C" {
 # define CC_BACKTRACE 1
 #endif
 
+#ifdef HAVE_ACCEPT4
+# define CC_ACCEPT4 1
+#endif
+
 #ifdef HAVE_DEBUG_MM
 #define CC_DEBUG_MM 1
 #endif

diff --git a/src/channel/cc_tcp.c b/src/channel/cc_tcp.c
@@ -18,6 +18,7 @@
 #include <channel/cc_tcp.h>
 
 #include <cc_debug.h>
+#include <cc_define.h>
 #include <cc_mm.h>
 #include <cc_pool.h>
 #include <cc_util.h>
@@ -321,7 +322,11 @@ _tcp_accept(struct tcp_conn *sc)
     ASSERT(sc->sd > 0);
 
     for (;;) { /* we accept at most one tcp_conn with the 'break' at the end */
+#ifdef CC_ACCEPT4
+        sd = accept4(sc->sd, NULL, NULL, SOCK_NONBLOCK);
+#else
         sd = accept(sc->sd, NULL, NULL);
+#endif /* CC_ACCEPT4 */
         if (sd < 0) {
             if (errno == EINTR) {
                 log_debug("accept on sd %d not ready: eintr", sc->sd);
@@ -360,11 +365,13 @@ tcp_accept(struct tcp_conn *sc, struct tcp_conn *c)
     c->level = CHANNEL_BASE;
     c->state = CHANNEL_ESTABLISHED;
 
+#ifndef CC_ACCEPT4 /* if we have accept4, nonblock will already have been set */
     ret = tcp_set_nonblocking(sd);
     if (ret < 0) {
         log_warn("set nonblock on sd %d failed, ignored: %s", sd,
                 strerror(errno));
     }
+#endif
 
     ret = tcp_set_tcpnodelay(sd);
     if (ret < 0) {