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authorIgor Slepchin <[email protected]>2018-09-24 22:44:03 -0400
committerIgor Slepchin <[email protected]>2018-10-11 01:07:19 -0400
commit210665e8a252faecf28ccebade999e734ab92582 (patch)
tree8b81350cb43fd9a59ea13e34e03017f82fccbef3 /erts/emulator/drivers/common
parent3daef1a4ee8cfce90d0220be3695809ccbb8ea58 (diff)
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Add nopush TCP socket option
This translates to TCP_CORK on Linux and TCP_NOPUSH on BSD. In effect, this acts as super-Nagle: no partial TCP segments are sent out until this option is turned off. Once turned off, all accumulated unsent data is sent out immediately. The latter is *not* the case on OSX, hence the implementation ignores "nopush" on OSX to reduce confusion.
Diffstat (limited to 'erts/emulator/drivers/common')
-rw-r--r--erts/emulator/drivers/common/inet_drv.c30
1 files changed, 30 insertions, 0 deletions
diff --git a/erts/emulator/drivers/common/inet_drv.c b/erts/emulator/drivers/common/inet_drv.c
index 7f20477363..c13ceb14ad 100644
--- a/erts/emulator/drivers/common/inet_drv.c
+++ b/erts/emulator/drivers/common/inet_drv.c
@@ -812,6 +812,7 @@ static size_t my_strnlen(const char *s, size_t maxlen)
#define INET_OPT_PKTOPTIONS 45 /* IP(V6)_PKTOPTIONS get ancillary data */
#define INET_OPT_TTL 46 /* IP_TTL */
#define INET_OPT_RECVTTL 47 /* IP_RECVTTL ancillary data */
+#define TCP_OPT_NOPUSH 48 /* super-Nagle, aka TCP_CORK */
/* SCTP options: a separate range, from 100: */
#define SCTP_OPT_RTOINFO 100
#define SCTP_OPT_ASSOCINFO 101
@@ -955,6 +956,12 @@ static size_t my_strnlen(const char *s, size_t maxlen)
#endif
+#if defined(TCP_CORK)
+#define INET_TCP_NOPUSH TCP_CORK
+#elif defined(TCP_NOPUSH) && !defined(__DARWIN__)
+#define INET_TCP_NOPUSH TCP_NOPUSH
+#endif
+
#define BIN_REALLOC_MARGIN(x) ((x)/4) /* 25% */
/* The general purpose sockaddr */
@@ -6532,6 +6539,19 @@ static int inet_set_opts(inet_descriptor* desc, char* ptr, int len)
(long)desc->port, desc->s, ival));
break;
+ case TCP_OPT_NOPUSH:
+#if defined(INET_TCP_NOPUSH)
+ proto = IPPROTO_TCP;
+ type = INET_TCP_NOPUSH;
+ DEBUGF(("inet_set_opts(%ld): s=%d, t=%d TCP_NOPUSH=%d\r\n",
+ (long)desc->port, desc->s, type, ival));
+ break;
+#else
+ /* inet_fill_opts always returns a value for this option,
+ * so we need to ignore it if not implemented, just in case */
+ continue;
+#endif
+
#if defined(HAVE_MULTICAST_SUPPORT) && defined(IPPROTO_IP)
case UDP_OPT_MULTICAST_TTL:
@@ -7693,6 +7713,16 @@ static ErlDrvSSizeT inet_fill_opts(inet_descriptor* desc,
proto = IPPROTO_TCP;
type = TCP_NODELAY;
break;
+ case TCP_OPT_NOPUSH:
+#if defined(INET_TCP_NOPUSH)
+ proto = IPPROTO_TCP;
+ type = INET_TCP_NOPUSH;
+ break;
+#else
+ *ptr++ = opt;
+ put_int32(0, ptr);
+ continue;
+#endif
#if defined(HAVE_MULTICAST_SUPPORT) && defined(IPPROTO_IP)
case UDP_OPT_MULTICAST_TTL: