Merge pull request grpc#19296 from arjunroy/grpc_zcp

gRPC TCP Send Zerocopy

include/grpc/impl/codegen/grpc_types.h

@@ -323,6 +323,20 @@ typedef struct {
   "grpc.experimental.tcp_min_read_chunk_size"
 #define GRPC_ARG_TCP_MAX_READ_CHUNK_SIZE \
   "grpc.experimental.tcp_max_read_chunk_size"
+/* TCP TX Zerocopy enable state: zero is disabled, non-zero is enabled. By
+   default, it is disabled. */
+#define GRPC_ARG_TCP_TX_ZEROCOPY_ENABLED \
+  "grpc.experimental.tcp_tx_zerocopy_enabled"
+/* TCP TX Zerocopy send threshold: only zerocopy if >= this many bytes sent. By
+   default, this is set to 16KB. */
+#define GRPC_ARG_TCP_TX_ZEROCOPY_SEND_BYTES_THRESHOLD \
+  "grpc.experimental.tcp_tx_zerocopy_send_bytes_threshold"
+/* TCP TX Zerocopy max simultaneous sends: limit for maximum number of pending
+   calls to tcp_write() using zerocopy. A tcp_write() is considered pending
+   until the kernel performs the zerocopy-done callback for all sendmsg() calls
+   issued by the tcp_write(). By default, this is set to 4. */
+#define GRPC_ARG_TCP_TX_ZEROCOPY_MAX_SIMULT_SENDS \
+  "grpc.experimental.tcp_tx_zerocopy_max_simultaneous_sends"
 /* Timeout in milliseconds to use for calls to the grpclb load balancer.
    If 0 or unset, the balancer calls will have no deadline. */
 #define GRPC_ARG_GRPCLB_CALL_TIMEOUT_MS "grpc.grpclb_call_timeout_ms"

src/core/lib/iomgr/socket_utils_common_posix.cc

@@ -50,6 +50,20 @@
 #include "src/core/lib/iomgr/sockaddr.h"
 #include "src/core/lib/iomgr/sockaddr_utils.h"
 
+/* set a socket to use zerocopy */
+grpc_error* grpc_set_socket_zerocopy(int fd) {
+#ifdef GRPC_LINUX_ERRQUEUE
+  const int enable = 1;
+  auto err = setsockopt(fd, SOL_SOCKET, SO_ZEROCOPY, &enable, sizeof(enable));
+  if (err != 0) {
+    return GRPC_OS_ERROR(errno, "setsockopt(SO_ZEROCOPY)");
+  }
+  return GRPC_ERROR_NONE;
+#else
+  return GRPC_OS_ERROR(ENOSYS, "setsockopt(SO_ZEROCOPY)");
+#endif
+}
+
 /* set a socket to non blocking mode */
 grpc_error* grpc_set_socket_nonblocking(int fd, int non_blocking) {
   int oldflags = fcntl(fd, F_GETFL, 0);

src/core/lib/iomgr/socket_utils_posix.h

@@ -31,10 +31,22 @@
 #include "src/core/lib/iomgr/socket_factory_posix.h"
 #include "src/core/lib/iomgr/socket_mutator.h"
 
+#ifdef GRPC_LINUX_ERRQUEUE
+#ifndef SO_ZEROCOPY
+#define SO_ZEROCOPY 60
+#endif
+#ifndef SO_EE_ORIGIN_ZEROCOPY
+#define SO_EE_ORIGIN_ZEROCOPY 5
+#endif
+#endif /* ifdef GRPC_LINUX_ERRQUEUE */
+
 /* a wrapper for accept or accept4 */
 int grpc_accept4(int sockfd, grpc_resolved_address* resolved_addr, int nonblock,
                  int cloexec);
 
+/* set a socket to use zerocopy */
+grpc_error* grpc_set_socket_zerocopy(int fd);
+
 /* set a socket to non blocking mode */
 grpc_error* grpc_set_socket_nonblocking(int fd, int non_blocking);