test: Add a mock for writev

This is useful for testing partial sends in the socket layer.

Change-Id: Ib5bb62d641ad8d6a23a662261f7c72f5ba55c813
Signed-off-by: Ben Walker <benjamin.walker@intel.com>
Reviewed-on: https://review.gerrithub.io/c/spdk/spdk/+/470520
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Alexey Marchuk <alexeymar@mellanox.com>
Reviewed-by: Darek Stojaczyk <dariusz.stojaczyk@intel.com>
Reviewed-by: Tomasz Zawadzki <tomasz.zawadzki@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
Reviewed-by: Shuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>

include/spdk_internal/mock.h

@@ -116,4 +116,6 @@ DECLARE_WRAPPER(pthread_mutex_init, int,
 DECLARE_WRAPPER(pthread_mutexattr_init, int,
 		(pthread_mutexattr_t *attr));
 
+DECLARE_WRAPPER(writev, ssize_t, (int fd, const struct iovec *iov, int iovcnt));
+
 #endif /* SPDK_INTERNAL_MOCK_H */

lib/ut_mock/mock.c

@@ -41,3 +41,5 @@ DEFINE_WRAPPER(pthread_mutex_init, int,
 
 DEFINE_WRAPPER(pthread_mutexattr_init, int,
 	       (pthread_mutexattr_t *attr), (attr))
+
+DEFINE_WRAPPER(writev, ssize_t, (int fd, const struct iovec *iov, int iovcnt), (fd, iov, iovcnt))

mk/spdk.mock.unittest.mk

@@ -33,4 +33,5 @@
 LDFLAGS += \
 	-Wl,--wrap,calloc \
 	-Wl,--wrap,pthread_mutexattr_init \
-	-Wl,--wrap,pthread_mutex_init
+	-Wl,--wrap,pthread_mutex_init \
+	-Wl,--wrap,writev