Had a chance to port gRPC on FreeBSD 10.1. Basically created a FreeBSD 10.1 VM, cloned the gRPC git and with some changes in header file, makefiles & downloading few tools, was able to compile and run the sample app from the git.

Pasted below are the changes done. Please do have a look and let know your feedback. Also let know if gRPC can start supporting freeBSD.

I. grpc compilation for FreeBSD 10.1:
--------------------------------------------
a) Add support for FreeBSD platform in include/grpc/support/port_platform.h.
The following changes required to have support for FreeBSD platform.

+++ include/grpc/support/port_platform.h
@@ -75,6 +75,28 @@
#define GPR_POSIX_SYNC 1
#define GPR_POSIX_TIME 1
#define GPR_GETPID_IN_UNISTD_H 1
+/_/
+#elif defined(FreeBSD)
+#define GPR_GCC_ATOMIC 1
+#define GPR_CPU_POSIX 1
+#define GPR_POSIX_LOG 1
+#define GPR_POSIX_MULTIPOLL_WITH_POLL 1
+#define GPR_POSIX_WAKEUP_FD 1
+#define GPR_POSIX_NO_SPECIAL_WAKEUP_FD 1
+#define GPR_POSIX_SOCKET 1
+#define GPR_POSIX_SOCKETADDR 1
+#define GPR_POSIX_SOCKETUTILS 1
+#define GPR_POSIX_ENV 1
+#define GPR_POSIX_FILE 1
+#define GPR_POSIX_SYNC 1
+#define GPR_POSIX_STRING 1
+#define GPR_POSIX_TIME 1
+#ifdef LP64
+#define GPR_ARCH_64 1
+#else
+#define GPR_ARCH_32 1
+#endif
+/**/
#elif defined(linux)
#ifndef _BSD_SOURCE
#define _BSD_SOURCE

b) The tools automake, autoconf and libtool needs to installed to compile thirdparty/protobuf for protobuf 3.0.

c) A change is need to the Makefile under thirdparty/openssl/ to set C/C++ compilers appropriately.
The FreeBSD 10.x comes with clang and will not have gcc by default.
The Makefile under thirdparty/openssl/ sets C/C++ compilers to gcc and g++ which should be cc(clang) and c++(clang++) for FreeBSD 10.x.

d) A change is needed to the Makefile under thirdparty/zlib/ to set C/C++ compilers appropriately (same reason mentioned above).

II. grpc-common compilation for FreeBSD 10.1
--------------------------------------------------------
The following changes needed for Services (or Applications) Makefiles.

a) Need to set C/C++ compilers appropriately fro FreeBSD 10.x.

b) Need to link with the library libc.so (-lc) instead of the library libdl (-ldl) for FreeBSD 10.x for calls to deal with a shared library (eg, dlopen, dlsym etc.).

III. The environment and tools used for compilations as follows.
--------------------------------------------------------------------------
OS: FreeBSD 10.0-RELEASE FreeBSD 10.0-RELEASE #0 r260789: Thu Jan 16 22:34:59 UTC 2014 root@snap.freebsd.org:/usr/obj/usr/src/sys/GENERIC amd64

compiler: FreeBSD clang version 3.3 (tags/RELEASE_33/final 183502) 20130610
libtool: libtool (GNU libtool) 2.4.5
automake: automake (GNU automake) 1.15
autoconf: autoconf (GNU Autoconf) 2.69
host-triplet: amd64-portbld-freebsd10.1
shell: GNU bash, version 4.3.33(0)-release (amd64-portbld-freebsd10.1)

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