Unifying error handling within core

BUILD

Makefile

binding.gyp

build.yaml

config.m4

gRPC.podspec

grpc.gemspec

package.xml

src/core/lib/iomgr/closure.c

src/core/lib/iomgr/closure.h

src/core/lib/iomgr/error.c

src/core/lib/iomgr/error.h

src/core/lib/iomgr/ev_poll_and_epoll_posix.c

src/core/lib/iomgr/exec_ctx.c

src/core/lib/iomgr/exec_ctx.h

src/core/lib/iomgr/executor.c

src/core/lib/iomgr/executor.h

src/core/lib/iomgr/resolve_address_posix.c

src/core/lib/iomgr/socket_utils_common_posix.c

src/core/lib/iomgr/socket_utils_posix.h