Map order is non-deterministic. Introduce a new
environment string array that tracks the env map.
This allows us to produce identical results for
Environ() upon successive calls, as expected by the
TestConsistentEnviron test in package os.
R=rsc, ality, rminnich, bradfitz, r
CC=golang-dev
https://golang.org/cl/7411047
This decreases the amount of system calls during the
first call to Getenv. Calling Environ will still read
in all environment variables and populate the cache.
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6939048
This can drastically reduce the number of system
calls made by programs that repeatedly query the
environment.
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/5599054
The environment is needed by package time, which
we want not to depend on os (so that os can use
time.Time), so push down into syscall.
Delete syscall.Sleep, now unnecessary.
The package os environment API is preserved;
it is only the implementation that is moving to syscall.
Delete os.Envs, which was undocumented,
uninitialized on Windows and Plan 9, and
not maintained by Setenv and Clearenv.
Code can call os.Environ instead.
R=golang-dev, r
CC=golang-dev
https://golang.org/cl/5370091
