Fix memory leak in MacOS process handling.

Fix memory leak in MacOS process handling.

Report error for failing writes. We used to enter a poll loop
because we kept on attempting to write.

Currently the error handling in the socket interface is inconsistent.
We have a big TODO item on general error handling including the socket
interface.

R=sgjesse@google.com
BUG=
TEST=

Committed: https://code.google.com/p/dart/source/detail?r=1887

[Søren Gjesse, 2011-11-29 09:39:25]

lgtm with comments

http://codereview.chromium.org/8659032/diff/1/runtime/bin/process_linux.cc
File runtime/bin/process_linux.cc (right):

http://codereview.chromium.org/8659032/diff/1/runtime/bin/process_linux.cc#ne...
runtime/bin/process_linux.cc:233: if (dup2(write_out[0], STDIN_FILENO) == -1) {
As this is in the child process the output of these perror calls will not be
visible anywhere.

We should probably write something to the exec_control[1] file descriptor as
below and exit the child process.

http://codereview.chromium.org/8659032/diff/1/runtime/bin/process_macos.cc
File runtime/bin/process_macos.cc (right):

http://codereview.chromium.org/8659032/diff/1/runtime/bin/process_macos.cc#ne...
runtime/bin/process_macos.cc:233: if (dup2(write_out[0], STDIN_FILENO) == -1) {
Ditto.

[Mads Ager (google), 2011-11-29 10:10:13]

http://codereview.chromium.org/8659032/diff/1/runtime/bin/process_linux.cc
File runtime/bin/process_linux.cc (right):

http://codereview.chromium.org/8659032/diff/1/runtime/bin/process_linux.cc#ne...
runtime/bin/process_linux.cc:233: if (dup2(write_out[0], STDIN_FILENO) == -1) {
On 2011/11/29 09:39:25, Søren Gjesse wrote:
> As this is in the child process the output of these perror calls will not be
> visible anywhere.
> 
> We should probably write something to the exec_control[1] file descriptor as
> below and exit the child process.

Yes, refactored the code after execvp into a ReportChildError helper and called
it from each of these.

http://codereview.chromium.org/8659032/diff/1/runtime/bin/process_macos.cc
File runtime/bin/process_macos.cc (right):

http://codereview.chromium.org/8659032/diff/1/runtime/bin/process_macos.cc#ne...
runtime/bin/process_macos.cc:233: if (dup2(write_out[0], STDIN_FILENO) == -1) {
On 2011/11/29 09:39:25, Søren Gjesse wrote:
> Ditto.

Done.