Non-SFI mode: Use clone() instead of pthread_create()

Non-SFI mode: Use clone() instead of pthread_create()

This is a refactor to avoid using pthread_create when creating new
threads in non-SFI mode.  This is a first step towards implementing
asynchronous signals.  It also means that we can now use the provided
|stack| argument to the |thread_create| IRT call, which should improve
memory usage.

In ARC, this saves 26MB of virtual memory and 1MB of resident memory.

BUG=https://code.google.com/p/nativeclient/issues/detail?id=4065
TEST=git try

Committed: https://chromium.googlesource.com/native_client/src/native_client/+/e3168db25bbb64309eca9b9a1d83b86bf8cfb7e4

[Luis Héctor Chávez, 2015-07-06 23:58:45]

lhchavez@chromium.org changed reviewers:
+ mseaborn@chromium.org

[Luis Héctor Chávez, 2015-07-06 23:58:46]

Please take a look

[Mark Seaborn, 2015-07-08 04:11:21]

https://codereview.chromium.org/1222753005/diff/60001/src/nonsfi/linux/linux_...
File src/nonsfi/linux/linux_pthread_private.c (right):

https://codereview.chromium.org/1222753005/diff/60001/src/nonsfi/linux/linux_...
src/nonsfi/linux/linux_pthread_private.c:91: static void
nc_tdb_init(nc_thread_descriptor_t *tdb,
Rather than duplicating this from pthread/nc_thread.c, can you change
nc_thread.c's __nc_initialize_unjoinable_thread() to be defined unconditionally,
please?

https://codereview.chromium.org/1222753005/diff/60001/src/nonsfi/linux/linux_...
src/nonsfi/linux/linux_pthread_private.c:124: static void irt_start_thread() {
Can you add a comment saying that this is based on the equivalent function in
src/untrusted/irt/irt_thread.c?  Same for the next two functions too.

https://codereview.chromium.org/1222753005/diff/60001/src/nonsfi/linux/linux_...
src/nonsfi/linux/linux_pthread_private.c:160: /*
Nit: fix indentation

https://codereview.chromium.org/1222753005/diff/60001/src/nonsfi/linux/linux_...
src/nonsfi/linux/linux_pthread_private.c:167: void *irt_tp =
__nacl_tls_initialize_memory(combined_area, sizeof(*tdb));
Nit: fix indentation

[Luis Héctor Chávez, 2015-07-08 16:42:13]

https://codereview.chromium.org/1222753005/diff/60001/src/nonsfi/linux/linux_...
File src/nonsfi/linux/linux_pthread_private.c (right):

https://codereview.chromium.org/1222753005/diff/60001/src/nonsfi/linux/linux_...
src/nonsfi/linux/linux_pthread_private.c:91: static void
nc_tdb_init(nc_thread_descriptor_t *tdb,
On 2015/07/08 04:11:21, Mark Seaborn wrote:
> Rather than duplicating this from pthread/nc_thread.c, can you change
> nc_thread.c's __nc_initialize_unjoinable_thread() to be defined
unconditionally,
> please?

Done.

https://codereview.chromium.org/1222753005/diff/60001/src/nonsfi/linux/linux_...
src/nonsfi/linux/linux_pthread_private.c:124: static void irt_start_thread() {
On 2015/07/08 04:11:21, Mark Seaborn wrote:
> Can you add a comment saying that this is based on the equivalent function in
> src/untrusted/irt/irt_thread.c?  Same for the next two functions too.

Done.

https://codereview.chromium.org/1222753005/diff/60001/src/nonsfi/linux/linux_...
src/nonsfi/linux/linux_pthread_private.c:160: /*
On 2015/07/08 04:11:21, Mark Seaborn wrote:
> Nit: fix indentation

Done.

https://codereview.chromium.org/1222753005/diff/60001/src/nonsfi/linux/linux_...
src/nonsfi/linux/linux_pthread_private.c:167: void *irt_tp =
__nacl_tls_initialize_memory(combined_area, sizeof(*tdb));
On 2015/07/08 04:11:21, Mark Seaborn wrote:
> Nit: fix indentation

Done.

[Mark Seaborn, 2015-07-08 17:00:01]

LGTM, thanks

[Luis Héctor Chávez, 2015-07-08 18:44:56]

The CQ bit was checked by lhchavez@chromium.org

[commit-bot: I haz the power, 2015-07-08 18:45:10]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1222753005/80001

[commit-bot: I haz the power, 2015-07-08 21:54:03]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-07-08 21:54:04]

Try jobs failed on following builders:
  nacl-arm_opt_panda on tryserver.nacl (JOB_FAILED,
http://build.chromium.org/p/tryserver.nacl/builders/nacl-arm_opt_panda/builds...)

[Luis Héctor Chávez, 2015-07-08 21:59:18]

The CQ bit was checked by lhchavez@chromium.org

[commit-bot: I haz the power, 2015-07-08 21:59:32]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1222753005/80001

[commit-bot: I haz the power, 2015-07-09 03:59:51]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-07-09 03:59:52]

Try jobs failed on following builders:
  nacl-arm_opt_panda on tryserver.nacl (JOB_TIMED_OUT,
http://build.chromium.org/p/tryserver.nacl/builders/nacl-arm_opt_panda/builds...)

[Luis Héctor Chávez, 2015-07-09 14:44:48]

The CQ bit was checked by lhchavez@chromium.org

[commit-bot: I haz the power, 2015-07-09 14:45:06]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1222753005/80001

[commit-bot: I haz the power, 2015-07-09 14:46:19]

Committed patchset #5 (id:80001) as
https://chromium.googlesource.com/native_client/src/native_client/+/e3168db25...