bdwgc / bdwgc / 2107

81%

Build Type

push

travis-ci

Committed by ivmai

Commit Message

Fix deadlock in GC_start_mark_threads if redirect-malloc on Linux

Issue #909 (bdwgc).

In `GC_start_mark_threads_inner`, real `pthread_create()` could call
our `calloc()` redirecting to `GC_generic_malloc_uncollectable()`,
thus we should release the allocator lock temporarily (to avoid
a deadlock).  As a consequence, we need to prevent usage of the
markers till `GC_wait_for_markers_init()` completion - the easiest
way to achieve this is to disable collection temporarily.

* pthread_support.c [GC_PTHREADS_PARAMARK]
(GC_start_mark_threads_inner): Update comments for `if (GC_parallel)`
and `INIT_REAL_SYMS()`; define `res` local variable.
* pthread_support.c [GC_PTHREADS_PARAMARK && REDIRECT_MALLOC]
(GC_start_mark_threads_inner): Call `GC_disable_inner()` and `UNLOCK()`
before call `REAL_FUNC(pthread_create)()`, followed by call `LOCK()`
and `GC_enable_inner()`; add comment.

Co-authored-by: fcrwr <262846459+fcrwr@users.noreply.github.com>

Coverage Stats

3 of 3 new or added lines in 1 file covered. (100.0%)

290 existing lines in 9 files now uncovered.

7229 of 8965 relevant lines covered (80.64%)

18665721.63 hits per line