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Corinna Vinschen e528cfe919 Cygwin: split malloc_init
Cygwin 3.3 only: Replace SRWLOCK usage for malloc synchronization with
the first incarnation of the patch splitting malloc_init into two parts.
The SRWLOCK usage requires TryAcquireSRWLockExclusive, which isn't
available on Vista / Server 2008, unfortunately.

Per https://cygwin.com/pipermail/cygwin-developers/2021-October/012429.html,
we may encounter a crash when starting multiple threads during process
startup (here: fhandler_fifo::fixup_after_{fork,exec}) which in turn
allocate memory via malloc.

The problem is concurrent usage of malloc before the malloc muto has
been initialized.

To fix this issue, split malloc_init into malloc_init_0, called from
dll_crt0_0, and malloc_init_1, called from dll_crt_0_1.  malloc_init_0
just initializes the muto, malloc_init_1 checks for user space provided
malloc.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2021-10-28 22:35:17 +02:00

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455 B
C

/* heap.h: Cygwin heap manager definitions.
This file is part of Cygwin.
This software is a copyrighted work licensed under the terms of the
Cygwin license. Please consult the file "CYGWIN_LICENSE" for
details. */
#include "perprocess.h"
/* Heap management. */
void heap_init ();
#define inheap(s) \
(cygheap->user_heap.ptr && s \
&& ((char *) (s) >= (char *) cygheap->user_heap.base) \
&& ((char *) (s) <= (char *) cygheap->user_heap.top))