Thread-safe xmalloc and xrealloc needs a recursive mutex

The mutex used to protect object access (read_mutex) may need to be
acquired recursively.  Introduce init_recursive_mutex() helper function
in thread-utils.c that constructs a mutex with the PHREAD_MUTEX_RECURSIVE
attribute.

pthread_mutex_init() emulation on Win32 is already recursive as it is
implemented on top of the CRITICAL_SECTION type, which is recursive.

    http://msdn.microsoft.com/en-us/library/ms682530%28VS.85%29.aspx

Add do-nothing compatibility wrappers for pthread_mutexattr* functions.

Initial-version-by: Fredrik Kuivinen <frekui@gmail.com>
Signed-off-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Johannes Sixt
2010-04-08 09:15:39 +02:00
committed by Junio C Hamano
parent a9a746364b
commit 9374919442
5 changed files with 27 additions and 4 deletions

View File

@@ -1,4 +1,5 @@
#include "cache.h"
#include <pthread.h>
#if defined(hpux) || defined(__hpux) || defined(_hpux)
# include <sys/pstat.h>
@@ -43,3 +44,18 @@ int online_cpus(void)
return 1;
}
int init_recursive_mutex(pthread_mutex_t *m)
{
pthread_mutexattr_t a;
int ret;
ret = pthread_mutexattr_init(&a);
if (!ret) {
ret = pthread_mutexattr_settype(&a, PTHREAD_MUTEX_RECURSIVE);
if (!ret)
ret = pthread_mutex_init(m, &a);
pthread_mutexattr_destroy(&a);
}
return ret;
}