From c0f86547c522906da7538c0d2b7b0de608499c23 Mon Sep 17 00:00:00 2001
From: Junio C Hamano <gitster@pobox.com>
Date: Tue, 26 Jun 2012 19:19:32 +0100
Subject: [PATCH] index-pack: Disable threading on cygwin
The Cygwin implementation of pread() is not thread-safe since, just
like the emulation provided by compat/pread.c, it uses a sequence of
seek-read-seek calls. In order to avoid failues due to thread-safety
issues, commit b038a61 disables threading when NO_PREAD is defined.
(ie when using the emulation code in compat/pread.c).
We introduce a new build variable, NO_THREAD_SAFE_PREAD, which allows
use to disable the threaded index-pack code on cygwin, in addition to
the above NO_PREAD case.
Signed-off-by: Ramsay Jones <ramsay@ramsay1.demon.co.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
Makefile | 8 ++++++++
builtin/index-pack.c | 4 ++--
2 files changed, 10 insertions(+), 2 deletions(-)
diff --git a/Makefile b/Makefile
index 4592f1f2ee8..67d761e83ad 100644
--- a/Makefile
+++ b/Makefile
@@ -158,6 +158,9 @@ all::
# Define NO_PREAD if you have a problem with pread() system call (e.g.
# cygwin1.dll before v1.5.22).
#
+# Define NO_THREAD_SAFE_PREAD if your pread() implementation is not
+# thread-safe. (e.g. compat/pread.c or cygwin)
+#
# Define NO_FAST_WORKING_DIRECTORY if accessing objects in pack files is
# generally faster on your platform than accessing the working directory.
#
@@ -1051,6 +1054,7 @@ ifeq ($(uname_O),Cygwin)
NO_IPV6 = YesPlease
OLD_ICONV = UnfortunatelyYes
endif
+ NO_THREAD_SAFE_PREAD = YesPlease
NEEDS_LIBICONV = YesPlease
NO_FAST_WORKING_DIRECTORY = UnfortunatelyYes
NO_TRUSTABLE_FILEMODE = UnfortunatelyYes
@@ -1659,6 +1663,10 @@ endif
ifdef NO_PREAD
COMPAT_CFLAGS += -DNO_PREAD
COMPAT_OBJS += compat/pread.o
+ NO_THREAD_SAFE_PREAD = YesPlease
+endif
+ifdef NO_THREAD_SAFE_PREAD
+ BASIC_CFLAGS += -DNO_THREAD_SAFE_PREAD
endif
ifdef NO_FAST_WORKING_DIRECTORY
BASIC_CFLAGS += -DNO_FAST_WORKING_DIRECTORY
diff --git a/builtin/index-pack.c b/builtin/index-pack.c
index dc2cfe6e6f6..470547835ca 100644
--- a/builtin/index-pack.c
+++ b/builtin/index-pack.c
@@ -39,8 +39,8 @@ struct base_data {
int ofs_first, ofs_last;
};
-#if !defined(NO_PTHREADS) && defined(NO_PREAD)
-/* NO_PREAD uses compat/pread.c, which is not thread-safe. Disable threading. */
+#if !defined(NO_PTHREADS) && defined(NO_THREAD_SAFE_PREAD)
+/* pread() emulation is not thread-safe. Disable threading. */
#define NO_PTHREADS
#endif