Rainer Orth <r...@cebitec.uni-bielefeld.de> writes:
> Ian Lance Taylor <i...@google.com> writes:
>
>> This patch updates the implementations of locks and notes used in libgo
>> to use the current version from the master Go library. This now uses
>> futexes when running on GNU/Linux, while still using semaphores on other
>> systems. This implementation should be faster, and does not require
>> explicit initialization. Bootstrapped and ran Go testsuite on
>> x86_64-unknown-linux-gnu. I tested both the futex and the semaphore
>> versions. Committed to mainline.
>
>> +static int32
>> +getproccount(void)
>> +{
>> + int32 fd, rd, cnt, cpustrlen;
>> + const byte *cpustr, *pos;
>> + byte *bufpos;
>> + byte buf[256];
>> +
>> + fd = open("/proc/stat", O_RDONLY|O_CLOEXEC, 0);
>
> This broke bootstrap on Linux/x86_64 (CentOS 5.5), which lacks
> O_CLOEXEC.
Thanks for the report. Fixed in the obvious way as follows. The use of
O_CLOEXEC provides extra safety but is not essential, since the program
is single-threaded when the file is used. Bootstrapped on
x86_64-unknown-linux-gnu. Committed to mainline.
Ian
diff -r 295f86b18961 libgo/runtime/thread-linux.c
--- a/libgo/runtime/thread-linux.c Tue Nov 29 11:02:01 2011 -0800
+++ b/libgo/runtime/thread-linux.c Tue Nov 29 11:24:45 2011 -0800
@@ -62,6 +62,10 @@
*(int32*)0x1006 = 0x1006;
}
+#ifndef O_CLOEXEC
+#define O_CLOEXEC 0
+#endif
+
static int32
getproccount(void)
{
