This is the mail archive of the mailing list for the Cygwin project.

Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: SIGSEGV when called sem_init() with gdb.

Just add a breakpoint after the sem_init call.
To avoid multiple initializations sem_init checks if the semaphore is already initialized and will return EBUSY in that case.
The check is done via IsBadWritePtr which will trigger a SEGV if the pointer is invalid and not NULL.
The SEGV is handled internally and will not cause the program to stop.


Oreste Bernardi wrote:
I installed
gdb 20020718-1.

I tried again and I see same behavior.

By the way, is gdb 20020718-1 experimental version or stable version ?


----- Original Message ----- From: <>
To: <>; <>
Sent: Tuesday, December 10, 2002 5:03 PM
Subject: RE: SIGSEGV when called sem_init() with gdb.

Rerun setup and update your gdb. If that doesn't help, let the list know.


Original Message:
From: Oreste Bernardi
Date: Tue, 10 Dec 2002 16:01:16 +0100
Subject: SIGSEGV when called sem_init() with gdb.

Dear, all

#include <semaphore.h>
int main () {
int p;
sem_t sem;
int i=0,d;
//sem=(sem_t)NULL; //With this There isn't any problem
sem_init (&sem,0,1);
sem_post (&sem);
return i;

cygwin 1.3.17-1
gcc 3.2-3
gdb 20010428-3

When executing this source code with gdb I get an SIGSEGV signal when
sem_init() function is called.
If I continue on, program works fine.
If program is not executed from gdb, it works without any error.
If I initialize it with NULL, I don't get any error.

I think that is the same behavior as described by following mail:
Is this true ?

To avoid annoying gdb error message, is my solution ("sem=(sem_t)NULL")
reliable and portable ?

Best Regards
Oreste Bernardi

Unsubscribe info:
Bug reporting:

mail2web - Check your email from the web at .

Unsubscribe info:
Bug reporting:

Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]