g_mem_set_vtable() doesn't really help (at least right now) because I can't get any definitive information on whether malloc() and free() are thread-safe. I am building with -D_REENTRANT so the thread-safe versions of malloc() and free() should be already/automatically implemented. Somewhere I read that the reentrant versions of malloc(), calloc(), and realloc() lock the heap but free() does not resulting in possible heap corruption. That really doesn't make sense to me (that is locking during allocation but not release) and I wasn't sure with what authority the person made those claims. It would however, explain my problem. Any thoughts? BTW... It is documented that g_malloc() indeed aborts during failure. This is infact why I am using g_try_malloc() instead. The information for the documentation of g_try_malloc() states: "Attempts to allocate n_bytes, and returns NULL on failure. Contrast with g_malloc(), which aborts the program on failure." -----Original Message----- From: gtk-list-bounces@xxxxxxxxx [mailto:gtk-list-bounces@xxxxxxxxx] On Behalf Of Ben Johnson Sent: Monday, February 07, 2005 11:30 PM To: gtk-list@xxxxxxxxx Subject: Re: Are g_try_malloc() and g_free() thread-safe? I was given and found some answers to my questions. thought I'd share for the good of the curious. On Mon, Feb 07, 2005 at 03:41:42PM -0800, Ben Johnson wrote: ... > how do you remove the risk? you have to compile libc with _REENTRANT? g_malloc(), g_free(), and associated functions are wrappers for the libc malloc() and free(). I'm told that when the program is linked against a thread library (not sure which thread lib... maybe all of them?) there's some symbol magic that happens and thread safe versions of these functions in the thread library are called instead. (I'm paraphrasing, so this may not be entirely accurate... or may be in need of serious correction, but that's my understanding.) > Also, the g_mem_set_vtable() function does not appear to be thread safe. if g_mem_set_vtable() is used, it MUST be called BEFORE any other glib function, so this is a non-issue. BTW, I also found out that g_malloc() (and therefore all glib functions that use g_malloc()) will call abort() if the wrapped malloc() fails. Does everyone know that? I was surprised to find out. I think this tidbit could use a little more publicity than the blurb in the glib docs about g_try_malloc(). - Ben _______________________________________________ gtk-list@xxxxxxxxx http://mail.gnome.org/mailman/listinfo/gtk-list _______________________________________________ gtk-list@xxxxxxxxx http://mail.gnome.org/mailman/listinfo/gtk-list
