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Drop memory-related trap variables

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These are just more lo-tech conditional breakpoint wannabes.
Debuggers can be trusted to support conditional breakpoints
nowadays.
This commit is contained in:
Matthias Clasen 2013-12-30 10:53:32 -05:00
parent 6d3b83a8c1
commit 58cdf0b474
2 changed files with 0 additions and 67 deletions
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42
docs/reference/glib/running.xml
View File

@ -274,48 +274,6 @@ returned by functions like <function>strftime()</function>.
</refsect2>
<refsect2>
<title>Traps and traces</title>
<para>
<indexterm><primary>g_trap_free_size</primary></indexterm>
<indexterm><primary>g_trap_realloc_size</primary></indexterm>
<indexterm><primary>g_trap_malloc_size</primary></indexterm>
Some code portions contain trap variables that can be set during debugging
time if GLib has been configured with <option>--enable-debug=yes</option>.
Such traps lead to immediate code halts to examine the current program state
and backtrace.
</para>
<para>
Currently, the following trap variables exist:
<programlisting>
static volatile gulong g_trap_free_size;
static volatile gulong g_trap_realloc_size;
static volatile gulong g_trap_malloc_size;
</programlisting>
If set to a size > 0, <link linkend="g-free">g_free</link>(),
<link linkend="g-realloc">g_realloc</link>() and
<link linkend="g-malloc">g_malloc</link>() will be intercepted if the size
matches the size of the corresponding memory block. This will only work with
<literal>g_mem_set_vtable (glib_mem_profiler_table)</literal> upon startup
though, because memory profiling is required to match on the memory block sizes.
</para>
<para>
Note that many modern debuggers support conditional breakpoints, which achieve
pretty much the same. E.g. in gdb, you can do
<programlisting>
break g_malloc
condition 1 n_bytes == 20
</programlisting>
to break only on g_malloc() calls where the size of the allocated memory block
is 20.
</para>
</refsect2>
<refsect2>
<title>Gdb debugging macros</title>
<para>
glib ships with a set of python macros for the gdb debugger. These includes pretty
printers for lists, hashtables and gobject types. It also has a backtrace filter

25
glib/gmem.c
View File

@ -556,11 +556,6 @@ static gsize profile_allocs = 0;
static gsize profile_zinit = 0;
static gsize profile_frees = 0;
static GMutex gmem_profile_mutex;
#ifdef G_ENABLE_DEBUG
static volatile gsize g_trap_free_size = 0;
static volatile gsize g_trap_realloc_size = 0;
static volatile gsize g_trap_malloc_size = 0;
#endif /* G_ENABLE_DEBUG */
#define PROFILE_TABLE(f1,f2,f3) ( ( ((f3) << 2) | ((f2) << 1) | (f1) ) * (MEM_PROFILE_TABLE_SIZE + 1))
@ -700,11 +695,6 @@ profiler_try_malloc (gsize n_bytes)
{
gsize *p;
#ifdef G_ENABLE_DEBUG
if (g_trap_malloc_size == n_bytes)
G_BREAKPOINT ();
#endif /* G_ENABLE_DEBUG */
p = malloc (sizeof (gsize) * 2 + n_bytes);
if (p)
@ -738,11 +728,6 @@ profiler_calloc (gsize n_blocks,
gsize l = n_blocks * n_block_bytes;
gsize *p;
#ifdef G_ENABLE_DEBUG
if (g_trap_malloc_size == l)
G_BREAKPOINT ();
#endif /* G_ENABLE_DEBUG */
p = calloc (1, sizeof (gsize) * 2 + l);
if (p)
@ -777,11 +762,6 @@ profiler_free (gpointer mem)
}
else
{
#ifdef G_ENABLE_DEBUG
if (g_trap_free_size == p[1])
G_BREAKPOINT ();
#endif /* G_ENABLE_DEBUG */
profiler_log (PROFILER_FREE,
p[1], /* length */
TRUE);
@ -802,11 +782,6 @@ profiler_try_realloc (gpointer mem,
gsize *p = mem;
p -= 2;
#ifdef G_ENABLE_DEBUG
if (g_trap_realloc_size == n_bytes)
G_BREAKPOINT ();
#endif /* G_ENABLE_DEBUG */
if (mem && p[0]) /* free count */
{