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PYMALLOC_{CLEAN, DEAD, FORBIDDEN}BYTE symbols: remove the PYMALLOC_

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prefix.  These symbols are private to the file, and the PYMALLOC_ gets
in the way (overly long code lines, comments, and error messages).
This commit is contained in:
Tim Peters 2002-04-12 07:38:53 +00:00
parent af3e8de580
commit f6fb501c57
1 changed files with 39 additions and 34 deletions
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73
Objects/obmalloc.c
View file

@ -876,9 +876,16 @@ PyObject_Free(void *p)
* it wraps a real allocator, adding extra debugging info to the memory blocks.
*/
#define PYMALLOC_CLEANBYTE 0xCB /* uninitialized memory */
#define PYMALLOC_DEADBYTE 0xDB /* free()ed memory */
#define PYMALLOC_FORBIDDENBYTE 0xFB /* unusable memory */
/* Special bytes broadcast into debug memory blocks at appropriate times.
* Strings of these are unlikely to be valid addresses, floats, ints or
* 7-bit ASCII.
*/
#undef CLEANBYTE
#undef DEADBYTE
#undef FORBIDDENBYTE
#define CLEANBYTE 0xCB /* clean (newly allocated) memory */
#define DEADBYTE 0xDB /* deed (newly freed) memory */
#define FORBIDDENBYTE 0xFB /* untouchable bytes at each end of a block */
static ulong serialno = 0; /* incremented on each debug {m,re}alloc */
@ -922,16 +929,14 @@ p[0:4]
Number of bytes originally asked for. 4-byte unsigned integer,
big-endian (easier to read in a memory dump).
p[4:8]
Copies of PYMALLOC_FORBIDDENBYTE. Used to catch under- writes
and reads.
Copies of FORBIDDENBYTE. Used to catch under- writes and reads.
p[8:8+n]
The requested memory, filled with copies of PYMALLOC_CLEANBYTE.
The requested memory, filled with copies of CLEANBYTE.
Used to catch reference to uninitialized memory.
&p[8] is returned. Note that this is 8-byte aligned if pymalloc
handled the request itself.
p[8+n:8+n+4]
Copies of PYMALLOC_FORBIDDENBYTE. Used to catch over- writes
and reads.
Copies of FORBIDDENBYTE. Used to catch over- writes and reads.
p[8+n+4:8+n+8]
A serial number, incremented by 1 on each call to _PyObject_DebugMalloc
and _PyObject_DebugRealloc.
@ -964,21 +969,21 @@ _PyObject_DebugMalloc(size_t nbytes)
return NULL;
write4(p, nbytes);
p[4] = p[5] = p[6] = p[7] = PYMALLOC_FORBIDDENBYTE;
p[4] = p[5] = p[6] = p[7] = FORBIDDENBYTE;
if (nbytes > 0)
memset(p+8, PYMALLOC_CLEANBYTE, nbytes);
memset(p+8, CLEANBYTE, nbytes);
tail = p + 8 + nbytes;
tail[0] = tail[1] = tail[2] = tail[3] = PYMALLOC_FORBIDDENBYTE;
tail[0] = tail[1] = tail[2] = tail[3] = FORBIDDENBYTE;
write4(tail + 4, serialno);
return p+8;
}
/* The debug free first checks the 8 bytes on each end for sanity (in
particular, that the PYMALLOC_FORBIDDENBYTEs are still intact).
Then fills the original bytes with PYMALLOC_DEADBYTE.
particular, that the FORBIDDENBYTEs are still intact).
Then fills the original bytes with DEADBYTE.
Then calls the underlying free.
*/
void
@ -992,7 +997,7 @@ _PyObject_DebugFree(void *p)
_PyObject_DebugCheckAddress(p);
nbytes = read4(q-8);
if (nbytes > 0)
memset(q, PYMALLOC_DEADBYTE, nbytes);
memset(q, DEADBYTE, nbytes);
PyObject_Free(q-8);
}
@ -1024,9 +1029,9 @@ _PyObject_DebugRealloc(void *p, size_t nbytes)
write4(q-8, nbytes);
/* kill the excess bytes plus the trailing 8 pad bytes */
q += nbytes;
q[0] = q[1] = q[2] = q[3] = PYMALLOC_FORBIDDENBYTE;
q[0] = q[1] = q[2] = q[3] = FORBIDDENBYTE;
write4(q+4, serialno);
memset(q+8, PYMALLOC_DEADBYTE, excess);
memset(q+8, DEADBYTE, excess);
return p;
}
@ -1059,7 +1064,7 @@ _PyObject_DebugCheckAddress(const void *p)
}
for (i = 4; i >= 1; --i) {
if (*(q-i) != PYMALLOC_FORBIDDENBYTE) {
if (*(q-i) != FORBIDDENBYTE) {
msg = "bad leading pad byte";
goto error;
}
@ -1069,7 +1074,7 @@ _PyObject_DebugCheckAddress(const void *p)
const ulong nbytes = read4(q-8);
const uchar *tail = q + nbytes;
for (i = 0; i < 4; ++i) {
if (tail[i] != PYMALLOC_FORBIDDENBYTE) {
if (tail[i] != FORBIDDENBYTE) {
msg = "bad trailing pad byte";
goto error;
}
@ -1103,19 +1108,19 @@ _PyObject_DebugDumpAddress(const void *p)
the serial number (the address deref could blow up). */
fputs(" the 4 pad bytes at p-4 are ", stderr);
if (*(q-4) == PYMALLOC_FORBIDDENBYTE &&
*(q-3) == PYMALLOC_FORBIDDENBYTE &&
*(q-2) == PYMALLOC_FORBIDDENBYTE &&
*(q-1) == PYMALLOC_FORBIDDENBYTE) {
fputs("PYMALLOC_FORBIDDENBYTE, as expected\n", stderr);
if (*(q-4) == FORBIDDENBYTE &&
*(q-3) == FORBIDDENBYTE &&
*(q-2) == FORBIDDENBYTE &&
*(q-1) == FORBIDDENBYTE) {
fputs("FORBIDDENBYTE, as expected\n", stderr);
}
else {
fprintf(stderr, "not all PYMALLOC_FORBIDDENBYTE (0x%02x):\n",
PYMALLOC_FORBIDDENBYTE);
fprintf(stderr, "not all FORBIDDENBYTE (0x%02x):\n",
FORBIDDENBYTE);
for (i = 4; i >= 1; --i) {
const uchar byte = *(q-i);
fprintf(stderr, " at p-%d: 0x%02x", i, byte);
if (byte != PYMALLOC_FORBIDDENBYTE)
if (byte != FORBIDDENBYTE)
fputs(" *** OUCH", stderr);
fputc('\n', stderr);
}
@ -1123,20 +1128,20 @@ _PyObject_DebugDumpAddress(const void *p)
tail = q + nbytes;
fprintf(stderr, " the 4 pad bytes at tail=%p are ", tail);
if (tail[0] == PYMALLOC_FORBIDDENBYTE &&
tail[1] == PYMALLOC_FORBIDDENBYTE &&
tail[2] == PYMALLOC_FORBIDDENBYTE &&
tail[3] == PYMALLOC_FORBIDDENBYTE) {
fputs("PYMALLOC_FORBIDDENBYTE, as expected\n", stderr);
if (tail[0] == FORBIDDENBYTE &&
tail[1] == FORBIDDENBYTE &&
tail[2] == FORBIDDENBYTE &&
tail[3] == FORBIDDENBYTE) {
fputs("FORBIDDENBYTE, as expected\n", stderr);
}
else {
fprintf(stderr, "not all PYMALLOC_FORBIDDENBYTE (0x%02x):\n",
PYMALLOC_FORBIDDENBYTE);
fprintf(stderr, "not all FORBIDDENBYTE (0x%02x):\n",
FORBIDDENBYTE);
for (i = 0; i < 4; ++i) {
const uchar byte = tail[i];
fprintf(stderr, " at tail+%d: 0x%02x",
i, byte);
if (byte != PYMALLOC_FORBIDDENBYTE)
if (byte != FORBIDDENBYTE)
fputs(" *** OUCH", stderr);
fputc('\n', stderr);
}