MacOSX has a paranoid malloc/free built-in, you just have to activate it with environment variables.hgm wrote:Yes, but the purpose is not to write a new malloc, but to reproduce an error that occur with the existing one, and print diagnostics when it occurs. So in any case I want to exactly the same malloc calls as would be done when you call it directly.
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DEBUGGING ALLOCATION ERRORS
A number of facilities are provided to aid in debugging allocation errors
in applications. These facilities are primarily controlled via environ-
ment variables. The recognized environment variables and their meanings
are documented below.
ENVIRONMENT
The following environment variables change the behavior of the alloca-
tion-related functions.
MallocLogFile <f> Create/append messages to the given file
path <f> instead of writing to the standard
error.
MallocGuardEdges If set, add a guard page before and after
each large block.
MallocDoNotProtectPrelude If set, do not add a guard page before large
blocks, even if the MallocGuardEdges envi-
ronment variable is set.
MallocDoNotProtectPostlude If set, do not add a guard page after large
blocks, even if the MallocGuardEdges envi-
ronment variable is set.
MallocStackLogging If set, record all stacks, so that tools
like leaks can be used.
MallocStackLoggingNoCompact If set, record all stacks in a manner that
is compatible with the malloc_history pro-
gram.
MallocStackLoggingDirectory If set, records stack logs to the directory
specified instead of saving them to the
default location (/tmp).
MallocScribble If set, fill memory that has been allocated
with 0xaa bytes. This increases the likeli-
hood that a program making assumptions about
the contents of freshly allocated memory
will fail. Also if set, fill memory that
has been deallocated with 0x55 bytes. This
increases the likelihood that a program will
fail due to accessing memory that is no
longer allocated.
MallocCheckHeapStart <s> If set, specifies the number of allocations
<s> to wait before begining periodic heap
checks every <n> as specified by
MallocCheckHeapEach. If
MallocCheckHeapStart is set but
MallocCheckHeapEach is not specified, the
default check repetition is 1000.
MallocCheckHeapEach <n> If set, run a consistency check on the heap
every <n> operations. MallocCheckHeapEach
is only meaningful if MallocCheckHeapStart
is also set.
MallocCheckHeapSleep <t> Sets the number of seconds to sleep (waiting
for a debugger to attach) when
MallocCheckHeapStart is set and a heap cor-
ruption is detected. The default is 100
seconds. Setting this to zero means not to
sleep at all. Setting this to a negative
number means to sleep (for the positive num-
ber of seconds) only the very first time a
heap corruption is detected.
MallocCheckHeapAbort <b> When MallocCheckHeapStart is set and this is
set to a non-zero value, causes abort(3) to
be called if a heap corruption is detected,
instead of any sleeping.
MallocErrorAbort If set, causes abort(3) to be called if an
error was encountered in malloc(3) or
free(3) , such as a calling free(3) on a
pointer previously freed.
MallocCorruptionAbort Similar to MallocErrorAbort but will not
abort in out of memory conditions, making it
more useful to catch only those errors which
will cause memory corruption. MallocCorrup-
tionAbort is always set on 64-bit processes.
MallocHelp If set, print a list of environment vari-
ables that are paid heed to by the alloca-
tion-related functions, along with short
descriptions. The list should correspond to
this documentation.
