_C_Quickpool_Debug() — Modify Quick Pool Memory Manager Characteristics

Format

#include <stdlib.h>
_C_Quickpool_Debug_T _C_Quickpool_Debug(_C_Quickpool_Debug_T *newval);

Language Level: Extended

Threadsafe: Yes.

Description

The _C_Quickpool_Debug() function modifies Quick Pool memory manager characteristics. Environment variables can also be used to configure this support (reference section Environment Variables).

The parameters for _C_Quickpool_Debug() are as follows:

newval

A pointer to a _C_Quickpool_Debug_T structure. The structure contains the following fields:

flags

An unsigned integer value that indicates the characteristics to be modified. The flags field can contain the following values (which can be used in any combination):

_C_INIT_MALLOC

Initializes all allocated storage to a specified value.

_C_INIT_FREE

Initializes all freed storage to a specified value.

_C_COLLECT_STATS

Collects statistics on the Quick Pool memory manager for use with the _C_Quickpool_Report() function.

malloc_val

A 1-byte unsigned character value that is used to initialize each byte of allocated memory. This field is in use only when the _C_INIT_MALLOC flag is specified.

free_val

A 1-byte unsigned character value that is used to initialize each byte of freed memory. This field is in use only when the _C_INIT_FREE flag is specified.

If the value of newval is NULL, a structure containing the current Quick Pool memory manager characteristics is returned and none of the Quick Pool memory manager characteristics are modified.

Return Value

The return value is a structure that contains the _C_Quickpool_Debug() values before the changes requested by the current function call are made. This value can be used on a later call to restore the _C_Quickpool_Debug() values to a prior state.

Example that uses _C_Quickpool_Debug()

The following example uses _C_Quickpool_Debug() with the _C_INIT_MALLOC and _C_INIT_FREE flags to initialize memory on the malloc and free functions.

#include <stdlib.h>
#include <stdio.h>
int main(void) {
  char *p;
  char *mtest = "AAAAAAAAAA";
  char *ftest = "BBBBBBBBBB";
  unsigned int cell_sizes[2]       = { 16, 64 };
  unsigned int cells_per_extent[2] = { 16, 16 };
  _C_Quickpool_Debug_T  dbgVals = { _C_INIT_MALLOC | _C_INIT_FREE, 'A', 'B' };

  if (_C_Quickpool_Init(2, cell_sizes, cells_per_extent)) {
    printf("Error initializing Quick Pool memory manager.\n");
    return -1;
  }

  _C_Quickpool_Debug(&dbgVals);

  if ((p = malloc(10)) == NULL) {
    printf("Error during malloc.\n");
    return -2;
  }
  if (memcmp(p, mtest, 10)) {
    printf("malloc test failed\n");
  }
  free(p);
  if (memcmp(p, ftest, 10)) {
    printf("free test failed\n");
  }
  printf("Test successful!\n");
  return 0;
}
/*****************Output should be similar to:*****************
Test successful!
*******************************************************************/

Related Information

• _C_Quickpool_Init() — Initialize Quick Pool Memory Manager
• _C_Quickpool_Report() — Generate Quick Pool Memory Manager Report
• <stdlib.h>
• Heap Memory