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procps/proc/meminfo.c
Jim Warner eff9fbc06e library: standardize extents_free_all() logic, 3rd gen 
As those 3rd generation newlib APIs evolved so too did
the extents_free_all() function. Most versions of this
function required the callers to first verify that the
extents anchor wasn't empty, which was poor etiquette.

This simple function should have been much more robust
and forgiving. With this commit, it fnally becomes so.

Signed-off-by: Jim Warner <james.warner@comcast.net>
2016-07-02 16:33:01 +10:00

849 lines
26 KiB
C
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/*
* libprocps - Library to read proc filesystem
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <errno.h>
#include <fcntl.h>
#include <search.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <proc/procps-private.h>
#include <proc/meminfo.h>
#define MEMINFO_FILE "/proc/meminfo"
struct meminfo_data {
unsigned long Active;
unsigned long Active_anon; // as: Active(anon):
unsigned long Active_file; // as: Active(file):
unsigned long AnonHugePages;
unsigned long AnonPages;
unsigned long Bounce;
unsigned long Buffers;
unsigned long Cached;
unsigned long CmaFree; // man 5 proc: 'to be documented'
unsigned long CmaTotal; // man 5 proc: 'to be documented'
unsigned long CommitLimit;
unsigned long Committed_AS;
unsigned long DirectMap1G; // man 5 proc: 'to be documented'
unsigned long DirectMap2M; // man 5 proc: 'to be documented'
unsigned long DirectMap4k; // man 5 proc: 'to be documented'
unsigned long Dirty;
unsigned long HardwareCorrupted;
unsigned long HighFree;
unsigned long HighTotal;
unsigned long HugePages_Free;
unsigned long HugePages_Rsvd;
unsigned long HugePages_Surp;
unsigned long HugePages_Total;
unsigned long Hugepagesize;
unsigned long Inactive;
unsigned long Inactive_anon; // as: Inactive(anon):
unsigned long Inactive_file; // as: Inactive(file):
unsigned long KernelStack;
unsigned long LowFree;
unsigned long LowTotal;
unsigned long Mapped;
unsigned long MemAvailable;
unsigned long MemFree;
unsigned long MemTotal;
unsigned long Mlocked;
unsigned long NFS_Unstable;
unsigned long PageTables;
unsigned long SReclaimable;
unsigned long SUnreclaim;
unsigned long Shmem;
unsigned long Slab;
unsigned long SwapCached;
unsigned long SwapFree;
unsigned long SwapTotal;
unsigned long Unevictable;
unsigned long VmallocChunk;
unsigned long VmallocTotal;
unsigned long VmallocUsed;
unsigned long Writeback;
unsigned long WritebackTmp;
unsigned long derived_mem_hi_used;
unsigned long derived_mem_lo_used;
unsigned long derived_mem_used;
unsigned long derived_swap_used;
};
struct mem_hist {
struct meminfo_data new;
struct meminfo_data old;
};
struct stacks_extent {
int ext_numstacks;
struct stacks_extent *next;
struct meminfo_stack **stacks;
};
struct procps_meminfo {
int refcount;
int meminfo_fd;
int meminfo_was_read;
int dirty_stacks;
struct mem_hist hist;
int numitems;
enum meminfo_item *items;
struct stacks_extent *extents;
struct hsearch_data hashtab;
struct meminfo_result get_this;
};
// ___ Results 'Set' Support ||||||||||||||||||||||||||||||||||||||||||||||||||
#define setNAME(e) set_results_ ## e
#define setDECL(e) static void setNAME(e) \
(struct meminfo_result *R, struct mem_hist *H)
// regular assignment
#define MEM_set(e,t,x) setDECL(e) { R->result. t = H->new . x; }
// delta assignment
#define HST_set(e,t,x) setDECL(e) { R->result. t = ( H->new . x - H->old. x ); }
setDECL(noop) { (void)R; (void)H; }
setDECL(extra) { (void)R; (void)H; }
MEM_set(MEM_ACTIVE, ul_int, Active)
MEM_set(MEM_ACTIVE_ANON, ul_int, Active_anon)
MEM_set(MEM_ACTIVE_FILE, ul_int, Active_file)
MEM_set(MEM_ANON, ul_int, AnonPages)
MEM_set(MEM_AVAILABLE, ul_int, MemAvailable)
MEM_set(MEM_BOUNCE, ul_int, Bounce)
MEM_set(MEM_BUFFERS, ul_int, Buffers)
MEM_set(MEM_CACHED, ul_int, Cached)
MEM_set(MEM_COMMIT_LIMIT, ul_int, CommitLimit)
MEM_set(MEM_COMMITTED_AS, ul_int, Committed_AS)
MEM_set(MEM_HARD_CORRUPTED, ul_int, HardwareCorrupted)
MEM_set(MEM_DIRTY, ul_int, Dirty)
MEM_set(MEM_FREE, ul_int, MemFree)
MEM_set(MEM_HUGE_ANON, ul_int, AnonHugePages)
MEM_set(MEM_HUGE_FREE, ul_int, HugePages_Free)
MEM_set(MEM_HUGE_RSVD, ul_int, HugePages_Rsvd)
MEM_set(MEM_HUGE_SIZE, ul_int, Hugepagesize)
MEM_set(MEM_HUGE_SURPLUS, ul_int, HugePages_Surp)
MEM_set(MEM_HUGE_TOTAL, ul_int, HugePages_Total)
MEM_set(MEM_INACTIVE, ul_int, Inactive)
MEM_set(MEM_INACTIVE_ANON, ul_int, Inactive_anon)
MEM_set(MEM_INACTIVE_FILE, ul_int, Inactive_file)
MEM_set(MEM_KERNEL_STACK, ul_int, KernelStack)
MEM_set(MEM_LOCKED, ul_int, Mlocked)
MEM_set(MEM_MAPPED, ul_int, Mapped)
MEM_set(MEM_NFS_UNSTABLE, ul_int, NFS_Unstable)
MEM_set(MEM_PAGE_TABLES, ul_int, PageTables)
MEM_set(MEM_SHARED, ul_int, Shmem)
MEM_set(MEM_SLAB, ul_int, Slab)
MEM_set(MEM_SLAB_RECLAIM, ul_int, SReclaimable)
MEM_set(MEM_SLAB_UNRECLAIM, ul_int, SUnreclaim)
MEM_set(MEM_TOTAL, ul_int, MemTotal)
MEM_set(MEM_UNEVICTABLE, ul_int, Unevictable)
MEM_set(MEM_USED, ul_int, derived_mem_used)
MEM_set(MEM_VM_ALLOC_CHUNK, ul_int, VmallocChunk)
MEM_set(MEM_VM_ALLOC_TOTAL, ul_int, VmallocTotal)
MEM_set(MEM_VM_ALLOC_USED, ul_int, VmallocUsed)
MEM_set(MEM_WRITEBACK, ul_int, Writeback)
MEM_set(MEM_WRITEBACK_TMP, ul_int, WritebackTmp)
HST_set(DELTA_ACTIVE, s_int, Active)
HST_set(DELTA_ACTIVE_ANON, s_int, Active_anon)
HST_set(DELTA_ACTIVE_FILE, s_int, Active_file)
HST_set(DELTA_ANON, s_int, AnonPages)
HST_set(DELTA_AVAILABLE, s_int, MemAvailable)
HST_set(DELTA_BOUNCE, s_int, Bounce)
HST_set(DELTA_BUFFERS, s_int, Buffers)
HST_set(DELTA_CACHED, s_int, Cached)
HST_set(DELTA_COMMIT_LIMIT, s_int, CommitLimit)
HST_set(DELTA_COMMITTED_AS, s_int, Committed_AS)
HST_set(DELTA_HARD_CORRUPTED, s_int, HardwareCorrupted)
HST_set(DELTA_DIRTY, s_int, Dirty)
HST_set(DELTA_FREE, s_int, MemFree)
HST_set(DELTA_HUGE_ANON, s_int, AnonHugePages)
HST_set(DELTA_HUGE_FREE, s_int, HugePages_Free)
HST_set(DELTA_HUGE_RSVD, s_int, HugePages_Rsvd)
HST_set(DELTA_HUGE_SIZE, s_int, Hugepagesize)
HST_set(DELTA_HUGE_SURPLUS, s_int, HugePages_Surp)
HST_set(DELTA_HUGE_TOTAL, s_int, HugePages_Total)
HST_set(DELTA_INACTIVE, s_int, Inactive)
HST_set(DELTA_INACTIVE_ANON, s_int, Inactive_anon)
HST_set(DELTA_INACTIVE_FILE, s_int, Inactive_file)
HST_set(DELTA_KERNEL_STACK, s_int, KernelStack)
HST_set(DELTA_LOCKED, s_int, Mlocked)
HST_set(DELTA_MAPPED, s_int, Mapped)
HST_set(DELTA_NFS_UNSTABLE, s_int, NFS_Unstable)
HST_set(DELTA_PAGE_TABLES, s_int, PageTables)
HST_set(DELTA_SHARED, s_int, Shmem)
HST_set(DELTA_SLAB, s_int, Slab)
HST_set(DELTA_SLAB_RECLAIM, s_int, SReclaimable)
HST_set(DELTA_SLAB_UNRECLAIM, s_int, SUnreclaim)
HST_set(DELTA_TOTAL, s_int, MemTotal)
HST_set(DELTA_UNEVICTABLE, s_int, Unevictable)
HST_set(DELTA_USED, s_int, derived_mem_used)
HST_set(DELTA_VM_ALLOC_CHUNK, s_int, VmallocChunk)
HST_set(DELTA_VM_ALLOC_TOTAL, s_int, VmallocTotal)
HST_set(DELTA_VM_ALLOC_USED, s_int, VmallocUsed)
HST_set(DELTA_WRITEBACK, s_int, Writeback)
HST_set(DELTA_WRITEBACK_TMP, s_int, WritebackTmp)
MEM_set(MEMHI_FREE, ul_int, HighFree)
MEM_set(MEMHI_TOTAL, ul_int, HighTotal)
MEM_set(MEMHI_USED, ul_int, derived_mem_hi_used)
MEM_set(MEMLO_FREE, ul_int, LowFree)
MEM_set(MEMLO_TOTAL, ul_int, LowTotal)
MEM_set(MEMLO_USED, ul_int, derived_mem_lo_used)
MEM_set(SWAP_CACHED, ul_int, SwapCached)
MEM_set(SWAP_FREE, ul_int, SwapFree)
MEM_set(SWAP_TOTAL, ul_int, SwapTotal)
MEM_set(SWAP_USED, ul_int, derived_swap_used)
#undef setDECL
#undef MEM_set
#undef HST_set
// ___ Controlling Table ||||||||||||||||||||||||||||||||||||||||||||||||||||||
typedef void (*SET_t)(struct meminfo_result *, struct mem_hist *);
#define RS(e) (SET_t)setNAME(e)
/*
* Need it be said?
* This table must be kept in the exact same order as
* those 'enum meminfo_item' guys ! */
static struct {
SET_t setsfunc; // the actual result setting routine
} Item_table[] = {
/* setsfunc
-------------------------- */
{ RS(noop) },
{ RS(extra) },
{ RS(MEM_ACTIVE) },
{ RS(MEM_ACTIVE_ANON) },
{ RS(MEM_ACTIVE_FILE) },
{ RS(MEM_ANON) },
{ RS(MEM_AVAILABLE) },
{ RS(MEM_BOUNCE) },
{ RS(MEM_BUFFERS) },
{ RS(MEM_CACHED) },
{ RS(MEM_COMMIT_LIMIT) },
{ RS(MEM_COMMITTED_AS) },
{ RS(MEM_HARD_CORRUPTED) },
{ RS(MEM_DIRTY) },
{ RS(MEM_FREE) },
{ RS(MEM_HUGE_ANON) },
{ RS(MEM_HUGE_FREE) },
{ RS(MEM_HUGE_RSVD) },
{ RS(MEM_HUGE_SIZE) },
{ RS(MEM_HUGE_SURPLUS) },
{ RS(MEM_HUGE_TOTAL) },
{ RS(MEM_INACTIVE) },
{ RS(MEM_INACTIVE_ANON) },
{ RS(MEM_INACTIVE_FILE) },
{ RS(MEM_KERNEL_STACK) },
{ RS(MEM_LOCKED) },
{ RS(MEM_MAPPED) },
{ RS(MEM_NFS_UNSTABLE) },
{ RS(MEM_PAGE_TABLES) },
{ RS(MEM_SHARED) },
{ RS(MEM_SLAB) },
{ RS(MEM_SLAB_RECLAIM) },
{ RS(MEM_SLAB_UNRECLAIM) },
{ RS(MEM_TOTAL) },
{ RS(MEM_UNEVICTABLE) },
{ RS(MEM_USED) },
{ RS(MEM_VM_ALLOC_CHUNK) },
{ RS(MEM_VM_ALLOC_TOTAL) },
{ RS(MEM_VM_ALLOC_USED) },
{ RS(MEM_WRITEBACK) },
{ RS(MEM_WRITEBACK_TMP) },
{ RS(DELTA_ACTIVE) },
{ RS(DELTA_ACTIVE_ANON) },
{ RS(DELTA_ACTIVE_FILE) },
{ RS(DELTA_ANON) },
{ RS(DELTA_AVAILABLE) },
{ RS(DELTA_BOUNCE) },
{ RS(DELTA_BUFFERS) },
{ RS(DELTA_CACHED) },
{ RS(DELTA_COMMIT_LIMIT) },
{ RS(DELTA_COMMITTED_AS) },
{ RS(DELTA_HARD_CORRUPTED) },
{ RS(DELTA_DIRTY) },
{ RS(DELTA_FREE) },
{ RS(DELTA_HUGE_ANON) },
{ RS(DELTA_HUGE_FREE) },
{ RS(DELTA_HUGE_RSVD) },
{ RS(DELTA_HUGE_SIZE) },
{ RS(DELTA_HUGE_SURPLUS) },
{ RS(DELTA_HUGE_TOTAL) },
{ RS(DELTA_INACTIVE) },
{ RS(DELTA_INACTIVE_ANON) },
{ RS(DELTA_INACTIVE_FILE) },
{ RS(DELTA_KERNEL_STACK) },
{ RS(DELTA_LOCKED) },
{ RS(DELTA_MAPPED) },
{ RS(DELTA_NFS_UNSTABLE) },
{ RS(DELTA_PAGE_TABLES) },
{ RS(DELTA_SHARED) },
{ RS(DELTA_SLAB) },
{ RS(DELTA_SLAB_RECLAIM) },
{ RS(DELTA_SLAB_UNRECLAIM) },
{ RS(DELTA_TOTAL) },
{ RS(DELTA_UNEVICTABLE) },
{ RS(DELTA_USED) },
{ RS(DELTA_VM_ALLOC_CHUNK) },
{ RS(DELTA_VM_ALLOC_TOTAL) },
{ RS(DELTA_VM_ALLOC_USED) },
{ RS(DELTA_WRITEBACK) },
{ RS(DELTA_WRITEBACK_TMP) },
{ RS(MEMHI_FREE) },
{ RS(MEMHI_TOTAL) },
{ RS(MEMHI_USED) },
{ RS(MEMLO_FREE) },
{ RS(MEMLO_TOTAL) },
{ RS(MEMLO_USED) },
{ RS(SWAP_CACHED) },
{ RS(SWAP_FREE) },
{ RS(SWAP_TOTAL) },
{ RS(SWAP_USED) },
// dummy entry corresponding to PROCPS_MEMINFO_logical_end ...
{ NULL, }
};
/* please note,
* this enum MUST be 1 greater than the highest value of any enum */
enum meminfo_item PROCPS_MEMINFO_logical_end = PROCPS_MEMINFO_SWAP_USED + 1;
#undef setNAME
#undef RS
// ___ Private Functions ||||||||||||||||||||||||||||||||||||||||||||||||||||||
static inline void assign_results (
struct meminfo_stack *stack,
struct mem_hist *hist)
{
struct meminfo_result *this = stack->head;
for (;;) {
enum meminfo_item item = this->item;
if (item >= PROCPS_MEMINFO_logical_end)
break;
Item_table[item].setsfunc(this, hist);
++this;
}
return;
} // end: assign_results
static inline void cleanup_stack (
struct meminfo_result *this)
{
for (;;) {
if (this->item >= PROCPS_MEMINFO_logical_end)
break;
if (this->item > PROCPS_MEMINFO_noop)
this->result.ul_int = 0;
++this;
}
} // end: cleanup_stack
static inline void cleanup_stacks_all (
struct procps_meminfo *info)
{
int i;
struct stacks_extent *ext = info->extents;
while (ext) {
for (i = 0; ext->stacks[i]; i++)
cleanup_stack(ext->stacks[i]->head);
ext = ext->next;
};
info->dirty_stacks = 0;
} // end: cleanup_stacks_all
static void extents_free_all (
struct procps_meminfo *info)
{
while (info->extents) {
struct stacks_extent *p = info->extents;
info->extents = info->extents->next;
free(p);
};
} // end: extents_free_all
static inline struct meminfo_result *itemize_stack (
struct meminfo_result *p,
int depth,
enum meminfo_item *items)
{
struct meminfo_result *p_sav = p;
int i;
for (i = 0; i < depth; i++) {
p->item = items[i];
p->result.ul_int = 0;
++p;
}
return p_sav;
} // end: itemize_stack
static inline int items_check_failed (
int numitems,
enum meminfo_item *items)
{
int i;
/* if an enum is passed instead of an address of one or more enums, ol' gcc
* will silently convert it to an address (possibly NULL). only clang will
* offer any sort of warning like the following:
*
* warning: incompatible integer to pointer conversion passing 'int' to parameter of type 'enum meminfo_item *'
* my_stack = procps_meminfo_select(info, PROCPS_MEMINFO_noop, num);
* ^~~~~~~~~~~~~~~~
*/
if (numitems < 1
|| (void *)items < (void *)(unsigned long)(2 * PROCPS_MEMINFO_logical_end))
return -1;
for (i = 0; i < numitems; i++) {
// a meminfo_item is currently unsigned, but we'll protect our future
if (items[i] < 0)
return -1;
if (items[i] >= PROCPS_MEMINFO_logical_end)
return -1;
}
return 0;
} // end: items_check_failed
static int make_hash_failed (
struct procps_meminfo *info)
{
#define htVAL(f) e.key = STRINGIFY(f) ":"; e.data = &info->hist.new. f; \
if (!hsearch_r(e, ENTER, &ep, &info->hashtab)) return -errno;
#define htXTRA(k,f) e.key = STRINGIFY(k) ":"; e.data = &info->hist.new. f; \
if (!hsearch_r(e, ENTER, &ep, &info->hashtab)) return -errno;
ENTRY e, *ep;
size_t n;
// will also include those 4 derived fields (more is better)
n = sizeof(struct meminfo_data) / sizeof(unsigned long);
// we'll follow the hsearch recommendation of an extra 25%
hcreate_r(n + (n / 4), &info->hashtab);
htVAL(Active)
htXTRA(Active(anon), Active_anon)
htXTRA(Active(file), Active_file)
htVAL(AnonHugePages)
htVAL(AnonPages)
htVAL(Bounce)
htVAL(Buffers)
htVAL(Cached)
htVAL(CmaFree)
htVAL(CmaTotal)
htVAL(CommitLimit)
htVAL(Committed_AS)
htVAL(DirectMap1G)
htVAL(DirectMap2M)
htVAL(DirectMap4k)
htVAL(Dirty)
htVAL(HardwareCorrupted)
htVAL(HighFree)
htVAL(HighTotal)
htVAL(HugePages_Free)
htVAL(HugePages_Rsvd)
htVAL(HugePages_Surp)
htVAL(HugePages_Total)
htVAL(Hugepagesize)
htVAL(Inactive)
htXTRA(Inactive(anon), Inactive_anon)
htXTRA(Inactive(file), Inactive_file)
htVAL(KernelStack)
htVAL(LowFree)
htVAL(LowTotal)
htVAL(Mapped)
htVAL(MemAvailable)
htVAL(MemFree)
htVAL(MemTotal)
htVAL(Mlocked)
htVAL(NFS_Unstable)
htVAL(PageTables)
htVAL(SReclaimable)
htVAL(SUnreclaim)
htVAL(Shmem)
htVAL(Slab)
htVAL(SwapCached)
htVAL(SwapFree)
htVAL(SwapTotal)
htVAL(Unevictable)
htVAL(VmallocChunk)
htVAL(VmallocTotal)
htVAL(VmallocUsed)
htVAL(Writeback)
htVAL(WritebackTmp)
return 0;
#undef htVAL
#undef htXTRA
} // end: make_hash_failed
/*
* read_meminfo_failed():
*
* Read the data out of /proc/meminfo putting the information
* into the supplied info structure
*/
PROCPS_EXPORT int read_meminfo_failed (
struct procps_meminfo *info)
{
/* a 'memory history reference' macro for readability,
so we can focus the field names ... */
#define mHr(f) info->hist.new. f
char buf[8192];
char *head, *tail;
int size;
unsigned long *valptr;
signed long mem_used;
if (info == NULL)
return -1;
// remember history from last time around
memcpy(&info->hist.old, &info->hist.new, sizeof(struct meminfo_data));
// clear out the soon to be 'current' values
memset(&info->hist.new, 0, sizeof(struct meminfo_data));
if (-1 == info->meminfo_fd
&& (info->meminfo_fd = open(MEMINFO_FILE, O_RDONLY)) == -1)
return -errno;
if (lseek(info->meminfo_fd, 0L, SEEK_SET) == -1)
return -errno;
for (;;) {
if ((size = read(info->meminfo_fd, buf, sizeof(buf)-1)) < 0) {
if (errno == EINTR || errno == EAGAIN)
continue;
return -errno;
}
break;
}
if (size == 0)
return 0;
buf[size] = '\0';
head = buf;
do {
static ENTRY e; // just to keep coverity off our backs (e.data)
ENTRY *ep;
tail = strchr(head, ' ');
if (!tail)
break;
*tail = '\0';
valptr = NULL;
e.key = head;
if (hsearch_r(e, FIND, &ep, &info->hashtab))
valptr = ep->data;
head = tail+1;
if (valptr) {
*valptr = strtoul(head, &tail, 10);
}
tail = strchr(head, '\n');
if (!tail)
break;
head = tail + 1;
} while(tail);
if (0 == mHr(MemAvailable))
mHr(MemAvailable) = mHr(MemFree);
/* if 'available' is greater than 'total' or our calculation of mem_used
overflows, that's symptomatic of running within a lxc container where
such values will be dramatically distorted over those of the host. */
if (mHr(MemAvailable) > mHr(MemTotal))
mHr(MemAvailable) = mHr(MemFree);
mem_used = mHr(MemTotal) - mHr(MemFree) - mHr(Cached) - mHr(Buffers);
if (mem_used < 0)
mem_used = mHr(MemTotal) - mHr(MemFree);
mHr(derived_mem_used) = (unsigned long)mem_used;
if (mHr(HighFree) < mHr(HighTotal))
mHr(derived_mem_hi_used) = mHr(HighTotal) - mHr(HighFree);
mHr(Cached) += mHr(SReclaimable);
if (0 == mHr(LowTotal)) {
mHr(LowTotal) = mHr(MemTotal);
mHr(LowFree) = mHr(MemFree);
}
if (mHr(LowFree) < mHr(LowTotal))
mHr(derived_mem_lo_used) = mHr(LowTotal) - mHr(LowFree);
if (mHr(SwapFree) < mHr(SwapTotal))
mHr(derived_swap_used) = mHr(SwapTotal) - mHr(SwapFree);
// let's not distort the deltas the first time thru ...
if (!info->meminfo_was_read)
memcpy(&info->hist.old, &info->hist.new, sizeof(struct meminfo_data));
info->meminfo_was_read = 1;
return 0;
#undef mHr
} // end: read_meminfo_failed
/*
* stacks_alloc():
*
* Allocate and initialize one or more stacks each of which is anchored in an
* associated meminfo_stack structure.
*
* All such stacks will have their result structures properly primed with
* 'items', while the result itself will be zeroed.
*
* Returns a stacks_extent struct anchoring the 'heads' of each new stack.
*/
static struct stacks_extent *stacks_alloc (
struct procps_meminfo *info,
int maxstacks)
{
struct stacks_extent *p_blob;
struct meminfo_stack **p_vect;
struct meminfo_stack *p_head;
size_t vect_size, head_size, list_size, blob_size;
void *v_head, *v_list;
int i;
if (info == NULL || info->items == NULL)
return NULL;
if (maxstacks < 1)
return NULL;
vect_size = sizeof(void *) * maxstacks; // size of the addr vectors |
vect_size += sizeof(void *); // plus NULL addr delimiter |
head_size = sizeof(struct meminfo_stack); // size of that head struct |
list_size = sizeof(struct meminfo_result)*info->numitems; // any single results stack |
blob_size = sizeof(struct stacks_extent); // the extent anchor itself |
blob_size += vect_size; // plus room for addr vects |
blob_size += head_size * maxstacks; // plus room for head thing |
blob_size += list_size * maxstacks; // plus room for our stacks |
/* note: all of our memory is allocated in a single blob, facilitating a later free(). |
as a minimum, it is important that the result structures themselves always be |
contiguous for every stack since they are accessed through relative position. | */
if (NULL == (p_blob = calloc(1, blob_size)))
return NULL;
p_blob->next = info->extents; // push this extent onto... |
info->extents = p_blob; // ...some existing extents |
p_vect = (void *)p_blob + sizeof(struct stacks_extent); // prime our vector pointer |
p_blob->stacks = p_vect; // set actual vectors start |
v_head = (void *)p_vect + vect_size; // prime head pointer start |
v_list = v_head + (head_size * maxstacks); // prime our stacks pointer |
for (i = 0; i < maxstacks; i++) {
p_head = (struct meminfo_stack *)v_head;
p_head->head = itemize_stack((struct meminfo_result *)v_list, info->numitems, info->items);
p_blob->stacks[i] = p_head;
v_list += list_size;
v_head += head_size;
}
p_blob->ext_numstacks = maxstacks;
return p_blob;
} // end: stacks_alloc
// ___ Public Functions |||||||||||||||||||||||||||||||||||||||||||||||||||||||
// --- standard required functions --------------------------------------------
/*
* procps_meminfo_new:
*
* Create a new container to hold the stat information
*
* The initial refcount is 1, and needs to be decremented
* to release the resources of the structure.
*
* Returns: a pointer to a new meminfo struct
*/
PROCPS_EXPORT int procps_meminfo_new (
struct procps_meminfo **info)
{
struct procps_meminfo *p;
int rc;
if (info == NULL || *info != NULL)
return -EINVAL;
if (!(p = calloc(1, sizeof(struct procps_meminfo))))
return -ENOMEM;
p->refcount = 1;
p->meminfo_fd = -1;
if ((rc = make_hash_failed(p))) {
free(p);
return rc;
}
*info = p;
return 0;
} // end: procps_meminfo_new
PROCPS_EXPORT int procps_meminfo_ref (
struct procps_meminfo *info)
{
if (info == NULL)
return -EINVAL;
info->refcount++;
return info->refcount;
} // end: procps_meminfo_ref
PROCPS_EXPORT int procps_meminfo_unref (
struct procps_meminfo **info)
{
if (info == NULL || *info == NULL)
return -EINVAL;
(*info)->refcount--;
if ((*info)->refcount == 0) {
if ((*info)->extents)
extents_free_all((*info));
if ((*info)->items)
free((*info)->items);
hdestroy_r(&(*info)->hashtab);
free(*info);
*info = NULL;
return 0;
}
return (*info)->refcount;
} // end: procps_meminfo_unref
// --- variable interface functions -------------------------------------------
PROCPS_EXPORT struct meminfo_result *procps_meminfo_get (
struct procps_meminfo *info,
enum meminfo_item item)
{
static time_t sav_secs;
time_t cur_secs;
if (info == NULL)
return NULL;
if (item < 0 || item >= PROCPS_MEMINFO_logical_end)
return NULL;
/* we will NOT read the meminfo file with every call - rather, we'll offer
a granularity of 1 second between reads ... */
cur_secs = time(NULL);
if (1 <= cur_secs - sav_secs) {
if (read_meminfo_failed(info))
return NULL;
sav_secs = cur_secs;
}
info->get_this.item = item;
// with 'get', we must NOT honor the usual 'noop' guarantee
// if (item > PROCPS_MEMINFO_noop)
info->get_this.result.ul_int = 0;
Item_table[item].setsfunc(&info->get_this, &info->hist);
return &info->get_this;
} // end: procps_meminfo_get
/* procps_meminfo_select():
*
* Harvest all the requested MEM and/or SWAP information then return
* it in a results stack.
*
* Returns: pointer to a meminfo_stack struct on success, NULL on error.
*/
PROCPS_EXPORT struct meminfo_stack *procps_meminfo_select (
struct procps_meminfo *info,
enum meminfo_item *items,
int numitems)
{
if (info == NULL || items == NULL)
return NULL;
if (items_check_failed(numitems, items))
return NULL;
/* is this the first time or have things changed since we were last called?
if so, gotta' redo all of our stacks stuff ... */
if (info->numitems != numitems + 1
|| memcmp(info->items, items, sizeof(enum meminfo_item) * numitems)) {
// allow for our PROCPS_MEMINFO_logical_end
if (!(info->items = realloc(info->items, sizeof(enum meminfo_item) * (numitems + 1))))
return NULL;
memcpy(info->items, items, sizeof(enum meminfo_item) * numitems);
info->items[numitems] = PROCPS_MEMINFO_logical_end;
info->numitems = numitems + 1;
if (info->extents)
extents_free_all(info);
}
if (!info->extents
&& !(stacks_alloc(info, 1)))
return NULL;
if (info->dirty_stacks)
cleanup_stacks_all(info);
if (read_meminfo_failed(info))
return NULL;
assign_results(info->extents->stacks[0], &info->hist);
info->dirty_stacks = 1;
return info->extents->stacks[0];
} // end: procps_meminfo_select
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