New upstream version 1.5.0+dfsgupstream/1.5.0+dfsg

1 files changed, 238 insertions, 0 deletions

diff --git a/src/ipc.c b/src/ipc.c
new file mode 100644
index 00000000..a5ab342d
--- /dev/null
+++ b/src/ipc.c
@@ -0,0 +1,238 @@
+#include "common.h"
+
+#include <sys/sem.h>
+#include <sys/msg.h>
+#include <sys/shm.h>
+
+
+#ifndef SEMVMX
+#define SEMVMX  32767  /* <= 32767 semaphore maximum value */
+#endif
+
+/* Some versions of libc only define IPC_INFO when __USE_GNU is defined. */
+#ifndef IPC_INFO
+#define IPC_INFO   3
+#endif
+
+struct ipc_limits {
+    uint64_t        shmmni;     /* max number of segments */
+    uint64_t        shmmax;     /* max segment size */
+    uint64_t        shmall;     /* max total shared memory */
+    uint64_t        shmmin;     /* min segment size */
+
+    int             semmni;     /* max number of arrays */
+    int             semmsl;     /* max semaphores per array */
+    int             semmns;     /* max semaphores system wide */
+    int             semopm;     /* max ops per semop call */
+    unsigned int    semvmx;     /* semaphore max value (constant) */
+
+    int             msgmni;     /* max queues system wide */
+    size_t          msgmax;     /* max size of message */
+    int             msgmnb;     /* default max size of queue */
+};
+
+struct ipc_status {
+    int             semusz;     /* current number of arrays */
+    int             semaem;     /* current semaphores system wide */
+};
+
+/*
+ *  The last arg of semctl is a union semun, but where is it defined? X/OPEN
+ *  tells us to define it ourselves, but until recently Linux include files
+ *  would also define it.
+ */
+#ifndef HAVE_UNION_SEMUN
+/* according to X/OPEN we have to define it ourselves */
+union semun {
+    int val;
+    struct semid_ds *buf;
+    unsigned short int *array;
+    struct seminfo *__buf;
+};
+#endif
+
+static inline int ipc_sem_get_limits(struct ipc_limits *lim) {
+    static procfile *ff = NULL;
+    static int error_shown = 0;
+    static char filename[FILENAME_MAX + 1] = "";
+
+    if(unlikely(!filename[0]))
+        snprintfz(filename, FILENAME_MAX, "%s/proc/sys/kernel/sem", global_host_prefix);
+
+    if(unlikely(!ff)) {
+        ff = procfile_open(filename, NULL, PROCFILE_FLAG_DEFAULT);
+        if(unlikely(!ff)) {
+            if(unlikely(!error_shown)) {
+                error("IPC: Cannot open file '%s'.", filename);
+                error_shown = 1;
+            }
+            goto ipc;
+        }
+    }
+
+    ff = procfile_readall(ff);
+    if(unlikely(!ff)) {
+        if(unlikely(!error_shown)) {
+            error("IPC: Cannot read file '%s'.", filename);
+            error_shown = 1;
+        }
+        goto ipc;
+    }
+
+    if(procfile_lines(ff) >= 1 && procfile_linewords(ff, 0) >= 4) {
+        lim->semvmx = SEMVMX;
+        lim->semmsl = str2i(procfile_lineword(ff, 0, 0));
+        lim->semmns = str2i(procfile_lineword(ff, 0, 1));
+        lim->semopm = str2i(procfile_lineword(ff, 0, 2));
+        lim->semmni = str2i(procfile_lineword(ff, 0, 3));
+        return 0;
+    }
+    else {
+        if(unlikely(!error_shown)) {
+            error("IPC: Invalid content in file '%s'.", filename);
+            error_shown = 1;
+        }
+        goto ipc;
+    }
+
+ipc:
+    // cannot do it from the file
+    // query IPC
+    {
+        struct seminfo seminfo = {.semmni = 0};
+        union semun arg = {.array = (ushort *) &seminfo};
+
+        if(unlikely(semctl(0, 0, IPC_INFO, arg) < 0)) {
+            error("IPC: Failed to read '%s' and request IPC_INFO with semctl().", filename);
+            goto error;
+        }
+
+        lim->semvmx = SEMVMX;
+        lim->semmni = seminfo.semmni;
+        lim->semmsl = seminfo.semmsl;
+        lim->semmns = seminfo.semmns;
+        lim->semopm = seminfo.semopm;
+        return 0;
+    }
+
+error:
+    lim->semvmx = 0;
+    lim->semmni = 0;
+    lim->semmsl = 0;
+    lim->semmns = 0;
+    lim->semopm = 0;
+    return -1;
+}
+
+/*
+printf ("------ Semaphore Limits --------\n");
+printf ("max number of arrays = %d\n", limits.semmni);
+printf ("max semaphores per array = %d\n", limits.semmsl);
+printf ("max semaphores system wide = %d\n", limits.semmns);
+printf ("max ops per semop call = %d\n", limits.semopm);
+printf ("semaphore max value = %u\n", limits.semvmx);
+
+printf ("------ Semaphore Status --------\n");
+printf ("used arrays = %d\n", status.semusz);
+printf ("allocated semaphores = %d\n", status.semaem);
+*/
+
+static inline int ipc_sem_get_status(struct ipc_status *st) {
+    struct seminfo seminfo;
+    union semun arg;
+
+    arg.array = (ushort *)  (void *) &seminfo;
+
+    if(unlikely(semctl (0, 0, SEM_INFO, arg) < 0)) {
+        /* kernel not configured for semaphores */
+        static int error_shown = 0;
+        if(unlikely(!error_shown)) {
+            error("IPC: kernel is not configured for semaphores");
+            error_shown = 1;
+        }
+        st->semusz = 0;
+        st->semaem = 0;
+        return -1;
+    }
+
+    st->semusz = seminfo.semusz;
+    st->semaem = seminfo.semaem;
+    return 0;
+}
+
+int do_ipc(int update_every, usec_t dt) {
+    (void)dt;
+
+    static int initialized = 0, read_limits_next = 0;
+    static struct ipc_limits limits;
+    static struct ipc_status status;
+    static RRDVAR *arrays_max = NULL, *semaphores_max = NULL;
+    static RRDSET *semaphores = NULL, *arrays = NULL;
+
+    if(unlikely(!initialized)) {
+        initialized = 1;
+        
+        // make sure it works
+        if(ipc_sem_get_limits(&limits) == -1) {
+            error("unable to fetch semaphore limits");
+            return 1;
+        }
+
+        // make sure it works
+        if(ipc_sem_get_status(&status) == -1) {
+            error("unable to fetch semaphore statistics");
+            return 1;
+        }
+
+        arrays_max     = rrdvar_custom_host_variable_create(&localhost, "ipc.semaphores.arrays.max");
+        semaphores_max = rrdvar_custom_host_variable_create(&localhost, "ipc.semaphores.max");
+
+        if(arrays_max)     rrdvar_custom_host_variable_set(arrays_max, limits.semmni);
+        if(semaphores_max) rrdvar_custom_host_variable_set(semaphores_max, limits.semmns);
+
+        // create the charts
+        semaphores = rrdset_find("system.ipc_semaphores");
+        if(!semaphores) {
+            semaphores = rrdset_create("system", "ipc_semaphores", NULL, "ipc semaphores", NULL, "IPC Semaphores", "semaphores", 1000, rrd_update_every, RRDSET_TYPE_AREA);
+            rrddim_add(semaphores, "semaphores", NULL, 1, 1, RRDDIM_ABSOLUTE);
+        }
+
+        arrays = rrdset_find("system.ipc_semaphore_arrays");
+        if(!arrays) {
+            arrays = rrdset_create("system", "ipc_semaphore_arrays", NULL, "ipc semaphores", NULL, "IPC Semaphore Arrays", "arrays", 1000, rrd_update_every, RRDSET_TYPE_AREA);
+            rrddim_add(arrays, "arrays", NULL, 1, 1, RRDDIM_ABSOLUTE);
+        }
+    }
+
+    if(unlikely(read_limits_next < 0)) {
+        if(unlikely(ipc_sem_get_limits(&limits) == -1)) {
+            error("Unable to fetch semaphore limits.");
+        }
+        else {
+            if(arrays_max)     rrdvar_custom_host_variable_set(arrays_max, limits.semmni);
+            if(semaphores_max) rrdvar_custom_host_variable_set(semaphores_max, limits.semmns);
+
+            arrays->red = limits.semmni;
+            semaphores->red = limits.semmns;
+
+            read_limits_next = 60 / update_every;
+        }
+    }
+    else
+        read_limits_next--;
+
+    if(unlikely(ipc_sem_get_status(&status) == -1)) {
+        error("Unable to get semaphore statistics");
+        return 0;
+    }
+
+    if(semaphores->counter_done) rrdset_next(semaphores);
+    rrddim_set(semaphores, "semaphores", status.semaem);
+    rrdset_done(semaphores);
+
+    if(arrays->counter_done) rrdset_next(arrays);
+    rrddim_set(arrays, "arrays", status.semusz);
+    rrdset_done(arrays);
+
+    return 0;
+}