[master] e4d1d36 Polish round over varnishd part of VSM
Poul-Henning Kamp
phk at varnish-cache.org
Mon Nov 21 00:39:22 CET 2011
commit e4d1d360beca6917fe2ee1f866ca1ed71302b639
Author: Poul-Henning Kamp <phk at FreeBSD.org>
Date: Sun Nov 20 12:44:19 2011 +0000
Polish round over varnishd part of VSM
diff --git a/bin/varnishd/cache/cache_shmlog.c b/bin/varnishd/cache/cache_shmlog.c
index 63157c7..950f57f 100644
--- a/bin/varnishd/cache/cache_shmlog.c
+++ b/bin/varnishd/cache/cache_shmlog.c
@@ -37,9 +37,7 @@
#include "cache_backend.h" // For w->vbc
-#include "vapi/vsm_int.h"
#include "vmb.h"
-#include "vtim.h"
/* These cannot be struct lock, which depends on vsm/vsl working */
static pthread_mutex_t vsl_mtx;
diff --git a/bin/varnishd/common/common.h b/bin/varnishd/common/common.h
index a35e649..a5d7633 100644
--- a/bin/varnishd/common/common.h
+++ b/bin/varnishd/common/common.h
@@ -75,30 +75,11 @@ void mgt_child_inherit(int fd, const char *what);
/* vsm.c */
struct vsm_sc;
-struct vsm_sc *VSM_common_new(void *ptr, unsigned len);
-void *VSM_common_alloc(struct vsm_sc *sc, unsigned size,
+struct vsm_sc *VSM_common_new(void *ptr, ssize_t len);
+void *VSM_common_alloc(struct vsm_sc *sc, ssize_t size,
const char *class, const char *type, const char *ident);
void VSM_common_free(struct vsm_sc *sc, void *ptr);
-void VSM_common_delete(struct vsm_sc *sc);
-
-// extern struct VSM_head *VSM_head;
-// extern const struct VSM_chunk *vsm_end;
-
-/*
- * These three should not be called directly, but only through
- * proper vectors in mgt.h/cache.h, hence the __
- */
-void *VSM__Alloc(unsigned size, const char *class, const char *type,
- const char *ident);
-void VSM__Free(const void *ptr);
-void VSM__Clean(void);
-
-/* These classes are opaque to other programs, so we define the here */
-#define VSM_CLASS_FREE "Free"
-#define VSM_CLASS_COOL "Cool"
-#define VSM_CLASS_PARAM "Params"
-#define VSM_CLASS_MARK "MgrCld"
-#define VSM_COOL_TIME 5
+void VSM_common_delete(struct vsm_sc **sc);
/*---------------------------------------------------------------------
* Generic power-2 rounding macros
diff --git a/bin/varnishd/common/common_vsm.c b/bin/varnishd/common/common_vsm.c
index 682f542..f525a1e 100644
--- a/bin/varnishd/common/common_vsm.c
+++ b/bin/varnishd/common/common_vsm.c
@@ -27,27 +27,8 @@
*
* VSM stuff common to manager and child.
*
- * We have three potential conflicts we need to deal with:
- *
- * VSM-studying programs (varnishstat...) vs. everybody else
- * The VSM studying programs only have read-only access to the VSM
- * so everybody else must use memory barriers, stable storage and
- * similar tricks to keep the VSM image in sync (long enough) for
- * the studying programs.
- * It can not be prevented, and may indeed in some cases be
- * desirable for such programs to write to VSM, for instance to
- * zero counters.
- * Varnishd should never trust the integrity of VSM content.
- *
- * Manager process vs child process.
- * The manager will create a fresh VSM for each child process launch
- * and not muck about with VSM while the child runs. If the child
- * crashes, the panicstring will be evacuated and the VSM possibly
- * saved for debugging, and a new VSM created before the child is
- * started again.
- *
- * Child process threads
- * Pthread locking necessary.
+ * Please see comments in <vapi/vsm_int.h> for details of protocols and
+ * data consistency.
*
*/
@@ -71,8 +52,8 @@ struct vsm_range {
unsigned magic;
#define VSM_RANGE_MAGIC 0x8d30f14
VTAILQ_ENTRY(vsm_range) list;
- unsigned off;
- unsigned len;
+ ssize_t off;
+ ssize_t len;
double cool;
struct VSM_chunk *chunk;
void *ptr;
@@ -82,7 +63,7 @@ struct vsm_sc {
unsigned magic;
#define VSM_SC_MAGIC 0x8b83270d
char *b;
- unsigned len;
+ ssize_t len;
struct VSM_head *head;
VTAILQ_HEAD(,vsm_range) r_used;
VTAILQ_HEAD(,vsm_range) r_cooling;
@@ -137,7 +118,7 @@ vsm_common_insert_free(struct vsm_sc *sc, struct vsm_range *vr)
*/
struct vsm_sc *
-VSM_common_new(void *p, unsigned l)
+VSM_common_new(void *p, ssize_t l)
{
struct vsm_sc *sc;
struct vsm_range *vr;
@@ -154,10 +135,13 @@ VSM_common_new(void *p, unsigned l)
sc->len = l;
sc->head = (void *)sc->b;
- memset(TRUST_ME(sc->head), 0, sizeof *sc->head);
+ /* This should not be necessary, but just in case...*/
+ memset(sc->head, 0, sizeof *sc->head);
sc->head->magic = VSM_HEAD_MAGIC;
sc->head->hdrsize = sizeof *sc->head;
sc->head->shm_size = l;
+ sc->head->alloc_seq = random() | 1;
+ VWMB();
ALLOC_OBJ(vr, VSM_RANGE_MAGIC);
AN(vr);
@@ -172,7 +156,7 @@ VSM_common_new(void *p, unsigned l)
*/
void *
-VSM_common_alloc(struct vsm_sc *sc, unsigned size,
+VSM_common_alloc(struct vsm_sc *sc, ssize_t size,
const char *class, const char *type, const char *ident)
{
struct vsm_range *vr, *vr2, *vr3;
@@ -238,15 +222,15 @@ VSM_common_alloc(struct vsm_sc *sc, unsigned size,
/* XXX: stats ? */
/* Zero the entire allocation, to avoid garbage confusing readers */
- memset(TRUST_ME(sc->b + vr->off), 0, vr->len);
+ memset(sc->b + vr->off, 0, vr->len);
vr->chunk = (void *)(sc->b + vr->off);
vr->ptr = (vr->chunk + 1);
vr->chunk->magic = VSM_CHUNK_MAGIC;
- strcpy(TRUST_ME(vr->chunk->class), class);
- strcpy(TRUST_ME(vr->chunk->type), type);
- strcpy(TRUST_ME(vr->chunk->ident), ident);
+ strcpy(vr->chunk->class, class);
+ strcpy(vr->chunk->type, type);
+ strcpy(vr->chunk->ident, ident);
VWMB();
vr3 = VTAILQ_FIRST(&sc->r_used);
@@ -258,6 +242,7 @@ VSM_common_alloc(struct vsm_sc *sc, unsigned size,
} else {
sc->head->first = vr->off;
}
+ sc->head->alloc_seq += 2;
VWMB();
return (vr->ptr);
}
@@ -289,6 +274,7 @@ VSM_common_free(struct vsm_sc *sc, void *ptr)
sc->head->first = vr->chunk->next;
VWMB();
vr->chunk->len = 0;
+ sc->head->alloc_seq += 2;
VWMB();
return;
}
@@ -298,7 +284,7 @@ VSM_common_free(struct vsm_sc *sc, void *ptr)
VTAILQ_REMOVE(&sc->r_bogus, vr, list);
FREE_OBJ(vr);
/* XXX: stats ? */
- free(TRUST_ME(ptr));
+ free(ptr);
return;
}
}
@@ -311,9 +297,14 @@ VSM_common_free(struct vsm_sc *sc, void *ptr)
*/
void
-VSM_common_delete(struct vsm_sc *sc)
+VSM_common_delete(struct vsm_sc **scp)
{
struct vsm_range *vr, *vr2;
+ struct vsm_sc *sc;
+
+ AN(scp);
+ sc =*scp;
+ *scp = NULL;
CHECK_OBJ_NOTNULL(sc, VSM_SC_MAGIC);
VTAILQ_FOREACH_SAFE(vr, &sc->r_free, list, vr2)
@@ -323,9 +314,10 @@ VSM_common_delete(struct vsm_sc *sc)
VTAILQ_FOREACH_SAFE(vr, &sc->r_cooling, list, vr2)
FREE_OBJ(vr);
VTAILQ_FOREACH_SAFE(vr, &sc->r_bogus, list, vr2) {
- free(TRUST_ME(vr->ptr));
+ free(vr->ptr);
FREE_OBJ(vr);
}
- sc->head->magic = 0;
+ sc->head->alloc_seq = 0;
+ VWMB();
FREE_OBJ(sc);
}
diff --git a/bin/varnishd/common/params.h b/bin/varnishd/common/params.h
index 95258fb..cab2f49 100644
--- a/bin/varnishd/common/params.h
+++ b/bin/varnishd/common/params.h
@@ -31,6 +31,8 @@
#include "vre.h"
+#define VSM_CLASS_PARAM "Params"
+
struct params {
/* Unprivileged user / group */
diff --git a/bin/varnishd/mgt/mgt.h b/bin/varnishd/mgt/mgt.h
index 571aa23..775fe2c 100644
--- a/bin/varnishd/mgt/mgt.h
+++ b/bin/varnishd/mgt/mgt.h
@@ -82,7 +82,6 @@ void mgt_sandbox_solaris_privsep(void);
/* mgt_shmem.c */
void mgt_SHM_Init(void);
-void mgt_SHM_Pid(void);
/* stevedore_mgt.c */
void STV_Config(const char *spec);
diff --git a/bin/varnishd/mgt/mgt_cli.c b/bin/varnishd/mgt/mgt_cli.c
index aa4fffe..d3b7396 100644
--- a/bin/varnishd/mgt/mgt_cli.c
+++ b/bin/varnishd/mgt/mgt_cli.c
@@ -493,13 +493,13 @@ mgt_cli_secret(const char *S_arg)
{
int i, fd;
char buf[BUFSIZ];
- volatile char *p;
+ char *p;
/* Save in shmem */
i = strlen(S_arg);
- p = VSM_Alloc(i + 1, "Arg", "-S", "");
+ p = VSM_Alloc(i + 1L, "Arg", "-S", "");
AN(p);
- memcpy(TRUST_ME(p), S_arg, i + 1);
+ memcpy(p, S_arg, i + 1L);
srandomdev(); /* XXX: why here ??? */
fd = open(S_arg, O_RDONLY);
@@ -527,7 +527,7 @@ mgt_cli_telnet(const char *T_arg)
struct vss_addr **ta;
int i, n, sock, good;
struct telnet *tn;
- volatile char *p;
+ char *p;
struct vsb *vsb;
char abuf[VTCP_ADDRBUFSIZE];
char pbuf[VTCP_PORTBUFSIZE];
@@ -566,7 +566,7 @@ mgt_cli_telnet(const char *T_arg)
/* Save in shmem */
p = VSM_Alloc(VSB_len(vsb) + 1, "Arg", "-T", "");
AN(p);
- memcpy(TRUST_ME(p), VSB_data(vsb), VSB_len(vsb) + 1);
+ memcpy(p, VSB_data(vsb), VSB_len(vsb) + 1);
VSB_delete(vsb);
}
diff --git a/bin/varnishd/mgt/mgt_main.c b/bin/varnishd/mgt/mgt_main.c
index 4e63c16..f782d03 100644
--- a/bin/varnishd/mgt/mgt_main.c
+++ b/bin/varnishd/mgt/mgt_main.c
@@ -630,8 +630,6 @@ main(int argc, char * const *argv)
if (!d_flag && !F_flag)
AZ(varnish_daemon(1, 0));
- mgt_SHM_Pid();
-
if (pfh != NULL && VPF_Write(pfh))
fprintf(stderr, "NOTE: Could not write PID file\n");
diff --git a/bin/varnishd/mgt/mgt_pool.c b/bin/varnishd/mgt/mgt_pool.c
index e8c4f27..badb3f4 100644
--- a/bin/varnishd/mgt/mgt_pool.c
+++ b/bin/varnishd/mgt/mgt_pool.c
@@ -48,7 +48,6 @@
#include <unistd.h>
#include "mgt/mgt.h"
-#include "common/heritage.h"
#include "common/params.h"
#include "mgt/mgt_param.h"
diff --git a/bin/varnishd/mgt/mgt_sandbox.c b/bin/varnishd/mgt/mgt_sandbox.c
index cdba825..3cd1d98 100644
--- a/bin/varnishd/mgt/mgt_sandbox.c
+++ b/bin/varnishd/mgt/mgt_sandbox.c
@@ -53,7 +53,6 @@
#include <unistd.h>
#include "mgt/mgt.h"
-#include "common/heritage.h"
#include "common/params.h"
/*--------------------------------------------------------------------*/
diff --git a/bin/varnishd/mgt/mgt_shmem.c b/bin/varnishd/mgt/mgt_shmem.c
index 6095d9f..6bb8e13 100644
--- a/bin/varnishd/mgt/mgt_shmem.c
+++ b/bin/varnishd/mgt/mgt_shmem.c
@@ -90,7 +90,6 @@
#include <sys/stat.h>
#include <fcntl.h>
-#include <signal.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
@@ -103,7 +102,6 @@
#include "flopen.h"
#include "vapi/vsc_int.h"
-#include "vapi/vsl_int.h"
#include "vapi/vsm_int.h"
#include "vmb.h"
@@ -117,88 +115,96 @@
struct VSC_C_main *VSC_C_main;
-static int vsl_fd = -1;
+static int vsm_fd = -1;
/*--------------------------------------------------------------------
* Check that we are not started with the same -n argument as an already
- * running varnishd
+ * running varnishd.
+ *
+ * Non-zero return means we should exit and not trample the file.
+ *
*/
-static void
-vsl_n_check(int fd)
+static int
+vsm_n_check(void)
{
- struct VSM_head slh;
- int i;
+ int fd, i;
struct stat st;
pid_t pid;
+ struct VSM_head vsmh;
+ int retval = 2;
- AZ(fstat(fd, &st));
- if (!S_ISREG(st.st_mode))
- ARGV_ERR("\tshmlog: Not a file\n");
-
- /* Test if the SHMFILE is locked by other Varnish */
- if (fltest(fd, &pid) > 0) {
- fprintf(stderr,
- "SHMFILE locked by running varnishd master (pid=%jd)\n",
- (intmax_t)pid);
- fprintf(stderr,
- "(Use unique -n arguments if you want multiple "
- "instances)\n");
- exit(2);
- }
+ fd = open(VSM_FILENAME, O_RDWR, 0644);
+ if (fd < 0)
+ return (0);
- /* Read owning pid from SHMFILE */
- memset(&slh, 0, sizeof slh); /* XXX: for flexelint */
- i = read(fd, &slh, sizeof slh);
- if (i != sizeof slh)
- return;
- if (slh.magic != VSM_HEAD_MAGIC)
- return;
- if (slh.hdrsize != sizeof slh)
- return;
- if (slh.master_pid != 0 && !kill(slh.master_pid, 0)) {
+ AZ(fstat(fd, &st));
+ if (!S_ISREG(st.st_mode)) {
fprintf(stderr,
- "WARNING: Taking over SHMFILE marked as owned by "
- "running process (pid=%jd)\n",
- (intmax_t)slh.master_pid);
+ "VSM (%s) not a regular file.\n", VSM_FILENAME);
+ } else {
+ i = fltest(fd, &pid);
+ if (i < 0) {
+ fprintf(stderr,
+ "Cannot determine locking status of VSM (%s)\n.",
+ VSM_FILENAME);
+ } else if (i == 0) {
+ /*
+ * File is unlocked, mark it as dead, to help any
+ * consumers still stuck on it.
+ */
+ if (pread(fd, &vsmh, sizeof vsmh, 0) == sizeof vsmh) {
+ vsmh.alloc_seq = 0;
+ (void)pwrite(fd, &vsmh, sizeof vsmh, 0);
+ }
+ retval = 0;
+ } else {
+ /* The VSM is locked, we won't touch it. */
+ fprintf(stderr,
+ "VSM locked by running varnishd master (pid=%jd)\n"
+ "(Use unique -n arguments if you want"
+ " multiple instances)\n", (intmax_t)pid);
+ }
}
+ (void)close(fd);
+ return (retval);
}
/*--------------------------------------------------------------------
- * Build a new shmlog file
+ * Build a zeroed file
*/
-static void
-vsl_buildnew(const char *fn, ssize_t size)
+static int
+vsm_zerofile(const char *fn, ssize_t size)
{
- int i;
- unsigned u;
+ int fd;
+ ssize_t i, u;
char buf[64*1024];
int flags;
- (void)unlink(fn);
- vsl_fd = flopen(fn, O_RDWR | O_CREAT | O_EXCL | O_NONBLOCK, 0644);
- if (vsl_fd < 0) {
+ fd = flopen(fn, O_RDWR | O_CREAT | O_EXCL | O_NONBLOCK, 0644);
+ if (fd < 0) {
fprintf(stderr, "Could not create %s: %s\n",
fn, strerror(errno));
- exit (1);
+ return (-1);
}
- flags = fcntl(vsl_fd, F_GETFL);
+ flags = fcntl(fd, F_GETFL);
assert(flags != -1);
flags &= ~O_NONBLOCK;
- AZ(fcntl(vsl_fd, F_SETFL, flags));
+ AZ(fcntl(fd, F_SETFL, flags));
memset(buf, 0, sizeof buf);
for (u = 0; u < size; ) {
- i = write(vsl_fd, buf, sizeof buf);
+ i = write(fd, buf, sizeof buf);
if (i <= 0) {
fprintf(stderr, "Write error %s: %s\n",
fn, strerror(errno));
- exit (1);
+ return (-1);
}
u += i;
}
- AZ(ftruncate(vsl_fd, (off_t)size));
+ AZ(ftruncate(fd, (off_t)size));
+ return (fd);
}
/*--------------------------------------------------------------------
@@ -209,48 +215,59 @@ static
void
mgt_shm_atexit(void)
{
-#if 0
- if (getpid() == VSM_head->master_pid)
- VSM_head->master_pid = 0;
-#endif
+
+ if (heritage.vsm != NULL)
+ VSM_common_delete(&heritage.vsm);
}
void
mgt_SHM_Init(void)
{
- int i, fill;
+ int i;
uintmax_t size, ps;
void *p;
-#if 0
- uint32_t *vsl_log_start;
-#endif
-
- fill = 1;
+ char fnbuf[64];
size = mgt_param.vsl_space + mgt_param.vsm_space;
ps = getpagesize();
size += ps - 1;
size &= ~(ps - 1);
- i = open(VSM_FILENAME, O_RDWR, 0644);
- if (i >= 0) {
- vsl_n_check(i);
- (void)close(i);
- }
- vsl_buildnew(VSM_FILENAME, size);
+ /* Collision check with already running varnishd */
+ i = vsm_n_check();
+ if (i)
+ exit(i);
+
+ bprintf(fnbuf, "%s.%jd", VSM_FILENAME, (intmax_t)getpid());
+
+ vsm_fd = vsm_zerofile(fnbuf, size);
+ if (vsm_fd < 0)
+ exit(1);
p = (void *)mmap(NULL, size,
PROT_READ|PROT_WRITE,
MAP_HASSEMAPHORE | MAP_NOSYNC | MAP_SHARED,
- vsl_fd, 0);
- xxxassert(p != MAP_FAILED);
+ vsm_fd, 0);
- heritage.vsm = VSM_common_new(p, size);
+ if (p == MAP_FAILED) {
+ fprintf(stderr, "Mmap error %s: %s\n", fnbuf, strerror(errno));
+ exit (-1);
+ }
+ /* This may or may not work */
(void)mlock(p, size);
+
+ heritage.vsm = VSM_common_new(p, size);
+
+ if (rename(fnbuf, VSM_FILENAME)) {
+ fprintf(stderr, "Rename failed %s -> %s: %s\n",
+ fnbuf, VSM_FILENAME, strerror(errno));
+ (void)unlink(fnbuf);
+ exit (-1);
+ }
+
AZ(atexit(mgt_shm_atexit));
- /* XXX: We need to zero params if we dealloc/clean/wash */
cache_param = VSM_Alloc(sizeof *cache_param, VSM_CLASS_PARAM, "", "");
AN(cache_param);
*cache_param = mgt_param;
@@ -258,36 +275,4 @@ mgt_SHM_Init(void)
PAN_panicstr_len = 64 * 1024;
PAN_panicstr = VSM_Alloc(PAN_panicstr_len, PAN_CLASS, "", "");
AN(PAN_panicstr);
-
-#if 0
-
- VSM_head->master_pid = getpid();
-
- memset(&VSM_head->head, 0, sizeof VSM_head->head);
- VSM_head->head.magic = VSM_CHUNK_MAGIC;
- VSM_head->head.len =
- (uint8_t*)(VSM_head) + size - (uint8_t*)&VSM_head->head;
- bprintf(VSM_head->head.class, "%s", VSM_CLASS_FREE);
- VWMB();
-
- vsm_end = (void*)((uint8_t*)VSM_head + size);
-
- VSC_C_main = VSM_Alloc(sizeof *VSC_C_main,
- VSC_CLASS, VSC_TYPE_MAIN, "");
- AN(VSC_C_main);
-
- do
- VSM_head->alloc_seq = random();
- while (VSM_head->alloc_seq == 0);
-#endif
-
-}
-
-void
-mgt_SHM_Pid(void)
-{
-
-#if 0
- VSM_head->master_pid = getpid();
-#endif
}
diff --git a/include/vapi/vsm.h b/include/vapi/vsm.h
index fd7fbee..275f6d9 100644
--- a/include/vapi/vsm.h
+++ b/include/vapi/vsm.h
@@ -32,8 +32,16 @@
#define VAPI_VSM_H_INCLUDED
struct VSM_head;
+struct VSM_chunk;
struct VSM_data;
+struct VSM_fantom {
+ struct VSM_chunk *chunk;
+ void *b;
+ void *e;
+ uintptr_t priv;
+};
+
/*---------------------------------------------------------------------
* VSM level access functions
*/
@@ -46,6 +54,7 @@ struct VSM_data *VSM_New(void);
* referencing the same or different shared memory files.
* Returns:
* Pointer to usable VSL_data handle.
+ * NULL: malloc failed.
*/
typedef void VSM_diag_f(void *priv, const char *fmt, ...);
@@ -66,7 +75,7 @@ int VSM_n_Arg(struct VSM_data *vd, const char *n_arg);
* and VSC_Arg() functions.
* Returns:
* 1 on success
- * -1 on failure, with diagnostic on stderr.
+ * -1 on failure, with diagnostic.
*/
const char *VSM_Name(const struct VSM_data *vd);
diff --git a/include/vapi/vsm_int.h b/include/vapi/vsm_int.h
index cad1e36..c33ba35 100644
--- a/include/vapi/vsm_int.h
+++ b/include/vapi/vsm_int.h
@@ -29,6 +29,67 @@
* Define the layout of the shared memory log segment.
*
* NB: THIS IS NOT A PUBLIC API TO VARNISH!
+ *
+ * There is a lot of diplomacy and protocol involved with the VSM segment
+ * since there is no way to (and no desire to!) lock between the readers
+ * and the writer.
+ *
+ * In particular we want the readers to seamlessly jump from one VSM instance
+ * to another when the child restarts.
+ *
+ * The VSM life-cycle there is:
+ *
+ * Manager creates VSM file under temp name
+ *
+ * Temp VSM file is initialized such that VSM_head is consistent
+ * with a non-zero alloc_seq
+ *
+ * Manager renames Temp VSM file to correct filename as atomic
+ * operation.
+ *
+ * When manager abandons VSM file, alloc_seq is set to zero, which
+ * never happens in any other circumstances.
+ *
+ * If a manager is started and finds and old abandonned VSM segment
+ * it will zero the alloc_seq in it, before replacing the file.
+ *
+ * Subscribers will have to monitor two things to make sure they have
+ * the current VSM instance: The alloc_seq field and the inode number
+ * of the path-name. The former check is by far the cheaper and the
+ * latter check should only be employed when lack of activity in the
+ * VSM segment raises suspicion that something has happened.
+ *
+ * The allocations ("chunks") in the VSM forms a linked list, starting with
+ * VSM_head->first, with the first/next fields being byte offsets relative
+ * to the start of the VSM segment.
+ *
+ * The last chunk on the list, has next == 0.
+ *
+ * New chunks are appended to the list, no matter where in the VSM
+ * they happen to be allocated.
+ *
+ * Chunk allocation sequence is:
+ * Find free space
+ * Zero payload
+ * Init Chunk header
+ * Write memory barrier
+ * update hdr->first or $last->next pointer
+ * hdr->alloc_seq changes
+ * Write memory barrier
+ *
+ * Chunk contents should be designed so that zero bytes are not mistaken
+ * for valid contents.
+ *
+ * Chunk deallocation sequence is:
+ * update hdr->first or $prev->next pointer
+ * Write memory barrier
+ * this->len = 0
+ * hdr->alloc_seq changes
+ * Write memory barrier
+ *
+ * The space occupied by the chunk is put on a cooling list and is not
+ * recycled for at least a minute.
+ *
*/
#ifndef VSM_INT_H_INCLUDED
@@ -36,80 +97,23 @@
#define VSM_FILENAME "_.vsm"
-/*
- * This structure describes each allocation from the shmlog
- */
-
struct VSM_chunk {
#define VSM_CHUNK_MAGIC 0xa15712e5 /* From /dev/random */
unsigned magic;
- unsigned len; /* Incl VSM_chunk */
- unsigned next; /* Offset in shmem */
- unsigned state; /* XXX remove */
+ ssize_t len; /* Incl VSM_chunk */
+ ssize_t next; /* Offset in shmem */
char class[8];
char type[8];
char ident[64];
};
-#define VSM_NEXT(sha) ((void*)((uintptr_t)(sha) + (sha)->len))
-#define VSM_PTR(sha) ((void*)((uintptr_t)((sha) + 1)))
-
struct VSM_head {
#define VSM_HEAD_MAGIC 0xe75f7e91 /* From /dev/random */
unsigned magic;
-
- unsigned hdrsize;
- unsigned first; /* Offset, first chunk */
-
- uint64_t starttime;
- int64_t master_pid;
- int64_t child_pid;
-
- unsigned shm_size;
-
+ ssize_t hdrsize;
+ ssize_t shm_size;
+ ssize_t first; /* Offset, first chunk */
unsigned alloc_seq;
- /* Must be last element */
- struct VSM_chunk head;
};
-/*
- * You must include "miniobj.h" and have an assert function to be
- * able to use the VSM_ITER() macro.
- */
-#ifdef CHECK_OBJ_NOTNULL
-
-extern struct VSM_head *VSM_head;
-extern const struct VSM_chunk *vsm_end;
-
-static inline struct VSM_chunk *
-vsm_iter_0(void)
-{
-
- CHECK_OBJ_NOTNULL(VSM_head, VSM_HEAD_MAGIC);
- CHECK_OBJ_NOTNULL(&VSM_head->head, VSM_CHUNK_MAGIC);
- return (&VSM_head->head);
-}
-
-static inline void
-vsm_iter_n(struct VSM_chunk **pp)
-{
-
- CHECK_OBJ_NOTNULL(VSM_head, VSM_HEAD_MAGIC);
- CHECK_OBJ_NOTNULL(*pp, VSM_CHUNK_MAGIC);
- *pp = VSM_NEXT(*pp);
- if (*pp >= vsm_end) {
- *pp = NULL;
- return;
- }
- CHECK_OBJ_NOTNULL(*pp, VSM_CHUNK_MAGIC);
-}
-
-#define VSM_ITER(vd) for ((vd) = vsm_iter_0(); (vd) != NULL; vsm_iter_n(&vd))
-
-#else
-
-#define VSM_ITER(vd) while (YOU_NEED_MINIOBJ_TO_USE_VSM_ITER)
-
-#endif /* CHECK_OBJ_NOTNULL */
-
#endif /* VSM_INT_H_INCLUDED */
diff --git a/lib/libvarnishapi/vsl.c b/lib/libvarnishapi/vsl.c
index 88bd9d6..b17cd36 100644
--- a/lib/libvarnishapi/vsl.c
+++ b/lib/libvarnishapi/vsl.c
@@ -390,7 +390,8 @@ VSL_Open(struct VSM_data *vd, int diag)
/*--------------------------------------------------------------------*/
-int VSL_Matched(const struct VSM_data *vd, uint64_t bitmap)
+int
+VSL_Matched(const struct VSM_data *vd, uint64_t bitmap)
{
if (vd->vsl->num_matchers > 0) {
uint64_t t;
diff --git a/lib/libvarnishapi/vsm.c b/lib/libvarnishapi/vsm.c
index 8e8b27b..97e3847 100644
--- a/lib/libvarnishapi/vsm.c
+++ b/lib/libvarnishapi/vsm.c
@@ -62,7 +62,8 @@ VSM_New(void)
struct VSM_data *vd;
ALLOC_OBJ(vd, VSM_MAGIC);
- AN(vd);
+ if (vd == NULL)
+ return (vd);
vd->diag = (VSM_diag_f*)fprintf;
vd->priv = stderr;
@@ -132,15 +133,22 @@ VSM_Delete(struct VSM_data *vd)
if (vd->vsl != NULL)
VSL_Delete(vd);
- free(vd);
+ FREE_OBJ(vd);
}
-/*--------------------------------------------------------------------*/
+/*--------------------------------------------------------------------
+ * The internal VSM open function
+ *
+ * Return:
+ * 0 = sucess
+ * 1 = failure
+ *
+ */
static int
vsm_open(struct VSM_data *vd, int diag)
{
- int i, j;
+ int i;
struct VSM_head slh;
CHECK_OBJ_NOTNULL(vd, VSM_MAGIC);
@@ -155,7 +163,7 @@ vsm_open(struct VSM_data *vd, int diag)
return (1);
}
- assert(fstat(vd->vsm_fd, &vd->fstat) == 0);
+ AZ(fstat(vd->vsm_fd, &vd->fstat));
if (!S_ISREG(vd->fstat.st_mode)) {
if (diag)
vd->diag(vd->priv, "%s is not a regular file\n",
@@ -174,16 +182,16 @@ vsm_open(struct VSM_data *vd, int diag)
vd->vsm_fd = -1;
return (1);
}
- if (slh.magic != VSM_HEAD_MAGIC) {
+ if (slh.magic != VSM_HEAD_MAGIC || slh.alloc_seq == 0) {
if (diag)
- vd->diag(vd->priv, "Wrong magic number in file %s\n",
+ vd->diag(vd->priv, "Not a ready VSM file %s\n",
vd->fname);
AZ(close(vd->vsm_fd));
vd->vsm_fd = -1;
return (1);
}
- vd->VSM_head = (void *)mmap(NULL, slh.shm_size,
+ vd->VSM_head = mmap(NULL, slh.shm_size,
PROT_READ, MAP_SHARED|MAP_HASSEMAPHORE, vd->vsm_fd, 0);
if (vd->VSM_head == MAP_FAILED) {
if (diag)
@@ -195,20 +203,7 @@ vsm_open(struct VSM_data *vd, int diag)
return (1);
}
vd->vsm_end = (uint8_t *)vd->VSM_head + slh.shm_size;
-
- for (j = 0; j < 20 && vd->VSM_head->alloc_seq == 0; j++)
- (void)usleep(50000);
- if (vd->VSM_head->alloc_seq == 0) {
- if (diag)
- vd->diag(vd->priv, "File not initialized %s\n",
- vd->fname);
- assert(0 == munmap((void*)vd->VSM_head, slh.shm_size));
- AZ(close(vd->vsm_fd));
- vd->vsm_fd = -1;
- vd->VSM_head = NULL;
- return (1);
- }
- vd->alloc_seq = vd->VSM_head->alloc_seq;
+ vd->my_alloc_seq = vd->VSM_head->alloc_seq;
if (vd->vsl != NULL)
VSL_Open_CallBack(vd);
@@ -238,10 +233,10 @@ VSM_Close(struct VSM_data *vd)
CHECK_OBJ_NOTNULL(vd, VSM_MAGIC);
if (vd->VSM_head == NULL)
return;
- assert(0 == munmap((void*)vd->VSM_head, vd->VSM_head->shm_size));
+ AZ(munmap((void*)vd->VSM_head, vd->VSM_head->shm_size));
vd->VSM_head = NULL;
assert(vd->vsm_fd >= 0);
- assert(0 == close(vd->vsm_fd));
+ AZ(close(vd->vsm_fd));
vd->vsm_fd = -1;
}
@@ -330,10 +325,10 @@ VSM_iter0(struct VSM_data *vd)
{
CHECK_OBJ_NOTNULL(vd, VSM_MAGIC);
- vd->alloc_seq = vd->VSM_head->alloc_seq;
- while (vd->alloc_seq == 0) {
+ vd->my_alloc_seq = vd->VSM_head->alloc_seq;
+ while (vd->my_alloc_seq == 0) {
(void)usleep(50000);
- vd->alloc_seq = vd->VSM_head->alloc_seq;
+ vd->my_alloc_seq = vd->VSM_head->alloc_seq;
}
CHECK_OBJ_NOTNULL(&vd->VSM_head->head, VSM_CHUNK_MAGIC);
return (&vd->VSM_head->head);
@@ -344,7 +339,7 @@ VSM_itern(const struct VSM_data *vd, struct VSM_chunk **pp)
{
CHECK_OBJ_NOTNULL(vd, VSM_MAGIC);
- if (vd->alloc_seq != vd->VSM_head->alloc_seq) {
+ if (vd->my_alloc_seq != vd->VSM_head->alloc_seq) {
*pp = NULL;
return;
}
diff --git a/lib/libvarnishapi/vsm_api.h b/lib/libvarnishapi/vsm_api.h
index 519e46d..da5222e 100644
--- a/lib/libvarnishapi/vsm_api.h
+++ b/lib/libvarnishapi/vsm_api.h
@@ -44,13 +44,12 @@ struct VSM_data {
char *n_opt;
char *fname;
-
struct stat fstat;
int vsm_fd;
struct VSM_head *VSM_head;
void *vsm_end;
- unsigned alloc_seq;
+ unsigned my_alloc_seq;
/* Stuff relating the stats fields start here */
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