/*
** 2017 June 7
**
** The author disclaims copyright to this source code. In place of
** a legal notice, here is a blessing:
**
** May you do good and not evil.
** May you find forgiveness for yourself and forgive others.
** May you share freely, never taking more than you give.
**
*************************************************************************
**
** Simple multi-threaded server used for informal testing of concurrency
** between connections in different threads. Listens for tcp/ip connections
** on port 9999 of the 127.0.0.1 interface only. To build:
**
** gcc -g $(TOP)/tool/tserver.c sqlite3.o -lpthread -o tserver
**
** To run using "x.db" as the db file:
**
** ./tserver x.db
**
** To connect, open a client socket on port 9999 and start sending commands.
** Commands are either SQL - which must be terminated by a semi-colon, or
** dot-commands, which must be terminated by a newline. If an SQL statement
** is seen, it is prepared and added to an internal list.
**
** Dot-commands are:
**
** .list Display all SQL statements in the list.
** .quit Disconnect.
** .run Run all SQL statements in the list.
** .repeats N Configure the number of repeats per ".run".
** .seconds N Configure the number of seconds to ".run" for.
** .mutex_commit Add a "COMMIT" protected by a g.commit_mutex
** to the current SQL.
** .stop Stop the tserver process - exit(0).
** .checkpoint N
** .integrity_check
**
** Example input:
**
** BEGIN;
** INSERT INTO t1 VALUES(randomblob(10), randomblob(100));
** INSERT INTO t1 VALUES(randomblob(10), randomblob(100));
** INSERT INTO t1 VALUES(randomblob(10), randomblob(100));
** COMMIT;
** .repeats 100000
** .run
**
*/
#define TSERVER_PORTNUMBER 9999
#include <arpa/inet.h>
#include <assert.h>
#include <pthread.h>
#include <signal.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <unistd.h>
#include "sqlite3.h"
#define TSERVER_DEFAULT_CHECKPOINT_THRESHOLD 3900
/* Global variables */
struct TserverGlobal {
char *zDatabaseName; /* Database used by this server */
char *zVfs;
sqlite3_mutex *commit_mutex;
sqlite3 *db; /* Global db handle */
/* The following use native pthreads instead of a portable interface. This
** is because a condition variable, as well as a mutex, is required. */
pthread_mutex_t ckpt_mutex;
pthread_cond_t ckpt_cond;
int nThreshold; /* Checkpoint when wal is this large */
int bCkptRequired; /* True if wal checkpoint is required */
int nRun; /* Number of clients in ".run" */
int nWait; /* Number of clients waiting on ckpt_cond */
};
static struct TserverGlobal g = {0};
typedef struct ClientSql ClientSql;
struct ClientSql {
sqlite3_stmt *pStmt;
int flags;
};
#define TSERVER_CLIENTSQL_MUTEX 0x0001
#define TSERVER_CLIENTSQL_INTEGRITY 0x0002
typedef struct ClientCtx ClientCtx;
struct ClientCtx {
sqlite3 *db; /* Database handle for this client */
int fd; /* Client fd */
int nRepeat; /* Number of times to repeat SQL */
int nSecond; /* Number of seconds to run for */
ClientSql *aPrepare; /* Array of prepared statements */
int nPrepare; /* Valid size of apPrepare[] */
int nAlloc; /* Allocated size of apPrepare[] */
int nClientThreshold; /* Threshold for checkpointing */
int bClientCkptRequired; /* True to do a checkpoint */
};
static int is_eol(int i){
return (i=='\n' || i=='\r');
}
static int is_whitespace(int i){
return (i==' ' || i=='\t' || is_eol(i));
}
/*
** Implementation of SQL scalar function usleep().
*/
static void usleepFunc(
sqlite3_context *context,
int argc,
sqlite3_value **argv
){
int nUs;
sqlite3_vfs *pVfs = (sqlite3_vfs*)sqlite3_user_data(context);
assert( argc==1 );
nUs = sqlite3_value_int64(argv[0]);
pVfs->xSleep(pVfs, nUs);
}
static void trim_string(const char **pzStr, int *pnStr){
const char *zStr = *pzStr;
int nStr = *pnStr;
while( nStr>0 && is_whitespace(zStr[0]) ){
zStr++;
nStr--;
}
while( nStr>0 && is_whitespace(zStr[nStr-1]) ){
nStr--;
}
*pzStr = zStr;
*pnStr = nStr;
}
static int send_message(ClientCtx *p, const char *zFmt, ...){
char *zMsg;
va_list ap; /* Vararg list */
va_start(ap, zFmt);
int res = -1;
zMsg = sqlite3_vmprintf(zFmt, ap);
if( zMsg ){
res = write(p->fd, zMsg, strlen(zMsg));
}
sqlite3_free(zMsg);
va_end(ap);
return (res<0);
}
static int handle_some_sql(ClientCtx *p, const char *zSql, int nSql){
const char *zTail = zSql;
int nTail = nSql;
int rc = SQLITE_OK;
while( rc==SQLITE_OK ){
if( p->nPrepare>=p->nAlloc ){
int nByte = (p->nPrepare+32) * sizeof(ClientSql);
ClientSql *aNew = sqlite3_realloc(p->aPrepare, nByte);
if( aNew ){
memset(&aNew[p->nPrepare], 0, sizeof(ClientSql)*32);
p->aPrepare = aNew;
p->nAlloc = p->nPrepare+32;
}else{
rc = SQLITE_NOMEM;
break;
}
}
rc = sqlite3_prepare_v2(
p->db, zTail, nTail, &p->aPrepare[p->nPrepare].pStmt, &zTail
);
if( rc!=SQLITE_OK ){
send_message(p, "error - %s (eec=%d)\n", sqlite3_errmsg(p->db),
sqlite3_extended_errcode(p->db)
);
rc = 1;
break;
}
if( p->aPrepare[p->nPrepare].pStmt==0 ){
break;
}
p->nPrepare++;
nTail = nSql - (zTail-zSql);
rc = send_message(p, "ok (%d SQL statements)\n", p->nPrepare);
}
return rc;
}
/*
** Return a micro-seconds resolution timer.
*/
static sqlite3_int64 get_timer(void){
struct timeval t;
gettimeofday(&t, 0);
return (sqlite3_int64)t.tv_usec + ((sqlite3_int64)t.tv_sec * 1000000);
}
static void clear_sql(ClientCtx *p){
int j;
for(j=0; j<p->nPrepare; j++){
sqlite3_finalize(p->aPrepare[j].pStmt);
}
p->nPrepare = 0;
}
/*
** The sqlite3_wal_hook() callback used by all client database connections.
*/
static int clientWalHook(void *pArg, sqlite3 *db, const char *zDb, int nFrame){
if( g.nThreshold>0 ){
if( nFrame>=g.nThreshold ){
g.bCkptRequired = 1;
}
}else{
ClientCtx *pCtx = (ClientCtx*)pArg;
if( pCtx->nClientThreshold && nFrame>=pCtx->nClientThreshold ){
pCtx->bClientCkptRequired = 1;
}
}
return SQLITE_OK;
}
static int handle_run_command(ClientCtx *p){
int i, j;
int nBusy = 0;
sqlite3_int64 t0 = get_timer();
sqlite3_int64 t1 = t0;
sqlite3_int64 tCommit = 0;
int nT1 = 0;
int nTBusy1 = 0;
int rc = SQLITE_OK;
pthread_mutex_lock(&g.ckpt_mutex);
g.nRun++;
pthread_mutex_unlock(&g.ckpt_mutex);
for(j=0; (p->nRepeat<=0 || j<p->nRepeat) && rc==SQLITE_OK; j++){
sqlite3_int64 t2;
for(i=0; i<p->nPrepare && rc==SQLITE_OK; i++){
sqlite3_stmt *pStmt = p->aPrepare[i].pStmt;
/* If the MUTEX flag is set, grab g.commit_mutex before executing
** the SQL statement (which is always "COMMIT" in this case). */
if( p->aPrepare[i].flags & TSERVER_CLIENTSQL_MUTEX ){
sqlite3_mutex_enter(g.commit_mutex);
tCommit -= get_timer();
}
/* Execute the statement */
if( p->aPrepare[i].flags & TSERVER_CLIENTSQL_INTEGRITY ){
sqlite3_step(pStmt);
if( sqlite3_stricmp("ok", (const char*)sqlite3_column_text(pStmt, 0)) ){
send_message(p, "error - integrity_check failed: %s\n",
sqlite3_column_text(pStmt, 0)
);
}
sqlite3_reset(pStmt);
}
while( sqlite3_step(pStmt)==SQLITE_ROW );
rc = sqlite3_reset(pStmt);
/* Relinquish the g.commit_mutex mutex if required. */
if( p->aPrepare[i].flags & TSERVER_CLIENTSQL_MUTEX ){
tCommit += get_timer();
sqlite3_mutex_leave(g.commit_mutex);
}
if( (rc & 0xFF)==SQLITE_BUSY ){
if( sqlite3_get_autocommit(p->db)==0 ){
sqlite3_exec(p->db, "ROLLBACK", 0, 0, 0);
}
nBusy++;
rc = SQLITE_OK;
break;
}
else if( rc!=SQLITE_OK ){
send_message(p, "error - %s (eec=%d)\n", sqlite3_errmsg(p->db),
sqlite3_extended_errcode(p->db)
);
}
}
t2 = get_timer();
if( t2>=(t1+1000000) ){
sqlite3_int64 nUs = (t2 - t1);
sqlite3_int64 nDone = (j+1 - nBusy - nT1);
rc = send_message(
p, "(%d done @ %lld per second, %d busy)\n",
(int)nDone, (1000000*nDone + nUs/2) / nUs, nBusy - nTBusy1
);
t1 = t2;
nT1 = j+1 - nBusy;
nTBusy1 = nBusy;
if( p->nSecond>0 && ((sqlite3_int64)p->nSecond*1000000)<=t1-t0 ) break;
}
/* Global checkpoint handling. */
if( g.nThreshold>0 ){
pthread_mutex_lock(&g.ckpt_mutex);
if( rc==SQLITE_OK && g.bCkptRequired ){
if( g.nWait==g.nRun-1 ){
/* All other clients are already waiting on the condition variable.
** Run the checkpoint, signal the condition and move on. */
rc = sqlite3_wal_checkpoint(p->db, "main");
g.bCkptRequired = 0;
pthread_cond_broadcast(&g.ckpt_cond);
}else{
assert( g.nWait<g.nRun-1 );
g.nWait++;
pthread_cond_wait(&g.ckpt_cond, &g.ckpt_mutex);
g.nWait--;
}
}
pthread_mutex_unlock(&g.ckpt_mutex);
}
if( rc==SQLITE_OK && p->bClientCkptRequired ){
rc = sqlite3_wal_checkpoint(p->db, "main");
if( rc==SQLITE_BUSY ) rc = SQLITE_OK;
assert( rc==SQLITE_OK );
p->bClientCkptRequired = 0;
}
}
if( rc==SQLITE_OK ){
int nMs = (get_timer() - t0) / 1000;
send_message(p, "ok (%d/%d SQLITE_BUSY)\n", nBusy, j);
if( p->nRepeat<=0 ){
send_message(p, "### ok %d busy %d ms %d commit-ms %d\n",
j-nBusy, nBusy, nMs, (int)(tCommit / 1000)
);
}
}
clear_sql(p);
pthread_mutex_lock(&g.ckpt_mutex);
g.nRun--;
pthread_mutex_unlock(&g.ckpt_mutex);
return rc;
}
static int handle_dot_command(ClientCtx *p, const char *zCmd, int nCmd){
int n;
int rc = 0;
const char *z = &zCmd[1];
const char *zArg;
int nArg;
assert( zCmd[0]=='.' );
for(n=0; n<(nCmd-1); n++){
if( is_whitespace(z[n]) ) break;
}
zArg = &z[n];
nArg = nCmd-n;
trim_string(&zArg, &nArg);
if( n>=1 && n<=4 && 0==strncmp(z, "list", n) ){
int i;
for(i=0; rc==0 && i<p->nPrepare; i++){
const char *zSql = sqlite3_sql(p->aPrepare[i].pStmt);
int nSql = strlen(zSql);
trim_string(&zSql, &nSql);
rc = send_message(p, "%d: %.*s\n", i, nSql, zSql);
}
}
else if( n>=1 && n<=4 && 0==strncmp(z, "quit", n) ){
rc = -1;
}
else if( n>=2 && n<=7 && 0==strncmp(z, "repeats", n) ){
if( nArg ){
p->nRepeat = strtol(zArg, 0, 0);
if( p->nRepeat>0 ) p->nSecond = 0;
}
rc = send_message(p, "ok (repeat=%d)\n", p->nRepeat);
}
else if( n>=2 && n<=3 && 0==strncmp(z, "run", n) ){
rc = handle_run_command(p);
}
else if( n>=2 && n<=7 && 0==strncmp(z, "seconds", n) ){
if( nArg ){
p->nSecond = strtol(zArg, 0, 0);
if( p->nSecond>0 ) p->nRepeat = 0;
}
rc = send_message(p, "ok (seconds=%d)\n", p->nSecond);
}
else if( n>=1 && n<=12 && 0==strncmp(z, "mutex_commit", n) ){
rc = handle_some_sql(p, "COMMIT;", 7);
if( rc==SQLITE_OK ){
p->aPrepare[p->nPrepare-1].flags |= TSERVER_CLIENTSQL_MUTEX;
}
}
else if( n>=1 && n<=10 && 0==strncmp(z, "checkpoint", n) ){
if( nArg ){
p->nClientThreshold = strtol(zArg, 0, 0);
}
rc = send_message(p, "ok (checkpoint=%d)\n", p->nClientThreshold);
}
else if( n>=2 && n<=4 && 0==strncmp(z, "stop", n) ){
sqlite3_close(g.db);
exit(0);
}
else if( n>=2 && n<=15 && 0==strncmp(z, "integrity_check", n) ){
rc = handle_some_sql(p, "PRAGMA integrity_check;", 23);
if( rc==SQLITE_OK ){
p->aPrepare[p->nPrepare-1].flags |= TSERVER_CLIENTSQL_INTEGRITY;
}
}
else{
send_message(p,
"unrecognized dot command: %.*s\n"
"should be \"list\", \"run\", \"repeats\", \"mutex_commit\", "
"\"checkpoint\", \"integrity_check\" or \"seconds\"\n", n, z
);
rc = 1;
}
return rc;
}
static void *handle_client(void *pArg){
char zCmd[32*1024]; /* Read buffer */
int nCmd = 0; /* Valid bytes in zCmd[] */
int res; /* Result of read() call */
int rc = SQLITE_OK;
ClientCtx ctx;
memset(&ctx, 0, sizeof(ClientCtx));
ctx.fd = (int)(intptr_t)pArg;
ctx.nRepeat = 1;
rc = sqlite3_open_v2(g.zDatabaseName, &ctx.db,
SQLITE_OPEN_READWRITE|SQLITE_OPEN_CREATE, g.zVfs
);
if( rc!=SQLITE_OK ){
fprintf(stderr, "sqlite3_open(): %s\n", sqlite3_errmsg(ctx.db));
return 0;
}
sqlite3_create_function(
ctx.db, "usleep", 1, SQLITE_UTF8, (void*)sqlite3_vfs_find(0),
usleepFunc, 0, 0
);
/* Register the wal-hook with the new client connection */
sqlite3_wal_hook(ctx.db, clientWalHook, (void*)&ctx);
while( rc==SQLITE_OK ){
int i;
int iStart;
int nConsume;
res = read(ctx.fd, &zCmd[nCmd], sizeof(zCmd)-nCmd-1);
if( res<=0 ) break;
nCmd += res;
if( nCmd>=sizeof(zCmd)-1 ){
fprintf(stderr, "oversized (>32KiB) message\n");
res = 0;
break;
}
zCmd[nCmd] = '\0';
do {
nConsume = 0;
/* Gobble up any whitespace */
iStart = 0;
while( is_whitespace(zCmd[iStart]) ) iStart++;
if( zCmd[iStart]=='.' ){
/* This is a dot-command. Search for end-of-line. */
for(i=iStart; i<nCmd; i++){
if( is_eol(zCmd[i]) ){
rc = handle_dot_command(&ctx, &zCmd[iStart], i-iStart);
nConsume = i+1;
break;
}
}
}else{
int iSemi;
char c = 0;
for(iSemi=iStart; iSemi<nCmd; iSemi++){
if( zCmd[iSemi]==';' ){
c = zCmd[iSemi+1];
zCmd[iSemi+1] = '\0';
break;
}
}
if( iSemi<nCmd ){
if( sqlite3_complete(zCmd) ){
rc = handle_some_sql(&ctx, zCmd, iSemi+1);
nConsume = iSemi+1;
}
if( c ){
zCmd[iSemi+1] = c;
}
}
}
if( nConsume>0 ){
nCmd = nCmd-nConsume;
if( nCmd>0 ){
memmove(zCmd, &zCmd[nConsume], nCmd);
}
}
}while( rc==SQLITE_OK && nConsume>0 );
}
fprintf(stdout, "Client %d disconnects (rc=%d)\n", ctx.fd, rc);
fflush(stdout);
close(ctx.fd);
clear_sql(&ctx);
sqlite3_free(ctx.aPrepare);
sqlite3_close(ctx.db);
return 0;
}
static void usage(const char *zExec){
fprintf(stderr, "Usage: %s ?-vfs VFS? DATABASE\n", zExec);
exit(1);
}
int main(int argc, char *argv[]) {
int sfd;
int rc;
int yes = 1;
struct sockaddr_in server;
int i;
/* Ignore SIGPIPE. Otherwise the server exits if a client disconnects
** abruptly. */
signal(SIGPIPE, SIG_IGN);
g.nThreshold = TSERVER_DEFAULT_CHECKPOINT_THRESHOLD;
if( (argc%2) ) usage(argv[0]);
for(i=1; i<(argc-1); i+=2){
int n = strlen(argv[i]);
if( n>=2 && 0==sqlite3_strnicmp("-walautocheckpoint", argv[i], n) ){
g.nThreshold = strtol(argv[i+1], 0, 0);
}else
if( n>=2 && 0==sqlite3_strnicmp("-vfs", argv[i], n) ){
g.zVfs = argv[i+1];
}
}
g.zDatabaseName = argv[argc-1];
g.commit_mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_FAST);
pthread_mutex_init(&g.ckpt_mutex, 0);
pthread_cond_init(&g.ckpt_cond, 0);
rc = sqlite3_open_v2(g.zDatabaseName, &g.db,
SQLITE_OPEN_READWRITE|SQLITE_OPEN_CREATE, g.zVfs
);
if( rc!=SQLITE_OK ){
fprintf(stderr, "sqlite3_open(): %s\n", sqlite3_errmsg(g.db));
return 1;
}
rc = sqlite3_exec(g.db, "SELECT * FROM sqlite_master", 0, 0, 0);
if( rc!=SQLITE_OK ){
fprintf(stderr, "sqlite3_exec(): %s\n", sqlite3_errmsg(g.db));
return 1;
}
sfd = socket(AF_INET, SOCK_STREAM, 0);
if( sfd<0 ){
fprintf(stderr, "socket() failed\n");
return 1;
}
rc = setsockopt(sfd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes));
if( rc<0 ){
perror("setsockopt");
return 1;
}
memset(&server, 0, sizeof(server));
server.sin_family = AF_INET;
server.sin_addr.s_addr = inet_addr("127.0.0.1");
server.sin_port = htons(TSERVER_PORTNUMBER);
rc = bind(sfd, (struct sockaddr *)&server, sizeof(struct sockaddr));
if( rc<0 ){
fprintf(stderr, "bind() failed\n");
return 1;
}
rc = listen(sfd, 8);
if( rc<0 ){
fprintf(stderr, "listen() failed\n");
return 1;
}
while( 1 ){
pthread_t tid;
int cfd = accept(sfd, NULL, NULL);
if( cfd<0 ){
perror("accept()");
return 1;
}
fprintf(stdout, "Client %d connects\n", cfd);
fflush(stdout);
rc = pthread_create(&tid, NULL, handle_client, (void*)(intptr_t)cfd);
if( rc!=0 ){
perror("pthread_create()");
return 1;
}
pthread_detach(tid);
}
return 0;
}