1                 : /*
       2                 :  * Copyright (c) 2011 The Native Client Authors. All rights reserved.
       3                 :  * Use of this source code is governed by a BSD-style license that can be
       4                 :  * found in the LICENSE file.
       5                 :  */
       6                 : 
       7                 : #include "native_client/src/trusted/simple_service/nacl_simple_ltd_service.h"
       8                 : 
       9                 : #include "native_client/src/include/nacl_compiler_annotations.h"
      10                 : 
      11                 : #include "native_client/src/shared/platform/nacl_check.h"
      12                 : #include "native_client/src/shared/platform/nacl_log.h"
      13                 : #include "native_client/src/shared/platform/nacl_sync.h"
      14                 : #include "native_client/src/shared/platform/nacl_sync_checked.h"
      15                 : #include "native_client/src/shared/platform/nacl_threads.h"
      16                 : #include "native_client/src/shared/srpc/nacl_srpc.h"
      17                 : 
      18                 : int NaClSimpleLtdServiceCtor(
      19                 :     struct NaClSimpleLtdService       *self,
      20                 :     struct NaClSrpcHandlerDesc const  *srpc_handlers,
      21                 :     int                               max_cli,
      22                 :     NaClThreadIfFactoryFunction       thread_factory_fn,
      23              19 :     void                              *thread_factory_data) {
      24              19 :   NaClLog(4, "Entered NaClSimpleLtdServiceCtor\n");
      25              19 :   if (!NaClSimpleServiceCtor((struct NaClSimpleService *) self,
      26                 :                              srpc_handlers,
      27                 :                              thread_factory_fn,
      28                 :                              thread_factory_data)) {
      29               0 :     NaClLog(4, "NaClSimpleServiceCtor failed\n");
      30               0 :     goto base_ctor_fail;
      31                 :   }
      32              19 :   if (!NaClMutexCtor(&self->mu)) {
      33               0 :     NaClLog(4, "NaClSimpleLtdServiceCtor: NaClMutexCtor failed\n");
      34               0 :     goto mutex_ctor_fail;
      35                 :   }
      36              19 :   if (!NaClCondVarCtor(&self->cv)) {
      37               0 :     NaClLog(4, "NaClSimpleLtdServiceCtor: NaClCondVarCtor failed\n");
      38               0 :     goto condvar_ctor_fail;
      39                 :   }
      40              19 :   self->max_clients = max_cli;
      41              19 :   self->num_clients = 0;
      42              19 :   NACL_VTBL(NaClRefCount, self) =
      43                 :       (struct NaClRefCountVtbl *) &kNaClSimpleLtdServiceVtbl;
      44              19 :   NaClLog(4, "NaClSimpleLtdServiceCtor: success\n");
      45              19 :   return 1;
      46                 : 
      47                 :   /* failure cascade, in reverse construction order */
      48               0 :  condvar_ctor_fail:
      49               0 :   NaClMutexDtor(&self->mu);
      50               0 :  mutex_ctor_fail:
      51               0 :   (*NACL_VTBL(NaClRefCount, self)->Dtor)((struct NaClRefCount *) self);
      52               0 :  base_ctor_fail:
      53               0 :   return 0;
      54                 : }
      55                 : 
      56               0 : void NaClSimpleLtdServiceDtor(struct NaClRefCount *vself) {
      57                 :   struct NaClSimpleLtdService *self =
      58               0 :       (struct NaClSimpleLtdService *) vself;
      59                 : 
      60               0 :   CHECK(0 == self->num_clients);
      61               0 :   NaClCondVarDtor(&self->cv);
      62               0 :   NaClMutexDtor(&self->mu);
      63               0 :   NACL_VTBL(NaClRefCount, self) =
      64                 :       (struct NaClRefCountVtbl *) &kNaClSimpleServiceVtbl;
      65               0 :   (*NACL_VTBL(NaClRefCount, self)->Dtor)((struct NaClRefCount *) self);
      66               0 : }
      67                 : 
      68                 : 
      69                 : int NaClSimpleLtdServiceAcceptConnection(
      70                 :     struct NaClSimpleService            *vself,
      71               3 :     struct NaClSimpleServiceConnection  **out) {
      72                 :   struct NaClSimpleLtdService *self =
      73               3 :       (struct NaClSimpleLtdService *) vself;
      74                 :   int                         rv;
      75                 : 
      76               3 :   NaClXMutexLock(&self->mu);
      77               6 :   while (self->num_clients >= self->max_clients) {
      78               0 :     NaClXCondVarWait(&self->cv, &self->mu);
      79                 :   }
      80               3 :   NaClXMutexUnlock(&self->mu);
      81                 : 
      82                 :   /*
      83                 :    * Other threads can only decrement num_clients.
      84                 :    */
      85               3 :   rv = (*kNaClSimpleServiceVtbl.AcceptConnection)(vself, out);
      86                 : 
      87               0 :   NaClXMutexLock(&self->mu);
      88               0 :   self->num_clients++;
      89               0 :   NaClXMutexUnlock(&self->mu);
      90                 : 
      91               0 :   return rv;
      92                 : }
      93                 : 
      94                 : void NaClSimpleLtdServiceRpcHandler(
      95                 :     struct NaClSimpleService            *vself,
      96               0 :     struct NaClSimpleServiceConnection  *conn) {
      97                 :   struct NaClSimpleLtdService *self =
      98               0 :       (struct NaClSimpleLtdService *) vself;
      99                 : 
     100               0 :   (*kNaClSimpleServiceVtbl.RpcHandler)(vself, conn);
     101               0 :   NaClXMutexLock(&self->mu);
     102               0 :   self->num_clients--;
     103               0 :   NaClXCondVarBroadcast(&self->cv);
     104               0 :   NaClXMutexUnlock(&self->mu);
     105               0 : }
     106                 : 
     107                 : 
     108                 : struct NaClSimpleServiceVtbl const kNaClSimpleLtdServiceVtbl = {
     109                 :   {
     110                 :     NaClSimpleLtdServiceDtor,
     111                 :   },
     112                 :   NaClSimpleServiceConnectionFactory,
     113                 :   NaClSimpleLtdServiceAcceptConnection,
     114                 :   NaClSimpleServiceAcceptAndSpawnHandler,
     115                 :   NaClSimpleLtdServiceRpcHandler,
     116                 : };