quadrilateralcowboy/sys/posix/posix_threads.cpp
2020-06-12 14:06:25 -07:00

292 lines
8.6 KiB
C++

/*
===========================================================================
Doom 3 GPL Source Code
Copyright (C) 1999-2011 id Software LLC, a ZeniMax Media company.
This file is part of the Doom 3 GPL Source Code (?Doom 3 Source Code?).
Doom 3 Source Code is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
Doom 3 Source Code 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with Doom 3 Source Code. If not, see <http://www.gnu.org/licenses/>.
In addition, the Doom 3 Source Code is also subject to certain additional terms. You should have received a copy of these additional terms immediately following the terms and conditions of the GNU General Public License which accompanied the Doom 3 Source Code. If not, please request a copy in writing from id Software at the address below.
If you have questions concerning this license or the applicable additional terms, you may contact in writing id Software LLC, c/o ZeniMax Media Inc., Suite 120, Rockville, Maryland 20850 USA.
===========================================================================
*/
#include <sys/types.h>
#include <sys/stat.h>
#include <errno.h>
#include <stdio.h>
#include <dirent.h>
#include <unistd.h>
#include <sys/mman.h>
#include <sys/time.h>
#include <pwd.h>
#include <pthread.h>
#include "../../idlib/precompiled.h"
#include "posix_public.h"
#if defined(_DEBUG)
// #define ID_VERBOSE_PTHREADS
#endif
/*
======================================================
locks
======================================================
*/
// we use an extra lock for the local stuff
const int MAX_LOCAL_CRITICAL_SECTIONS = MAX_CRITICAL_SECTIONS + 1;
static pthread_mutex_t global_lock[ MAX_LOCAL_CRITICAL_SECTIONS ];
/*
==================
Sys_EnterCriticalSection
==================
*/
void Sys_EnterCriticalSection( int index ) {
assert( index >= 0 && index < MAX_LOCAL_CRITICAL_SECTIONS );
#ifdef ID_VERBOSE_PTHREADS
if ( pthread_mutex_trylock( &global_lock[index] ) == EBUSY ) {
Sys_Printf( "busy lock %d in thread '%s'\n", index, Sys_GetThreadName() );
if ( pthread_mutex_lock( &global_lock[index] ) == EDEADLK ) {
Sys_Printf( "FATAL: DEADLOCK %d, in thread '%s'\n", index, Sys_GetThreadName() );
}
}
#else
pthread_mutex_lock( &global_lock[index] );
#endif
}
/*
==================
Sys_LeaveCriticalSection
==================
*/
void Sys_LeaveCriticalSection( int index ) {
assert( index >= 0 && index < MAX_LOCAL_CRITICAL_SECTIONS );
#ifdef ID_VERBOSE_PTHREADS
if ( pthread_mutex_unlock( &global_lock[index] ) == EPERM ) {
Sys_Printf( "FATAL: NOT LOCKED %d, in thread '%s'\n", index, Sys_GetThreadName() );
}
#else
pthread_mutex_unlock( &global_lock[index] );
#endif
}
/*
======================================================
wait and trigger events
we use a single lock to manipulate the conditions, MAX_LOCAL_CRITICAL_SECTIONS-1
the semantics match the win32 version. signals raised while no one is waiting stay raised until a wait happens (which then does a simple pass-through)
NOTE: we use the same mutex for all the events. I don't think this would become much of a problem
cond_wait unlocks atomically with setting the wait condition, and locks it back before exiting the function
the potential for time wasting lock waits is very low
======================================================
*/
pthread_cond_t event_cond[ MAX_TRIGGER_EVENTS ];
bool signaled[ MAX_TRIGGER_EVENTS ];
bool waiting[ MAX_TRIGGER_EVENTS ];
/*
==================
Sys_WaitForEvent
==================
*/
void Sys_WaitForEvent( int index ) {
assert( index >= 0 && index < MAX_TRIGGER_EVENTS );
Sys_EnterCriticalSection( MAX_LOCAL_CRITICAL_SECTIONS - 1 );
assert( !waiting[ index ] ); // WaitForEvent from multiple threads? that wouldn't be good
if ( signaled[ index ] ) {
// emulate windows behaviour: signal has been raised already. clear and keep going
signaled[ index ] = false;
} else {
waiting[ index ] = true;
pthread_cond_wait( &event_cond[ index ], &global_lock[ MAX_LOCAL_CRITICAL_SECTIONS - 1 ] );
waiting[ index ] = false;
}
Sys_LeaveCriticalSection( MAX_LOCAL_CRITICAL_SECTIONS - 1 );
}
/*
==================
Sys_TriggerEvent
==================
*/
void Sys_TriggerEvent( int index ) {
assert( index >= 0 && index < MAX_TRIGGER_EVENTS );
Sys_EnterCriticalSection( MAX_LOCAL_CRITICAL_SECTIONS - 1 );
if ( waiting[ index ] ) {
pthread_cond_signal( &event_cond[ index ] );
} else {
// emulate windows behaviour: if no thread is waiting, leave the signal on so next wait keeps going
signaled[ index ] = true;
}
Sys_LeaveCriticalSection( MAX_LOCAL_CRITICAL_SECTIONS - 1 );
}
/*
======================================================
thread create and destroy
======================================================
*/
// not a hard limit, just what we keep track of for debugging
#define MAX_THREADS 10
xthreadInfo *g_threads[MAX_THREADS];
int g_thread_count = 0;
typedef void *(*pthread_function_t) (void *);
/*
==================
Sys_CreateThread
==================
*/
void Sys_CreateThread( xthread_t function, void *parms, xthreadPriority priority, xthreadInfo& info, const char *name, xthreadInfo **threads, int *thread_count ) {
Sys_EnterCriticalSection( );
pthread_attr_t attr;
pthread_attr_init( &attr );
if ( pthread_attr_setdetachstate( &attr, PTHREAD_CREATE_JOINABLE ) != 0 ) {
common->Error( "ERROR: pthread_attr_setdetachstate %s failed\n", name );
}
if ( pthread_create( ( pthread_t* )&info.threadHandle, &attr, ( pthread_function_t )function, parms ) != 0 ) {
common->Error( "ERROR: pthread_create %s failed\n", name );
}
pthread_attr_destroy( &attr );
info.name = name;
if ( *thread_count < MAX_THREADS ) {
threads[ ( *thread_count )++ ] = &info;
} else {
common->DPrintf( "WARNING: MAX_THREADS reached\n" );
}
Sys_LeaveCriticalSection( );
}
/*
==================
Sys_DestroyThread
==================
*/
void Sys_DestroyThread( xthreadInfo& info ) {
// the target thread must have a cancelation point, otherwise pthread_cancel is useless
assert( info.threadHandle );
if ( pthread_cancel( ( pthread_t )info.threadHandle ) != 0 ) {
common->Error( "ERROR: pthread_cancel %s failed\n", info.name );
}
if ( pthread_join( ( pthread_t )info.threadHandle, NULL ) != 0 ) {
common->Error( "ERROR: pthread_join %s failed\n", info.name );
}
info.threadHandle = 0;
Sys_EnterCriticalSection( );
for( int i = 0 ; i < g_thread_count ; i++ ) {
if ( &info == g_threads[ i ] ) {
g_threads[ i ] = NULL;
int j;
for( j = i+1 ; j < g_thread_count ; j++ ) {
g_threads[ j-1 ] = g_threads[ j ];
}
g_threads[ j-1 ] = NULL;
g_thread_count--;
Sys_LeaveCriticalSection( );
return;
}
}
Sys_LeaveCriticalSection( );
}
/*
==================
Sys_GetThreadName
find the name of the calling thread
==================
*/
const char* Sys_GetThreadName( int *index ) {
Sys_EnterCriticalSection( );
pthread_t thread = pthread_self();
for( int i = 0 ; i < g_thread_count ; i++ ) {
if ( thread == (pthread_t)g_threads[ i ]->threadHandle ) {
if ( index ) {
*index = i;
}
Sys_LeaveCriticalSection( );
return g_threads[ i ]->name;
}
}
if ( index ) {
*index = -1;
}
Sys_LeaveCriticalSection( );
return "main";
}
/*
=========================================================
Async Thread
=========================================================
*/
xthreadInfo asyncThread;
/*
=================
Posix_StartAsyncThread
=================
*/
void Posix_StartAsyncThread() {
if ( asyncThread.threadHandle == 0 ) {
Sys_CreateThread( (xthread_t)Sys_AsyncThread, NULL, THREAD_NORMAL, asyncThread, "Async", g_threads, &g_thread_count );
} else {
common->Printf( "Async thread already running\n" );
}
common->Printf( "Async thread started\n" );
}
/*
==================
Posix_InitPThreads
==================
*/
void Posix_InitPThreads( ) {
int i;
pthread_mutexattr_t attr;
// init critical sections
for ( i = 0; i < MAX_LOCAL_CRITICAL_SECTIONS; i++ ) {
pthread_mutexattr_init( &attr );
pthread_mutexattr_settype( &attr, PTHREAD_MUTEX_ERRORCHECK );
pthread_mutex_init( &global_lock[i], &attr );
pthread_mutexattr_destroy( &attr );
}
// init event sleep/triggers
for ( i = 0; i < MAX_TRIGGER_EVENTS; i++ ) {
pthread_cond_init( &event_cond[ i ], NULL );
signaled[i] = false;
waiting[i] = false;
}
// init threads table
for ( i = 0; i < MAX_THREADS; i++ ) {
g_threads[ i ] = NULL;
}
}