Commit ecaa81bd authored by José Fonseca's avatar José Fonseca

c11: Import threads.h emulation library.

Implementation is based of https://gist.github.com/2223710 with the
following modifications:
- inline implementatation
- retain XP compatability
- add temporary hack for static mutex initializers (as they are not part
  of the stack but still widely used internally)
- make TIME_UTC a conditional macro (some system headers already define
  it, so this prevents conflict)
- respect HAVE_PTHREAD macro
Reviewed-by: default avatarBrian Paul <brianp@vmware.com>
Acked-by: default avatarIan Romanick <ian.d.romanick@intel.com>
Acked-by: default avatarChad Versace <chad.versace@linux.intel.com>
parent 349f0a94
/*
* C11 <threads.h> emulation library
*
* (C) Copyright yohhoy 2012.
* Distributed under the Boost Software License, Version 1.0.
* (See copy at http://www.boost.org/LICENSE_1_0.txt)
*/
#ifndef EMULATED_THREADS_H_INCLUDED_
#define EMULATED_THREADS_H_INCLUDED_
#include <time.h>
#ifndef TIME_UTC
#define TIME_UTC 1
#endif
#include "c99_compat.h" /* for `inline` */
/*---------------------------- types ----------------------------*/
typedef void (*tss_dtor_t)(void*);
typedef int (*thrd_start_t)(void*);
struct xtime {
time_t sec;
long nsec;
};
typedef struct xtime xtime;
/*-------------------- enumeration constants --------------------*/
enum {
mtx_plain = 0,
mtx_try = 1,
mtx_timed = 2,
mtx_recursive = 4
};
enum {
thrd_success = 0, // succeeded
thrd_timeout, // timeout
thrd_error, // failed
thrd_busy, // resource busy
thrd_nomem // out of memory
};
/*-------------------------- functions --------------------------*/
#if defined(_WIN32) && !defined(__CYGWIN__)
#include "threads_win32.h"
#elif defined(HAVE_PTHREAD)
#include "threads_posix.h"
#else
#error Not supported on this platform.
#endif
#endif /* EMULATED_THREADS_H_INCLUDED_ */
/*
* C11 <threads.h> emulation library
*
* (C) Copyright yohhoy 2012.
* Distributed under the Boost Software License, Version 1.0.
* (See copy at http://www.boost.org/LICENSE_1_0.txt)
*/
#include <stdlib.h>
#include <assert.h>
#include <limits.h>
#include <errno.h>
#include <unistd.h>
#include <sched.h>
#include <stdint.h> /* for intptr_t */
/*
Configuration macro:
EMULATED_THREADS_USE_NATIVE_TIMEDLOCK
Use pthread_mutex_timedlock() for `mtx_timedlock()'
Otherwise use mtx_trylock() + *busy loop* emulation.
*/
#if !defined(__CYGWIN__)
#define EMULATED_THREADS_USE_NATIVE_TIMEDLOCK
#endif
#include <pthread.h>
/*---------------------------- macros ----------------------------*/
#define ONCE_FLAG_INIT PTHREAD_ONCE_INIT
#ifdef INIT_ONCE_STATIC_INIT
#define TSS_DTOR_ITERATIONS PTHREAD_DESTRUCTOR_ITERATIONS
#else
#define TSS_DTOR_ITERATIONS 1 // assume TSS dtor MAY be called at least once.
#endif
// FIXME: temporary non-standard hack to ease transition
#define _MTX_INITIALIZER_NP PTHREAD_MUTEX_INITIALIZER
/*---------------------------- types ----------------------------*/
typedef pthread_cond_t cnd_t;
typedef pthread_t thrd_t;
typedef pthread_key_t tss_t;
typedef pthread_mutex_t mtx_t;
typedef pthread_once_t once_flag;
/*
Implementation limits:
- Conditionally emulation for "mutex with timeout"
(see EMULATED_THREADS_USE_NATIVE_TIMEDLOCK macro)
*/
struct impl_thrd_param {
thrd_start_t func;
void *arg;
};
static inline void *
impl_thrd_routine(void *p)
{
struct impl_thrd_param pack = *((struct impl_thrd_param *)p);
free(p);
return (void*)(intptr_t)pack.func(pack.arg);
}
/*--------------- 7.25.2 Initialization functions ---------------*/
// 7.25.2.1
static inline void
call_once(once_flag *flag, void (*func)(void))
{
pthread_once(flag, func);
}
/*------------- 7.25.3 Condition variable functions -------------*/
// 7.25.3.1
static inline int
cnd_broadcast(cnd_t *cond)
{
if (!cond) return thrd_error;
pthread_cond_broadcast(cond);
return thrd_success;
}
// 7.25.3.2
static inline void
cnd_destroy(cnd_t *cond)
{
assert(cond);
pthread_cond_destroy(cond);
}
// 7.25.3.3
static inline int
cnd_init(cnd_t *cond)
{
if (!cond) return thrd_error;
pthread_cond_init(cond, NULL);
return thrd_success;
}
// 7.25.3.4
static inline int
cnd_signal(cnd_t *cond)
{
if (!cond) return thrd_error;
pthread_cond_signal(cond);
return thrd_success;
}
// 7.25.3.5
static inline int
cnd_timedwait(cnd_t *cond, mtx_t *mtx, const xtime *xt)
{
struct timespec abs_time;
int rt;
if (!cond || !mtx || !xt) return thrd_error;
rt = pthread_cond_timedwait(cond, mtx, &abs_time);
if (rt == ETIMEDOUT)
return thrd_busy;
return (rt == 0) ? thrd_success : thrd_error;
}
// 7.25.3.6
static inline int
cnd_wait(cnd_t *cond, mtx_t *mtx)
{
if (!cond || !mtx) return thrd_error;
pthread_cond_wait(cond, mtx);
return thrd_success;
}
/*-------------------- 7.25.4 Mutex functions --------------------*/
// 7.25.4.1
static inline void
mtx_destroy(mtx_t *mtx)
{
assert(mtx);
pthread_mutex_destroy(mtx);
}
// 7.25.4.2
static inline int
mtx_init(mtx_t *mtx, int type)
{
pthread_mutexattr_t attr;
if (!mtx) return thrd_error;
if (type != mtx_plain && type != mtx_timed && type != mtx_try
&& type != (mtx_plain|mtx_recursive)
&& type != (mtx_timed|mtx_recursive)
&& type != (mtx_try|mtx_recursive))
return thrd_error;
pthread_mutexattr_init(&attr);
if ((type & mtx_recursive) != 0) {
#if defined(__linux__) || defined(__linux)
pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE_NP);
#else
pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE);
#endif
}
pthread_mutex_init(mtx, &attr);
pthread_mutexattr_destroy(&attr);
return thrd_success;
}
// 7.25.4.3
static inline int
mtx_lock(mtx_t *mtx)
{
if (!mtx) return thrd_error;
pthread_mutex_lock(mtx);
return thrd_success;
}
// 7.25.4.4
static inline int
mtx_timedlock(mtx_t *mtx, const xtime *xt)
{
if (!mtx || !xt) return thrd_error;
{
#ifdef EMULATED_THREADS_USE_NATIVE_TIMEDLOCK
struct timespec ts;
int rt;
ts.tv_sec = xt->sec;
ts.tv_nsec = xt->nsec;
rt = pthread_mutex_timedlock(mtx, &ts);
if (rt == 0)
return thrd_success;
return (rt == ETIMEDOUT) ? thrd_busy : thrd_error;
#else
time_t expire = time(NULL);
expire += xt->sec;
while (mtx_trylock(mtx) != thrd_success) {
time_t now = time(NULL);
if (expire < now)
return thrd_busy;
// busy loop!
thrd_yield();
}
return thrd_success;
#endif
}
}
// 7.25.4.5
static inline int
mtx_trylock(mtx_t *mtx)
{
if (!mtx) return thrd_error;
return (pthread_mutex_trylock(mtx) == 0) ? thrd_success : thrd_busy;
}
// 7.25.4.6
static inline int
mtx_unlock(mtx_t *mtx)
{
if (!mtx) return thrd_error;
pthread_mutex_unlock(mtx);
return thrd_success;
}
/*------------------- 7.25.5 Thread functions -------------------*/
// 7.25.5.1
static inline int
thrd_create(thrd_t *thr, thrd_start_t func, void *arg)
{
struct impl_thrd_param *pack;
if (!thr) return thrd_error;
pack = (struct impl_thrd_param *)malloc(sizeof(struct impl_thrd_param));
if (!pack) return thrd_nomem;
pack->func = func;
pack->arg = arg;
if (pthread_create(thr, NULL, impl_thrd_routine, pack) != 0) {
free(pack);
return thrd_error;
}
return thrd_success;
}
// 7.25.5.2
static inline thrd_t
thrd_current(void)
{
return pthread_self();
}
// 7.25.5.3
static inline int
thrd_detach(thrd_t thr)
{
return (pthread_detach(thr) == 0) ? thrd_success : thrd_error;
}
// 7.25.5.4
static inline int
thrd_equal(thrd_t thr0, thrd_t thr1)
{
return pthread_equal(thr0, thr1);
}
// 7.25.5.5
static inline void
thrd_exit(int res)
{
pthread_exit((void*)(intptr_t)res);
}
// 7.25.5.6
static inline int
thrd_join(thrd_t thr, int *res)
{
void *code;
if (pthread_join(thr, &code) != 0)
return thrd_error;
if (res)
*res = (int)(intptr_t)code;
return thrd_success;
}
// 7.25.5.7
static inline void
thrd_sleep(const xtime *xt)
{
struct timespec req;
assert(xt);
req.tv_sec = xt->sec;
req.tv_nsec = xt->nsec;
nanosleep(&req, NULL);
}
// 7.25.5.8
static inline void
thrd_yield(void)
{
sched_yield();
}
/*----------- 7.25.6 Thread-specific storage functions -----------*/
// 7.25.6.1
static inline int
tss_create(tss_t *key, tss_dtor_t dtor)
{
if (!key) return thrd_error;
return (pthread_key_create(key, dtor) == 0) ? thrd_success : thrd_error;
}
// 7.25.6.2
static inline void
tss_delete(tss_t key)
{
pthread_key_delete(key);
}
// 7.25.6.3
static inline void *
tss_get(tss_t key)
{
return pthread_getspecific(key);
}
// 7.25.6.4
static inline int
tss_set(tss_t key, void *val)
{
return (pthread_setspecific(key, val) == 0) ? thrd_success : thrd_error;
}
/*-------------------- 7.25.7 Time functions --------------------*/
// 7.25.6.1
static inline int
xtime_get(xtime *xt, int base)
{
if (!xt) return 0;
if (base == TIME_UTC) {
xt->sec = time(NULL);
xt->nsec = 0;
return base;
}
return 0;
}
/*
* C11 <threads.h> emulation library
*
* (C) Copyright yohhoy 2012.
* Distributed under the Boost Software License, Version 1.0.
* (See copy at http://www.boost.org/LICENSE_1_0.txt)
*/
#include <assert.h>
#include <limits.h>
#include <errno.h>
#include <process.h> // MSVCRT
/*
Configuration macro:
EMULATED_THREADS_USE_NATIVE_CALL_ONCE
Use native WindowsAPI one-time initialization function.
(requires WinVista or later)
Otherwise emulate by mtx_trylock() + *busy loop* for WinXP.
EMULATED_THREADS_USE_NATIVE_CV
Use native WindowsAPI condition variable object.
(requires WinVista or later)
Otherwise use emulated implementation for WinXP.
EMULATED_THREADS_TSS_DTOR_SLOTNUM
Max registerable TSS dtor number.
*/
// XXX: Retain XP compatability
#if 0
#if _WIN32_WINNT >= 0x0600
// Prefer native WindowsAPI on newer environment.
#if !defined(__MINGW32__)
#define EMULATED_THREADS_USE_NATIVE_CALL_ONCE
#endif
#define EMULATED_THREADS_USE_NATIVE_CV
#endif
#endif
#define EMULATED_THREADS_TSS_DTOR_SLOTNUM 64 // see TLS_MINIMUM_AVAILABLE
#include <windows.h>
// check configuration
#if defined(EMULATED_THREADS_USE_NATIVE_CALL_ONCE) && (_WIN32_WINNT < 0x0600)
#error EMULATED_THREADS_USE_NATIVE_CALL_ONCE requires _WIN32_WINNT>=0x0600
#endif
#if defined(EMULATED_THREADS_USE_NATIVE_CV) && (_WIN32_WINNT < 0x0600)
#error EMULATED_THREADS_USE_NATIVE_CV requires _WIN32_WINNT>=0x0600
#endif
/*---------------------------- macros ----------------------------*/
#ifdef EMULATED_THREADS_USE_NATIVE_CALL_ONCE
#define ONCE_FLAG_INIT INIT_ONCE_STATIC_INIT
#else
#define ONCE_FLAG_INIT {0}
#endif
#define TSS_DTOR_ITERATIONS 1
// FIXME: temporary non-standard hack to ease transition
#define _MTX_INITIALIZER_NP {(PCRITICAL_SECTION_DEBUG)-1, -1, 0, 0, 0, 0}
/*---------------------------- types ----------------------------*/
typedef struct cnd_t {
#ifdef EMULATED_THREADS_USE_NATIVE_CV
CONDITION_VARIABLE condvar;
#else
int blocked;
int gone;
int to_unblock;
HANDLE sem_queue;
HANDLE sem_gate;
CRITICAL_SECTION monitor;
#endif
} cnd_t;
typedef HANDLE thrd_t;
typedef DWORD tss_t;
typedef CRITICAL_SECTION mtx_t;
#ifdef EMULATED_THREADS_USE_NATIVE_CALL_ONCE
typedef INIT_ONCE once_flag;
#else
typedef struct once_flag_t {
volatile LONG status;
} once_flag;
#endif
static inline void * tss_get(tss_t key);
static inline void thrd_yield(void);
static inline int mtx_trylock(mtx_t *mtx);
static inline int mtx_lock(mtx_t *mtx);
static inline int mtx_unlock(mtx_t *mtx);
/*
Implementation limits:
- Conditionally emulation for "Initialization functions"
(see EMULATED_THREADS_USE_NATIVE_CALL_ONCE macro)
- Emulated `mtx_timelock()' with mtx_trylock() + *busy loop*
*/
static void impl_tss_dtor_invoke(void); // forward decl.
struct impl_thrd_param {
thrd_start_t func;
void *arg;
};
static unsigned __stdcall impl_thrd_routine(void *p)
{
struct impl_thrd_param pack;
int code;
memcpy(&pack, p, sizeof(struct impl_thrd_param));
free(p);
code = pack.func(pack.arg);
impl_tss_dtor_invoke();
return (unsigned)code;
}
static DWORD impl_xtime2msec(const xtime *xt)
{
return (DWORD)((xt->sec * 1000u) + (xt->nsec / 1000));
}
#ifdef EMULATED_THREADS_USE_NATIVE_CALL_ONCE
struct impl_call_once_param { void (*func)(void); };
static BOOL CALLBACK impl_call_once_callback(PINIT_ONCE InitOnce, PVOID Parameter, PVOID *Context)
{
struct impl_call_once_param *param = (struct impl_call_once_param*)Parameter;
(param->func)();
((void)InitOnce); ((void)Context); // suppress warning
return TRUE;
}
#endif // ifdef EMULATED_THREADS_USE_NATIVE_CALL_ONCE
#ifndef EMULATED_THREADS_USE_NATIVE_CV
/*
Note:
The implementation of condition variable is ported from Boost.Interprocess
See http://www.boost.org/boost/interprocess/sync/windows/condition.hpp
*/
static void impl_cond_do_signal(cnd_t *cond, int broadcast)
{
int nsignal = 0;
EnterCriticalSection(&cond->monitor);
if (cond->to_unblock != 0) {
if (cond->blocked == 0) {
LeaveCriticalSection(&cond->monitor);
return;
}
if (broadcast) {
cond->to_unblock += nsignal = cond->blocked;
cond->blocked = 0;
} else {
nsignal = 1;
cond->to_unblock++;
cond->blocked--;
}
} else if (cond->blocked > cond->gone) {
WaitForSingleObject(cond->sem_gate, INFINITE);
if (cond->gone != 0) {
cond->blocked -= cond->gone;
cond->gone = 0;
}
if (broadcast) {
nsignal = cond->to_unblock = cond->blocked;
cond->blocked = 0;
} else {
nsignal = cond->to_unblock = 1;
cond->blocked--;
}
}
LeaveCriticalSection(&cond->monitor);
if (0 < nsignal)
ReleaseSemaphore(cond->sem_queue, nsignal, NULL);
}
static int impl_cond_do_wait(cnd_t *cond, mtx_t *mtx, const xtime *xt)
{
int nleft = 0;
int ngone = 0;
int timeout = 0;
DWORD w;
WaitForSingleObject(cond->sem_gate, INFINITE);
cond->blocked++;
ReleaseSemaphore(cond->sem_gate, 1, NULL);
mtx_unlock(mtx);
w = WaitForSingleObject(cond->sem_queue, xt ? impl_xtime2msec(xt) : INFINITE);
timeout = (w == WAIT_TIMEOUT);
EnterCriticalSection(&cond->monitor);
if ((nleft = cond->to_unblock) != 0) {
if (timeout) {
if (cond->blocked != 0) {
cond->blocked--;
} else {
cond->gone++;
}
}
if (--cond->to_unblock == 0) {
if (cond->blocked != 0) {
ReleaseSemaphore(cond->sem_gate, 1, NULL);
nleft = 0;
}
else if ((ngone = cond->gone) != 0) {
cond->gone = 0;
}
}
} else if (++cond->gone == INT_MAX/2) {
WaitForSingleObject(cond->sem_gate, INFINITE);
cond->blocked -= cond->gone;
ReleaseSemaphore(cond->sem_gate, 1, NULL);
cond->gone = 0;
}
LeaveCriticalSection(&cond->monitor);
if (nleft == 1) {