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Diffstat (limited to 'src/openbsd/threads.h')
| -rw-r--r-- | src/openbsd/threads.h | 479 |
1 files changed, 479 insertions, 0 deletions
diff --git a/src/openbsd/threads.h b/src/openbsd/threads.h new file mode 100644 index 0000000..2fc7f62 --- /dev/null +++ b/src/openbsd/threads.h @@ -0,0 +1,479 @@ +/* -*- mode: c; tab-width: 2; indent-tabs-mode: nil; -*- +Copyright (c) 2012 Marcus Geelnard +Copyright (c) 2013-2016 Evan Nemerson + +This software is provided 'as-is', without any express or implied +warranty. In no event will the authors be held liable for any damages +arising from the use of this software. + +Permission is granted to anyone to use this software for any purpose, +including commercial applications, and to alter it and redistribute it +freely, subject to the following restrictions: + + 1. The origin of this software must not be misrepresented; you must not + claim that you wrote the original software. If you use this software + in a product, an acknowledgment in the product documentation would be + appreciated but is not required. + + 2. Altered source versions must be plainly marked as such, and must not be + misrepresented as being the original software. + + 3. This notice may not be removed or altered from any source + distribution. +*/ + +#ifndef _TINYCTHREAD_H_ +#define _TINYCTHREAD_H_ + +#ifdef __cplusplus +extern "C" { +#endif + +/** +* @file +* @mainpage TinyCThread API Reference +* +* @section intro_sec Introduction +* TinyCThread is a minimal, portable implementation of basic threading +* classes for C. +* +* They closely mimic the functionality and naming of the C11 standard, and +* should be easily replaceable with the corresponding standard variants. +* +* @section port_sec Portability +* The Win32 variant uses the native Win32 API for implementing the thread +* classes, while for other systems, the POSIX threads API (pthread) is used. +* +* @section misc_sec Miscellaneous +* The following special keywords are available: #_Thread_local. +* +* For more detailed information, browse the different sections of this +* documentation. A good place to start is: +* tinycthread.h. +*/ + +/* Which platform are we on? */ +#if !defined(_TTHREAD_PLATFORM_DEFINED_) + #if defined(_WIN32) || defined(__WIN32__) || defined(__WINDOWS__) + #define _TTHREAD_WIN32_ + #else + #define _TTHREAD_POSIX_ + #endif + #define _TTHREAD_PLATFORM_DEFINED_ +#endif + +/* Activate some POSIX functionality (e.g. clock_gettime and recursive mutexes) */ +#if defined(_TTHREAD_POSIX_) + #undef _FEATURES_H + #if !defined(_GNU_SOURCE) + #define _GNU_SOURCE + #endif + #if !defined(_POSIX_C_SOURCE) || ((_POSIX_C_SOURCE - 0) < 199309L) + #undef _POSIX_C_SOURCE + #define _POSIX_C_SOURCE 199309L + #endif + #if !defined(_XOPEN_SOURCE) || ((_XOPEN_SOURCE - 0) < 500) + #undef _XOPEN_SOURCE + #define _XOPEN_SOURCE 500 + #endif + #define _XPG6 +#endif + +/* Generic includes */ +#include <time.h> + +/* Platform specific includes */ +#if defined(_TTHREAD_POSIX_) + #include <pthread.h> +#elif defined(_TTHREAD_WIN32_) + #ifndef WIN32_LEAN_AND_MEAN + #define WIN32_LEAN_AND_MEAN + #define __UNDEF_LEAN_AND_MEAN + #endif + #include <windows.h> + #ifdef __UNDEF_LEAN_AND_MEAN + #undef WIN32_LEAN_AND_MEAN + #undef __UNDEF_LEAN_AND_MEAN + #endif +#endif + +/* Compiler-specific information */ +#if defined(__STDC_VERSION__) && __STDC_VERSION__ >= 201112L + #define TTHREAD_NORETURN _Noreturn +#elif defined(__GNUC__) + #define TTHREAD_NORETURN __attribute__((__noreturn__)) +#else + #define TTHREAD_NORETURN +#endif + +/* If TIME_UTC is missing, provide it and provide a wrapper for + timespec_get. */ +#ifndef TIME_UTC +#define TIME_UTC 1 +#define _TTHREAD_EMULATE_TIMESPEC_GET_ + +#if defined(_TTHREAD_WIN32_) +struct _tthread_timespec { + time_t tv_sec; + long tv_nsec; +}; +#define timespec _tthread_timespec +#endif + +int _tthread_timespec_get(struct timespec *ts, int base); +#define timespec_get _tthread_timespec_get +#endif + +/** TinyCThread version (major number). */ +#define TINYCTHREAD_VERSION_MAJOR 1 +/** TinyCThread version (minor number). */ +#define TINYCTHREAD_VERSION_MINOR 2 +/** TinyCThread version (full version). */ +#define TINYCTHREAD_VERSION (TINYCTHREAD_VERSION_MAJOR * 100 + TINYCTHREAD_VERSION_MINOR) + +/** +* @def _Thread_local +* Thread local storage keyword. +* A variable that is declared with the @c _Thread_local keyword makes the +* value of the variable local to each thread (known as thread-local storage, +* or TLS). Example usage: +* @code +* // This variable is local to each thread. +* _Thread_local int variable; +* @endcode +* @note The @c _Thread_local keyword is a macro that maps to the corresponding +* compiler directive (e.g. @c __declspec(thread)). +* @note This directive is currently not supported on Mac OS X (it will give +* a compiler error), since compile-time TLS is not supported in the Mac OS X +* executable format. Also, some older versions of MinGW (before GCC 4.x) do +* not support this directive, nor does the Tiny C Compiler. +* @hideinitializer +*/ + +#if !(defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 201102L)) && !defined(_Thread_local) + #if defined(__GNUC__) || defined(__INTEL_COMPILER) || defined(__SUNPRO_CC) || defined(__IBMCPP__) + #define _Thread_local __thread + #else + #define _Thread_local __declspec(thread) + #endif +#elif defined(__GNUC__) && defined(__GNUC_MINOR__) && (((__GNUC__ << 8) | __GNUC_MINOR__) < ((4 << 8) | 9)) + #define _Thread_local __thread +#endif + +/* Macros */ +#if defined(_TTHREAD_WIN32_) +#define TSS_DTOR_ITERATIONS (4) +#else +#define TSS_DTOR_ITERATIONS PTHREAD_DESTRUCTOR_ITERATIONS +#endif + +/* Function return values */ +#define thrd_error 0 /**< The requested operation failed */ +#define thrd_success 1 /**< The requested operation succeeded */ +#define thrd_timedout 2 /**< The time specified in the call was reached without acquiring the requested resource */ +#define thrd_busy 3 /**< The requested operation failed because a tesource requested by a test and return function is already in use */ +#define thrd_nomem 4 /**< The requested operation failed because it was unable to allocate memory */ + +/* Mutex types */ +#define mtx_plain 0 +#define mtx_timed 1 +#define mtx_recursive 2 + +/* Mutex */ +#if defined(_TTHREAD_WIN32_) +typedef struct { + union { + CRITICAL_SECTION cs; /* Critical section handle (used for non-timed mutexes) */ + HANDLE mut; /* Mutex handle (used for timed mutex) */ + } mHandle; /* Mutex handle */ + int mAlreadyLocked; /* TRUE if the mutex is already locked */ + int mRecursive; /* TRUE if the mutex is recursive */ + int mTimed; /* TRUE if the mutex is timed */ +} mtx_t; +#else +typedef pthread_mutex_t mtx_t; +#endif + +/** Create a mutex object. +* @param mtx A mutex object. +* @param type Bit-mask that must have one of the following six values: +* @li @c mtx_plain for a simple non-recursive mutex +* @li @c mtx_timed for a non-recursive mutex that supports timeout +* @li @c mtx_plain | @c mtx_recursive (same as @c mtx_plain, but recursive) +* @li @c mtx_timed | @c mtx_recursive (same as @c mtx_timed, but recursive) +* @return @ref thrd_success on success, or @ref thrd_error if the request could +* not be honored. +*/ +int mtx_init(mtx_t *mtx, int type); + +/** Release any resources used by the given mutex. +* @param mtx A mutex object. +*/ +void mtx_destroy(mtx_t *mtx); + +/** Lock the given mutex. +* Blocks until the given mutex can be locked. If the mutex is non-recursive, and +* the calling thread already has a lock on the mutex, this call will block +* forever. +* @param mtx A mutex object. +* @return @ref thrd_success on success, or @ref thrd_error if the request could +* not be honored. +*/ +int mtx_lock(mtx_t *mtx); + +/** Lock the given mutex, or block until a specific point in time. +* Blocks until either the given mutex can be locked, or the specified TIME_UTC +* based time. +* @param mtx A mutex object. +* @param ts A UTC based calendar time +* @return @ref The mtx_timedlock function returns thrd_success on success, or +* thrd_timedout if the time specified was reached without acquiring the +* requested resource, or thrd_error if the request could not be honored. +*/ +int mtx_timedlock(mtx_t *mtx, const struct timespec *ts); + +/** Try to lock the given mutex. +* The specified mutex shall support either test and return or timeout. If the +* mutex is already locked, the function returns without blocking. +* @param mtx A mutex object. +* @return @ref thrd_success on success, or @ref thrd_busy if the resource +* requested is already in use, or @ref thrd_error if the request could not be +* honored. +*/ +int mtx_trylock(mtx_t *mtx); + +/** Unlock the given mutex. +* @param mtx A mutex object. +* @return @ref thrd_success on success, or @ref thrd_error if the request could +* not be honored. +*/ +int mtx_unlock(mtx_t *mtx); + +/* Condition variable */ +#if defined(_TTHREAD_WIN32_) +typedef struct { + HANDLE mEvents[2]; /* Signal and broadcast event HANDLEs. */ + unsigned int mWaitersCount; /* Count of the number of waiters. */ + CRITICAL_SECTION mWaitersCountLock; /* Serialize access to mWaitersCount. */ +} cnd_t; +#else +typedef pthread_cond_t cnd_t; +#endif + +/** Create a condition variable object. +* @param cond A condition variable object. +* @return @ref thrd_success on success, or @ref thrd_error if the request could +* not be honored. +*/ +int cnd_init(cnd_t *cond); + +/** Release any resources used by the given condition variable. +* @param cond A condition variable object. +*/ +void cnd_destroy(cnd_t *cond); + +/** Signal a condition variable. +* Unblocks one of the threads that are blocked on the given condition variable +* at the time of the call. If no threads are blocked on the condition variable +* at the time of the call, the function does nothing and return success. +* @param cond A condition variable object. +* @return @ref thrd_success on success, or @ref thrd_error if the request could +* not be honored. +*/ +int cnd_signal(cnd_t *cond); + +/** Broadcast a condition variable. +* Unblocks all of the threads that are blocked on the given condition variable +* at the time of the call. If no threads are blocked on the condition variable +* at the time of the call, the function does nothing and return success. +* @param cond A condition variable object. +* @return @ref thrd_success on success, or @ref thrd_error if the request could +* not be honored. +*/ +int cnd_broadcast(cnd_t *cond); + +/** Wait for a condition variable to become signaled. +* The function atomically unlocks the given mutex and endeavors to block until +* the given condition variable is signaled by a call to cnd_signal or to +* cnd_broadcast. When the calling thread becomes unblocked it locks the mutex +* before it returns. +* @param cond A condition variable object. +* @param mtx A mutex object. +* @return @ref thrd_success on success, or @ref thrd_error if the request could +* not be honored. +*/ +int cnd_wait(cnd_t *cond, mtx_t *mtx); + +/** Wait for a condition variable to become signaled. +* The function atomically unlocks the given mutex and endeavors to block until +* the given condition variable is signaled by a call to cnd_signal or to +* cnd_broadcast, or until after the specified time. When the calling thread +* becomes unblocked it locks the mutex before it returns. +* @param cond A condition variable object. +* @param mtx A mutex object. +* @param xt A point in time at which the request will time out (absolute time). +* @return @ref thrd_success upon success, or @ref thrd_timeout if the time +* specified in the call was reached without acquiring the requested resource, or +* @ref thrd_error if the request could not be honored. +*/ +int cnd_timedwait(cnd_t *cond, mtx_t *mtx, const struct timespec *ts); + +/* Thread */ +#if defined(_TTHREAD_WIN32_) +typedef HANDLE thrd_t; +#else +typedef pthread_t thrd_t; +#endif + +/** Thread start function. +* Any thread that is started with the @ref thrd_create() function must be +* started through a function of this type. +* @param arg The thread argument (the @c arg argument of the corresponding +* @ref thrd_create() call). +* @return The thread return value, which can be obtained by another thread +* by using the @ref thrd_join() function. +*/ +typedef int (*thrd_start_t)(void *arg); + +/** Create a new thread. +* @param thr Identifier of the newly created thread. +* @param func A function pointer to the function that will be executed in +* the new thread. +* @param arg An argument to the thread function. +* @return @ref thrd_success on success, or @ref thrd_nomem if no memory could +* be allocated for the thread requested, or @ref thrd_error if the request +* could not be honored. +* @note A thread’s identifier may be reused for a different thread once the +* original thread has exited and either been detached or joined to another +* thread. +*/ +int thrd_create(thrd_t *thr, thrd_start_t func, void *arg); + +/** Identify the calling thread. +* @return The identifier of the calling thread. +*/ +thrd_t thrd_current(void); + +/** Dispose of any resources allocated to the thread when that thread exits. + * @return thrd_success, or thrd_error on error +*/ +int thrd_detach(thrd_t thr); + +/** Compare two thread identifiers. +* The function determines if two thread identifiers refer to the same thread. +* @return Zero if the two thread identifiers refer to different threads. +* Otherwise a nonzero value is returned. +*/ +int thrd_equal(thrd_t thr0, thrd_t thr1); + +/** Terminate execution of the calling thread. +* @param res Result code of the calling thread. +*/ +TTHREAD_NORETURN void thrd_exit(int res); + +/** Wait for a thread to terminate. +* The function joins the given thread with the current thread by blocking +* until the other thread has terminated. +* @param thr The thread to join with. +* @param res If this pointer is not NULL, the function will store the result +* code of the given thread in the integer pointed to by @c res. +* @return @ref thrd_success on success, or @ref thrd_error if the request could +* not be honored. +*/ +int thrd_join(thrd_t thr, int *res); + +/** Put the calling thread to sleep. +* Suspend execution of the calling thread. +* @param duration Interval to sleep for +* @param remaining If non-NULL, this parameter will hold the remaining +* time until time_point upon return. This will +* typically be zero, but if the thread was woken up +* by a signal that is not ignored before duration was +* reached @c remaining will hold a positive time. +* @return 0 (zero) on successful sleep, -1 if an interrupt occurred, +* or a negative value if the operation fails. +*/ +int thrd_sleep(const struct timespec *duration, struct timespec *remaining); + +/** Yield execution to another thread. +* Permit other threads to run, even if the current thread would ordinarily +* continue to run. +*/ +void thrd_yield(void); + +/* Thread local storage */ +#if defined(_TTHREAD_WIN32_) +typedef DWORD tss_t; +#else +typedef pthread_key_t tss_t; +#endif + +/** Destructor function for a thread-specific storage. +* @param val The value of the destructed thread-specific storage. +*/ +typedef void (*tss_dtor_t)(void *val); + +/** Create a thread-specific storage. +* @param key The unique key identifier that will be set if the function is +* successful. +* @param dtor Destructor function. This can be NULL. +* @return @ref thrd_success on success, or @ref thrd_error if the request could +* not be honored. +* @note On Windows, the @c dtor will definitely be called when +* appropriate for threads created with @ref thrd_create. It will be +* called for other threads in most cases, the possible exception being +* for DLLs loaded with LoadLibraryEx. In order to be certain, you +* should use @ref thrd_create whenever possible. +*/ +int tss_create(tss_t *key, tss_dtor_t dtor); + +/** Delete a thread-specific storage. +* The function releases any resources used by the given thread-specific +* storage. +* @param key The key that shall be deleted. +*/ +void tss_delete(tss_t key); + +/** Get the value for a thread-specific storage. +* @param key The thread-specific storage identifier. +* @return The value for the current thread held in the given thread-specific +* storage. +*/ +void *tss_get(tss_t key); + +/** Set the value for a thread-specific storage. +* @param key The thread-specific storage identifier. +* @param val The value of the thread-specific storage to set for the current +* thread. +* @return @ref thrd_success on success, or @ref thrd_error if the request could +* not be honored. +*/ +int tss_set(tss_t key, void *val); + +#if defined(_TTHREAD_WIN32_) + typedef struct { + LONG volatile status; + CRITICAL_SECTION lock; + } once_flag; + #define ONCE_FLAG_INIT {0,} +#else + #define once_flag pthread_once_t + #define ONCE_FLAG_INIT PTHREAD_ONCE_INIT +#endif + +/** Invoke a callback exactly once + * @param flag Flag used to ensure the callback is invoked exactly + * once. + * @param func Callback to invoke. + */ +#if defined(_TTHREAD_WIN32_) + void call_once(once_flag *flag, void (*func)(void)); +#else + #define call_once(flag,func) pthread_once(flag,func) +#endif + +#ifdef __cplusplus +} +#endif + +#endif /* _TINYTHREAD_H_ */ |