diff options
Diffstat (limited to '')
| -rw-r--r-- | src/common/mythread.h | 513 |
1 files changed, 402 insertions, 111 deletions
diff --git a/src/common/mythread.h b/src/common/mythread.h index 637b8ac3..4a885474 100644 --- a/src/common/mythread.h +++ b/src/common/mythread.h @@ -15,8 +15,84 @@ #include "sysdefs.h" +// If any type of threading is enabled, #define MYTHREAD_ENABLED. +#if defined(MYTHREAD_POSIX) || defined(MYTHREAD_WIN95) \ + || defined(MYTHREAD_VISTA) +# define MYTHREAD_ENABLED 1 +#endif + + +#ifdef MYTHREAD_ENABLED + +//////////////////////////////////////// +// Shared betewen all threading types // +//////////////////////////////////////// + +// Locks a mutex for a duration of a block. +// +// Perform mythread_mutex_lock(&mutex) in the beginning of a block +// and mythread_mutex_unlock(&mutex) at the end of the block. "break" +// may be used to unlock the mutex and jump out of the block. +// mythread_sync blocks may be nested. +// +// Example: +// +// mythread_sync(mutex) { +// foo(); +// if (some_error) +// break; // Skips bar() +// bar(); +// } +// +// At least GCC optimizes the loops completely away so it doesn't slow +// things down at all compared to plain mythread_mutex_lock(&mutex) +// and mythread_mutex_unlock(&mutex) calls. +// +#define mythread_sync(mutex) mythread_sync_helper1(mutex, __LINE__) +#define mythread_sync_helper1(mutex, line) mythread_sync_helper2(mutex, line) +#define mythread_sync_helper2(mutex, line) \ + for (unsigned int mythread_i_ ## line = 0; \ + mythread_i_ ## line \ + ? (mythread_mutex_unlock(&(mutex)), 0) \ + : (mythread_mutex_lock(&(mutex)), 1); \ + mythread_i_ ## line = 1) \ + for (unsigned int mythread_j_ ## line = 0; \ + !mythread_j_ ## line; \ + mythread_j_ ## line = 1) +#endif + + +#if !defined(MYTHREAD_ENABLED) + +////////////////// +// No threading // +////////////////// + +// Calls the given function once. This isn't thread safe. +#define mythread_once(func) \ +do { \ + static bool once_ = false; \ + if (!once_) { \ + func(); \ + once_ = true; \ + } \ +} while (0) + + +#if !(defined(_WIN32) && !defined(__CYGWIN__)) +// Use sigprocmask() to set the signal mask in single-threaded programs. +static inline void +mythread_sigmask(int how, const sigset_t *restrict set, + sigset_t *restrict oset) +{ + int ret = sigprocmask(how, set, oset); + assert(ret == 0); + (void)ret; +} +#endif -#ifdef HAVE_PTHREAD + +#elif defined(MYTHREAD_POSIX) //////////////////// // Using pthreads // @@ -26,83 +102,117 @@ #include <pthread.h> #include <signal.h> #include <time.h> +#include <errno.h> + +#define MYTHREAD_RET_TYPE void * +#define MYTHREAD_RET_VALUE NULL + +typedef pthread_t mythread; +typedef pthread_mutex_t mythread_mutex; + +typedef struct { + pthread_cond_t cond; +#ifdef HAVE_CLOCK_GETTIME + // Clock ID (CLOCK_REALTIME or CLOCK_MONOTONIC) associated with + // the condition variable. + clockid_t clk_id; +#endif +} mythread_cond; + +typedef struct timespec mythread_condtime; +// Calls the given function once in a thread-safe way. +#define mythread_once(func) \ + do { \ + static pthread_once_t once_ = PTHREAD_ONCE_INIT; \ + pthread_once(&once_, &func); \ + } while (0) + + +// Use pthread_sigmask() to set the signal mask in multi-threaded programs. +// Do nothing on OpenVMS since it lacks pthread_sigmask(). +static inline void +mythread_sigmask(int how, const sigset_t *restrict set, + sigset_t *restrict oset) +{ #ifdef __VMS -// Do nothing on OpenVMS. It doesn't have pthread_sigmask(). -#define mythread_sigmask(how, set, oset) do { } while (0) + (void)how; + (void)set; + (void)oset; #else -/// \brief Set the process signal mask -/// -/// If threads are disabled, sigprocmask() is used instead -/// of pthread_sigmask(). -#define mythread_sigmask(how, set, oset) \ - pthread_sigmask(how, set, oset) + int ret = pthread_sigmask(how, set, oset); + assert(ret == 0); + (void)ret; #endif +} -/// \brief Call the given function once -/// -/// If threads are disabled, a thread-unsafe version is used. -#define mythread_once(func) \ -do { \ - static pthread_once_t once_ = PTHREAD_ONCE_INIT; \ - pthread_once(&once_, &func); \ -} while (0) +// Creates a new thread with all signals blocked. Returns zero on success +// and non-zero on error. +static inline int +mythread_create(mythread *thread, void *(*func)(void *arg), void *arg) +{ + sigset_t old; + sigset_t all; + sigfillset(&all); + + mythread_sigmask(SIG_SETMASK, &all, &old); + const int ret = pthread_create(thread, NULL, func, arg); + mythread_sigmask(SIG_SETMASK, &old, NULL); -/// \brief Lock a mutex for a duration of a block -/// -/// Perform pthread_mutex_lock(&mutex) in the beginning of a block -/// and pthread_mutex_unlock(&mutex) at the end of the block. "break" -/// may be used to unlock the mutex and jump out of the block. -/// mythread_sync blocks may be nested. -/// -/// Example: -/// -/// mythread_sync(mutex) { -/// foo(); -/// if (some_error) -/// break; // Skips bar() -/// bar(); -/// } -/// -/// At least GCC optimizes the loops completely away so it doesn't slow -/// things down at all compared to plain pthread_mutex_lock(&mutex) -/// and pthread_mutex_unlock(&mutex) calls. -/// -#define mythread_sync(mutex) mythread_sync_helper1(mutex, __LINE__) -#define mythread_sync_helper1(mutex, line) mythread_sync_helper2(mutex, line) -#define mythread_sync_helper2(mutex, line) \ - for (unsigned int mythread_i_ ## line = 0; \ - mythread_i_ ## line \ - ? (pthread_mutex_unlock(&(mutex)), 0) \ - : (pthread_mutex_lock(&(mutex)), 1); \ - mythread_i_ ## line = 1) \ - for (unsigned int mythread_j_ ## line = 0; \ - !mythread_j_ ## line; \ - mythread_j_ ## line = 1) + return ret; +} +// Joins a thread. Returns zero on success and non-zero on error. +static inline int +mythread_join(mythread thread) +{ + return pthread_join(thread, NULL); +} -typedef struct { - /// Condition variable - pthread_cond_t cond; -#ifdef HAVE_CLOCK_GETTIME - /// Clock ID (CLOCK_REALTIME or CLOCK_MONOTONIC) associated with - /// the condition variable - clockid_t clk_id; -#endif +// Initiatlizes a mutex. Returns zero on success and non-zero on error. +static inline int +mythread_mutex_init(mythread_mutex *mutex) +{ + return pthread_mutex_init(mutex, NULL); +} -} mythread_cond; +static inline void +mythread_mutex_destroy(mythread_mutex *mutex) +{ + int ret = pthread_mutex_destroy(mutex); + assert(ret == 0); + (void)ret; +} +static inline void +mythread_mutex_lock(mythread_mutex *mutex) +{ + int ret = pthread_mutex_lock(mutex); + assert(ret == 0); + (void)ret; +} -/// \brief Initialize a condition variable to use CLOCK_MONOTONIC -/// -/// Using CLOCK_MONOTONIC instead of the default CLOCK_REALTIME makes the -/// timeout in pthread_cond_timedwait() work correctly also if system time -/// is suddenly changed. Unfortunately CLOCK_MONOTONIC isn't available -/// everywhere while the default CLOCK_REALTIME is, so the default is -/// used if CLOCK_MONOTONIC isn't available. +static inline void +mythread_mutex_unlock(mythread_mutex *mutex) +{ + int ret = pthread_mutex_unlock(mutex); + assert(ret == 0); + (void)ret; +} + + +// Initializes a condition variable. +// +// Using CLOCK_MONOTONIC instead of the default CLOCK_REALTIME makes the +// timeout in pthread_cond_timedwait() work correctly also if system time +// is suddenly changed. Unfortunately CLOCK_MONOTONIC isn't available +// everywhere while the default CLOCK_REALTIME is, so the default is +// used if CLOCK_MONOTONIC isn't available. +// +// If clock_gettime() isn't available at all, gettimeofday() will be used. static inline int mythread_cond_init(mythread_cond *mycond) { @@ -131,6 +241,8 @@ mythread_cond_init(mythread_cond *mycond) } // If anything above fails, fall back to the default CLOCK_REALTIME. + // POSIX requires that all implementations of clock_gettime() must + // support at least CLOCK_REALTIME. # endif mycond->clk_id = CLOCK_REALTIME; @@ -139,89 +251,268 @@ mythread_cond_init(mythread_cond *mycond) return pthread_cond_init(&mycond->cond, NULL); } +static inline void +mythread_cond_destroy(mythread_cond *cond) +{ + int ret = pthread_cond_destroy(&cond->cond); + assert(ret == 0); + (void)ret; +} + +static inline void +mythread_cond_signal(mythread_cond *cond) +{ + int ret = pthread_cond_signal(&cond->cond); + assert(ret == 0); + (void)ret; +} + +static inline void +mythread_cond_wait(mythread_cond *cond, mythread_mutex *mutex) +{ + int ret = pthread_cond_wait(&cond->cond, mutex); + assert(ret == 0); + (void)ret; +} + +// Waits on a condition or until a timeout expires. If the timeout expires, +// non-zero is returned, otherwise zero is returned. +static inline int +mythread_cond_timedwait(mythread_cond *cond, mythread_mutex *mutex, + const mythread_condtime *condtime) +{ + int ret = pthread_cond_timedwait(&cond->cond, mutex, condtime); + assert(ret == 0 || ret == ETIMEDOUT); + return ret; +} -/// \brief Convert relative time to absolute time for use with timed wait -/// -/// The current time of the clock associated with the condition variable -/// is added to the relative time in *ts. +// Sets condtime to the absolute time that is timeout_ms milliseconds +// in the future. The type of the clock to use is taken from cond. static inline void -mythread_cond_abstime(const mythread_cond *mycond, struct timespec *ts) +mythread_condtime_set(mythread_condtime *condtime, const mythread_cond *cond, + uint32_t timeout_ms) { + condtime->tv_sec = timeout_ms / 1000; + condtime->tv_nsec = (timeout_ms % 1000) * 1000000; + #ifdef HAVE_CLOCK_GETTIME struct timespec now; - clock_gettime(mycond->clk_id, &now); + int ret = clock_gettime(cond->clk_id, &now); + assert(ret == 0); + (void)ret; - ts->tv_sec += now.tv_sec; - ts->tv_nsec += now.tv_nsec; + condtime->tv_sec += now.tv_sec; + condtime->tv_nsec += now.tv_nsec; #else - (void)mycond; + (void)cond; struct timeval now; gettimeofday(&now, NULL); - ts->tv_sec += now.tv_sec; - ts->tv_nsec += now.tv_usec * 1000L; + condtime->tv_sec += now.tv_sec; + condtime->tv_nsec += now.tv_usec * 1000L; #endif // tv_nsec must stay in the range [0, 999_999_999]. - if (ts->tv_nsec >= 1000000000L) { - ts->tv_nsec -= 1000000000L; - ++ts->tv_sec; + if (condtime->tv_nsec >= 1000000000L) { + condtime->tv_nsec -= 1000000000L; + ++condtime->tv_sec; } - - return; } -#define mythread_cond_wait(mycondptr, mutexptr) \ - pthread_cond_wait(&(mycondptr)->cond, mutexptr) +#elif defined(MYTHREAD_WIN95) || defined(MYTHREAD_VISTA) + +///////////////////// +// Windows threads // +///////////////////// + +#define WIN32_LEAN_AND_MEAN +#ifdef MYTHREAD_VISTA +# undef _WIN32_WINNT +# define _WIN32_WINNT 0x0600 +#endif +#include <windows.h> +#include <process.h> + +#define MYTHREAD_RET_TYPE unsigned int __stdcall +#define MYTHREAD_RET_VALUE 0 + +typedef HANDLE mythread; +typedef CRITICAL_SECTION mythread_mutex; + +#ifdef MYTHREAD_WIN95 +typedef HANDLE mythread_cond; +#else +typedef CONDITION_VARIABLE mythread_cond; +#endif + +typedef struct { + // Tick count (milliseconds) in the beginning of the timeout. + // NOTE: This is 32 bits so it wraps around after 49.7 days. + // Multi-day timeouts may not work as expected. + DWORD start; + + // Length of the timeout in milliseconds. The timeout expires + // when the current tick count minus "start" is equal or greater + // than "timeout". + DWORD timeout; +} mythread_condtime; -#define mythread_cond_timedwait(mycondptr, mutexptr, abstimeptr) \ - pthread_cond_timedwait(&(mycondptr)->cond, mutexptr, abstimeptr) -#define mythread_cond_signal(mycondptr) \ - pthread_cond_signal(&(mycondptr)->cond) +// mythread_once() is only available with Vista threads. +#ifdef MYTHREAD_VISTA +#define mythread_once(func) \ + do { \ + static INIT_ONCE once_ = INIT_ONCE_STATIC_INIT; \ + BOOL pending_; \ + if (!InitOnceBeginInitialize(&once_, 0, &pending_, NULL)) \ + abort(); \ + if (pending_) \ + func(); \ + if (!InitOnceComplete(&once, 0, NULL)) \ + abort(); \ + } while (0) +#endif -#define mythread_cond_broadcast(mycondptr) \ - pthread_cond_broadcast(&(mycondptr)->cond) -#define mythread_cond_destroy(mycondptr) \ - pthread_cond_destroy(&(mycondptr)->cond) +// mythread_sigmask() isn't available on Windows. Even a dummy version would +// make no sense because the other POSIX signal functions are missing anyway. -/// \brief Create a thread with all signals blocked static inline int -mythread_create(pthread_t *thread, void *(*func)(void *arg), void *arg) +mythread_create(mythread *thread, + unsigned int (__stdcall *func)(void *arg), void *arg) { - sigset_t old; - sigset_t all; - sigfillset(&all); + uintptr_t ret = _beginthreadex(NULL, 0, func, arg, 0, NULL); + if (ret == 0) + return -1; - pthread_sigmask(SIG_SETMASK, &all, &old); - const int ret = pthread_create(thread, NULL, func, arg); - pthread_sigmask(SIG_SETMASK, &old, NULL); + *thread = (HANDLE)ret; + return 0; +} + +static inline int +mythread_join(mythread thread) +{ + int ret = 0; + + if (WaitForSingleObject(thread, INFINITE) != WAIT_OBJECT_0) + ret = -1; + + if (!CloseHandle(thread)) + ret = -1; return ret; } + +static inline int +mythread_mutex_init(mythread_mutex *mutex) +{ + InitializeCriticalSection(mutex); + return 0; +} + +static inline void +mythread_mutex_destroy(mythread_mutex *mutex) +{ + DeleteCriticalSection(mutex); +} + +static inline void +mythread_mutex_lock(mythread_mutex *mutex) +{ + EnterCriticalSection(mutex); +} + +static inline void +mythread_mutex_unlock(mythread_mutex *mutex) +{ + LeaveCriticalSection(mutex); +} + + +static inline int +mythread_cond_init(mythread_cond *cond) +{ +#ifdef MYTHREAD_WIN95 + *cond = CreateEvent(NULL, FALSE, FALSE, NULL); + return *cond == NULL ? -1 : 0; #else + InitializeConditionVariable(cond); + return 0; +#endif +} -////////////////// -// No threading // -////////////////// +static inline void +mythread_cond_destroy(mythread_cond *cond) +{ +#ifdef MYTHREAD_WIN95 + CloseHandle(*cond); +#else + (void)cond; +#endif +} -#define mythread_sigmask(how, set, oset) \ - sigprocmask(how, set, oset) +static inline void +mythread_cond_signal(mythread_cond *cond) +{ +#ifdef MYTHREAD_WIN95 + SetEvent(*cond); +#else + WakeConditionVariable(cond); +#endif +} +static inline void +mythread_cond_wait(mythread_cond *cond, mythread_mutex *mutex) +{ +#ifdef MYTHREAD_WIN95 + LeaveCriticalSection(mutex); + WaitForSingleObject(*cond, INFINITE); + EnterCriticalSection(mutex); +#else + BOOL ret = SleepConditionVariableCS(cond, mutex, INFINITE); + assert(ret); + (void)ret; +#endif +} -#define mythread_once(func) \ -do { \ - static bool once_ = false; \ - if (!once_) { \ - func(); \ - once_ = true; \ - } \ -} while (0) +static inline int +mythread_cond_timedwait(mythread_cond *cond, mythread_mutex *mutex, + const mythread_condtime *condtime) +{ +#ifdef MYTHREAD_WIN95 + LeaveCriticalSection(mutex); +#endif + + DWORD elapsed = GetTickCount() - condtime->start; + DWORD timeout = elapsed >= condtime->timeout + ? 0 : condtime->timeout - elapsed; + +#ifdef MYTHREAD_WIN95 + DWORD ret = WaitForSingleObject(*cond, timeout); + assert(ret == WAIT_OBJECT_0 || ret == WAIT_TIMEOUT); + + EnterCriticalSection(mutex); + + return ret == WAIT_TIMEOUT; +#else + BOOL ret = SleepConditionVariableCS(cond, mutex, timeout); + assert(ret || GetLastError() == ERROR_TIMEOUT); + return !ret; +#endif +} + +static inline void +mythread_condtime_set(mythread_condtime *condtime, const mythread_cond *cond, + uint32_t timeout) +{ + (void)cond; + condtime->start = GetTickCount(); + condtime->timeout = timeout; +} #endif |