From 84adefa331c4159d432d22840663c38f155cd4c1 Mon Sep 17 00:00:00 2001 From: Erlang/OTP Date: Fri, 20 Nov 2009 14:54:40 +0000 Subject: The R13B03 release. --- lib/erl_interface/src/misc/ei_pthreads.c | 226 +++++++++++++++++++++++++++++++ 1 file changed, 226 insertions(+) create mode 100644 lib/erl_interface/src/misc/ei_pthreads.c (limited to 'lib/erl_interface/src/misc/ei_pthreads.c') diff --git a/lib/erl_interface/src/misc/ei_pthreads.c b/lib/erl_interface/src/misc/ei_pthreads.c new file mode 100644 index 0000000000..a741dfd5c2 --- /dev/null +++ b/lib/erl_interface/src/misc/ei_pthreads.c @@ -0,0 +1,226 @@ +/* + * %CopyrightBegin% + * + * Copyright Ericsson AB 2001-2009. All Rights Reserved. + * + * The contents of this file are subject to the Erlang Public License, + * Version 1.1, (the "License"); you may not use this file except in + * compliance with the License. You should have received a copy of the + * Erlang Public License along with this software. If not, it can be + * retrieved online at http://www.erlang.org/. + * + * Software distributed under the License is distributed on an "AS IS" + * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See + * the License for the specific language governing rights and limitations + * under the License. + * + * %CopyrightEnd% + * + + */ + +/* FIXME why not use ei_malloc here? */ + +#include "eidef.h" + +#include +#include "ei.h" +#include "ei_locking.h" + +#ifdef __WIN32__ +#ifdef USE_DECLSPEC_THREAD +/* Define (and initialize) the variable __erl_errno */ +volatile __declspec(thread) int __erl_errno = 0; +#else +static volatile DWORD errno_tls_index = TLS_OUT_OF_INDEXES; +static LONG volatile tls_init_mutex = 0; +#endif +#endif + +#if defined(VXWORKS) + +/* + Moved to each of the erl_*threads.c files, as they seem to know how + to get thread-safety. +*/ +static volatile int __erl_errno; +volatile int *__erl_errno_place(void) +{ + /* This check is somewhat insufficient, double task var entries will occur + if __erl_errno is actually -1, which on the other hand is an invalid + error code. */ + if (taskVarGet(taskIdSelf(), &__erl_errno) == ERROR) { + taskVarAdd(taskIdSelf(), &__erl_errno); + } + return &__erl_errno; +} +#endif /* VXWORKS */ + +#if defined(__WIN32__) + +#ifdef USE_DECLSPEC_THREAD + +volatile int *__erl_errno_place(void) +{ + return &__erl_errno; +} + +#else +static void tls_init_once(void) +{ + + if (errno_tls_index != TLS_OUT_OF_INDEXES) { + return; + } + if (InterlockedExchange((LPLONG) &tls_init_mutex,1L) == 0) { + /* I was first */ + errno_tls_index = TlsAlloc(); + if (errno_tls_index == TLS_OUT_OF_INDEXES) { + fprintf(stderr, + "FATAL ERROR: can not allocate TLS index for " + "erl_errno (error code = %d)!\n",GetLastError()); + exit(1); + } + } else { + while (errno_tls_index == TLS_OUT_OF_INDEXES) { + SwitchToThread(); + } + } +} + +volatile int *__erl_errno_place(void) +{ + volatile int *ptr; + tls_init_once(); + ptr = TlsGetValue(errno_tls_index); + if (ptr == NULL) { + ptr = malloc(sizeof(int)); + *ptr = 0; + TlsSetValue(errno_tls_index, (PVOID) ptr); + } + return ptr; +} + +#endif /* USE_DECLSPEC_THREAD */ + +#endif /* __WIN32__ */ + +#if defined(_REENTRANT) && !defined(VXWORKS) && !defined(__WIN32__) + +#if defined(HAVE_PTHREAD_H) || defined(HAVE_MIT_PTHREAD_H) + +void *ei_m_create(void) +{ + pthread_mutex_t *l; + + if ((l = malloc(sizeof(*l)))) { /* FIXME get memory or abort */ + pthread_mutex_init(l,NULL); + } + + return l; +} + +int ei_m_destroy(void *l) +{ + int r = pthread_mutex_destroy(l); + free(l); + + return r; +} + +int ei_m_lock(void *l) +{ + return pthread_mutex_lock(l); +} + +int ei_m_trylock(void *l) +{ + return pthread_mutex_trylock(l); +} + +int ei_m_unlock(void *l) +{ + return pthread_mutex_unlock(l); +} + + +/* + * Thread-specific erl_errno variable. + * + * The second line below will give a "missing braces around initializer" + * on Solaris but the code will work. + */ + +static pthread_key_t erl_errno_key; +static pthread_once_t erl_errno_key_once = PTHREAD_ONCE_INIT; + +/* + * Destroy per-thread erl_errno locus + */ +static void erl_errno_destroy(void * ptr) +{ + free(ptr); +} + +/* + * Allocate erl_errno key. + * This will be done once for all threads + */ +static void erl_errno_key_alloc(void) +{ + pthread_key_create(&erl_errno_key, erl_errno_destroy); +} + +/* + * Return a pointer to the erl_errno locus. + * If pthread functions fail we fall back to using fallback_errno + * so that the main thread (actually not a thread in all ascpects) + * still will set and get an erl_errno value. + * Actually this is a bit to nice, it would be preferrable to exit fatal + * as we do on windows, but we might break some code with one thread + * but still compiled with -D_REENTRANT, so we'll leave it here. + */ +volatile int *__erl_errno_place(void) +{ + int *erl_errno_p; + static volatile int use_fallback = 0; + static volatile int fallback_errno = 0; + + if (use_fallback) { + return &fallback_errno; + } + + /* This will create the key once for all threads */ + if (pthread_once(&erl_errno_key_once, erl_errno_key_alloc) != 0) { + use_fallback = 1; + return &fallback_errno; + } + + /* This is the normal case, return the pointer to the data */ + if ((erl_errno_p = pthread_getspecific(erl_errno_key)) != NULL) { + return erl_errno_p; + } + + if ((erl_errno_p = malloc(sizeof(int))) == NULL) { + use_fallback = 1; + return &fallback_errno; + } + + if (pthread_setspecific(erl_errno_key, erl_errno_p) != 0 || + (erl_errno_p = pthread_getspecific(erl_errno_key)) == NULL) { + free(erl_errno_p); + return &fallback_errno; + } + + return erl_errno_p; +} + +#endif /* HAVE_PTHREAD_H || HAVE_MIT_PTHREAD_H */ + +#endif /* _REENTRANT && !VXWORKS && !__WIN32__ */ + +#if !defined(_REENTRANT) && !defined(VXWORKS) && !defined(__WIN32__) + +volatile int __erl_errno; + +#endif -- cgit v1.2.3