73 lines
2.2 KiB
C++
73 lines
2.2 KiB
C++
/*
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Copyright (c) 2014 Arduino. All right reserved.
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This library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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This library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
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See the GNU Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with this library; if not, write to the Free Software
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Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#include <abi.h>
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#include <stdint.h>
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#include <exception>
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#include <avr/io.h>
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#include <avr/interrupt.h>
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namespace {
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// guard is an integer type big enough to hold flag and a mutex.
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// By default gcc uses long long int and avr ABI does not change it
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// So we have 32 or 64 bits available. Actually, we need 16.
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inline char& flag_part(__guard *g) {
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return *(reinterpret_cast<char*>(g));
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}
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inline uint8_t& sreg_part(__guard *g) {
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return *(reinterpret_cast<uint8_t*>(g) + sizeof(char));
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}
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}
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int __cxa_guard_acquire(__guard *g) {
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uint8_t oldSREG = SREG;
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cli();
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// Initialization of static variable has to be done with blocked interrupts
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// because if this function is called from interrupt and sees that somebody
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// else is already doing initialization it MUST wait until initializations
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// is complete. That's impossible.
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// If you don't want this overhead compile with -fno-threadsafe-statics
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if (flag_part(g)) {
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SREG = oldSREG;
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return false;
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} else {
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sreg_part(g) = oldSREG;
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return true;
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}
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}
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void __cxa_guard_release (__guard *g) {
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flag_part(g) = 1;
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SREG = sreg_part(g);
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}
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void __cxa_guard_abort (__guard *g) {
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SREG = sreg_part(g);
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}
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void __cxa_pure_virtual(void) {
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// We might want to write some diagnostics to uart in this case
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std::terminate();
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}
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void __cxa_deleted_virtual(void) {
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// We might want to write some diagnostics to uart in this case
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std::terminate();
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} |