1.3.5
00001 00006 /* 00007 * The contents of this file are subject to the Mozilla Public License 00008 * Version 1.0 (the "License"); you may not use this file except in 00009 * compliance with the License. You may obtain a copy of the License at 00010 * http://www.mozilla.org/MPL/ 00011 * 00012 * Software distributed under the License is distributed on an "AS IS" 00013 * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See the 00014 * License for the specific language governing rights and limitations 00015 * under the License. 00016 * 00017 * The Original Code is legOS code, released October 17, 1999. 00018 * 00019 * The Initial Developer of the Original Code is Markus L. Noga. 00020 * Portions created by Markus L. Noga are Copyright (C) 1999 00021 * Markus L. Noga. All Rights Reserved. 00022 * 00023 * Contributor(s): Markus L. Noga <markus@noga.de> 00024 */ 00025 00026 #include <semaphore.h> 00027 00028 #ifdef CONF_SEMAPHORES 00029 00030 #include <unistd.h> 00031 00033 // 00034 // Functions 00035 // 00037 00039 00041 wakeup_t sem_event_wait(wakeup_t data) { 00042 sem_t *sem=(sem_t*) ((unsigned)data); 00043 00044 // we're called by the scheduler, therefore in an IRQ handler, 00045 // so no worrying about IRQs. 00046 // 00047 if(*sem) { 00048 (*sem)--; 00049 return 1; // sem!=0 -> wakeup 00050 } 00051 return 0; 00052 } 00053 00055 00063 int sem_wait(sem_t * sem) { 00064 // check if semaphore is available, if not, go to sleep 00065 00066 if(sem_trywait(sem)) 00067 if (wait_event(sem_event_wait,(unsigned long) ((unsigned)sem)) == 0) 00068 return -1; 00069 00070 return 0; 00071 } 00072 00074 00084 int sem_trywait(sem_t * sem); 00085 #ifndef DOXYGEN_SHOULD_SKIP_THIS 00086 __asm__(" 00087 .text 00088 .align 1 00089 .globl _sem_trywait 00090 _sem_trywait: 00091 stc ccr,r1h ; save flags 00092 orc #0x80,ccr ; block all but NMI 00093 mov.b @r0,r1l 00094 beq sem_fail ; !=0 -> decrease, return 0 00095 dec r1l 00096 mov.b r1l,@r0 00097 sub.w r0,r0 00098 bra sem_ok 00099 sem_fail:mov #0xffff,r0 ; else return 0xffff 00100 sem_ok:ldc r1h,ccr ; restore flags 00101 rts 00102 "); 00103 #endif // DOXYGEN_SHOULD_SKIP_THIS 00104 00106 00112 int sem_post(sem_t * sem); 00113 #ifndef DOXYGEN_SHOULD_SKIP_THIS 00114 __asm__(" 00115 .text 00116 .align 1 00117 .globl _sem_post 00118 _sem_post: 00119 stc ccr,r1h ; save flags 00120 orc #0x80,ccr ; disable all but NMI 00121 mov.b @r0,r1l 00122 inc r1l 00123 mov.b r1l,@r0 00124 ldc r1h,ccr ; restore flags 00125 00126 sub r0,r0 ; return 0 00127 rts 00128 "); 00129 #endif // DOXYGEN_SHOULD_SKIP_THIS 00130 00131 00132 #endif // CONF_SEMAPHORES
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brickOS is released under the
Mozilla Public License.
Original code copyright 1998-2002 by the authors. |
1.3.5