The Tor Browser / file comparison
comparison: nsprpub/pr/src/bthreads/btsem.c
nsprpub/pr/src/bthreads/btsem.c
- changeset 1
- ca08bd8f51b2
equal
deleted
inserted
replaced
| -1:000000000000 | 0:d22ed3c63575 |
|---|---|
| 1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- */ | |
| 2 /* This Source Code Form is subject to the terms of the Mozilla Public | |
| 3 * License, v. 2.0. If a copy of the MPL was not distributed with this | |
| 4 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ | |
| 5 | |
| 6 #include <kernel/OS.h> | |
| 7 | |
| 8 #include "primpl.h" | |
| 9 | |
| 10 /* | |
| 11 ** Create a new semaphore object. | |
| 12 */ | |
| 13 PR_IMPLEMENT(PRSemaphore*) | |
| 14 PR_NewSem (PRUintn value) | |
| 15 { | |
| 16 PRSemaphore *semaphore; | |
| 17 | |
| 18 if (!_pr_initialized) _PR_ImplicitInitialization(); | |
| 19 | |
| 20 semaphore = PR_NEWZAP(PRSemaphore); | |
| 21 if (NULL != semaphore) { | |
| 22 if ((semaphore->sem = create_sem(value, "nspr_sem")) < B_NO_ERROR) | |
| 23 return NULL; | |
| 24 else | |
| 25 return semaphore; | |
| 26 } | |
| 27 return NULL; | |
| 28 } | |
| 29 | |
| 30 /* | |
| 31 ** Destroy the given semaphore object. | |
| 32 ** | |
| 33 */ | |
| 34 PR_IMPLEMENT(void) | |
| 35 PR_DestroySem (PRSemaphore *sem) | |
| 36 { | |
| 37 status_t result; | |
| 38 | |
| 39 PR_ASSERT(sem != NULL); | |
| 40 result = delete_sem(sem->sem); | |
| 41 PR_ASSERT(result == B_NO_ERROR); | |
| 42 PR_DELETE(sem); | |
| 43 } | |
| 44 | |
| 45 /* | |
| 46 ** Wait on a Semaphore. | |
| 47 ** | |
| 48 ** This routine allows a calling thread to wait or proceed depending upon | |
| 49 ** the state of the semahore sem. The thread can proceed only if the | |
| 50 ** counter value of the semaphore sem is currently greater than 0. If the | |
| 51 ** value of semaphore sem is positive, it is decremented by one and the | |
| 52 ** routine returns immediately allowing the calling thread to continue. If | |
| 53 ** the value of semaphore sem is 0, the calling thread blocks awaiting the | |
| 54 ** semaphore to be released by another thread. | |
| 55 ** | |
| 56 ** This routine can return PR_PENDING_INTERRUPT if the waiting thread | |
| 57 ** has been interrupted. | |
| 58 */ | |
| 59 PR_IMPLEMENT(PRStatus) | |
| 60 PR_WaitSem (PRSemaphore *sem) | |
| 61 { | |
| 62 PR_ASSERT(sem != NULL); | |
| 63 if (acquire_sem(sem->sem) == B_NO_ERROR) | |
| 64 return PR_SUCCESS; | |
| 65 else | |
| 66 return PR_FAILURE; | |
| 67 } | |
| 68 | |
| 69 /* | |
| 70 ** This routine increments the counter value of the semaphore. If other | |
| 71 ** threads are blocked for the semaphore, then the scheduler will | |
| 72 ** determine which ONE thread will be unblocked. | |
| 73 */ | |
| 74 PR_IMPLEMENT(void) | |
| 75 PR_PostSem (PRSemaphore *sem) | |
| 76 { | |
| 77 status_t result; | |
| 78 | |
| 79 PR_ASSERT(sem != NULL); | |
| 80 result = release_sem_etc(sem->sem, 1, B_DO_NOT_RESCHEDULE); | |
| 81 PR_ASSERT(result == B_NO_ERROR); | |
| 82 } | |
| 83 | |
| 84 /* | |
| 85 ** Returns the value of the semaphore referenced by sem without affecting | |
| 86 ** the state of the semaphore. The value represents the semaphore value | |
| 87 ** at the time of the call, but may not be the actual value when the | |
| 88 ** caller inspects it. | |
| 89 */ | |
| 90 PR_IMPLEMENT(PRUintn) | |
| 91 PR_GetValueSem (PRSemaphore *sem) | |
| 92 { | |
| 93 sem_info info; | |
| 94 | |
| 95 PR_ASSERT(sem != NULL); | |
| 96 get_sem_info(sem->sem, &info); | |
| 97 return info.count; | |
| 98 } |
