10625e402b
The mirror_super signals the commit state to the control thread via an mbox, and this mbox is moved to control. It was owned by mirror_super, but the problem with that is that mirror_super can free the mbox before the control client has been scheduled to receive the message. If it's owned by the control object, that can't happen.
78 lines
1.6 KiB
C
78 lines
1.6 KiB
C
#include "mbox.h"
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#include "util.h"
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#include <pthread.h>
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struct mbox * mbox_create( void )
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{
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struct mbox * mbox = xmalloc( sizeof( struct mbox ) );
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FATAL_UNLESS( 0 == pthread_cond_init( &mbox->filled_cond, NULL ),
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"Failed to initialise a condition variable" );
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FATAL_UNLESS( 0 == pthread_cond_init( &mbox->emptied_cond, NULL ),
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"Failed to initialise a condition variable" );
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FATAL_UNLESS( 0 == pthread_mutex_init( &mbox->mutex, NULL ),
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"Failed to initialise a mutex" );
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return mbox;
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}
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void mbox_post( struct mbox * mbox, void * contents )
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{
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pthread_mutex_lock( &mbox->mutex );
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{
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if (mbox->full){
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pthread_cond_wait( &mbox->emptied_cond, &mbox->mutex );
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}
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mbox->contents = contents;
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mbox->full = 1;
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while( 0 != pthread_cond_signal( &mbox->filled_cond ) );
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}
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pthread_mutex_unlock( &mbox->mutex );
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}
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void * mbox_contents( struct mbox * mbox )
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{
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return mbox->contents;
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}
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int mbox_is_full( struct mbox * mbox )
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{
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return mbox->full;
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}
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void * mbox_receive( struct mbox * mbox )
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{
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NULLCHECK( mbox );
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void * result;
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pthread_mutex_lock( &mbox->mutex );
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{
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if ( !mbox->full ) {
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pthread_cond_wait( &mbox->filled_cond, &mbox->mutex );
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}
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mbox->full = 0;
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result = mbox->contents;
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mbox->contents = NULL;
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while( 0 != pthread_cond_signal( &mbox->emptied_cond));
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}
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pthread_mutex_unlock( &mbox->mutex );
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return result;
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}
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void mbox_destroy( struct mbox * mbox )
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{
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NULLCHECK( mbox );
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while( 0 != pthread_cond_destroy( &mbox->emptied_cond ) );
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while( 0 != pthread_cond_destroy( &mbox->filled_cond ) );
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while( 0 != pthread_mutex_destroy( &mbox->mutex ) );
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free( mbox );
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}
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