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| Rev | Author | Line No. | Line |
|---|---|---|---|
| 4973 | right-hear | 1 | #include"ipc.h" |
| 2 | #include |
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| 3 | #include |
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| 4 | |||
| 5 | inline int ipc_messages_avail(ipc_hdr_t * hdr) |
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| 6 | { |
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| 7 | return hdr->free_ptr!=8; |
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| 8 | } |
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| 9 | |||
| 10 | static inline void lock_msg_queue(ipc_hdr_t * hdr) |
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| 11 | { |
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| 12 | int d0; |
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| 13 | __asm__ __volatile__( |
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| 14 | "2:\t" |
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| 15 | "movb $1,%%al\n\t" |
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| 16 | "xchgb %%al,%0\n\t" |
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| 17 | "andb %%al,%%al\n\t" |
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| 18 | "jnz 2b\n\t" |
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| 19 | "incb %0" |
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| 20 | :"=m"(hdr->lock),"=a"(d0) |
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| 21 | :"m"(hdr->lock) |
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| 22 | :"memory"); |
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| 23 | } |
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| 24 | |||
| 25 | static inline void unlock_msg_queue(ipc_hdr_t * hdr) |
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| 26 | { |
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| 27 | __asm__ __volatile__( |
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| 28 | "movl $0,%0" |
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| 29 | :"=m"(hdr->lock) |
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| 30 | :"m"(hdr->lock) |
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| 31 | :"memory"); |
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| 32 | } |
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| 33 | |||
| 34 | ipc_msg_t * ipc_receive_msg(ipc_hdr_t * hdr) |
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| 35 | { |
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| 36 | ipc_msg_t * msg, * tmp; |
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| 37 | lock_msg_queue(hdr); |
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| 38 | if(!ipc_messages_avail(hdr)) |
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| 39 | { |
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| 40 | unlock_msg_queue(hdr); |
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| 41 | return NULL; |
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| 42 | } |
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| 43 | tmp=(ipc_msg_t *)hdr->__mem; |
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| 44 | msg=(ipc_msg_t *)malloc(tmp->msg_length); |
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| 45 | if(!msg) |
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| 46 | { |
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| 47 | unlock_msg_queue(hdr); |
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| 48 | return NULL; |
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| 49 | } |
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| 50 | memcpy(msg,tmp,tmp->msg_length); |
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| 51 | if(hdr->free_ptr>(8+tmp->msg_length)) |
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| 52 | { |
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| 53 | memcpy(tmp,tmp+1,hdr->free_ptr-8-tmp->msg_length); |
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| 54 | hdr->free_ptr-=tmp->msg_length; |
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| 55 | } |
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| 56 | unlock_msg_queue(hdr); |
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| 57 | return msg; |
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| 58 | } |