46bbd72f3e
wakeup1() assumes you hold proc_table_lock sleep(chan, lock) provides atomic sleep-and-release to wait for condition ugly code in swtch/scheduler to implement new sleep fix lots of bugs in pipes, wait, and exit fix bugs if timer interrupt goes off in schedule() console locks per line, not per byte
79 lines
2 KiB
C
79 lines
2 KiB
C
/*
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* p->mem:
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* text
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* original data and bss
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* fixed-size stack
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* expandable heap
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*/
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/*
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* segments in proc->gdt
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*/
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#define SEG_KCODE 1 // kernel code
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#define SEG_KDATA 2 // kernel data+stack
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#define SEG_UCODE 3
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#define SEG_UDATA 4
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#define SEG_TSS 5 // this process's task state
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#define NSEGS 6
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struct jmpbuf {
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// saved registers for kernel context switches
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// don't need to save all the fs etc. registers because
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// they are constant across kernel contexts
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// save all the regular registers so we don't care which are caller save
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// don't save eax because that's the return register
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// layout known to swtch.S
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int jb_ebx;
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int jb_ecx;
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int jb_edx;
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int jb_esi;
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int jb_edi;
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int jb_esp;
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int jb_ebp;
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int jb_eip;
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};
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enum proc_state { UNUSED, EMBRYO, WAITING, RUNNABLE, RUNNING, ZOMBIE };
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struct proc{
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char *mem; // start of process's physical memory
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unsigned sz; // total size of mem, including kernel stack
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char *kstack; // kernel stack, separate from mem so it doesn't move
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enum proc_state state;
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enum proc_state newstate; // desired state after swtch()
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struct spinlock *mtx; // mutex for condition variable
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int pid;
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int ppid;
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void *chan; // sleep
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int killed;
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int locks; // # of locks currently held
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struct fd *fds[NOFILE];
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struct Taskstate ts; // only to give cpu address of kernel stack
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struct Segdesc gdt[NSEGS];
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struct Pseudodesc gdt_pd;
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unsigned esp; // kernel stack pointer
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unsigned ebp; // kernel frame pointer
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struct jmpbuf jmpbuf;
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struct Trapframe *tf; // points into kstack, used to find user regs
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};
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extern struct proc proc[];
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extern struct proc *curproc[NCPU]; // can be NULL if no proc running.
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// XXX move curproc into cpu structure?
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#define MPSTACK 512
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struct cpu {
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uint8_t apicid; // Local APIC ID
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struct jmpbuf jmpbuf;
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char mpstack[MPSTACK]; // per-cpu start-up stack, only used to get into main()
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struct proc *lastproc; // last proc scheduled on this cpu (never NULL)
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int clis; // cli() nesting depth
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};
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extern struct cpu cpus[NCPU];
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extern int ncpu;
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