pthread-like thing

beed8e04 · Nickolai Zeldovich · c132eade · beed8e04 · beed8e04 · beed8e04
--- a/bin/mapbench.cc
+++ b/bin/mapbench.cc
@@ -4,12 +4,13 @@
 #include "mtrace.h"
 #include "amd64.h"
 #include "uspinlock.h"
+#include "pthread.h"

 enum { readaccess = 0 };
 enum { verbose = 0 };
 enum { npg = 1 };

-void
+void*
 thr(void *arg)
 {
  u64 tid = (u64)arg;
@@ -34,6 +35,7 @@ thr(void *arg)
      exit();
    }
  }
+  return 0;
 }

 int
@@ -50,11 +52,9 @@ main(int ac, char **av)

  // fprintf(1, "mapbench[%d]: start esp %x, nthread=%d\n", getpid(), rrsp(), nthread);

-  for(int i = 0; i < nthread; i++) {
-    sbrk(8192);
-    void *tstack = sbrk(0);
-    // fprintf(1, "tstack %lx\n", tstack);
-    int tid = forkt(tstack, (void*) thr, (void *)(u64)i);
+  for(u64 i = 0; i < nthread; i++) {
+    pthread_t tid;
+    pthread_create(&tid, 0, thr, (void*) i);
    if (0) fprintf(1, "mapbench[%d]: child %d\n", getpid(), tid);
  }


--- a/bin/maptest.cc
+++ b/bin/maptest.cc
@@ -4,6 +4,7 @@
 #include "mtrace.h"
 #include "amd64.h"
 #include "uspinlock.h"
+#include "pthread.h"

 static volatile char *p;
 static struct uspinlock l;
@@ -17,8 +18,8 @@ spin(void)
    ;
 }

-void
-thr(void)
+void*
+thr(void*)
 {
  for (;;) {
    acquire(&l);
@@ -54,8 +55,8 @@ main(void)
    exit();
  }

-  sbrk(4096);
-  forkt(sbrk(0), (void*) thr, 0);
+  pthread_t tid;
+  pthread_create(&tid, 0, thr, 0);

  acquire(&l);
  state = 1;

--- a/bin/thrtest.cc
+++ b/bin/thrtest.cc
@@ -4,12 +4,13 @@
 #include "mtrace.h"
 #include "amd64.h"
 #include "uspinlock.h"
+#include "pthread.h"

 static struct uspinlock l;
 static volatile int tcount;
 enum { nthread = 8 };

-void
+void*
 thr(void *arg)
 {
  acquire(&l);
@@ -26,9 +27,8 @@ main(void)
  fprintf(1, "thrtest[%d]: start esp %x\n", getpid(), rrsp());

  for(int i = 0; i < nthread; i++) {
-    sbrk(8192);
-    void *tstack = sbrk(0);
-    int tid = forkt(tstack, (void*) thr, (void*)(u64)(0xc0ffee00|i));
+    pthread_t tid;
+    pthread_create(&tid, 0, &thr, (void*) (0xc0ffee00ULL | i));
    fprintf(1, "thrtest[%d]: child %d\n", getpid(), tid);
  }


--- a/include/pthread.h
+++ b/include/pthread.h
+/*
+ * Our minimal version of pthreads
+ */
+
+typedef int pthread_t;
+typedef int pthread_attr_t;
+typedef int pthread_key_t;
+
+int       pthread_create(pthread_t* tid, const pthread_attr_t* attr, void* (*start)(void*), void* arg);
+pthread_t pthread_self(void);
+
+int       pthread_key_create(pthread_key_t* key, void (*destructor)(void*));
+void*     pthread_getspecific(pthread_key_t key);
+int       pthread_setspecific(pthread_key_t key, void* value);
--- a/include/user.h
+++ b/include/user.h
@@ -50,6 +50,7 @@ int atoi(const char*);

 // uthread.S
 int forkt(void *sp, void *pc, void *arg);
+void forkt_setup(void);

 // printf.c
 void printf(const char*, ...);

--- a/lib/Makefrag
+++ b/lib/Makefrag
-ULIB = ulib.o usys.o printf.o umalloc.o uthread.o fmt.o stream.o ipc.o
+ULIB = ulib.o usys.o printf.o umalloc.o uthread.o fmt.o stream.o ipc.o \
+       threads.o
 ULIB := $(addprefix $(O)/lib/, $(ULIB))

 .PRECIOUS: $(O)/lib/%.o

--- a/lib/threads.cc
+++ b/lib/threads.cc
+#include "types.h"
+#include "pthread.h"
+#include "user.h"
+#include "atomic.hh"
+
+enum { stack_size = 8192 };
+static std::atomic<int> nextkey;
+
+struct tlsdata {
+  void* buf[128];
+};
+
+void
+forkt_setup()
+{
+  printf("forkt_setup: pid %d\n", getpid());
+
+  tlsdata* t = (tlsdata*) sbrk(sizeof(*t));
+  setfs((u64) t);
+}
+
+int
+pthread_create(pthread_t* tid, const pthread_attr_t* attr,
+               void* (*start)(void*), void* arg)
+{
+  char* base = (char*) sbrk(stack_size);
+  int t = forkt(base + stack_size, (void*) start, arg);
+  if (t < 0)
+    return t;
+
+  *tid = t;
+  return 0;
+}
+
+pthread_t
+pthread_self()
+{
+  return getpid();
+}
+
+int
+pthread_key_create(pthread_key_t *key, void (*destructor)(void*))
+{
+  // Ignore the destructor for now.
+  *key = nextkey++;
+  return 0;
+}
+
+void*
+pthread_getspecific(pthread_key_t key)
+{
+  u64 v;
+  __asm volatile("movq %%fs:(%1), %0" : "=r" (v) : "r" (key * 8));
+  return (void*) v;
+}
+
+int
+pthread_setspecific(pthread_key_t key, void* value)
+{
+  __asm volatile("movq %0, %%fs:(%1)" : : "r" (value), "r" (key * 8));
+  return 0;
+}